..

.f

L-4/T-lICHE Date: 29/1012019

BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA

L-4!T-I B.Sc. Engineering Examinations 2018-2019

Sub: CHE 401 (Reaction Engineering)

Full Marks: 210 Time: 3 Hours
The figures in the margin indicate full marks.
USE SEPARATE SCRIPTS FOR EACH SECTION

SECTION-A
There are FOUR questions in this section. Answer any THREE.
Symbols have their usual meaning.

I. (a) Reactant A decomposes with stoichiometry A ~ R and with rate dependent only on CA,
The following data on this aqueous decomposition are obtained in a mixed flow reactor:
1, sec CAO CA
14 200 100
25 190 90
29 180 80
30 170 70
29 160 60
27 150 50
24 140 40
19 130 30
15 120 20
12 I 10 10
20 101 1

Determine which setup, plug flow, mixed flow, or any two-reactor combination gIves
minimum 1 for 90% conversion of a feed consisting of CAO= 100. Also find this 1minimum.

If a two-reactor scheme is found to be optimum, give CA between stages and 1 for each stage.
Unit for concentration terms is mol/liter. (25)
(b) You have rate vs concentration data for the reaction A ~ R. A combination of four
unequal-size mixed flow reactors are being used for carrying out the reaction at 350 K. Feed
concentration of A is CAOand the outlet concentration of A from the fourth reactor is CM.
How would you detennine the concentrations.of A at the outlet streams of intennediate
stages? (10)

2. (a) Dibutyl phthalate (DBP) is produced by reaction of n-butanol with monobutyl phthalate
(MBP). The reaction follows an elementary rate law and is catalyzed by H2S04.
H SO
MBP + n - butanol 2 4) DBP + H 0
2
A stream containing MBP and butanol is to be mixed with the H2S04 catalyst immediately
before the stream enters the reactor. The concentration of MBP is the stream entering the
reactor is 0.2 Ib mol/ft3, and the molar feed rate of butanol is five times that of MBP. The
specific reaction rate at IOO°F is 1.2 ft3/lbmoI.h. There is a IOOO-gallon CSTR available for
use on this for 30 days a year, operating 24 hlday. [Hint: 1 ft3 = 7.48 gal]

Contd P2

•
j
 l
/

=2=
CHE 401
Contd .... Q. NO.2
(a) Detennine the exit conversion in the available 1000-gallon reactor if you were to produce
4 million Ib/yr. Molar mass ofDSP is 278.
(b) How might you increase the conversion for the same molar flow rate?
(c) What CSTR volume would be necessary to active a conversion of 85% for a molar feed
rate ofMSP of 1 lb mol/min? (15+5+ 15)

3. To remove oxides of nitrogen (NO) from automobile exhaust, a scheme has been proposed
that uses unburned carbon monoxide (CO) in the exhaust to reduce the NO over a copper
catalyst to fonn environmentally acceptable products, N2 and CO2:
CO + NO ~ C02 + Y2 N2
The following mechanism has been proposed for this reaction:
CO + S <=> CO.S
NO + S <=> NO.S
NO.S+CO.S <=> CO2+N.S+S
N.S+ N.S <=> N2.S
N2.S <=> N2 + S

The rate is limited by the surface-reaction, i.e., third step in the mechanism.
(a) Using the proposed mechanism and the concept of rate limiting step find a rate expression
that is consistent with the proposed mechanism.
(b) Using the rate expression derived in part (a), comment on the absorbance of CO, NO,
CO2, and N2 on the copper catalyst.
(c) A certain engineer thinks that it would be desirable to operate with a very large
stoichiometric excess of CO to minimize catalytic reactor volume. Do you agree or disagree?
Explain. (20+10+5)

4. (a) Consider the aqueous reactions

dCD I dt=1.0CAO.5CBO.2mollliter.min
A+B~D
2 k U dCu I dt=1.0C~.5C12mollliter.min

For 90% conversion of A find the concentration of D in the product stream. Equal volumetric
flow rates of the A and S streams are fed to the reactor, and each stream has a concentration
of 20 Mol/liter of reactant. The flow in the reactor follows (i) plug flow, (ii) mixed flow. (15)
(b) Under appropriate conditions A decomposes as follows:
,.
A k1=IOlmin )R k2=O.llmin )S

