Modelling and Simulation of Dimethyl Ether Dual Reactor
Supervisor: DR, Shahir Sadek
DR, Mamdouh Gad-Allah
Student Name: Yasser Ashour Ramadan
ID:127978
Faculty of Engineering
Petrochemical engineering
1|Page YASSER ASHOUR 127978
Table of Contents
1. List of Figures .................................................................................................................... 3
2. List of Tables ..................................................................................................................... 4
3. Chapter I............................................................................................................................. 5
3.1 Introduction ................................................................................................................. 5
3.1.1 Historical Background About DME .................................................................... 5
1.2 Conversion of Methanol to DME .......................................................................... 10
4. Chapter II ......................................................................................................................... 14
4.1 Literature review ....................................................................................................... 14
4.1.1 The development of a new fuel .......................................................................... 14
4.1.2 Physical and chemical Properties of DME and its fuel use ............................... 15
4.1.3 Characteristics of DME Synthesis Reaction and Synthesis Gas Production ..... 17
4.1.4 DME synthesis reaction and catalyst system ..................................................... 18
4.1.5 Methods of production ....................................................................................... 20
4.1.6 DME production from renewable energies ........................................................ 22
4.1.7 DME production as a CO2 valorisation process ................................................ 24
4.1.8 Reaction kinetics of the dual reactor .................................................................. 24
4.1.9 Applications ....................................................................................................... 27
5. References ........................................................................................................................ 29
2|Page YASSER ASHOUR 127978
1. List of Figures
Figure 1 dehydration of methanol to DME by in situ water removal ...................................... 10
Figure 2 (a,c) modified top view, (b,d) cross sectional view, (b) double layer membrane, (d)
orientation of the LTA crystals ................................................................................................ 11
Figure 3 DME selectivity in the CMR and conversion of methanol into DME ...................... 12
Figure 4 DIESEL Fuel VS DME Exhaust Emissions (Adrian & Perry, 2007) ....................... 16
Figure 5 Direct Synthesis Process (Bernard, 1998) ................................................................. 17
Figure 6 Equilibrium Conversion (260C,5MPa) ..................................................................... 19
Figure 7 one step process (Adrian & Perry, 2007) .................................................................. 21
Figure 8 Two-step process block diagram ............................................................................... 22
Figure 9 DME from renewable energy (Fuat E. & Tae‐Jin, 2009) .......................................... 23
Figure 10 DME production from solar and biomass (Fuat E. & Tae‐Jin, 2009) ..................... 23
3|Page YASSER ASHOUR 127978
2. List of Tables
Table 1Reaction kinetic parameters (Charles, 1981) ............................................................... 26
4|Page YASSER ASHOUR 127978
3. Chapter I
3.1 Introduction
3.1.1 Historical Background About DME
In summarizing products with growing concerns about climate change, depletion of fossil
fuels, the global community has been encouraged to explore clean alternative fuels and energy
demand also reduce emissions of greenhouse gasses by increasing CO2. In the catalytic process
of syngas better methods have been developed to reduce CO2 efficiently to dimethyl ether
(DME). DME may be used mainly in a wide A range of solvent, aerosol propellant and
domestic fuel applications. The basic use of DME in compressive ignition engines as a possible
diesel substitute. Moreover, because carbon dioxide is not connected and DME uses about 35
percent oxygen as a combustion product CO2 emission are lower. DME synthesis methods,
depending on the type of raw material, mainly as direct and indirect are categorized. Methanol
is generated indirectly from methanol and then purified into DME syngas. By combining
methanol synthesis and dehydration, DME can be produced directly. The two steps are
conducted simultaneously in one single reactor using two-function catalysts. The preferred
route for large-scope production from a cost-and production point DME synthesis from syngas
is direct in comparison to both methods. DME synthesis has been suggested for strengthening
innovative multifunctional reactors in recent years. Heat exchangers, membrane reactors and
reactive distillation promise great improvements to chemical processes. The optimal gas and
reactive DME process design was proposed by Bondarenko.
