1

CHAPTER 1

INTRODUCTION

Over the past centuries huge amount of air pollution like carbon monoxide,
hydrocarbon, oxides of nitrogen and particulate matter have been released to the atmosphere.
It is an irony that while pours engine inhales filtered pure air; we inhale polluted air emitted
by the engine. There exist a close relationship between fuel used and the engine emission.
The main sources of emission from the engine are from engine exhaust system and other
from the crankcase. The former is the main cause of air pollution. The main constituents of
the engine exhaust gases are unburnt hydrocarbons, carbon­di­oxide, carbon monoxide,
oxides of nitrogen and particulate matter.

The world at present is heavily dependent on petroleum fuels, due to the fast
depletion of petroleum reserves, the importance of alternate fuel research for internal
combustion engines needs emphasis. Diesel engines are the main prime movers for public
transportation vehicles, stationary power generation units and for agricultural applications.
So it is very important to find a best alternate fuel, which emits fewer pollutants to the
atmosphere form diesel engines. In this regard hydrogen is receiving considerable attention
as an alternative source of energy to replace the rapidly depleting petroleum resources. Its
clean burning characteristic provides a strong incentive to study its utilization as a possible
alternate fuel. While electrochemically reacting hydrogen in fuel cell is considered to be the
cleanest and most efficient means of using hydrogen, it is believed by many to be a
technology of the distant future. Currently fuel cell technology is expensive and bulky. In the
near term, the use of hydrogen in internal combustion engine may be feasible as a low cost
technology to reduce emissions. The hydrogen can be adopted to both SI engine and CI
engine. In SI engine the hydrogen can used as a sole fuel, but in case of CI engine dual
fuelling technique was used when hydrogen was used as a fuel.
 2

1.1 HYDROGEN ENGINE EMISSION

The most important advantage of hydrogen fueled engine is that they emit fewer
pollutants than comparable diesel fueled engine. For hydrogen fueled engine the principal
exhaust product are water vapor and NOx. Emission such as HC, CO, CO2, SOx and smoke
are either not observed or are very much lower than those of diesel engine. Small amount of
hydrogen per oxide may be found in the exhaust of the hydrogen operated engine. Unburnt
hydrogen may also come out of the engine, but this is not a problem since hydrogen is non­
toxic and cannot involve in any smog producing reaction.
NOx are the most significant emission of concern from a hydrogen engine.
Unfortunately, NOx have an adverse effect on air quality through the formation of ozone or
acid rain.

1.2 CONTROLL OF NOX

Figure 1.1 Strategies to reduce diesel emission

To meet the forth­coming emission norms there are two ways one was to use EGR
with Diesel particulate filter (DPF) and the other is to optimize the combustion and using the
selective catalytic reduction (SCR). Figure 1.1 shows the path to meet future EURO 5
emission norm. In EGR part of the exhaust gas was recirculated into the intake charge. This
 3

in turns reduces the peak combustion temperature by dilution of the oxygen content and act’s
as a heat sink. In SCR a reduction agent was introduced in the exhaust stream before the SCR
catalytic converter. Normally aqueous urea solution was used as the reduction agent.

1.3 PRESENT WORK

In the present work, a single cylinder water cooled DI diesel engine was converted to
operate on dual fuel mode with hydrogen in Timed Port Injection (TPI) and Timed Manifold
Injection (TMI) technique. A cooled replacement EGR was used and the EGR rate varied
from 0 % to 25 % in steps of 5 %. In SCR technique aqueous urea solution containing 32.5 %
of urea by weight was used as reduction agent. The SCR catalyst used was ferric oxide and
calcium oxide combined metal oxide catalyst. The ferric oxide is the catalyst and the calcium
oxide is binder, both are used in weight ratio of 15:85 on weight basis. An electronic control
system was used to control the injection timings of hydrogen and urea solution injection. The
experimental work comprises of development of hydrogen injection setup for TPI and TMI,
EGR connections by modifying the intake and exhaust piping, injection setup for urea
solution and fabrication of SCR catalytic converter. The performance and emission
characterization of the modified system was compared with the base reading of hydrogen as
well as diesel.
 4

CHAPTER 2

LITERATURE SURVEY

Abd­Alla .G.H et al. (2002) has studied EGR system for various engines. Fuel consumption
will improve with high EGR due to reduced pumping work, reduced heat loss to cylinder
wall and reduced degree of dissociation. It was found that cooled EGR gives lower thermal
efficiency but higher NOx reduction than the hot EGR. Engine wear will increase due to the
sulfur oxide in the exhaust gas. At part load high EGR is required due to low CO2 and H2O
concentration in the exhaust gas. Suggested using additional EGR instead of replacement
EGR will provide better NOx reduction.

Das. L. M (1996) investigated the use of hydrogen in both S.I and C.I engine. He described
the various induction techniques such as Carburetion, Inlet Manifold Injection, Inlet Port
Injection, and Direct Injection techniques. He observed that the carburetion technique results
in more backfire and NOx. He suggested that the EGR technique was a better choice NOx
reduction. He observed timed manifold injection system overcome the problem of backfire.

Das .L.M (2002) tried the various fuel induction techniques. EGR has been found to be very
effective method for NOx control. He used simulated EGR for his test. He found that NOx
reduction was high at 15 % EGR. Charge dilution technique was used, 10 % helium by
volume of H2 was found to be optimum for the performance characteristics. He achieved best
thermal efficiency and power output when nitrogen was substituted by 30 % of volume of
hydrogen. Hydrogen­CNG blend gives a significant thermal efficiency and power output than
near CNG.

Engler .B.H et al. (1993) Investigated zeolite based monolith catalyst with special coating.
They observed increase in space velocity would reduce the NOx conversion. If the HC
 5

concentration in the exhaust gas increased the NOx conversion will be more. By increasing
the HC concentration the NOx conversion was shifted towards high temperature. In contrast
with HC, CO is almost not effective. Suggested that the Zeolite based catalysts are
significantly deactivated by adsorption of water. The NOx conversion of zeolite based
catalyst was absorbed as 50 % up to the temperature of 300º C, the efficiency will increase
upto 85 % when the temperature exceeds 350º C.

Farshchi. M et al. (2001) investigated the NOx emission of a heavy­duty diesel engine with
urea SCR. NOx absorber requires fuel sulfur less than 30ppm. He used aqueous urea solution
with 32.5% urea (by weight) was used a reduction agent. He used air assisted urea injection
system, which use compressed air of 3 bar to inject the urea. He suggested that the distance
between urea injection and the catalyst must be long enough to allow homogeneous mixture
of exhaust gas and ammonia. He concludes that by using SCR co will increase by 15% and
20% reduction in particulate matter. From the results it was found that the ammonia slip was
2.9 ppm on the FTP cycle. Due to the use of SCR the HC emission was reduced about 80 %
and the particulate matter reduced by 20 %. For optimized SCR system the NOx reduction
was 74 % and the ammonia slip was 4.44 ppm per test cycle.

Gieshoff. J et al. (2001) investigate the urea SCR with zeolite catalyst by model gas
analysis and engine test. Found that activity of zeolite material is higher than metal oxide
catalyst at higher temperature. Two model gases were used one with NO2 and the other with
out NO2. He used aqueous urea solution as reduction agent, the ratio of NH3/NO of the
solution was 0.9. He found that the NOx conversion was maximum between 250º C to 350º C
and after aging also the conversion efficiency was high at high temperature. He found that
the NOx conversion starts at the temperature of 150º C and reach its maximum value at 280º
C, during the fresh condition. After aging the maximum NOx conversion was achieved at
500º C. From the result it was found that for the ECE part of the NEDC cycle the NOx
conversion of 49 % was achieved and for the EUDC part of the cycle the NOx conversion
reaches 73 %. The overall the NOx conversion was 63 % for the whole NEDC cycle.
 6

Haragopala Rao. B et al. (1983) investigated the operation of dual fueled diesel engine. He
found out that the NOx emission would be higher than the diesel operation. To prevent any
crankcase explosion due to possible leakage of hydrogen past the piston into the crankcase he
removed crankcase gases frequently. Maximum of 30% of energy input can be achieved by
hydrogen without knocking. Thermal efficiency will increase for full load of hydrogen fueled
operation but at low load there was a reduction in the thermal efficiency. He found that the
use of hydrogen the exhaust gas temperature due to the early release of the energy. The
unburnt hydrocarbon emission was reduced over the entire load range.

James W.Heffel et al. (2003) investigated the NOx and performance of hydrogen fueled
engine with exhaust gas recirculation and three way catalytic converter. He used dedicated
hydrogen operated engine from Ford motors. Hydrogen was injected in the intake port and
ignited by a spark plug. He has adopted cooled EGR through out his research. He reduce the
NOx emission up to the level of 1ppm. He kept the manifold absolute temperature below
100°C to make the water vapour in the exhaust to act as water injection. From the results it is
observed that with the use of EGR and a standard 3­way catalytic converter system the NOX
emissions from a hydrogen­fuelled engine could be reduced even to 1 ppm. If NOX emissions
(< 10 ppm) are the requirement instead of 1 ppm than the adaptation of EGR produces 30 %
more torque than by adopting lean burn strategy.

Jehad A.A. Yamin et.al. (2000) studied the effect of combustion duration on engines
operating parameters like compression ratio, equivalence ratio, spark plug location, spark
timing and engine speed and also they studied the engine’s performance parameters like SC,
BMEP, Thermal efficiency as well as emission characteristics. The combustion duration (in
ms) decreases as the engine speed (in rpm) increases. This is due to the clear effect of
turbulence. As the engine speed increases, the turbulence inside the cylinder increases,
leading to a better heat transfer between the burned and unburned zones.

Increasing combustion duration increases the lean misfire limit; there is a decrease in
the BSFC to certain limit. Any attempt to increase the combustion duration either by
reducing the compression ratio, locating the spark near the periphery or operating at leaner
 7

mixtures is going to improve the engine’s economy. The effective combustion duration is
between 4­6 ms and engine should run on a mixture slightly leaner than the stoichiometric
(l=0.9­1.0). From the emission point of view it was found that NOx emissions re lower when
combustion duration is high. This is because it allows more time for the combustion to
complete further at higher combustion duration the peak temperature is low and therefore the
formation of NOx is reduced on other hand decreasing the combustion duration beyond a
certain limit reduces the concentrations of NOx because the lesser time of exposure of
products of combustion to cylinder’s peak temperature and if the mixture is made
progressively rich, the combustion duration decreased.

Ladommates. N et al. (1998) investigated the effect of EGR on heat release in combustion
and co­relates with the exhaust. The EGR cause an increase in ignition delay and a shoft in
the location of start of combustion. This results in the products of combustion spending
shorter periods at high temperatures which lowered the NOx formation rate. The shift of the
combustion process towards the expansion stroke resulted in earlier quenching of the
combustion process that is shorter combustion duration, which yielded higher levels of
products of incomplete combustion in the exhaust. By using the hot EGR there will be an
increase in inlet charge temperature which shortens the ignition delay period which also
enhances the evaporation of the fuel which could result in fuel rich mixtures in regions of the
combustion chamber where air entrainment is restricted by the high viscosity of the hot air.
As a result, high levels of soot can be produced due to increased rates of fuel pyrolysis at the
high temperatures prevailing during combustion.