R is to be produced from 1000 literlhr of feed in which CAO= I mol/liter, CRO = Cso = 0.
What size of plug flow reactor will maximize the concentration of R, and what is that
concentration in the effluent stream from this reactor? (10)
(c) Distribution and average value of reactant concentration within a catalyst pore as a
function of Thiele within modulus (mL) is shown in Figure 4(c). With the help of this Figure
explain the relation between Thiele modulus and effectiveness factor. (10)
 =3=
CHE 401
SECTION -B
There are FOUR questions in ,this Section. Answer any THREE.

5. (a) Define the rate of reaction with respect to all fundamental basis. Also name the variables
which influence the rate of reaction. (6+4)
(b) A reaction rate expression has the following fonn -

r = kC, (6+4)
l+k'C,

Describe how k and k' can be determined by initial rate measurement method. State the
disadvantages of initial rate measurement method.
(c) Lithium iodide (LiI) is fonned by the reaction given below-
C,H,Li + C,H,l ~ 2C,H, + Lil

The initial concentration of reactants, C2HsLi and C2HsI arc 2 and I kmol/m3, respectively.
The reaction progress data arc as follows- (15)
Time(s) Concentration of LiI
600 0.167
1200 0.306
1800 0.412
2400 0.498
3000 0.569
Detennine the order and rate constant which are consistent with the above data.

6. (a) What do you understand by reaction mechanism? Write down the preliminary criterion
for testing a proposed reaction mechanism. (4+5)
(b) Briefly discuss the four basic assumptions involved in the derivation of a rate expression
from a proposed reaction mechanism. (8)
(c) The formation reaction of phosgene gas (CO+Ch~COCI2) has the following two
proposed mechanisms: (18)
C/ ~ 2Cl; Equlibrium constantk1 C/ CO> 2C/; Equlibrium constantk1
2 2
Cl + co ~ COC/; Equlibrium constantk C/ + C/2 CO> C/); Equlibrium constantk
2 2
k
k CI) +CO~COCl2 +CI
COC1+C/2~COC/2 +Cl
k
k CI+COCl2~Cl) +CO
COC12 +C/~COC1+CI2

Which mechanism is correct?

7. (a) First-order irreversible reactions in series are given below-

A~R *, )S

Derive the expression for the time at which the maximum concentration of R occurs. Also
show clearly the concentration-time curves for this system. (II +5)
(b) For the irreversible reactions given in (a), consider that no R is present initially. First
reaction (A~R) is of zero-order and the second reaction (R~S) is of first-order. Determine
the steady state value of the concentration of R when kl = 0.835 mol/m3-ksec and
k2 = 0.767 sec-I. (13)
Contd P3
 Contd P3
=4=
CHE 401
(c) Writc down the different equations for the following cases: (3+3)
(i) Reversiblc first order parallel reaction
(ii) Opposing second order reaction.

8. (a) The first-order reversible liquid reaction A<=> R, CAO = 0.5 mol/liter, CRO = 0 takes place

in a batch reactor. After 8 minutes, conversion of A is 33.3% while equilibrium conversion is

66.7%. Find the rate equation for this reaction. (12)
(b) Draw the five types of isotherms found for adsorption. (7.5)
(c) Explain with illustration how does the heterogeneous catalytic reaction occurs On a
porous catalyst. (8)
(d) Discuss briefly different types of deactivation of catalyst. (7.5)

.1
/ilL = 0.5
-----, 1 _

0,8

0.6
e
8-
.=
c.
------ ------ =O.~
~
~
c:., 0.4
. u
.c
8

0.2 = 0.20

= 0.10

0.2 0.4 0.6 0.8 I 1.0

Fractional distance into pore,:cIL

i. Figure.4{c)
i .
j

'" ,,' Formula sheet for CHE401

.dXA '.
NAO(it= -rAV

V = FAoXA
. -rA

b . b
C = F8 = FAo(M8 - iiXA) To P = C (M8 - iiXA) To!-
AO
8 .v vo(1 + 6AXA) T Po . (1 + 6AXA) T Po