In terms of energy efficiency and lower investment costs compare to traditional processes,
the proposed process demonstrated improved performance. This procedure is used for DME
5|Page YASSER ASHOUR 127978
synthesis indirectly, which makes a completely different process of syngas methanol necessary.
The 2-stage model for the new fluidised cloth and tube sheet membrane was developed by
Mardanpour et al. and it was shown that hydrogen penetration might increase the DME and
CO production.
In exothermal and reversible reactions, they considered a constant temperature in the bed
unacceptable. Catalytic dehydration is a two - armed reactor, DME and catalytic cyclohexane-
benzene dehydrogenation, in Farsi, etc. During these investigations, an integral reactor was
established. This reactor has made considerable improvements, which include reducing the
reactor size, changing the thermodynamic balance and auto thermality of the reactor Despite a
favourable temperature profile, this process still meets the conversion limits of the fixed bed
reactors. In synthesis with DME, Omata etal. developed a small-scale reactor, which shows a
much higher efficiency than the isothermal reactor. Other work by using a neuro-artificial
network and network search, optimized TGR temperature settings and found the combination
of high temperatures on bed entry and low temperatures on bed entry was beneficial. The
reaction balance can also be overcome by removing water on the spot in membrane reactors.
In order to ensure the best rate of entry and water disposal, Irananshahi et al. proposed a method
for optimizing a reactor länge in 20 segments. In practice these optimal profiles are hard to get.
The desired temperature profile can be achieved in the dual reactor configuration consisting of
two reactors operating under different conditions. Rahimpour suggested this configuration for
the production of methanol in the conversion section of the High temperature reactor first the
second reactor synthesis of methanol at low temperatures. In order to overcome the limitations
of the reaction balance, Vakili and Eslamloueyan have developed 2 industrial reactor types
Comprised of two reactors in fixed bed. They have developed and in a one - dimensional model,
maximized DME outlet mole fraction. The proposed optimal reactor depends on its results can
increase the DME output to sixty tons per one day in comparison with the standard process.
6|Page YASSER ASHOUR 127978
The current study is focused on the presentation, taking into account the significant benefits of
the configuration, of an industrial reactor with two reactors fluidised for direct DME synthesis.
Because of its lowest mass transmission resistance, and the better thermal remove, good
temperature and high conversion control, fluidized beds are superior to stationary beds. A
fluidized bed reactor of two types was modelled under the Traditional DME synthesis working
conditions (TOPSOE process). Working conditions an evolutionary (DE) difference is also
used to improve the desired production rate to achieve the most advantageous operational
conditions. (Bondarenko, 2004)
As a promising and clean alternative, dimethyl ether (DME) has received increasing
attention Diesel fuel due to its high cetin, low automatic temperature and low pollutant
emissions. In order to produce a number of platform chemicals, DME also is an important
feedstock, including lower olefines, methyl acetity and formaldehyde. Production of DME,
methanolic Solid acid catalysts and transformation in the syngas dehydration as intermediate,
there were two important synthetic pathways have so far been developed to produce two phases
methanol.
The DME synthesis is traditionally achieved by the use of various solid acid catalysts like
G-Al-2O3 and (H - ZSM-5,H - Y and H - ZSM-22) acidified zeolites ;considered to be The
most advanced route and commonly Available in the chemical industry. Because of its low cost
and acidity, G-Al2O3 is the greatest. commonly catalyst used. However, their low activity and
its hydrothermal stability limit the catalyst performance and life of the g-Al2O 3 catalyser.
H-ZSM-5 among the zeolites is by its high catalytic performance and stability, the most
widely studied acid catalyst. Its bronze acidity is strong., it can however be easily made with
the DME synthesis that significant Side Product quantities, like Coke and even hydrocarbons.