Ladommates. N et al. (1998) investigated the effect of reduction in intake charge mass due
to thermal throttling with hot EGR on diesel combustion and emission. Hot EGR affect the
combustion and emission in two ways one is by reduction in intake charge and the other is by
increase in intake temperature. He tried two types of throttling first one is simply throttled the
air isothermal from 10 g/s to 8.5 g/s and the second one is throttling the intake air and
maintaining the intake oxygen concentration as constant. The overall effect of thermal
throttling increases the ignition delay and the throttling with constant O2 shorten the ignition
 8

delay. The CO emission throttling with constant O2 is reduced from the baseline reading but
for the air throttling the CO emission increases due to the reduction in the O2 content.

Ladommates. N et al. (1997) investigated the dilution, chemical and thermal effect of the
carbon­di­oxide and water vapour. The whole test was carried out at a test condition of 2000
RPM and 40 % load. Increase in EGR level increases the dilution of oxygen significantly. He
found that the dilution would be the most significant effect that influences the combustion
emission. Comparing H2O with CO2 as a means of controlling NOx emissions, H2O could be
slightly more effective. But at the same time it increase the smoke and particulate emission.
Rather than displacing air in diesel engine, if EGR is applied such that the O2 concentration
in the intake as constant this will lower the NOx emissions substantially with no significant
increase in smoke and particulate emission.

Masanori lwasaki et al. (1995) had compares the Pt/ZSM­5 and Cu/ZSM­5 catalyst. They
used ethylene, kerosene and N­Hexane as reducing agent. Observed the Ethylene shows best
result for Pt/ZSM­5 catalyst with the NOx reduction of 49 % and kerosene shows best result
for Cu/ZSM­5 catalyst with the NOx reduction of 15 % and the NOx reduction catalyst will
emit N2O as a by­product. Concluded that NOx reduction was almost proportional to
concentration of the reducing agent. Pt/ZSM­5 has higher NOx reduction at low temperature
itself and it emits low N2O. The Pt/ZSM­5 and Cu/ZSM­5 catalyst both maintains 89 % and
81 % of the initial NOx reduction efficiency after 500 hours.

Ming Zheng et al. (2004) studied various types of EGR system for diesel engine. He used
simulated exhaust gas to study the effect of addition of the CO2 with constant oxygen and
variable oxygen. EGR rate is directly proportional to delay period. Low EGR rate is
sufficient at high load due to low concentration of oxygen in the exhaust gas. At high EGR
rate smoke is more due to insufficient oxygen.

Naber. J. D et al. (1997) Al studied the conditions under which the compression ignition of
Hydrogen can be achieved and also he studied the effect of Exhaust gas re­circulation (EGR)
on the ignition and combustion of Hydrogen. Hydrogen injection is achieved by injecting
 9

the fuel directly inside the combustion chamber by using Hydrogen Incylinder Injector at a
pressure of 35 Mpa and with a injector duration of 100 MS.

The ignition delay of hydrogen has a strong Arrhenius temperature dependence and
he found that a five­fold decrease in ignition delay was observed with a 10% increase in the
ambient Air temperature, and also he studied that the effect of ambient pressure on ignition
delay will be small. The effect of fuel temperature chows that its dependence on ignition
delay will be smaller comparer to the effect of ambient gas temperature. The effect of
ignition delay on H2O and CO2 concentrations are found to be negligible and also the
variation of O2 concentration from 5­21% on mixing controlled rate of combustion was
negligible.

Pratyush Nag et al. (1998) investigate NOx conversion over a SCR with copper ion­
exchanged X­zeolite catalyst for SI engine operation. He used low feed rate of urea was used
to reduce the deactivation of zeolite due to presence of water. Space velocity doesn’t have
much effect on NOx conversion efficiency. Over the wide range of λ (from 0.77 to 1.18) the
conversion efficiency will be high. The maximum efficiency was achieved when the λ was
1.1. The conversion efficiency was maximum in the temperature range of 350ºC to 400ºC.
With in the space velocity range of 25000–35000 h­1 the conversion efficiency was constant.
The back pressure due to the catalytic bed was found to be 20 to 40 mm of water column.
The maximum NOx reduction achieved was 68 %.

Rolf egnell (2000) investigated the effect of EGR on heat release and NO formation. He used
a model and he separate the no formation during the pre mixed combustion from diffusive
combustion. Another improvement is the addition of radiative looses in the sub model that
calculates the local temperature. Another improvement is the addition of radiative losses in
the sub model that calculates the local temperature. Totally he used four models for his
analysis they are net heat release rate model, convective heat loss model, combustion and
radiative heat loss model and NO formation model. From the results it was seen that by
adopting EGR technique the NOx emissions reduce almost by 70 % with a loss of 8 % is
indicated thermal efficiency and increases the smoke emissions about the 40 times. CO
 10

increases 6 times and HC decreases possibly due to the higher exhaust temperature that
promotes oxidation in the exhaust pipe.

Sung­mu Choi et al. (2001) investigated urea SCR with Pt/Al2O3 and V2O5/TiO2 catalyst.
They used urea with various injection durations and with different intervals. Maximum NOx
conversion will be 150ºC to 300 º C temperature ranges for Pt/Al2O3 but for Pt/Al2O3
+V2O5/TiO2 combined catalyst it was 190ºC to 400 º C . Found that space velocity dose not
have serious effect on NOx conversion efficiency. Observed that increase in NH3/NO ratio
shift the conversion window towards higher temperature. He concluded that the maximum
NOx conversion efficiency of the urea­SCR system with combined catalyst was 82 % at 325º
C and 1500 rpm. The NOx conversion efficiency was above 50 % in the temperature range of
300º C to 375º C.

Wolfgang held et al. (1990) investigate the NOx reduction by catalytic reduction and SCR
with ZSM­5 catalyst. Synthetically produced zeolites are used for catalyst. He stated that the
water vapour in the exhaust affects the NOx conversion efficiency of the catalytic converter.
He found that for 11 % increase in H2O of exhaust gas the NOx conversion efficiency drops
by13 %. The decomposition and the hydrolyze takes place at a temperature of 160°C. He
used the urea solution with ratio of NH3/NO varies from 0 to 1 and he found that from 0.6 to
1 will provide best result. NOx conversion using NH3, was independent of oxygen
concentration over a wide range. Decomposition of NH3 was confirmed by the development
of CO2. NOx conversion efficiency up to 90% was possible. He found that the oxygen
content doesn’t have any effect on the NOx conversion.

Yi. H. S et al. (2000) have done the work on both port injection and in­cylinder injection
type hydrogen fuel supply systems. From their results it is observed that the thermal
efficiency of the intake port injection is clearly higher than in­cylinder injection at all
equivalence ratios. The maximum indicated thermal efficiency of 41 % is achieved at a fuel /
air equivalence ratio of 0.3 compared to an indicated thermal efficiency of 30 % for in
cylinder injection. The brake thermal efficiency at 1500 rpm WOT, MBT is 34 % for port
injection system and 31 % for in cylinder injection.
 11

The unburned hydrogen concentration is also measured with various fuel air
equivalence ratios and it is found that for all fuel air equivalence ratios the port injection
system gave lower unburned hydrogen concentration. Compared to in­cylinder injection for a
fuel air equivalence ratio of 0.2 and 1 it is found that the unburned hydrogen concentration is
0.3 % and 0.05 % for port injection system compared to 1.2 % and 0.15 % for in cylinder
injection system. From the results it is found that the in­cylinder direct injection does not
have the problems of either power reduction or abnormal combustion; however at low fuel
air equivalence ratio the thermal efficiency is low and operational stability deteriorated. The
optimized operation of the hydrogen­fuelled engine can be achieved with intake port
injection for part load conditions and with in­cylinder injection for full load conditions.
 12

CHAPTER 3

EXHAUST GAS RECIRCULATION

Exhaust gas recirculation is one of the well known method to reduce NOx formation.
The basics principal of the EGR is diversion of some of the exhaust gas back into the intake
stream of the engine. This will reduce the intake oxygen concentration and increase the
specific heat of the intake charge due to replacement of intake oxygen and nitrogen with CO2
and H2O. Due to this the peak combustion temperature will be reduced. This ultimately
reduces the NOx formation, since the key factor of the NOx formation was peak combustion
temperature. The amount of NOx reduction was based on the amount of exhaust gas
recirculated. The main disadvantage was the increase in smoke and particulate emission at
higher EGR rate the combustion was not stable due to the lack of oxygen.

3.1 EFFECT OF EGR

While using EGR the NOx formation was reduced by three effects namely dilution
effect, thermal effect and chemical effect. Out of this dilution effect has major contribution
towards NOx reduction. Followed by the thermal effect and chemical effect.

3.1.1 Dilution effect

The maximum NOx reduction was achieved by the dilution effect of the EGR. In
EGR part of the intake air was replaced by using the exhaust gases, which mainly consists of
CO2 and H2O. Due to this replacement the O2 and the N2 concentration in the intake charge
got reduced. This reduction in availability of oxygen reduces the peak cylinder temperature,
which in turns reduces the amount of N2 dissociated in to monatomic N. At the same time the
 13

reduction in availability of O2 results in less amount of mono atom O. Due to the reduction of
both N and O the formation of NOx reduced considerably.

3.1.2 Thermal effect

While replacing the intake air with H2O and CO2, the specific heat capacity of the
overall charge trapped inside the cylinder will raised. This is because H2O and CO2 have
higher specific heat capacity than that of air. Due to this the unburnt fresh charge acts as a
heat sink and absorbs the heat from the burning fuel. This ultimately reduce the peak
combustion temperature, in turns reduces the NOx formation. While replacing the air with
H2O and CO2, the replacement of air with H2O have higher thermal effect than that of the
CO2, but the particulate emission increased due to the higher replacement of H2O.

3.1.3 Chemical effect

The chemical effect of the EGR deals with the dissociation of CO2, which was higher
in case of the EGR. Due to this the peak cylinder temperature drops down, this will reduce
the NOx formation. Considering the dilution effect and the thermal effect the chemical effect
have very little impact on the NOx formation.

3.2 TYPES OF EGR

Basically there are two types of EGR for naturally aspirated engine namely internal
EGR and external EGR. Figure 3.1 presents the different types of EGR. In internal EGR
system a part of the burnt gas of the preceding cycle was trapped inside the cylinder for the
next cycle. This charge acts as a dilution source for consecutive cycle. This trapping of the
exhaust gas was achieved by chancing the valve timings, but the problem was fixed EGR
flow rate for all the loads and the EGR flow rate cannot be varied. Variable valve timing can
rectify this problem, by adopting electronic control system we can get any EGR rate for the
required load and engine speed.
 14

In external EGR the product of combustion was allowed to come out of the engine
and than diverted back into the intake manifold. There are four main classification of the
external EGR for the naturally aspirated engine; they are hot EGR, cooled EGR, additional
EGR and replacement EGR.

3.2.1 Hot EGR

In hot EGR the raw exhaust gas was recirculated directly to the intake system without
any sort of treatment. This hot EGR system was not producing favorable results. Due to the
use of hot exhaust gas the density of the intake charge reduces, this inturns reduces the mass
of the intake air and consequently the power output of the engine also reduced. Mean while
the reduced mass of the exhaust gas cause reduction in dilution effect. This will results in
lower NOx reduction ratio. The schematic of the hot EGR was shown in Figure 3.2.
The increase in the intake charge temperature results in decrease in ignition delay and
increase in the charge temperature before the start combustion. Both this results in increase in
NOx level, due to this the effect of the EGR was reversed. Even though the replacement of
the oxygen content in the intake reduces the NOx formation, the increase in NOx formation
due to the high temperature of the recirculated gas dominate at light loads.