M, = FiO = CiO = YiO

FAo CAO YAO

deb
0=-+----1
a a a

-k t
CA = CAOe 1

.
CR,max (k 1
)k,/(k2-k')
~= kz'

x dx 1
L --=!n--
o 1-x 1-x

~ dx 1 1
f
x, (1 - x)z
=-----
1- Xz 1- X,

(dx X

. JO (1 - X)2 = 1 - x

x dx 1
I o
-1+' = -In(1 + ex)
ex. 6 .

(X (1 + ex)dx 1'
(1 + 6) In-- - ex
Jo '1 - x 1-x

.. ,.t'.
•

, Formula sheet for CHE401

x (1 + ex)dx = (1 + E)X 1
l o (1-x)21-x
Eln--
1-x

x (1 + ex)2dx (1 + E)2X
l o (1 -:-x )
2 = 2&(1 + E) In(l - x) + e2x + ---
1-x

Table 5.1 Perfonnancc Equations for nth-order Kinetics and F./l. =0

Plug Flow or Batch Mixl,;d Flow

11 ~ 0 k., CAn - C" _ X (20) kr GAO - CA - X

-'" = k CAO = CAO A c:;; "'" C..••
o It

GAO
k.,=ln-=!n--
I
(3,U) kTl:
c"o- C" --- X" (140)
Cit 1 - X", Cit I - XII

k.,CAO'"
c"o-
ell
c" ~~ X" (3,16) k., = (CAn- C••.) E: XA (IS)
Cl. C",{1 - X.l'

any fJ C )'-' - I = (1 -
(n - 1)0.,'kT o....!;..
( C. x.)'-. - I
-r" c kC'). O
(3,29)

"
", Oeneml rate (19) (13)

Table 5.2 Performance Equations for Illh-ordcr Kinetics nnd 11.••~ ()

Plug Aow Mixed Flow

(U1)

. 1
kT"'" ~1+ tl.>ln~ - tAX", (21) kr= XA,(l + tAXA) . (14b)
) -Xl.

kTCAO = 2IJ,,{J + c,.)ln(1 - X,,)_+ C~XA + (ll"+ 1)1.~ (23) krC ." X,,(.1 + c"X"Y' (15)
I-X" AO (1 _ X,,)2
, I any n k C~~I (l + tAX,,)"
eo X •••
-'A'" keA TAO (I-X"l"
11""1
, kT X,,{l + £"X,.,)
AyrR (22)
x .•.,"" X,.,-x"
CRO=O

General expression (17) (11)

I
I
I

'----

/
L-4ff-lIChE Date: 19/10/2019

BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA

L-4ff-l B. Se. Engineering Examinations 2018-2019

Sub: CHE 403 (Process Control)

Full Marks: 210 Time: 3 Hours

USE SEPARATE SCRIPTS FOR EACH SECTION

The figures in the margin indicate full marks.

SECTION-A

There are FOUR questions in this section. Answer any THREE.

I. (a) Compare advantages and disadvantages ofDCS and PLC. (5)

(b) Describe the concept of cascade control and split-range control using an example for each

case. (8)
(c) Design Steady-state feedforward controller for controlling the overhead and bottom

compositions of a distillation column. Sketch the feed forward control loop. (6+4)
(d) What is on-off control? Explain with an example. What are its advantages and

disadvantages? (5+3)
(e) What is integral-wind up? How can it be avoided? (2+2)

2. (a) Describe the derivative mode of feedback controllers with their respective merits and

demerits. How can the demerits be overcome? (2+4+4)

(b) Derive the expression of amplitude ratio and phase difference for sinusoidal excitation of

a First Order plus Time Delay system. Sketch the Bode diagram. (10+5)
(c) A process instrumentation diagram of a flash drum is shown in Fig. 2c. There are five
control values. Determine which of the five values should be fail-close (F/C) or fail open

(FlO) for safe operation for the following two cases: (10)
(i) The safest conditions are achieved by the lowest temperature and pressure in the flash
vessel.
(ii) Liquid flow to a downstream equipment can cause a hazardous situation.