7|Page YASSER ASHOUR 127978
As a result of coke formation or water presence, H - ZSM-5 catalytic activity is quickly
declining. In addition, methanol dehydration is balanced by DME [ Eq.1]. Catalytic reactor in
a classic fixed bed. (Bondarenko, 2004)
Equation 1
2𝐶𝐻3 𝑂𝐻 ⥦ 𝐶𝐻3 𝑂𝐶𝐻3 + 𝐻2 𝑂
∆𝐻 = −23.4𝐾𝐽 𝑚𝑜𝑙 −1
(Bondarenko, 2004)
DME from methanol usually depends on the catalyst's inherent activity and process
conditions, and on their productivity and DME selectivity. Therefore, new simultaneous
strategies increase methanol dehydration Conversion and selection to DME continue to be an
important challenge. In the last two decades of the intensification process through combining
catalytic and molecular sieving in a single device, the focus on the selective removal of one or
more product on site during a reaction is on the increase, to overcome a balance limit, thereby
increasing conversion. Within the last two decades, CMRs are becoming increasingly
important. Taking into account DME dehydration Equation. It is expected that the balance limit
will be eliminated by the Le ChatelierQs the principle if water is to be removed selectively
from the reaction system and thereby increase methanol dehydration to DME conversion and
selectivity. In the course of methanol dehydration, several efforts have been made to use
hydrophilic membranes to remove water on the spot. It was possible to increase the conversion
of methanol from an 8% membrane-free conversion by 250𝐶 0 to 88% via membrane-support.
8|Page YASSER ASHOUR 127978
The LTA membrane reactor zeolite is used. Bondarenko said that the water was removed
by an alumina silica membrane, the DME yield was increasing from 68 % to 83 % percent. An
alumina silica membrane to extract water in situ can also be used in a separate report for
converting methanol from 80 percent to 86 percent. (Bondarenko, 2004)
9|Page YASSER ASHOUR 127978
1.2 Conversion of Methanol to DME
Methanol is then transformed into DME, water, and the Na-LTA hydrophilic zeolite
membranes into the H-FAU membrane shown in Figure 1. But a DME is not possible with the
Zeolite LTA membrane because the kinetical diameter of DME exceeds the pores of the Na-
LTA membrane (about 0.4 nm), so both the reaction process and the separation process can be
carried out in one single reactor. The reaction on the product side should be shifted due to the
selective and continuous removal of the produced water and production of DMEs should
significantly increase. In addition, water from the reaction system could be removed
continuously to prevent deactivation of catalysts and the formation of secondary products
during DME synthesis. (Bjorn.Wygrala, 2009)
Figure 1 dehydration of methanol to DME by in situ water removal
This FAU-LTA membrane was prepared with a porous a-Al2O3 tube with a covalent
APTES (Aminopropyltrietaxylane) connector from Zeolite LTA to the Al2O3 base. FESEM
pictures show a zeolite LTA membrane on an APTES al2O3 tube in figures 2a, b. In good
coordination with earlier reports and without any cracks, tubers or other defects it has been
10 | P a g e YASSER ASHOUR 127978
developed a well grown Zeolite LTA membrane with a width of approximately 4 mm with
APTES modified Al2O3 tubes. After a modification of the LTA-like-synectical zeolite and the
subsequent hydrothermal synthesis leading to zeolite FAU–LTA sandwich membranes on the
surface of a zeolite layer, the compact zeolite FAU was formed. (Figure 2 c and d)
Figure 2 (a,c) modified top view, (b,d) cross sectional view, (b) double layer membrane, (d) orientation of the LTA crystals
performance in DME methanol dehydration of zeolite H-FAU / Na-LTA CMR has then
been assessed. In contrast, zeolite powder of H-FAU performance has also been tested in CFR
during dehydration in DME. As illustrated in Fig 3, and the conversion methanol to DME in
CFR is fairly low, while the maximum methanol conversion in DME in existing jobs was just
9.5% at 310 𝐶 0 This low conversion of methanol in CFR can be justified by two reasons:
(1) The reaction of methanol dehydration to DME is balanced, reducing water conversion
to acid catalytic pores and blocks of water. In contrast, with the increase of the reaction
temperature in the CMR, there has been significant improvement in methanol
conversion to DME (Figure 3). The maximum conversion of methanol within the CMR
11 | P a g e YASSER ASHOUR 127978
to DME was 90.9% at 310 𝐶 0 which in the CFR is significantly higher (9.5%)