3.2.2 Cooled EGR

In cooled EGR the exhaust gas was cooled before it enters the intake manifold.
Due to the cooling the intake charge density was brought to normal condition. So there will
not much power deterioration, at the same time for the same volume flow rate of EGR there
will be more replacement of oxygen. This evident that the NOx reduction capacity of the
cooled EGR was very high than that of the hot EGR. So for the same engine and same EGR
rate cooled egr will provide higher NOx reduction than the hot EGR. A schematic of the
cooled EGR was shown in Figure 3.3. in this the exhaust gas was passed through the cooler
before it enters the intake manifold.
 15

EGR

Internal External
EGR EGR

Fixed valve Variable valve

timing timing

Hot Cooled Additional Replacement

EGR EGR EGR EGR

Figure 3.1 Types of EGR for naturally aspirated engines

15
 16

Hot Exhaust
Gas

Figure 3.2 Hot EGR System

Figure 3.3 Cooled EGR System

 17

3.2.3 Additional EGR

In additional EGR the exhaust gas was added to the intake air flowing to the engine.
By this the air/fuel ratio was kept constant. Due to this the EGR system will also work as a
super charging system. Normally this method was adopted in SI engines, where the
additional EGR was achieved by wide opening the throttle, there by increasing the inlet
charge pressure, density and consequently the intake mass. Cooled EGR is used in order to
reduce the thermal throttling and the connected increase in equivalence ratio (ER). Thus
cooling the EGR can be seen as an alternative to additional EGR. Figure 3.4 shows the
schematic that shows the different between the additional EGR and the replacement EGR. In
this it can be found that for additional EGR the total mass inside the cylinder was the sum of
the mass of intake air ‘M’ and mass of the EGR ‘m’. For the same air fuel ratio the amount of
charge inside the cylinder was increased, this was the main advantage of additional EGR.

NO EGR Additional EGR Replacement EGR

EGR of EGR of
mass m mass m
Charge of
mass M Charge of Charge of
mass M mass M­m

Figure 3.4 Comparison of additional EGR and replacement EGR

3.2.4 Replacement EGR

The replacement EGR was normally used in the diesel engines, in which a part of the
intake air was replaced by the exhaust gas. This results in reduction of both the air/fuel ratio
and the exhaust gas leaving the engine.
 18

3.3 EGR RATE

The EGR rate was ratio between the amount of exhaust gas recirculated to the total
charge intake. It may be expressed either in volume basis or mass basis.

mEGR
In mass basis EGR rate = ´ 100
mair + m fuel + mEGR

VEGR
In volume basis EGR rate = ´100
Vair + V fuel + VEGR
But in actual practice it was difficult to calculate the volume of the gases, so it was
quit normal to express the EGR rate on the amount of CO2 basic.
[CO2 ]Intake gas - [CO2 ] Ambient
EGR rate =
[CO2 ]Exhaust gas - [CO2 ] Ambient

The exhaust gas CO2 level was measured first and the required CO2 level in the intake
charge was calculated based on the required EGR rate. Then the EGR valve was opened until
the required CO2 level reached in the intake charge.
 19

CHAPTER 4

SELECTIVE CATALYTIC REDUCTION

Selective catalytic reduction is one of the most efficient technologies to reduce oxides
of nitrogen from the combustion process. This technology was widely used in power plants,
gas turbines and marine engines. In this system a reduction agent was used along with a
catalytic converter. The reduction agent was injected before the SCR catalytic converter, the
distance between the injector and the SCR catalytic converter must be sufficient to vaporise
the reduction agent and allow the homogenous mixture of the exhaust gas and the reduction
agent.
Various reduction agents were available for NOx reduction such as ethylene,
kerosene, N­Hexan, ammonia and other HC sources. Out of this ammonia have a good
affinity to reduce the NOx emission. But the problem in using ammonia as a reduction agent
was the toxic nature of the ammonia. It is very difficult to handle the ammonia since it was
corrosive. To overcome this problems aqueous urea solution was used as the reduction agent,
since it can be easily decompose into ammonia under the heat of the exhaust gas itself.
The solubility of the urea is water was too high; 108 g of urea can be dissolved in 100
g of water. So high concentration urea solution was stored in the tank and it can be diluted in
the passage itself. A typical aqueous urea solution used in road application has 32.5 % of
urea by weight. The solution was almost colorless and stable. The properties of the aqueous
urea solution was given in Table 4.1

4.1 NET SCR REACTION

The aqueous urea solution was injected in the exhaust stream, this solution of water
and urea absorb the heat and decompose into ammonia and carbon di oxide at a temperature
above 150° C. This reaction was called as hydrolysis reaction, apart from producing the NH3
in the reaction NH2. Both this reaction where given below.
 20

Table 4.1 Property of aqueous urea solution

Property Value
Chemical formula (NH2)2CO­H2O
Molecular weight 60.06 kg/kmole
Urea content 32.05 % by weight
Density 1085kg/m3
pH 9­11
Appearance Colourless
Point of crystallisation ­11 oC
Carbon as CO2 Max. 0.4%

( NH 2 ) 2 CO + H 2O ® 2 NH 3 + CO2

( NH 2 ) 2 CO ® 2 NH 2 + CO
This NH3 and NH2 react with NO and N2O in the exhaust gas to form N2 and H2O.
Some of the NH3 will directly react with the oxygen in the exhaust gas and converted into N2
and leave the system. This cause the loss in the reduction agent without doing its work. The
main SCR reactions are as follows,
NH 2 + NO ® N 2 + H 2O

4 NH 3 + 6 NO ® 5 N 2 + 6 H 2O

4 NH 3 + 4 NO + O2 ® 4 N 2 + 6 H 2O

4 NH 3 + 2 NO2 + O2 ® 3 N 2 + 6 H 2O

2 NH 3 + NO + NO2 ® 2 N 2 + 3H 2O

2 NH 3 + 8 NO ® 5 N 2O + 3H 2O

4 NH 3 + 4 NO + 3O2 ® 4 N 2O + 6 H 2O
Apart from the main reactions of SCR there are some undesirable reactions occurring
in the SCR process includes several competitive reactions with oxygen, which was
abundantly available in the diesel engine exhaust. These reactions can produce secondary
emissions or unproductively consume ammonia. This reaction are given below,
4 NH 3 + 3O2 ® 2 N 2 + 6 H 2O
 21

2 NH 3 + 2O2 ® N 2O + 3H 2O

4 NH 3 + 5O2 ® 4 NO + 6 H 2O
One of the end products that can also occur was nitrous oxide. Due to the fact that
nitrous oxide can also contribute to the warming up of the earth’s atmosphere and has an
extremely long life, it was undesirable as an end product of SCR. The typical layout of a
SCR system was shown in the Figure 4.1.

01. Air intake system 02. Engine

03. Exhaust piping 04. Urea injector
05. Urea pump 06. Urea storage tank
07. SCR catalyst

Fig. 4.1 Layout of the SCR system

4.2 SCR CATALYTIC CONVERTER

The SCR catalytic converters consist of a catalyst that will enhance the NOx reduction
mechanism. Many kinds of catalyst where tried in the past for the SCR in diesel engine, in
this zeolite catalyst shows superior performance than the other. But the real problem in using
this catalyst for the hydrogen fueled engine application is the water vapour present in the
exhaust gas. The zeolite catalysts are very sensitive towards the water content, for 10 %
 22

increase in the water content of the exhaust gas the NOx conversion drops by 13 %. So it was
not far to use the zeolite as the catalyst for hydrogen fueled engine with SCR. On the other
hand metal oxide catalyst shows nice performance towards diesel fuel operation and it was
not much sensitivity towards water vapour.
In metal oxide catalyst ferric oxide gives NOx reduction efficiency as of the zeolite
catalyst. So ferric oxide catalyst was used for the SCR application. The ferric was not able to
coated on the substracta so it was decided to use it in the pellet form. The ferric oxide alone
cannot be made into pellets, it needs some binder to hold it in pellet form. So calcium oxide
was used as the binder. The ferric oxide and the calcium oxide was mixed in the ratio of
15:85 in weight basic and made into pellets and this was used as the catalyst.
 23

CHAPTER 5

EXPERIMENTAL SETUP

The experiments were conducted on a single cylinder, naturally aspirated, water

cooled, direct injection diesel engine. The specification of the test engine was given in
Appendix­1. The experimental setup consists of three setups they are hydrogen injection
setup, cooled exhaust gas recirculation setup and selective catalytic reduction setup.

5.1 HYDROGEN INJECTION SETUP

Hydrogen is stored on a high­pressure storage tank at a pressure of 150 bar having a

capacity of 7 cubic meter (0.5 kg) of hydrogen. A double stage pressure regulator is used to
control the hydrogen from the cylinder. The pressure is reduced to the range of 1­4 bar based
on the flow requirements. The hydrogen from the pressure regulator is passed through a shut
off valve, which can be closed if any backfire results in the fuel pipeline.
The hydrogen after passing through the shut off valve is allowed to pass through the
digital mass flow controller (DFC). The DFC precisely measures the flow rate of hydrogen in
standard liters per minute (SLPM). The specification of the DFC was given in the Appendix ­
6. Since the hydrogen flow to the injector should be free from any impurities the hydrogen is
passed through a filtering device. The hydrogen from the filter is passed to a flame arrestor.
The flame arrestor act as a non­return valve and also it acts a visible indicator for hydrogen
flow. The hydrogen from the flame arrestor is then passed to the flame trap, which consists of
wire mesh. The wire mesh will prevent the penetration of flame to the hydrogen cylinder.
The flame arrestor also acts as a non­return valve (NRV). The flame arrestor also consists of
bursting diaphragm, which punctures of when the pressure built on the system exceeds 10 bar
during backfire conditions.
 24

The hydrogen from the flame trap is passed to the 2­way valve. One end of the two­
way valve is connected to the pipeline and it is kept away from the working area. This is
done to remove the excess hydrogen on the fuel line during the engine shutoff time. The
other end of the two­way valve is connected to a selector switch, which will supply the
hydrogen to either the port fuel injector or the manifold injector. The port injector was placed
in the engine head 13 mm above the intake valve and the manifold injector was placed at a
distance of 100 mm away from the engine head in the intake manifold. The injector was a
Quantum make gas injector, which can adopt the flow of hydrogen, LPG and CNG. The
details of the gas injector was given in Appendix 7.

The electronic control unit (ECU) controls the operation of fuel injector. The one end
of the positive power supply from the 12 V battery is connected to the injector; the other
negative terminal of the injector is connected to the ECU, which is having the control of
injector opening timing and duration. The electronic control unit is also having the input
from the infrared detector. The IR Detector is used to give the signal to the ECU for the
injector opening. The negative terminal of the injector is connected to the ECU. Based on the
presetted timing and duration the injector will be opened for injection and closed after
injection. The injection timing and injection duration can able to vary within the specified
range by using the knob control. The power supply for opening the injector opening was 4A
and for holding the armature to inject the fuel was 1A.

Based on the presetting the hydrogen flow will be taking place and the flow is
controlled by using the pressure regulator and also by using the digital mass flow controller.
The layout of the experimental setup system is shown in the Figure 6.1.