I.T -~
I .
I
I
I
I

Fig 2c: Instrumentation Diagram of a Flash Drum'

Contd 1'/2
 =2=
,-----"

CHE 403
p
3.

hm~
--~--- liP

.\
.'. Figure 3: Figure for Question 3a)

(a) Find the closed loop transfer function between H'(s) and Q' ,(s) assumll1g q3 ,s
proportional to the square root of the available liquid head. [Hint: First find the open loop
transfer function, then draw a closed loop block diagram and find the closed loop transfer
function]. (20)
(b) Starting from the expression of part (a) show that a proportional controller cannot track
the set-point for a unit step change in input. Find the offset. (10)
(c) Describe the Zeigler-Nichol's continuous cycling method for tuning PID controllers. (5)

4. (a) A process stream is heated using a shell and tube heat exchanger. The exit temperature is
controlled using a steam control valve as illustrated in Fig QA. A open loop test is conducted
and the steam supply pressure is suddenly changed from 12 to 16 psig. At the nominal
condition, the control valve and the lIP converter have the gains of Kv = 0.75 psi/psi and
K,p = 0.75 psi/rnA, respectively.

r":~-"""-"
I .~~.
TibnI'I
I
I
Steam

'1:'
•
~ '_~.r _ " .Heat T,
Exchangar

Fig. Q4: Heat Exchanger Temperature Control

The open loop test data is given in Table Q4.
Table Q4: Open Loop Test data
Time (min) 0 1 2 3 4 5 6 7 8 9 10 11
T2m (rnA) 12.0 12.0 12.5 13.1 14.0 14.8 15.4 16.1 16.4 16.8 17.0 17.0

Contd 1'/3
 =3=

CHE403
Contd .... Q. NO.4

(i) Plot the process response data and find the transfer function for this process using any
method of your choice. (10)
(ii) Draw the block diagram of this closed loop system using proper labels and
appropriate units. (5)
(iii) Find appropriate PI controller settings using direct synthesis method. (5)
(b) Sketch and describe 3-element control of a boiler drum level. (9)
(c) Explain the concept of gain margin, phase margin and Bode stability criterion. (6)

SECTION -B

There are FOUR questions in this Section. Answer any THREE.

5. (a) Distillation is a very important separation process that presents a major control problem.
Each column has a control system that consists of several control loops. The loops adjust
process variables as needed to compensate for changes due to disturbances during plant
operation. Each of the process variables has its own control loop, which typically consists of
a sensor and transmitter, controller and control valve. See Figure for Q. No. 5(a) and draw

the control loops for the following control objectives: (20)

(i) to control the level of the column at desired value to avoid flooding.
(ii) to control the operating pressure of the column at desired value to achieve the desired
operation.
(iii) to maintain the feed flow rate of the column at desired value.
(iv) to control the boltom column temperature at a desirable degree.
(v) to control the level of.the condenser at desired value.

(b) Write in your own words why you need to study process control as a chemical engineer. (10)
(c) Apply the initial and final value theorems to the following transfer function. (15)

X(s) + s+1 e-05s

s(s + 2Xs +3)
6. (a) Discuss the steps for developing dynamic models of chemical processes. (10)
(b) For the process modeled by (15)

2 dYI = -2YI -3y, + 2u1

dt
dy, 6
-=4YI - Y, +2u1 +4u,
dt

Find the four transfer functions relating the outputs (Yb yz) to the inputs (Ub uz). The Uj and Yi
are deviation variables.
(c) A heater for a semiconductor wafer has first-order dynamics, that is, the transfer function
relating changes in temperature T to changes in the heater input power level P is
T'(s) K (10)
p'(s ( 1:1' +I
Contd P/4
 =4=

CHE403
Contd .... Q. No. 6(c)
where, K has units [OCIKw) and T has units [min). The process is at steady state when an
engineer changes the power input stepwise from I to 1.5 Kw, She notes the following:
(i) The process temperature initially is 80°C.
(ii) Four minutes after changing the power input, the temperature is 230°C.
(iii) Thirty minutes later the tempcrature is 280°C.
What are the values of K and r in the process transfer function?