(Bjorn.Wygrala, 2009)
(2) The thermodynamic balance limitation for DME dehydration in CMR can be removed
selectively and continuously using the hydrographic zeolite Na-LTA membrane for the
reaction system, significantly improving methanol transformation. The catalyst's
stability is also improved by removing the water produced locally and increasing the
selectivity of DME formation. (Bjorn.Wygrala, 2009)
Figure 3 DME selectivity in the CMR and conversion of methanol into DME
In addition, we found that the conversion from methanol to DME within a packaged reactor
(PBMR) was also comparatively low, and the maximum conversion was about 35.4% from
methanol to DME in the 310 𝐶 0 . The excellent performance of the CMR was confirmed by a
mathematical simulation. The DME level increases and methanol decrease, with a catalytic
response mostly occurring on the membrane surface, from the reactor chamber to the
membrane surface as illustrated in figure 3. The hydrophilic FAU and LTA membrane removed
the water quickly, there was virtually no water content. However, no DME or methanol
gradients in the PBMR were found, and only near the LTA membrane surface zeolite water
may be removed, causing a poor methanol conversion. DME was found to be the only product
when DME synthesis was performed at CMR even at high temperatures 310 𝐶 0 . suggesting
12 | P a g e YASSER ASHOUR 127978
that the desired DME product was essentially 100% selective. There are well-known factors in
CFRs with acid catalysts like HY, HZSM-5, heteropolyic acid, and MFI that can easily reduce
the selection and deactivation of the DME. Small quantities of side products are easily formed
in acidic CFRs. As Fig 4 shows, the conversion of Methanol and Selective DME after 60 hours
were nearly consistent and the entire test time was not accelerated. Methanol conversion to
CFR for H-Y has been reported to be rapidly decreasing from 87.5 (2 h) to 83.4 (7 h), 46.2 (10
h) and 19.0% (14 h), and hastened deactivation was observed after 7 hours at stream. The
presence of water damages catalysts ' activity. It is well known. The selective and continuous
removal of water generated from the reaction system has effectively prevented the deactivation
of the catalyst. (Bjorn.Wygrala, 2009)
13 | P a g e YASSER ASHOUR 127978
4. Chapter II
4.1 Literature review
4.1.1 The development of a new fuel
Innovative clean fuels are Dimethyl ether (DME), because their features are similar to
LPGs (fluid petroleum gas). DME is currently primarily utilized as a spray cans propellant. A
dehydration reaction of methanol produces about 150,000 tons per year worldwide. It must be
produced in large quantities at low cost to utilize DME as a fuel. Since metanol is generated
by synthesis gas (hydrogen and carbon monoxide), the production of DME directly from
synthesization gas would be more efficient. DME direct synthesis process technique developed
from synthesis gas over the last 15 years. In order to diversify energy resources in future DME
could be a promising option, the transport and use of DME in Japan is extensively studied as
well as the technological process for production. The properties of DME are similar to LPG
and can be used in different sectors: household, transportation, electricity generation, etc. DME
can be produced by synthesizing gas from different resources, including natural gas, coal or
coal bed methane. Different usage technologies are being developed for DME. An innovative
process has been developed for the direct synthesis of DME from synthesis gas. A high
conversion and high DME selectivity were achieved in the new developed catalogue in a slurry
phase reactor. In 2002, the project of the demonstration plant (100 tons per day) started with
the support of the japanese government, after the pilot plant (5 tons / day) testing, for further
technical development to marketing. Three continuous testing operations with a duration of
two to three months were successfully performed in 2003 and 2004. Several process parameters
were achieved under very stable conditions targeted for ATR and DME synthesis. On the basis
14 | P a g e YASSER ASHOUR 127978
of the data obtained, a commercial-scale project is being scale-up studies. (Jia-yan, 2003)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .. . . . .. . . .. . . . .. . . . . . . . .. . .. . .. . .. . . .. . . . .. . . . .. . . . . .. . . . . . . . . . . . . . . . . . . . . . . .