5.2 EGR SETUP

Cooled EGR was used through out this project, for this a custom designed exhaust
gas cooler was used. The cooler was capable of cooling the exhaust gas to 30° C for all load
condition. The exhaust of the engine was divided into two lines one is let to atmosphere, this
line consist of an exhaust throttling valve. The other line was feed to the exhaust gas cooler,
 25

before the dividing point two tapping where provided one is to measure the exhaust gas
temperature and the other is to measure the exhaust gas composition.
The exit of the cooler is connected to the engine intake pipe through EGR filter and
EGR valve. The temperature of the gas leaving the cooler was measured before it enters the
intake system. The EGR filter was basically a mineral wool filter in a wire mesh. On the
other hand the intake system air surge tank was connected with an orifice meter to measure
the intake air flow. After the mixing point of exhaust gas and intake air to tapping where
provided with needle valves to measure the intake charge temperature and to measure the
charge composition of the intake charge. The photographic view of the test engine setup with
EGR was shown in Figure 5.2.

01. Hydrogen tank 02. Pressure regulator

03. Filter 04. Digital mass flow controller (DFC)
05. Computer to control DFC 06. Flame arrestor
07. Flame trap 08. ECU for hydrogen
09. IR sensor 10. Hydrogen injector in intake system
11. Engine 12. Exhaust manifold
13. EGR valve 14. EGR cooler
Figure. 5.1 Schematic layout of the experimental setup
 26

5.3 SCR SETUP

The main parts of the SCR system were urea injection system and SCR catalytic
converter. These two parts are discussed in this chapter,

5.3.1 Urea injection system

The pump and the injector used in the urea injection system was Tata Indica fuel
pump. The pump was submersible type axial pump, which was driven by a DC motor. The
injector used was a solenoid operated gasoline injector, which was used in MPFI system. The
pump consist of a main line for the pressurized path and the other was the over flow line.
This was to achieve optimum performance of the pump. The outlet of the pump was
connected to a pressure reduction line, where the pressure was reduced in three stages from
maximum of 15 bar to 1 bar. The return line of the pressure reducer was connected back to
the pump. The pump itself contain strainer therefore no additional filter was used. The outlet
of the pressure reducer was connected to the injector. The urea injection pump and the
pressure reduction system were shown in Figure 5.4.
The injector and the pump where controlled by using an electronic control unit, which
works similar to that of the hydrogen injector control system. The injector was placed axially
to the SCR catalytic converter at a distance 700 mm before the converter. The optimum
position of the injector is chosen based on the conversion of the urea into ammonia.

5.3.2 SCR catalytic converter

The catalyst used in the SCR catalytic converter was ferric oxide and calcium oxide
combined metal oxide catalyst. Ferric oxide acts as the catalyst and calcium oxide acts as the
binder. Both ferric oxide and the calcium oxide are mixed in proportions of 15:85 on weight
basis. The mixture was pressed in hydraulic press at a load of 7 tones to make it into pellets.
The dimension of the pellets where 10mm in diameter and 5 mm in thickness. The pellets
where arranged in a wire mess, with the provision of exhaust gas to flow. Totally three wire
mess where used each consist of 75 pellets. A gap of 15 mm was maintained between the
 27

mesh to reduce the flow restriction and to reduce backpressure. The photographic view of the
pellets in the mesh was shown in Figure 5.5.

The converter housing was made of stainless steel, the dimension of the converter
was shown in figure 5.4. The converter was insulated to reduce the heat loss to the
atmosphere. Tapping was provided to measure the catalytic bed temperature. To measure the
back pressure created by the catalytic converter, two tapping were made in the upstream and
downstream of the converter. Both of this where connected to the U tube manometer to
measure the back pressure. The photographic view of the test engine setup with SCR was
shown in figure 5.6.

5.4 TEST PROCEDURE

Before starting the engine the lubricating oil level, water level in the flame trap and
the fuel level in the diesel tank where checked. The cooling water flow rate was fixed at a
uniform flow of 400 lpm. The engine was cranked and started by releasing the
decompression lever. The engine was allowed to reach steady state, than the speed of the
engine was set at 1500. Than the engine was allowed to warm up for 15 to 20 minutes. The
hydrogen leak detector was switched on and the circuit connection for the ECU with the
battery was connected. The hydrogen leak detector was used to detect the leak in the
hydrogen flow line, it uses the electrochemical cell to find the leak, it was capable of
measuring the hydrogen leak in the range of 0 to 1000 ppm. The details about the leak
detector were given in the Appendix 5. The regulator of the hydrogen cylinder was opened
and the line pressure was set at 1.5 bar. The required flow rate was set at the digital mass
flow controller. The hydrogen flow can be visualized in the flame trap in the form of gas
bubbles. The ECU switched on, this starts the injection of the hydrogen. Due to this there
will be a sudden change in the sound.

The exhaust gas emissions were measured by using Qrotech five gas analyzer, the
specification was given in Appendix 3. The time for 10CC diesel consumption was noted.
The value of peak cylinder pressure was get from the charge amplifier and the pressure crank
 28

Figure 5.2 Photographic view of the test engine setup with EGR

Figure 5.3 Photographic view of the test engine setup with SCR
 29

Figure 5.4 Photographic view of the urea pump and the flow line

Figure 5.5 Photographic view of the pellets in the wire mesh

 30

Φ100 Pellets in Mesh

Φ50

100 200 100

Figure 5.6 SCR catalytic converter

angle was printed from the oscilloscope. After getting the CO2 emission in the exhaust gas,
the amount of CO2 to be in the intake system for the required EGR rate was calculated. The
EGR valve was opened until the desired CO2 level was reached. Than the engine was
allowed to stabilize, after that the exhaust emission, peak cylinder pressure, pressure crank
angle diagram and the time taken to consume 10 CC diesel consumption where measured.

For SCR application initially the baseline reading where taken and based on the NOx
emission the amount of urea to be injected where calculated. Than the engine was allowed to
run, and the urea injector was placed in a graduated glass tube to find the flow rate of the
urea. The duration of the injection was altered to get the required flow rate, and this durations
where noted down for future settings. Again the urea injector was fitted on the exhaust line.
The engine was allowed to run on the dual fuel mode, based on the load the duration of the
injection was fitted. Now the exhaust gas allowed to flow over the converter at the same time
the urea injection was started. The emission from the catalytic converter was measured. The
back pressure was measured by U tube manometer and the time required for 10 CC
consumption of the diesel was measured.
 31

5.5 INSTRUMENTATION

The power output of the test engine was measured by an electrical dynamometer. The
power capacity of the dynamometer is 10 kW with a current rating of 43.5 amps. The
specification of the dynamometer was given in Appendix 2. The exhaust gas emission was
measured by using the Qrotech five gas analyzer. The analyzer was capable of measuring
HC, CO, CO2, O2 and NOx. The analyzer utilize the NDIR technique to measure the HC, CO,
CO2 and electrochemical cell to measure NOx and oxygen content. The detailed specification
of the exhaust gas analyzer was given in Appendix 3. The smoke emission from the engine
was measured by using the Bosch smoke meter, TI diesel tune, 114 smoke density tester. The
specification of the smoke meter was given in the Appendix 4.

The cylinder pressure was measured using kistler piezoelectric pressure transducer.
The signal from the sensor was feed to a charge amplifier which will convert the input signal
into readable value. The specification of the charge amplifier was given in Appendix 8. The
pressure signal and the crank angle signal where given to the oscilloscope to get the pressure
crank angle diagram. The crank angle signal was get from the IR sensor and a pointer. The
pointer was attached to the flywheel and the IR sensor was fitted on the frame. When the
pointer cuts the IR ray the pulse was generated, which will be the input signal for the
oscilloscope. The specification of the oscilloscope was given in Appendix 9.
 32

CHAPTER 6

RESULTS AND DISCUSSION

The results obtained from the experiments conducted on the hydrogen diesel dual
fueled engine were displayed and discussed in this chapter. The test engine was initially run
on the diesel and the performance and emission data’s where taken as the base line reading.
After the base line reading the dual fuel mode experiment where conducted.

EGR OPERATION

The dual fueled operation with EGR was conducted for port fuel injection technique
and manifold injection technique. In both the technique upto 25 % EGR was adopted beyond
that due to unstable combustion it was not possible to run the engine and also it results in
huge amount of smoke.

6.1 EGR with port fuel injection technique

In port fuel injection technique the hydrogen was injected in the intake port with
constant mass flow rate of 5.5 lpm and the diesel was injected inside the combustion chamber
at 23° Before Ignition TDC (BITDC). The amount of the diesel fuel injected was varied
corresponding to the engine load. Before adopting the EGR the injection parameters and the
flow rate of hydrogen where optimized based on the performance and emission
characteristics. The EGR rate was varied from 0 % to 25 % in the steps of 5 %. Cooled EGR
was used through out the experiments and the temperature of the exhaust gas before mixing
was kept constantly at 31° C.
 33

6.1.1 Optimization of injection timing and injection duration

The start of injection was varied from 5° Before Gas exchange TDC (BGTDC) to 25°
After Gas exchange TDC (AGTDC) in the steps of 5° crank angles and the duration used
where 30°, 60° and 90° crank angle. There are totally 21 combination of injection timing and
injection duration was used. The various start of injection and injection duration in crank
angle and milli second was given in Table 6.1. The variation of the brake thermal efficiency
for various start of injection and injection duration was shown in Figure 6.1. In this figure the
legend shows start of injection / injection duration. From the figure it can be seen that the
start of injection of 5° BGTDC and injection duration of 30°crank angle have the maximum
brake thermal efficiency over the entire load range, this is due to the enhanced combustion of
hydrogen which also helps the diesel combustion. The maximum efficiency of 25.66 % was
achieved at 75 % load, it was 19 % more than the diesel fuel operation. In the full load the
increase in efficiency decreases to 9 % this is due to the, reduction in the combustion
efficiency of the diesel fuel.
­5/30
­5/60
­5/90
0/30
Brake thermal efficiency, %

30 0/60
0/90

25 5/30
5/60

20 5/90
10/30

15 10/60
10/90
15/30
10
15/60
15/90
5 20/30
20/60
0 20/90
0 20 40 60 80 100 25/30
25/60
Load, % 25/90
Diesel

Figure 6.1 Variation of brake thermal efficiency with load for various injection timings
 34

Table 6.1 Start of injection and injection duration

S.No Start of Injection Injection Duration

Crank angle (Degrees) Time (ms) Crank angle (Degrees) Time (ms)
1 5° BGTDC 0.555 30 3.330
2 5° BGTDC 0.555 60 6.660
3 5° BGTDC 0.555 90 9.990
4 GTDC 1.110 30 3.330
5 GTDC 1.110 60 6.660
6 GTDC 1.110 90 9.990
7 5° AGTDC 1.665 30 3.330
8 5° AGTDC 1.665 60 6.660
9 5° AGTDC 1.665 90 9.990
10 10° AGTDC 2.220 30 3.330
11 10° AGTDC 2.220 60 6.660
12 10° AGTDC 2.220 90 9.990
13 15° AGTDC 2.775 30 3.330
14 15° AGTDC 2.775 60 6.660
15 15° AGTDC 2.775 90 9.990
16 20° AGTDC 3.330 30 3.330
17 20° AGTDC 3.330 60 6.660
18 20° AGTDC 3.330 90 9.990
19 25° AGTDC 3.885 30 3.330
20 25° AGTDC 3.885 60 6.660
21 25° AGTDC 3.885 90 9.990
 35

6.1.2 Optimization of hydrogen flow rate

The start of hydrogen is fixed at 5° BGTDC and injection duration of 30° crank angle
was fixed and the flow rate of hydrogen is varied to find the optimised flow. Figure 6.2
shows the variation of the brake thermal efficiency with load for different flow rate of
hydrogen from 2 lpm to 9.5 lpm. From the figure the flow rate of 9.5 lpm has the maximum
efficiency of 26.68 % at part load, but in the emission point of view HC is higher by 27 %
and CO is higher by 71 % than that of 7.5 lpm hydrogen flow. At the same time the
efficiency at full load is 24.15 % only, which is less than the brake thermal efficiency for 7.5
hydrogen flow. At lighter loads the cycle to cycle variation of cylinder pressure is high for
the flow rate of 9.5 lpm, this is due to the higher replacement of air by hydrogen which
results in instable combustion. Considering all this flow rate of 7.5 lpm is taken as the best
one. The optimized injection parameter for port fuel injection was shown in Table 6.2.