7. (a) Describe different types of process models along with their advantages and

disadvantages. (10)
(b) A process consists of an integrating element operating in parallel with a first - order

element as shown in figure for Question. No. 7(b). (17)

(i) What is the order of the overall function G(s) = Y(s) N(s)?
(ii) What is the gain ofG(s).
(iii) What are the poles of G(s)? Where are they located in the complex s-plane?
(iv) What are the zeros of G(s)? Where are they located? Under what condition(s) will
one or more of the zeros be located in the right-halfs-plane?
(v) Under what conditions, will this process exhibit a right-half plane zero?
(vi) For any input change, what functions of time (response modes) will be included in
the response, y(t)
(vii) Is the output bounded for any bounded input change, for example, u(t) = M?
(c) 'The dynamic behavior ofa transfer function model can be characterized by the numerical

value of its poles and zeros' - explain. (8)

8. (a) A number of standard types of input changes are widely used for process modeling. Draw
the time profiles of the following process inputs and write their mathematical representation.

(i) step input (ii) ramp input (iii) rectangular pulse (iv) sinusoidal input and (v) impulse input (15)
(b) A heat exchanger used to heat a glycol solution with a hot oil is known to exhibit FOPTD
behavior, Gl(s) = T(s)/Q'(s), where T is the outlet temperature deviation and Q'is the hot oil
flow rate deviation. A thermocouple is placed 3 m downstream from the outlet of the heat
exchanger. The average velocity of the glycol in the outlet pipe is 0.5 m/s. The thermocouple
also is known to exhibit to first-order behavior; however, its time constant is expected to be

considerably smaller than the heat exchanger time constant. (20)

(i) Data from a unit step test in Q' on the complete system are shown in Figure for
Question no. 8(b). Using a method of your choice, calculate the time constants of this
process from the step response.
(ii) From your empirical model, find transfer functions for the heat exchanger, pipe and
thermocouple. Think of the model as the product of three transfer functions: Process, pipe
flow, and sensor. What assumptions do you have to make to obtain these individual
transfer functions from the overall transfer function?
 )

Figurc for Qucstion no. 5(a).

U(s) y(s)

r
i',

i
I

Figurc for Qucstion no. 7(b).

,-
.......~

.,' .-'

.
.
,,
.i.
I

il
i
 -
-6=.
10.0
8.0
6.0
T' (oG)
4.0
2.0

00 5 10 15 20 25
. Time (min)

Figure forQuestion no. 8(b).

5.0

2.0

10.0 1.0

5.0 0.5

2.0 0.2

1.0 0.1
0.3 0.4 0.5
t20
t60
. Smith's method: relationship of ~ and 'I" to '1"20 and '1"60•

Figure for Question no. 8(b)

..
.~

/'
 L-4ff-l/CHE '. Date: 24/10/2019
BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA
L-4/T - J B. Sc. Engineering Examinations 2018-2019
-. Sub: ChE 405 (Process Design I)
Full Marks: 210 Time: 3 Hours
The figures in the margin indicate full marks.
USE SEPARATE SCRIPTS FOR EACH SECTION
SECTION -A

There are FOUR questions in this section. Questions no. I is compulsory. Answer any Two
from the rest of the questions. Design Data Booklet will be Supplied.