4.1.2 Physical and chemical Properties of DME and its fuel use
Dimethyl ether (DME) is the simplest ether with a chemical formula: CH3OCH3. DME is
a colorless, chemical stable gas that boils at an ambient temperature below 25.1C, and DME is
easily liquefied due to its pressure of around 0.6 MPa at 25C. It is so physical that DME can
be distributed, saved and similar to the properties of LPG. Use LPG handling technology and
facilities. A toxicity study with fluorocarbon substitution propellants confirmed that its toxicity
is extremely low, similar to LPG, below the level of methanol. DME is broken down in the
troposphere for several 10 hours and does not concern the effect of greenhouse and ozone
depletion. DME can be used as a new, clean fuel for various areas; residential, transportation,
power generation, etc. DME's flames are blue visible. DME is equipped with a Wob index of
52 to 54, similar to that for natural gas (heat ratio, resistance to gas flow) and thus can be used
for DME natural gas cooking stoves without any modification. DME is almost the same as
natural gas for thermal efficiency and emission. DME Cetane is high, so it can be used as fuel
in diesel engines. DME has a much lower viscosity and a much lower lubricity than diesel fuel.
Changes to the fuel injection system are required in order to keep the fuel injection stable in
the engine cylinder. The DME diesel test showed that no black diesel (particular) exhaust fuel,
15 | P a g e YASSER ASHOUR 127978
NOx emissions were significantly lower and that the calorie fuel consumption was the same as
that of diesel as shown in Figure 5. (Adrian & Perry, 2007)
Figure 4 DIESEL Fuel VS DME Exhaust Emissions (Adrian & Perry, 2007)
Several cars were modified to power DME and public road tests were performed
successfully. DME has a huge fuel potential of fuel cell automobiles in the future, since it is
easily transformed into hydrogen as methanol. Gas turbine testing with DME was successfully
conducted for power generation. Oil or coal-fired boiler combustion tests were carried out.
With almost the same thermal efficiency, emissions were greatly improved. (Adrian & Perry,
2007)
16 | P a g e YASSER ASHOUR 127978
4.1.3 Characteristics of DME Synthesis Reaction and Synthesis Gas
Production
A newly developed autothermal reformer with a carbon cycle for the production of
synthesis gas from natural gas, a slurry reactor for easy control of the temperature thanks to the
highly efficient thermal heat convection and a newly designed catalytic system suitable for the
slurry phase of the reactor are the main features of this process. Figure 2 shows the DME natural
gas production block-flow diagram, which is being developed by direct synthetization process.
(Bernard, 1998)
Figure 5 Direct Synthesis Process (Bernard, 1998)
17 | P a g e YASSER ASHOUR 127978
4.1.4 DME synthesis reaction and catalyst system
The reaction formulas and reaction heat concerning DME synthesis are as follows:
Equation 2
3𝐶𝑂 + 3𝐻2 → 𝐶𝐻3 𝑂𝐶𝐻3 + 𝐶𝑂2 − 246.0𝐾𝑗/𝐷𝑀𝐸-mol
Equation 3
2𝐶𝑂 + 4𝐻2 → 𝐶𝐻3 𝑂𝐶𝐻3 + 𝐻2 𝑂 − 205.0𝐾𝑗/𝐷𝑀𝐸-mol
Equation 4
2𝐶𝑂 + 4𝐻2 → 2𝐶𝐻3 𝑂𝐻 − 181.6𝐾𝑗/𝐷𝑀𝐸-mol
Equation 5
2𝐶𝐻3 𝑂𝐻 → 𝐶𝐻3 𝑂𝐶𝐻3 + 𝐻2 𝑂 − 23.4𝐾𝑗/𝐷𝑀𝐸-mol
Equation 6
𝐶𝑂 + 𝐻2 𝑂 → 𝐶𝑂2 + 𝐻2 − 41.0𝐾𝑗/𝐷𝑀𝐸 -mol
Formula (2) reactions synthesized DME in three steps, synthesized by gas synthesis
(H2, CO): reaction methanol (4), reaction to dehydration () and shift reactivity (6). Reactions
(4) and (5) are combined into reactions (3), if the reaction is slow. The overall response to the
methanol synthesis is exothermic and the reaction heat dominates. Figure 7 below shows the
balance conversion of synthesis gas for the two DME synthesis reactions (CO conversion plus
H2 conversion). (Adrian & Perry, 2007)
18 | P a g e YASSER ASHOUR 127978
Figure 6 Equilibrium Conversion (260C,5MPa)
For methanol synthesis react as a function of the hydrogen / carbon monoxide relation
(H2/CO) of the gaseous synthesis, the Formula (2) and Formula (3) and Formula (4) formula.