30
Brake thermal efficiency, %

25

20 Diesel
2 lpm
15 3.5 lpm
5.5 lpm
7.5 lpm
10
9.5 lpm

0
0 20 40 60 80 100
Load, %

Figure 6.2 Variation of brake thermal efficiency with load for different hydrogen
flow rate
 36

Table 6.2 Optimized injection data for port fuel injection

INJECTION PARAMETER VALUE

Start of injection of hydrogen 5° BGTDC
Hydrogen injection duration 30° crank angle
Hydrogen flow rate 7.5lpm
Diesel start of injection 23° BITDC

6.1.3 Dilution effect of EGR

Figure 6.3 shows the variation of the oxygen concentration in percentage volume of
intake charge with respect to engine load. The oxygen concentration decreases continuously
with the load and EGR rate, this is due to the amount of excess oxygen content in the exhaust
gas decreases as the load increases. This reduction in the oxygen content provides adequate
dilution effect. The minimum oxygen content is 16.8% volume of the intake charge.
Oxygen concentration, %

22
21
Diesel
20 w/o EGR
19 5% EGR
vol

10% EGR
18 15% EGR
20% EGR
17 25% EGR

16
15
0 20 40 60 80 100
Load, %
Figure 6.3 Variation of oxygen concentration with load
 37

6.1.4 NOx reduction

The variation of the NOx emission with different EGR rate and load was shown in
Figure 6.4. The NOx emission without EGR reaches the maximum of 2240 ppm. During no
load operation the NOx emission is lesser than the diesel, this is due to very lean combustion.
As the load increases the NOx shoots up. While using the EGR the NOx emission brought
down, the minimum value of NOx emission is 380 ppm for full load with 25 % EGR rate.
This is 83 % less than the operation without EGR. The reduction in NOx emission is by three
effect called dilution effect, thermal effect and chemical effect. Out of this dilution effect
have the maximum effect in diesel fuel operation. But in case of hydrogen combustion water
vapour was formed, which becomes the main constituent of the EGR. Due to this apart from
dilution effect, which is due to reduction of O2 content, thermal effect also produces
considerable reduction in NOx.

2500

2000
NOx, ppm

1500 Diesel
w/o EGR
5%EGR
10%EGR
1000 15%EGR
20%EGR
25%EGR
500

0
0 20 40 60 80 100
Load, %

Figure 6.4 Variation of NOx emission with load

 38

6.1.5 CO2 emission

14
12
10
CO2, %vol

Diesel
w/o EGR
8
5%EGR
6 10%EGR
15%EGR
4 20%EGR
2 25%EGR

0
0 20 40 60 80 100
Load, %

Figure 6.5 Variation of CO2 emission with load

Figure 6.5 shows the variation of the CO2 emission with respect to various EGR flow
rate and load. The CO2 emission is comparatively lower than the diesel fuel operation for all
EGR rate. The main reason for the reduction of CO2 is the replacement of hydro carbon fuel
by hydrogen. While considering the hydrogen fuel operation the CO2 emission increases at
low load for all EGR rate and the CO2 emission decreases at high load, as the EGR rate
increases the CO2 emission starts to reduce. The main reason for the reduction of CO2 at high
load is due to the incomplete combustion of last part of diesel. At light load the O2 available
is enough for the complete combustion of both diesel and Hydrogen, so the CO2 emission is
high at light loads.

6.1.6 CO emission

The variation of the CO emission with respect to different load and EGR rate was
shown in Figure 6.6. The CO emission for the hydrogen fuelled operation is less than the CO
 39

emission produced by the diesel fueled operation. But during the EGR operation the CO
emission increases. At light load the increase in the CO emission is minimum and it is
negligible, but in full load the increase in CO emission is very high. The CO emission
reaches the maximum value of 1.3 % of the exhaust gas for 25 % EGR which is 8 times
higher than that of the diesel and 14 times higher than that of the without EGR operation.
This increase in the CO emission is due to the incomplete combustion of the last part of the
diesel. Since the flame speed of the hydrogen is high as soon as the combustion starts the
combustion of hydrogen completed rapidly so the final part of the diesel injected doesn’t
have enough air for complete combustion.

1.4
1.2 Diesel
1
CO, %vol

w/o EGR
5%EGR
0.8
10%EGR
0.6 15%EGR
0.4 20%EGR
25%EGR
0.2
0
0 20 40 60 80 100
Load, %

Figure 6.6 Variation of CO emission with load

6.1.7 Smoke emission

Figure 6.7 shows the variation of smoke emission with respect to load for various
EGR rate. For hydrogen fueled operation the smoke emission is less than the diesel fuel
operation for all load range. When using the EGR the smoke emission shoots up at higher
load and drops down at light load compared to operation without EGR. While using 25 %
EGR the smoke was very high above 75 % load. This is due to the in sufficient oxygen
content for the last part of the diesel fuel. At light load EGR enhance the combustion by
 40

increasing the overall charge temperature, which results in low smoke emission and CO2
emission is higher at light loads. Normally this type of engine is used for part load
application, considering this the smoke emission is lesser than diesel fuel operation up to
20 % EGR rate.

6
5 Diesel
Smoke, BSN

w/o EGR
4 5%EGR
10%EGR
3 15%EGR
20%EGR
2 25%EGR

1
0
0 20 40 60 80 100
Load, %

Figure 6.7 Variation smoke emission with load

6.1.8 HC emission
The variation of the HC emission is shown in Figure 6.8 for different load and EGR
rate. The HC emission is normally high for all operation with and without EGR. The main
reason for the increase in the HC emission is the incomplete combustion of the last part of
the diesel due to the lack of oxygen. Even though the diesel combustion starts prior to the
hydrogen combustion, the combustion of the hydrogen completed instantly before the diesel
combustion. The main reason for this was the higher flame speed of the hydrogen, so this
ends up with in sufficient air for the last part of the hydrocarbon fuel supplied, which was the
main source of the HC emission. The maximum value of the HC emission was 68 ppm,
which was at 25 % EGR and full load condition. It was 40 % higher than the hydrogen fuel
operation without EGR.
 41

80
70
60
HC, ppm

50
Diesel
40 w/o EGR
5%EGR
30 10%EGR
20 15%EGR
20%EGR
10 25%EGR

0
0 20 40 60 80 100
Load, %
Figure 6.8 Variation of HC emission with load

6.1.9 Brake thermal efficiency

30
25
Efficiency, %

20 Diesel
w/o EGR
15 5%EGR
10%EGR
10 15%EGR
20%EGR
5 25%EGR

0
0 20 40 60 80 100
Load, %

Figure 6.9 Variation of brake thermal efficiency with load

 42

Figure 6.9 shows the variation of the efficiency with respect to different load at
various EGR rate. The efficiency of the hydrogen fuel operation is quite higher than the
diesel fuel operation over the entire load range. While using EGR the efficiency drops down
as the load increases. Especially at full load the efficiency drops down below the diesel for
25 % EGR rate. This is due to the incomplete combustion of the diesel supplied. At part load
the efficiency is fairly better than the diesel fuel operation due to the enhanced combustion.

6.1.10 Pressure crank angle diagram

80
70
Cylinder pressure, bar

60
w/o EGR
50 5%EGR
10%EGR
40
15%EGR
30 20%EGR
25%EGR
20
10
0
100 130 160 190 220 250 280
Crank angle

Figure 6.10 Pressure crank angle diagram at 75% load

The pressure crank angle diagram for different EGR rate at part load was shown in
Figure 6.10. The peak cylinder pressure for hydrogen fuel with EGR occur 2 o to 3o later than
normal hydrogen fuel operation. This shift is due to the increase in ignition delay caused by
 43

the dilution effect of the EGR. At the same time the peak cylinder pressure was also drops
down as the EGR rate increases.

6.1.11 Heat release rate

Figure 6.11 shows the heat release rate at 75 % load for different EGR rate. As the
fuel air mixture is readily available and the flame speed of hydrogen is high, hydrogen
combustion was completed in the pre mixed combustion phase itself. As soon as the diesel
combustion was started, the hydrogen combustion also started and completed rapidly before
the completion of diesel injection. So the heat released after the premixed combustion was
absorbed by the diesel spray. When EGR was used the duration of the premixed combustion
was increased and the peak heat release is reduced to both the thermal and dilution effect of
the exhaust gas in the cylinder.

70

60 0%EGR

5%EGR
50
Heat Release Rate, J / deg CA

10%EGR
40 15%EGR

20%EGR
30
25%EGR
20

10

0
150 160 170 180 190 200
­10

­20
Crank Angle, deg

Figure 6.11 Heat release rate at 75% load

 44

6.2 EGR with manifold fuel injection technique

In manifold fuel injection technique the hydrogen injector was positioned at a point
100 mm away from intake manifold. The tapping for CO2 measurement was provided before
the hydrogen injector. Like in port injection technique, manifold injection technique injection
parameters where optimized.

6.2.1 Optimization of injection timing and injection duration

30 ­5/30
­5/60

25 ­5/90
0/30
0/60
Efficiency %

20 0/90
5/30
5/60

15 5/90
10/30
10/60

10 10/90
15/30
15/60
5 15/90
20/30
20/60
0 20/90
25/30
0 20 40 60 80 100 25/60
25/90
Load % Diesel

Figure 6.12 Variation of brake thermal efficiency with load for various injection timing

The variation of the brake thermal efficiency of various start of injection and injection
duration is shown in Figure 6.12. In this the legend shows start of injection / injection
duration. From the figure it can be seen that the start of injection at TDC and injection
duration of 30°crank angle have the maximum efficiency over the entire load range, this is
 45

due to the enhanced combustion of hydrogen which also helps the diesel combustion. The
maximum efficiency of 25.66 % was achieved at 75 % load.

6.2.2 Optimization of hydrogen flow rate

30

25
Efficiency, %

Diesel
20 2 lpm
3.5 lpm

15 5.5 lpm
7.5 lpm
9.5 lpm
10

0
0 20 40 60 80 100
Load, %
Figure 6.13 Variation brake thermal efficiency with load for different hydrogen
flow rate

The start of injection for hydrogen was fixed at TDC and injection duration of 30°
crank angle was fixed and the flow rate of hydrogen is varied to find the optimized flow.
Figure 6.13 shows the variation of brake thermal efficiency with respect to load for different
hydrogen flow rate. From the figure the flow rate of 9.5 lpm has the maximum brake thermal
efficiency of 26.08 % at 75 % load and 24 % at full load, but in the emission point of view
HC is higher by 12 % and CO is higher by 50 % than that for the flow rate of 7.5 lpm. At the
same time the efficiency at part load for 7.5 lpm and 9.5 lpm are same 26.08 %. At lighter
load the cycle to cycle variation of cylinder pressure is high for the flow rate of 9.5 lpm, this
 46

is due to the higher replacement of air by hydrogen which results in unstable combustion.
Considering all this flow rate of 7.5 lpm is taken as the best one. The final injection
parameter for manifold fuel injection was shown in table 6.3.