1. This question is compulsory.

(a) Write down the factors a design team should consider when developing a flow sheet

based on a commercially-proven technology. (10)

(b) Ethylene and dried air are mixed and fed to multi-tubular catalytic reactor for
producing ethylene oxide. The mixture is passed over a silver oxide catalyst supported on

a porous carrier at 200-300°C and 10-30 bar. (25)

The reactions are:

C2H4 + li 02 --+ C2H40 (Ethylene oxide)

C2H4 + 302 --+C02 +2H20
Ethylene is supplied at 30 bar and 25°C (may be assumed pure). Dried air is supplied at 1
atm, 25°C in excess so that ethylene is S; 3 vol % whcn mixed with air (to bc below
flammability limit for safety purposes). Pure water at 25°C is also available at nceded
pressure. In the reactor the conversion of ethylene, to all products, is 70%, and the
selectivity for ethylene oxide is 90%. The un-reacted ethylene is separated from the
reactor products and recycled to the reactor. All percentages given are in molar. Show the
following for 99% pure ethylene oxide product.
(i) Input-output model with necessary assumptions
(ii) Separation, Recycle and Purge scheme as a block diagram
(iii) Heating/cooling and compression/expansion scheme
Table for Question No. I (b): Boiling point of different component

Component b.p.@l atm

Ethylene -103.7°C
Ethylene oxide 10.4°C (water soluble)
Water lOO°C

2. (a) A preliminary design of a purge recovery system of a storage tank has been made. It

would consist of the following: (15)

(i) A small tower 0.5 m diameter, 4.0 m high (shell mass 300kg); packed with 25 mm
ceramic saddles, packed height 3.0 m
(ii) A small storage tank for the solution, 5m3 capacity
(iii) Instrumentation and pipework
Contd P/2
 =2=

ChE 405
Contd ..... Q. No.2
All the equipment can be constructed from carbon steel. Estimate the fixed capital
investment for this system using Hand factor. (15)
Table for Q 2 a): Installation factor Proposed by Hand (1958)
~lf{~~m'W~~~iftdtmt.!!t1!'a
:>~~llri"LH.'Y~ l~~ -'" ":'~o'li'<;~~- '" ~

Compn:ssors 2.5
Distillution(,.'Olumns 4
. Fired hc~tcts 2
Heat exchangers 3.5
In~l.I\Imcnts 4
Miscellaneous equipment '2.5'
Pressure vc.'\scls 4
Pumps . 4.

(b) Estimate the manufacturing cost per 100 kg of product under the following
conditions: (20)
Fixed-capital investment = $4 million.
Annual production output = 9 million kg of product
Raw materials cost = $0.25/kg of product.
Utilities 800 kPa steam = 50 kg/kg of product.
Purchased electric power = 0.9 kWh/kg of product.
3
Filtered and softened water = 0.083 m /kg of product.
Operating labor = 12 persons per shift at $25.00 per employee-hour.
Plant operates three hundred, 24-h, days per year.
Plant overhead costs amount to 50 percent of the cost for operating labor, supervision,
and maintenance. There are no patent, royalty, interest or rent charges. Consider linear
depreciation of Fixed Capital Investment for IS years.

3. (a) List different types of capital investment estimation methods of chemical plant along
with respective accuracy level and required information. (10)
(b) A company is launching a new product, P. The depreciable capital investment of the
process is $450 million and the salvage value is $50 million. A 10-year linear
depreciation scheme is to be used to calculate the Annual Fixed Charges (AFC). Other
fixed charges for the process (property taxes, insurance, etc.) are $5 million/yr. The
maximum production capacity of the process is 100,000 ton/yr of product, P. The
operating cost of the process is $ II Olton. [t is desired to break even at a production rate
of 40% of the maximum process capacity. When should be the selling price of the
product? (15)
(c) What are the main objectives of process safety management (PSM)? Write down the
key elements of a PSM system. (10)

4. (a) Show the steps of Hazard Identification and Risk Assessment procedure with the help (10)
of a block diagram.
Contd P/3
 =3=
ChE 405
Contd ..... Q. No.4
(b) Consider the reactor system shown in figure for Q no 4 b). The reaction is exothermic,
so a cooling system is provided to remove the excess energy of reaction. In the event that
the cooling function is .lost, the temperature of the reactor would increase. This would
lead to an increase in reaction rate. leading to additional energy release. The result would
be a runaway reaction with pressures exceeding the bursting pressure of the reactor
vessel. The temperature of the reactor outlet is measured and is used to control the
coolant flow rate by a valve. Perform a HAZOP study on this unit to improve the safety
of the process. Prepare your own HAZOP table and use the reactor as the study node. (25)

Figure for Question No 4 b

Reactant A
.M

Reactant B'

Coolant outlet.
Coolant inlet

i,---------
,
SECTION -B
There are FOUR questions in this section. Answer any THREE.