In each reaction, the balance conversion reaches its peak, with H2/CO equivalent to a
stochiometric, i.e. H2/CO for Formula (2), and 2.0 equivalents for both Formula (3) and
Formula (4). For Formula (2), the maximum balance is much higher than for Formula (3) and
(4). The Formula (2) by-product is CO2, which is effectively produced at cooler temperatures
with very little water, separating the liquid product from the reacted gas. By producing CO2,
dissolving in manufactured DME can be removed. The by-produced water content in the
reactor effluent is so high for the Formula (3) that the liquid gas separator's temperature is not
less than that of the water freezing. The recycling gas DME content is very high. For the
balance conversion of DME synthesis and for the gas-liquid separation, it is clear that Formula
(2) reagates superior to the Formula (3) reaction. The main reaction, Formula (2) or Formula
(3) depends upon the catalyst characteristics. In the slurry phase reactor, a catalyst system
appropriate for the slurry phase reactor must be developed, as catalyst particles are surrounded
by a solvent. In fundamental research, the catalyst system has three functions (Methanol
synthesis, dehydration, water gas shifting), efficient to perform Formula reaction (2). Catalyst
19 | P a g e YASSER ASHOUR 127978
production technology was also developed to allow for large-scale testing. (Adrian & Perry,
2007)
4.1.5 Methods of production
In industrial applications, the DME is produced from the syngas by means of two
different configurations:
4.1.5.1 one-step process
The DME is produced directly from syngas in one reactor during the one - stufled
production process, in which both methanol formation and methanol dehydration are
supported by a bifunctional catalyst, as follows:
Methanol formation:
CO + 2H2 ↔ CH3 OH ∆H = −90.4 Kj/mol
Water-gas shift:
CO + 𝐻2 𝑂 ↔ 𝐶𝑂2 + 𝐻2 ∆𝐻 = −41.0 𝐾𝑗/𝑚𝑜𝑙
Methanol dehydration:
2C𝐻3 𝑂𝐻 ↔ 𝐶𝐻3 𝑂𝐶𝐻3 + 𝐻2 𝑂 ∆𝐻 = −23.0 𝐾𝑗/𝑚𝑜𝑙
Overall reaction:
3CO + 3H2 ↔ CH3 OCH3 + CO2 ∆𝐻 = −258.3 𝐾𝑗/𝑚𝑜𝑙
Syngas is produced via a natural gas steam reform or coal / petroleum contaminants
gasification, and a purification unit is needed after a DME synthesis reactor, to separate the
DME in a dual distillation stage from water and methanol. A one-stage diagram is provided in
the following figure 7. (Adrian & Perry, 2007)
20 | P a g e YASSER ASHOUR 127978
Figure 7 one step process (Adrian & Perry, 2007)
4.1.5.2 two-steps process
The two (indirect) processes support the methanol formation of syngas and DME
methanol production in two separate reactors, which contain the specific catalysts (the first
based on copper, the second based on silica-alumina). The figure below shows this process '
block diagram.