Table 6.3 Optimized injection timings for manifold fuel injection

INJECTION PARAMETER VALUE

Start of injection TDC

Injection duration 30° crank angle

Hydrogen flow rate 7.5lpm

Start of injection for diesel 23° BITDC

6.2.3 Dilution effect of EGR

21
Oxygen concentration,

20
0% EGR
19 5% EGR
% vol

10% EGR
18 15% EGR
20% EGR
25% EGR
17
16
15
0 20 40 60 80 100
Load, %
Figure 6.14 Variation of oxygen concentration with load
 47

Figure 6.14 shows the variation of the O2 concentration in percentage volume of

intake charge with respect to engine load. The O2 concentration decreases continuously with
the load and EGR rate, this is due to the amount of excess oxygen content in the exhaust gas
decreases as the load increases. This reduction in the oxygen content provides adequate
dilution effect. The minimum oxygen content is 16.55 % volume of the intake charge for
20 % EGR at full load. For 25 % EGR full load was not obtained due to high smoke and
unstable combustion.

6.2.4 NOx reduction

2500

2000
Diesel
NOx, ppm

0%EGR
1500 5%EGR
10%EGR
15%EGR
1000 20%EGR
25%EGR

500

0
0 20 40 60 80 100
Load, %

Figure 6.15 Variation of NOx emission with load

The variation of the NOx emission with different EGR rate and load was shown in
Figure 6.15. The NOx emission with out EGR reaches the maximum of 2171 ppm. During no
load operation the NOx emission is lesser than the diesel fuel mode, this is due to very lean
combustion. As the load increases the NOx shoots up. While using the EGR the NOx
emission reduces, the minimum value of NOx emission is 339 ppm for full load with 20 %
EGR rate. This is 84.38 % less than the operation without EGR. The dilution effect have the
 48

maximum effect on NOx reduction in diesel fuel operation. But in the case of hydrogen
combustion water vapour was produced, which will become the main constituent of the EGR.
Due to this apart form dilution effect, thermal effect also plays a siginificant role in NOx
reduction.

6.2.5 CO2 emission

14
12
Diesel
10
CO2, %vol

0%EGR
5%EGR
8
10%EGR
6 15%EGR
20%EGR
4 25%EGR

2
0
0 20 40 60 80 100
Load, %
Figure 6.16 Variation of CO2 emission with load

Figure 6.16 shows the variation of the CO2 emission with respect to various EGR rate
and load. The CO2 emission is comparatively lower than the diesel fuel operation for all EGR
rate. The main reason for the reduction of CO2 is the replacement of hydrocarbon fuel by
hydrogen. While considering the hydrogen fuel operation the CO2 emission increases at low
load for all EGR rate and the CO2 emission decreases at high load, as the EGR rate increases
the CO2 emission starts to drop down. The main reason for the reduction of CO2 at high load
is due to the incomplete combustion of last part of diesel. At light load the O2 available is
enough for the complete combustion of both diesel and hydrogen, so the CO2 emission is
high at light loads.
 49

6.2.6 CO emission

The variation of the CO emission with respect to various load and different EGR rate
is shown in Figure 6.17. The CO emission for the hydrogen fuelled operation is less than the
CO emission produced by the diesel fueled operation. During the EGR operation the CO
emission increases with increase in load. At light load the increase in the CO emission was
minimum and it is negligible, but in full load the increase in CO emission is very high. The
CO emission reaches the maximum value of 1.49 % of the exhaust gas for 20 % EGR at full
load. The increase in CO emission is due to the incomplete combustion of the last part of the
diesel, because the hydrogen takes maximum amount of air during its combustion. Since the
flame speed of the hydrogen is high as soon as the combustion starts the combustion of
hydrogen completed rapidly so the final part of the diesel injected doesn’t have enough air
for combustion.

1.6
1.4
1.2 Diesel
CO, %vol

0%EGR
1
5%EGR
0.8 10%EGR
15%EGR
0.6 20%EGR
25%EGR
0.4
0.2
0
0 20 40 60 80 100
Load, %
Figure 6.17 Variation of CO emission with load
 50

6.2.7 Smoke emission

6
5
Smoke, BSN

Diesel
4 0%EGR
5%EGR
3 10%EGR
15%EGR
20%EGR
2
25%EGR

1
0
0 20 40 60 80 100
Load, %

Figure 6.18 Variation of smoke emission with load

Figure 6.18 shows the variation of smoke emission with respect to load for various
EGR rate. For hydrogen fueled operation the smoke emission less than the diesel fuel
operation for all load range. When using the EGR the smoke emission shoots up at higher
load and drops down at light load compared to operation without EGR. While using 25 %
EGR the smoke was very high at and above 75 % load. This is due to the in sufficient oxygen
content for the last part of the diesel. At light load EGR enhance the combustion by
increasing the overall charge temperature, which results in lower smoke and increase in CO2
emission at light loads. The test engine was normally used for part load application,
considering this the smoke emission is lesser than diesel fuel operation up to 20 % EGR rate.

6.2.8 HC emission

The variation of the HC emission is shown in Figure 6.19 for different load and EGR
rate. The HC emission is normally high for all EGR rates and without EGR also. The main
 51

reason for the increase in the HC emission is the incomplete combustion of the last part of
the diesel due to the lack of oxygen. The combustion of the hydrogen was almost completed
in the pre mixed phase of the combustion itself, so maximum part of the air supplied was
consumed by the hydrogen. In the later part, during the diffusion combustion the diesel spray
dose not able to find enough air for its complete combustion. In case of the EGR this effect
was more and hence the HC emission was more.

80
70
60 Diesel
0%EGR
HC, ppm

50 5%EGR

40 10%EGR
15%EGR
30 20%EGR

20 25%EGR

10
0
0 20 40 60 80 100
Load, %

Figure 6.19 Variation of HC emission with load

6.2.9 Brake thermal efficiency

Figure 6.20 shows the variation of the brake thermal efficiency with respect to
different load at various EGR rate. The efficiency of the hydrogen fuel operation is quite
higher than the diesel fuel operation over the entire load range. While going for EGR the
efficiency drops down as the load increases. Especially at full load the efficiency drops down
below the diesel for 20% EGR rate. This is due to the incomplete combustion of the diesel
 52

supplied. But seeing in the part load the efficiency is 25.05 %, which was fairly better than
the diesel fuel operation.

30

25
Efficiency, %

20

Dies el
15 0%EGR
5%EGR

10 10%EGR
15%EGR
20%EGR
5 25%EGR

0
0 20 40 60 80 100
Load, %

Figure 6.20 Variation of brake thermal efficiency with load

6.2.10 Pressure crank angle diagram

The pressure crank angle diagram for different EGR rate at part load was shown in
Figure 6.21. The peak cylinder pressure for hydrogen fuel with EGR occur 3o later than
normal hydrogen fuel operation. This shift is due to the increase in ignition delay caused by
the dilution effect of the EGR. At the same time the peak cylinder pressure was also drops
down as the EGR rate increases. The rate of pressure rise for the operation with EGR was
lesser than that of the operation without EGR.
 53

90
0% EGR
80 5% EGR
Peak cylinder pressure, bar

70 10% EGR

60 15% EGR
20% EGR
50
25% EGR
40
30
20
10
0
100 130 160 190 220 250 280
Crank angle, deg

Figure 6.21 Pressure crank angle diagram at 75% load

90

0% EGR
Heat Release Rate, J / deg

70

5% EGR

50 10% EGR

15% EGR
30
20% EGR

25% EGR
10

165 170 175 180 185 190 195 200

­10

­30
Crank Angle, deg
Figure 6.22 Heat release rate at 75% load
 54

6.2.11 Heat release rate

Figure 6.22 shows the heat release rate at 75 % load for different EGR rate. Normally
hydrogen combustion was completed in the pre mixed combustion phase itself, since the fuel
air mixture is readily available and the flame speed of hydrogen is high. As soon as the diesel
combustion was started, the hydrogen combustion also started and completed rapidly before
the completion of diesel injection. Show the heat released after the premixed combustion is
absorbed by the diesel spray.

6.3 SCR OPERATION

The hydrogen diesel dual fuel operation with selective catalytic reduction was
adopted for the port fuel injection technique. The optimized hydrogen injection parameter for
port fuel injection was used for the SCR operation.

1.4
1.2
Urea solution flow rate, cc/min

1
0.8 a = 0.9
0.6 a=1
0.4 a = 1.1

0.2
0
0 20 40 60 80 100
Load, %

Figure 6.23 Urea flow rate for different a values

 55

Initially the engine was run on hydrogen­diesel dual fuel mode and the amount of
NOx emitted was noted. Based on this the flow rate of the urea solution for the required ‘a’
was found. a is the ratio between flow rate of ammonia to floe arte of NO, in this work three
values where tested. The calculated urea flow rate for each a value with load was shown in
Figure 6.23. After calculating the required urea flow rate the injection duration for the
required flow rate was found out.

6.3.1 Brake thermal efficiency

The SCR operation was a tail pipe treatment, so it will not affect the combustion and
hence the brake thermal efficiency doesn’t affected much by the SCR application. Figure
6.24 shows the variation of the brake thermal efficiency with load for various a rates. The
maximum efficiency of the engine in dual fuel mode with SCR was 26 %, it was 0.23 % less
than the operation with out the SCR. The main reason for the slight reduction in the
efficiency was the backpressure created due to the flow restriction by the SCR catalytic
converter.

30
Brake thermal efficiency, %

25

20 Diesel
w/o SCR
15 a = 0.9
a=1
10
a = 1.1

0
0 20 40 60 80 100
Load, %

Figure 6.24 Variation of brake thermal efficiency with load

 56

6.3.2 Backpressure

The backpressure created due to the SCR catalytic converter for various load and a
value are presented in Figure 6.25. The maximum backpressure created was 4.2 cm of water
column. The backpressure is high for the low a values, this is probably due to the low flow
rate of the reduction agent.