21 | P a g e YASSER ASHOUR 127978
Figure 8 Two-step process block diagram
4.1.6 DME production from renewable energies
Renewable energy as biomass, solar and wind can be used to produce the reactants of the
DME synthesis process. This makes DME a liquid energy vector that can store renewable
energy in a high-energy, easy-to-use, high-density fuel. Biomass, agro-residue, forest residue,
as power crops. A gasifying process to generate a one-step or two-step synthesizing syngas
stream can be used, as shown below. In contrast, anaérobic digestion + pyrolysis may be
employed to generate the CO and H2 stream if the starting biomass consists of organic trash,
manure or sewage. (Fuat E. & Tae‐Jin, 2009)
22 | P a g e YASSER ASHOUR 127978
Figure 9 DME from renewable energy (Fuat E. & Tae‐Jin, 2009)
The syngas hydrogen stream can be generated by an electrolyser, provided by electricity
produced as photovoltaics, wind farms and then mixed with CO / CO2 from renewable energy
plants. In the DME, renewable energies are so "stored," which can easily be distributed, stored
and used as liquid fuel, differently than hydrogen itself, which has a number of unresolved
distribution and storage problems. A conceptual layout for solar / biomass DME production is
presented in the following plan. (Fuat E. & Tae‐Jin, 2009)
Figure 10 DME production from solar and biomass (Fuat E. & Tae‐Jin, 2009)
23 | P a g e YASSER ASHOUR 127978
4.1.7 DME production as a CO2 valorisation process
Instead of syngas, a DME production process can provide a CO2-rich feedstock to turn
CO2 into a high-value added product. This process does not emit CO2, which is the main
greenhouse gas (GHG), but turns it into a burning fuel which re-emits carbon dioxide. This
configuration is less well developed than the traditional synthesis method, but there is a great
deal of research to improve its performance since both DME production and GHG emissions
can be reduced, reducing DME's carbon footprint. The presence of CO2 in the reactor
environment leads to two main problems: carbon-rich feedstock affects the active status of a
methanol catalytic system, decreasing formation rates of methanol CO2 stimulates the reverse
reaction of a water gas shift to produce H2O, and preventing the dehydration of methanol. New
catalysts for carbon-rich mixing, selective membranes that remove water and promote
methanol dehydration and DME production from the response environment have primarily
been developed for research. They are adapted for carbon conversion. (Bernard, 1998)
4.1.8 Reaction kinetics of the dual reactor
For DME production based on the Langmuir-Hinshelwood and Hougen-Watson
mechanism the kinetics represented by Nie et al. have been selected This model was
experimentally validated. The following are eight components: H2, CO, CO2, H2O, methanol,
DME, N2, and CH4. H2 and CO are the principal reactants and control of the reactor is
facilitated due to the presence of inert components which absorb part of the reaction heating.
The following four reactions are involved in three syntheses approaches to dimethyl ether,
namely CO hydrogenation, CO2 hydrogenation and CO and CO2 parallel hydrogenation:
24 | P a g e YASSER ASHOUR 127978
(Charles, 1981)
Equation 7
Equation 8
Equation 9
Equation 10
The above reactions are not independent, and each reaction can be obtained from a
combination of the remaining three reactions. In this process, reactions 1, 3 and 4 were
considered for simulating the reactor behaviour. (Charles, 1981)
Equation 11
Equation 12
Equation 13
Where
Equation 14
25 | P a g e YASSER ASHOUR 127978
Equation 15
Equation 16
(Charles, 1981)
The kinetic parameters are given in Table 1.
Table 1Reaction kinetic parameters (Charles, 1981)
(Charles, 1981)
26 | P a g e YASSER ASHOUR 127978
4.1.9 Applications
4.1.9.1 Transportation
DME is one of the world's most promising automotive fuel alternatives for various ultra-
clean, renewables and low-carbon fuels. In diesel engines, gas engines (30% DME/70% LPG),
and gas turbines, DME is suitable as a fuel. There are only modest modifications to convert a
diesel engine to be used on DME, with heavy diesel engine powered DME vehicles developed
by engine manufacturers, including Nissan and Volvo. As a fuel for automobiles, DME's
performance shows several major advantages compared to petroleum-derived diesel:
• Ultra low exhaust emission
• No particles (PM), very low NOx, no SOx)
• Low CO2 emissions
• Low motor noise
• Hight fuel efficiency
• High well to wheel efficiency
• Thermal efficiency equivalent to diesel engine performance
(Shuyu & Yude, 2012)
Another important advantage is the reduction or the removal of particulate emissions, also
called soot or black smoke. Diesel engines running on a 100% DME were smoke-free and soot
was significantly reduced by motors using DME / diesel fuel mixing. A 55–60 high cetane
rating* (compared with approximately 45 for the diesel derived from petroleum) and a boiling
point of -25 ° C offer quick fuel-air mixing, a lower inflammation time and excellent cold
starting properties–two further key advantages for DME's fuel use. (Shuyu & Yude, 2012)
27 | P a g e YASSER ASHOUR 127978
4.1.9.2 Cooking and heating
DME is available to be mixed with LPG (up to 20 %) for cooking and cooking at home
without altering the distribution networks or machineries. DME use is expected, especially in
portable fuel countries in the developing world, to increase substantially in domestic
applications, as DME use and blend are spread across the growing LPM market. (Shuyu &
Yude, 2012)
4.1.9.3 Power generation
For electric power generation, DME has a performance comparable to natural gas and
manufacturers as fuel for use in their gas turbines, like General Electric and Hitachi and
Mitsubishi, have approved it. For medium-sized power stations, DME is an efficient alternative
to other energy sources, in particular in isolated or remote areas where the transportation of
natural gas is difficult and where the construction of regasification terminals for LNGs would
not be viable. (Shuyu & Yude, 2012)
28 | P a g e YASSER ASHOUR 127978
5. References
Adrian, D., & Perry, A. (2007). Enzymatic reaction mechanisms. Reaction Kinetics,
Mechanisms and Catalysis, 197-204.
Bernard, L. (1998). Introduction to the fourth symposium (international) on combustion.
Symposium (International) on Combustion, 397-404.
Bjorn.Wygrala. (2009). Petroleum Resource Assessment Methodologies and Petroleum
Systems Modeling. International Petroleum Technology Conference, 73-81.
Bondarenko, G. N. (2004). High Energy Chemistry. Russian Journal of Physical Chemistry
A, 284. doi:10.1023/b:hiec.0000035421.44417.cb
Charles, K. (1981). Chemical kinetics and modeling of combustion processes. Symposium
(International) on Combustion, 749-757. doi:10.1016/s0082-0784(81)80079-3
Fuat E., C., & Tae‐Jin, K. (2009, May 18). Vapor‐Phase Carbonylation of
Dimethoxymethane over H‐Faujasite. The Canadian Journal of Chemical
Engineering, 372-413. Retrieved from The Canadian Journal of Chemical
Engineering.
Jia-yan, W.-y.-c. (2003, June 22). Dual-level direct dynamics studies for the reactions of
CH3OCH3 and CF3OCH3 with the OH radical. Retrieved from Stability of plane
Couette flow of Carreau fluids past a deformable solid at arbitrary Reynolds numbers:
Physics of Fluids: Vol 30, No 7: https://aip.scitation.org/doi/10.1063/1.1575197
S.L.Fischer, & F.L.Dryer. (2000). The reaction kinetics of dimethyl ether. I: High-
temperature pyrolysis and oxidation in flow reactors. International Journal of
Chemical Kinetics, 713-740.
29 | P a g e YASSER ASHOUR 127978
Shuyu, L., & Yude, N. (2012). Optimal strategy of DME beacon distrbution for DME/DME
area navigation. 2012 IEEE 11th International Conference on Signal Processing, 200-
203.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .. . . . . .. . . . . . . . . .. . . . . . . . . . .. . . . . . .. . . . . . . . . .. . . . . . .. . . . . . . . . . .. . . . . . . . . .. . . . . . . . .. . . . . .. . . . . .. . . . . . . . . . . .. . . . . .. . . . . . . . . . . . .. . . . . . . . .. . . . . . . . .. . . . . . . . . . . . . . . .. . . . . .. . . . .. . . . . . .. . . . . . . . . . . . . . . .. . . . . . . .. . . . . .. . . . . . .. . . . . . . . .. . . . .. . . . . . . .. . . . . . . . . . . . . . . .. . . . . .. . . . . . . . . . . . . . . . .. . . . . . . . . .. . . . . . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . .. . . . . . . . . .. . . . . . . . . . . . . . . . .. .. . . . . . . . . . . .. . .. . . . . . . . . .. . . .. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .. . . . . . .. . . . . . . . .. . .. . . . . .. . . . .. . . . .
30 | P a g e YASSER ASHOUR 127978