4.5
Back pressure, cm of water

3.5 a = 0.9
a=1
3 a = 1.1

2.5

2
0 20 40 60 80 100
Load, %

Figure 6.25 Variation of backpressure with load

6.3.3 NOx emission

The main objective of the SCR was to reduce the NOx emission from internal
combustion engine. Figure 6.26 shows the variation of the NOx emission for different a
values and load. The NOx emission reduced considerably when using SCR, the minimum
value of the NOx emission at full load was 1067 ppm which is 52 % less than the operation
without SCR. The a value of 0.9 provides best NOx reduction than the other two a values.
The overall NOx reduction with a of 0.9 was 56.68 %. It seem that the NOx reduction level
was little bit low, this was due to the low temperature of the catalytic bed. Due to the heat
loss the decomposing capacity of the urea was also reduced. The difference in the NOx
conversion efficiency for different a value was less, the variation will be around 2 %.
 57

2500

2000

Diesel
NOx, ppm

1500 w/o SCR

a = 0.9
1000 a=1
a = 1.1

500

0
0 20 40 60 80 100
Load, %

Figure 6.26 Variation of the NOx emission with load

6.3.4 HC emission

The variation of the HC emission with load was shown in Figure 6.27. The HC
emission reduced drastically when SCR was used. The main reason for the reduction of the
HC emission was the HC itself acts as the reduction agent and take part in NOx reduction.
The overall HC emission reduction was 73 % for the a value of 0.9. As the load increases the
conversion efficiency of the HC drops down from 100 % to 50 %. The a ratio of 0.9 shows
better results in terms of both HC and NOx reduction. The HC emission for this a ratio was
just 24 ppm and the NOx emission was 1067 ppm, both are less than 50 % of the emission by
the hydrogen fuel operation without SCR. As the ratio of the a increases the utilization of the
HC as the reduction agent was reduced, this was evident by increase in HC emission with
increase in a ratio.
 58

60

50

40 Diesel
HC, ppm

w/o SCR
30 a = 0.9
a=1
20 a = 1.1

10

0
0 20 40 60 80 100
Load, %

Figure 6.27 Variation of HC emission with load

6.3.5 CO emission

0.16

0.14

0.12
Diesel
0.1
CO, % vol

w/o SCR
0.08 a = 0.9

0.06 a=1
a = 1.1
0.04

0.02

0
0 20 40 60 80 100
Load, %

Figure 6.28 Variation of CO emission with load

 59

The variation of the CO emission for various load and a ratio was presented in the
Figure 6.28. The CO emission was reduced to value lower than the hydrogen diesel dual fuel
operation without SCR, over the entire load range. Like HC, CO also oxidized and takes part
in NOx reduction. At no load the CO emission was almost negligible in quantity. The CO
emission trend remains same for all the a ratio.

6.3.6 CO2 emission

Figure 6.29 shows the variation of the CO2 emission with respect to the load and a
ratio. The CO2 emission seems to be slightly higher than the hydrogen diesel dual fuel
operation without SCR. There are two reasons for the increase in the CO2 emission one is the
oxidation of the CO and the other is the decomposition of the urea, which will produce some
CO2. The maximum value of the CO2 emission was 11.5 % of the exhaust gas, for the a ratio
of 0.9 at full load. This was 5 % higher than that of the hydrogen diesel dual fueled operation
without SCR.

14

12

10
Diesel
CO2, % vol

8 w/o SCR
a = 0.9
6 a=1
a = 1.1
4

0
0 20 40 60 80 100
Load, %

Figure 6.29 Variation of the CO2 emission with load

 60

6.3.7 Smoke emission

The variation of the smoke emission for various load and a ratios was given in the
Figure 6.30. The smoke emission from the engine using the SCR was very low. The highest
smoke value was 1.8 BSN, even this itself 0.2 BSN less than the hydrogen diesel dual fuel
operation without SCR. The a ratio of 0.9 have the minimum smoke level than the other two
a ratios.

3.5

3
Diesel
Smoke, BSN

2.5
w/o SCR
2 a = 0.9

1.5 a=1
a = 1.1
1

0.5

0
0 20 40 60 80 100
Load, %

Figure 6.30 Variation of the smoke emission with load

 61

CHAPTER 7

CONCLUSIONS

Based on the experiments conducted on the hydrogen diesel dual fuel DI diesel
engine with Exhaust gas recirculation and selective catalytic reduction the following
conclusion where drawn.

7.1 EGR IN PORT FUEL INJECTION TECHNIQUE

By using the Exhaust gas recirculation with port fuel injection of hydrogen, the
maximum EGR rate was 25 %. It was found that 20 % EGR would provide the better result.
The overall drop in the thermal efficiency was 4.5 %. The overall NOx reduction was 61 %
and the maximum NOx reduction was 76 % at full load. This NOx reduction was achieved at
the expense of increase in HC and smoke. The HC emission increase by 2.7 % and the smoke
emission increased twice. Even though the CO2 emission reduced at full load, considering the
overall operation CO2 emission increased by 8 %. Like the smoke emission the CO emission
was also increased by twice the amount.

7.2 EGR IN MANIFOLD FUEL INJECTION TECHNIQUE

Considering EGR in port fuel injection, EGR in manifold fuel injection shows better
results. In this technique the maximum EGR rate of 25 % was achieved but the 20 % EGR
rate shows favorable result than 25 % EGR rate. The drop in the brake thermal efficiency
was only 3.8 %. The maximum NOx reduction was found to be 84 %, which was quite higher
than that of the EGR in port fuel injection technique. Unlike EGR in port fuel injection
technique, the HC emission drops down for the entire load range except full load. The overall
reduction in the HC emission was 11 %. The increase in smoke level is also low in EGR
with manifold injection technique, the overall increase in smoke emission was just 9 %. The
 62

only problem in manifold injection technique was very high CO emission, the CO emission
will increase by around 3 times. The increase in CO2 emission was only 5 %. In overall
operation it is better to use EGR in manifold injection technique.

7.3 SELECTIVE CATALYTIC REDUCTION

The selective catalytic converter shows very attractive results than the exhaust gas
recirculation in both the performance and emission point of view. The drop in the brake
thermal efficiency due to the backpressure was only 0.8 % in part load and 0.4 % in full load.
Maximum NOx reduction of 74 % was achieved for the a of 1.1. But considering other
emission parameters the a of 0.9 shows the optimized performance. The NOx reduction for
the a of 0.9 was 70 % at load and the overall NOx reduction was 57 %. The reduction in HC
emission along with the NOx emission is the one of the main advantage of SCR system,
maximum HC reduction of 83 % was obtained at low loads and the overall reduction was 73
%. The CO emission was also reduced along with the HC, the overall CO reduction was 63
%. The CO2 emission was increased by 10 % due to the oxidation of the CO. the smoke
emission was also reduced to zero at low load at reach the maximum of 1.4 BSN at full load.

In general it is best to use the selective catalytic reduction than the exhaust gas
recirculation, due to its very low pollutant emission.

FUTURE WORK
§ Electronically controlled automatic EGR valve
§ Combining the EGR and SCR technique
§ Optimize the SCR with different reduction agents
§ SCR with different catalyst and automatic flow control of reduction agent
§ Analysis of material behaviors and engine tribology
§ Automated hydrogen flow rate for different load
 63

LIST OF PUBLICATIONS

INTERNATIONAL JOURNAL

1. Experimental Investigation of Hydrogen Fuel Injection in DI Dual Fuel Diesel

Engine, SAE 2007 World Congress, Detroit, SAE 2007­01­1465.

2. An Experimental Investigation on Hydrogen as a Dual Fuel for Diesel Engine System

with Exhaust Gas Recirculation Technique, Journal of Renewable Energy, Article in
press.

3. Experimental Investigation of Hydrogen Port Fuel Injection in DI Diesel Engine,

International Journal of Hydrogen Energy, Article in press.

INTERNATIONAL CONFERENCE

1. Performance and Emission Characteristics of Hydrogen – Diesel Dual Fuelled Engine

using Port Injection, PTNSS Congress­2007, 20­23 May, Poland.

2. Experimental Investigation of Hydrogen Fuel Injection in Direct Injection Diesel

Engine, International Green energy conference IGEC III, June 17­21,Sweden.

3. Exhaust Gas Recirculation For Hydrogen Dual Fueled DI Diesel Engine,

International Green energy conference IGEC III, June 17­21,Sweden.
 64

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From: "ptnss" <kongres@ptnss.pl>

To: kmkg17@yahoo.co.in
Subject:Fw: PTNSS Congress
Date: Wed, 13 Dec 2006 09:10:41 +0100

Paper Reference Number: P07­C093

Paper Title: NOx Reduction of hydrogen dual fuelled engine

Dear Mr. K.M. Kalaiselvan,

We are pleased to inform you that your abstract has been approved for oral presentation at
the International Congress on Combustion Engines PTNSS CONGRESS­2007, May 20th­
23th ,2007 – Krakow/ Polen.

Please prepare your Technical Paper, along with a Final Abstract, in accordance with the
instructions given at www.ptnss.pl

Your Final Paper and Final Abstract must be submitted no later than 31 th January 2007.
The Final Paper will be published in the Congress CD. The Final Abstract for each paper
will be printed in the Abstracts Book.
The both documents please send by e­mail to the congress secretariat: kongres@ptnss.pl

Please note that this message is e­mailed only to the corresponding author of the abstract. In
case there are more than one author, please inform your co authors about this approval.

On behalf the organizing committee

Zdzislaw Stelmasiak
Attachments

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 65

Date: Mon, 22 Jan 2007 15:39:56 +0100

To: kmkg17@yahoo.co.in
From: "registration@igec.info" <registration@igec.info>
Subject:Acceptance of Abstract for the 3rd International Green Energy Conference

RE: Abstract Acceptance for IGEC­III­Paper No. 176 (Cite this number for future correspondence)

Dear Kalaiselvan K.M:

We are very pleased to inform you that your paper entitled:

“EXHAUST GAS RECIRCULATION FOR HYDROGEN DUAL FUELED DI DIESEL ENGINE”

by Kalaiselvan.K.M, C.Dhanasekaran, N.Saravanan has been accepted for the Third International Green
Energy Conference (IGEC­III) to be held in Västerås, Sweden on June 17­21, 2007.

Your full­length paper (up to 12 pages) should be prepared according to the attached paper format.

Please upload your manuscript to the website at

http://www.igec.info/registration/login.php

in MS Word file no later than March 15, 2007.

All manuscripts will be reviewed and acceptance of the paper will be sent to you in May. All accepted
papers of the registered authors will be published in the conference proceedings, which will be available
during the Conference. The Conference requests at least one of the authors to present the accepted
paper at the Conference. Selected high­quality papers presented at the Conference will be further
published as special issues in one of prestigious international journals including International Journal of
Green Energy, International Journal of Energy Research, and International Journal of Exergy.

Further details of the Conference are available at www.igec.info.

Thank you very much for your contribution to the IGEC­III and we look forward to receiving your full
length manuscript soon. Please do not hesitate to contact us immediately if you have any questions.

Sincerely,

IGEC Conference Registration

Website: http://www.igec.info

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 66

Date: Tue, 13 Mar 2007 15:49:27 ­0400 (EDT)

From: blazekc@benetechusa.com
To: kmkg17@yahoo.co.in
Subject:POWER2007­22195 ­ Abstract Accepted

*** This is an auto­generated e­mail. There is no need to respond. ***

Congratulations kalaiselvan k.m!

The abstract you submitted to Power07 has been accepted. You will now need to submit a full­length
draft (full­length paper or two­page extended abstract) for a complete technical review. These drafts
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Here is a copy of what you have submitted:
Paper Number: POWER2007­22195
Abstract Title: Exhaust Gas Recirculation For Hydrogen Dual Fueled DI Diesel Engine
Abstract: Visit http://www.asmeconferences.org/Power07 and login to your author account. Click on the
paper number to view your abstract.

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REFERENCES

1. Abd­Alla. G. H. (2002), “Using Exhaust Gas Recirculation in Internal Combustion

Engines: A Review”, Energy Conversion and Management, vol.43, pp.1027­1042.
 67

2. Das. L.M. (2002), “Near – Term Introduction of Hydrogen Engines for Automotive
and Agricultural Application”, International Journal of Hydrogen Energy, Vol. 27,
pp. 479­487.

3. Das. L.M. (1996), “ Fuel Induction Techniques for a Hydrogen Operated Engine”,
Hydrogen fuel for surface transportation, College of Engineering, Centre for
environmental research and technology, University of California, Riverside,
published by Society of Automotive Engineers, Inc, Chapter No. 2, pp. 27 – 36.

4. Engler. B. H, J. Leyrer, E.S. Lox and K. ostgathe. (1993), “Catayltic Reduction of

NOx With Hydrocarbons Under Lean Diesel Exhaust Gas Conditions”, SAE
Transaction, SAE 930735.

5. Farshchi. M., C.J.Brodrick and H.A.Dwyer. (2001), “Dynamometer Testing of a

Heavy Duty Diesel Engine Equipped With a Urea­SCR System”, SAE Transaction,
SAE 2001­01­0516.

6. Gieshoff. J, M. Pfeifer, A. Schäfer­sindlinger, P.C. Spurk, G.Garr, T. Leprince and

M. Crocker. (2001), “Advanced Urea SCR catalysts for Automotive Applications”,
SAE Transaction, SAE 2001­01­0514.

7. Haragopala Rao. B, K.N. Shrivastava and H.N. Bhakta. (1983), “Hydrogen for dual
fuel engine operation”, International Journal of Hydrogen Energy, Vol.8, No.5,pp.
381­384.
8. James W. Heffel, (2003), “NOx Emission Reduction in a Hydrogen Fueled Internal
Combustion Engine at 1500 rpm Using Exhaust Gas Recirculation”, International
Journal of Hydrogen Energy, vol.28, pp.1285­1292.

9. Jehad A.A. Yamin, Gupta.H.N, Bansal.B.B. and Srivastava.O.N. (2000), “Effect of

Combustion Duration on the Performance and Emission Characteristics of a Spark
 68

Ignition Engine Using Hydrogen as a Fuel”, International Journal of Hydrogen

Energy, Vol 25­2000, pp.581­589.

10. Ladommatos.N., Abdelhalim.S.M., Zhao.H. and Hu.A. (1998), “Effects of EGR on

Heat Release in Diesel Combustion”, SAE Transaction, SAE 980184.

11. Ladommatos.N., Abdelhalim.S.M., Zhao.H. and Hu.A. (1998), “The Effect on Diesel
Combustion and Emissions of Reducing Inlet Charge Mass Due to Thermal
Throttling with Hot EGR”, SAE Transaction, SAE 980185.

12. Ladommatos.N., Abdelhalim.S.M., Zhao.H. and Hu.A. (1997), “The Dilution,

Chemical and Thermal Effects of Exhaust Gas Recirculation on Diesel Engine
Emission­Part 4: Effect Of Carbon Dioxide And Water Vapour”, SAE Transaction,
SAE 971660.

13. Masanori lwasaki, Nobuyuki lkeya, Masaaki ltoh and Hiroshi yamaguchi. (1995),
“Development and Evaluation of Catalysts to Remove NOx From Diesel Engine
Exhaust Gas”, SAE Transaction, SAE 950748.

14. Ming Zheng, Graham T. Reader, and Gary Hawley, (2004) “Diesel Engine Exhaust
Gas Recirculation­a Review on Advanced and Novel Concepts”, Energy Conversion
and Management, vol. 45 ,pp.883­900.

15. Naber.J.D. and Siebers.D.L. (1998), “Hydrogen Combustion Under Diesel Engine
Conditions”, International Journal of Hydrogen energy, Vol 23, No.5, pp. 363 –371.
16. Pratyush Nag, B. B. Ghosh, Randip K. Das and Maya DuttaGupta. (1998), “NOx
Reduction in SI Engine Exhaust Using Selective Catalytic Reduction Technique”,
SAE Transaction, SAE 980935.

17. Rolf Egnell. (2000), “The Influence of EGR on Heat Release Rate and NO Formation
in a DI Diesel Engine”. SAE Transaction, SAE 2000­01­1807.
 69

18. Sung­mu Choi, Yung­kee Yoon, Seok­jae Kim, Gwon­koo Yeo and Hyun­sik Han.
(2001), “Development of Urea­SCR System for Light­Duty Diesel Passenger Car”,
SAE Transaction, SAE 2001­01­0519.

19. Wolfgang, Axel König, Thomas Richter and Lothar Puppe. (1990), “Catalytic NOx
Reduction in Net Oxidizing Exhaust Gas”, SAE Transaction, SAE 900496.

20. Yi.H.S., Min.K. and Kim.E.S. (2000), “The Optimized Mixture Formation for
Hydrogen Fuelled Engine”, International Journal of Hydrogen energy Vol. 25­2000,
pp.685­690.

APPENDIX – 1

TEST ENGINE

Make and Model : Kirloskar, AVl make.

General Details : Four stroke, Compression ignition, Constant speed,
vertical, water cooled, direct injection.
 70

Number of cylinders : one

Bore : 80 mm
Stroke : 110mm
Swept Volume : 553 cc
Clearance Volume : 36.87 cc
Compression ratio : 16.5 : 1
Rated output : 3.7 kW at 1500 rpm
Rated speed : 1500 rpm
Injection Pressure : 240 bar
Fuel injection timing : 23 BTDC
Type of combustion chamber : Hemispherical open combustion chamber
Fuel : High speed diesel
Lubricating oil : SAE 40
Connecting rod length : 235 mm
Valve diameter 33.7 mm
Maximum Valve lift : 10.2 mm

APPENDIX – 2

ELECTICAL DYNAMOMETER

Make and Model : Laurence Scott and electromotor Ltd.,

Norwich and Manchester,UK
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Volts : 220/230
Power kW : 10
Windings : Shunt
Amps : 43.5
rpm : 1500
Rating : Continous

APPENDIX­3

EXHAUST GAS ANALYSER

Type and make : QRO 401, Qrotech corporation limited, Korea

Measuring items : CO, HC, CO2, O2, l, AFR, NOX
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Measuring method : CO,HC, CO2 : NDIR Method

O2 : Electrochemical cell
Measuring ranges : Oxygen (O2) : 0 to 25.00 % Vol
Carbon monoxide(CO) : 0 to 9.99 % Vol
Carbon dioxide (CO2) : 0 to 20.0 % Vol.
Hydrocarbon (HC) : 0 to 9999 ppm
l : 0 to 2.00
AFR : 0 to 99.00
Resolution : Oxygen (O2) : 0.01%
CO : 0.01%
CO2 : 0.1%
HC : 1ppm
l : 0.001
AFR : 0.1
Response time : Within 10 seconds(more than 90%)
Repeatability : Less than ±2% FS
Power supply : AC 110 or 220V only ±10%, 60 Hz
Power Consumption : About 50 W
Warming up time : About 2­8 minutes
Sample collecting quantity : 4­6 L/min
Operating Temperature : 0°C to 40°C
Display : 4 digit 7 segment LED

APPENDIX­ 4

SMOKE METER

Type and make : TI diesel tune, 114 smoke density tester TI

transervice.
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Piston displacement : 330 cc

Stabilisation time : 2 minutes
Range : 0 – 10 Bosch smoke number
Minimum time period : 30 sec
Calibrated reading : 5.0 + 0.2

APPENDIX – 5

HYDROGEN LEAK DETECTOR

Type And Make : Finch Mono II, Portable single gas monitor,
INFITRON INC ,Korea
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Measuring principle : Electrochemical cell

Measuring gas : Hydrogen
Range : 0­1000 ppm
Alarm device : LED, Buzzer(95dB at 10 cm) ,Vibrator­optional
Alarm kinds : 1st Level/2nd Level, TWA/STEL
Typical battery life : More than 2000 hrs
Display devices : 4x12 LCD with Backlight
Power supply : 3 Alkaline AA Battery
Operating voltage : 3.2 V to 4.7 V
Temperature : ­20° C to +50°C
Dimensions : 121.9mm(H)x63.5mm(W)x30.5mm(D)
Weight : 123 gm
Option : Vibration, Data logging
Case : RFI Protected ABS

APPENDIX­ 6

DIGITAL MASS FLOW CONTROLLER

Type and make : DFC 46 mass flow controller AALBORG USA

Flow Medium : Clean gases only
Flow range : 0 to 100 l/min
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Accuracy : ±1% full scale, Temperature range 15°C to 25°C

and pressure 0.7 to 4.1 bar
Repeatability : ±0.15% of full scale
Temperature coefficient : 0.1% of full scale/ °C
Pressure coefficient : 0.01% of full scale/ psi (0.07 bar)
Response time : DFC 36/46: 600ms time constant: approximately 2
seconds to within ±2% of set flow rate for 25% to
100% of full scale flow
Gas pressure : 34.5 bar maximum, optimum pressure 1.7 bar

Differential pressure required : 0.35 to 3.34 bar, optimum pressure 1.7 bar
Gas and ambient temperature : 5°C to 50°C
Relative gas humidity : up to 70%
Leak integrity : 1x10­9 sccs He max to the outside environment
Transducer input power : ±5% VDC, 6.75W max
Calibrated reading : 5.0 + 0.2
Weight : 1.29 kg

APPENDIX – 7

HYDROGEN INJECTOR

Injectors make : Quantum technologies

Operating gases : CNG, LPG, Hydrogen
Working pressure : 1.03 – 5.52 bar
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Supply voltage : 8 – 16 volts

Peak current : 4 amps
Holding current : 1 amps
Flow capacity : Hydrogen 0.8 g/s @4.83 ­ 5.32 bar
CNG 2.0 g/s @ 2.76 – 3.1 bar
LPG 2.0 g/s @ 1.17 – 1.38 bar
Injector coil resistance : 2.05 ± 0.25Ω at 20°C
Injector coil inductance : 3.98 ± 0.3 mH at 1000 Hz typical
Length : 79.8 mm
Diameter : 24.5 mm
Durability : >500 million cycle

APPENDIX­ 8

CHARGE AMPLIFIER

Type and make : Type 5015A Kistler instruments, Switzerland

Power supply unit : 230 V or 115 V AC –225 TO +155% tolerance 48­
62 Hz
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Dimensions(mm) : 105.3 (W) x 142 (H) x 253.15 (T)

Weight : 2.3 kg
Output voltage FS : ±10/±5/±2, 5/±2 V
Output current : <±2 mA
Relative humidity : 10­80%
Operating temperature : ­10°C to 70°C
Measuring range FS : ±2….2200000 pC
Measuring error FS : Range FS³100 pC <±0.5
Drift DC(Long) at 50°C : <±0.3 pC/s
Overload : ±105 %FS
Connector type : BNC negative
Zero error : <±2 mA
Output interference : 0.1 Hz… 1MHz LP Filter£ 30 kHz
Frequency response : 0…200 kHz bandwidth
Group delay : 10 ms
Liquid crystal display : 128x128 pixels

APPENDIX­ 9

OSCILLOSCOPE

Type and make : HP54600 B, Hewlett Packard, Europe

Bandwidth : DC to 100MHz –3 dB
Rise time : 3.5 ns
Dynamic range : ±32 V
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Input resistance : 1 MW
Input capacitance : 13 pf
Maximum input voltage : 400 V (dc+ peak ac)
Range : 2 mV/div to 5V/div
Accuracy : ±1.5%
Verniers : fully calibrated, accuracy about ±3%
Bandwidth limit : 20 MHz
Common mode rejection ratio: CMRR 20 Db at 50 MHz
Internal trigger : 10 mV
Evternal trigger : ±18 V
Display system : 7 inch raster CRT
Phase difference : ± 3 degrees at 100 kHz
Maximum sample rate : 20 Msa/s
Resolution : 8 bits
Single shot bandwidth : 2 MHz single channel
Record length : vectors on 2000 points
Line voltage range : 100 Vac to 240 Vac
Line frequency : 45 Hz to 440Hz
Maxi power consumption : 220 VA
Ambient temperature : ­10°C to 55°C
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