5. (a) What do you understand by the fabrication of equipment? Why are fabrication details

generally governed by codes and standards? (5x7= 35)

(b) What factors are considered in "storage" and "materials handling" for a chemical
process plant?
(c) "Stainless steel is not always stainless"- explain.
(d) List your reasons for choosing sieve tray for distillation columns.
(e) What are the factors affecting plate and column efficiencies?

6. (a) A distillation column is separating a feed that is 50 mole% n-hexane and 50 mole% n-
heptane. Feed is a saturated liquid. Average column pressure is 1 atm. Distillate
composition XD = 0.99 (mole fraction of n = hexane) and XB = 0.001. Feed rate is 1000

Ib moleslhr. Internal reflux ratio ~=0.8. The column has a total reboiler and a total

condenser. Determine the diameter and packing height of the column if random packing
is used. Physical properties of pure n - hexane at 69°C are given below:
Liquid specific gravity = 0.659
Surface tension (J = 13.2 dynes/cm
Saturated vapor density = O. I917 Ib/ftJ
Relative volatility, a. = 2.5
Contd P/4
 =4=

ChE 405
Contd ..... Q. No.6
Following design equations are also provided

Vnj = 0.38 (!!...-)0.2 (PL - PI' )0.5

20 PI'

N-Nmin -0.7 1- R-Rmin

0.566]
N+I { ( R+I )
For random packing:
o forD:5 0.5 m

HETP= 0.50°.3 forD> 0.5

0°.3 for absorption columns with 0> 0.5 m

7. (a) Write down the general aspects that need to be evaluated in selecting piping materials. (7)
(b) Why do you use expansion joints in a pipeline? Discuss with examples (6)
(c) List the stresses that you would consider while designing a large and tall packed
column. How would you support this column? (6)
(d) CUFL gets water from Kalurghat intake point through a 25 km long pipeline at the
rate of 1200 m3/hr. The delivery pressure at the plant receiving point is IS psig. At the
low side, the inlet of the pump remains 20 ft from the water level. Using a reasonable
pipe dia, calculate the pump size if the overall efficiency is 52%. The drive is to be 10%
oversize. Assume smooth pipe. Sketch the system neatly. List all assumptions made. (16)
Given: Viscosity = 0.88 cp
f = 0.79 Re-0.25for turbulent flow and

f =~ for laminar flow

Re

Equation for reasonable pipe diameter

D = 0.363 (rilv )0.45 (p )0.13

8. Eastern Refinery Ltd needs to design a heat transfer equipment for cooling one of the
product 40° API oil which comes from distillation column at 300°F. Their production
capacity is 3.2 x 105 Ib/day based on eight hour operation time per day. You need to cool
.the product stream to 100°F by using cooling water of 85°F, pumping at a rate of 2 x 105
Ib/hr. Pressure drop allowance is 10 psi for both streams and dirt factor of each stream is
0.002.
You may assume a 2-4 shell and tube heat exchanger and can assume overall heat
transfer coefficient from the range for organic water system of 80-120 Btu/hr. ft2 OF.
Table and graph for required data is provided in the Design data booklet. Assume
suitable values if you need additional data.
Contd P/4
 =5=

ChE 405
Contd ..... Q. NO.8

Given data:
Shell Side: 25% vertically cut baffle, Baffle spacing 8 inch

Tube Side: y,; inch aD, 16 BWG, 16 ft long, 1 inch square pitch.

Physical properties for Oil at avg T

Viscosity = 2.58 lb/ft.hr
Thermal conductivity = 0.085 Btulhr.ft.oF

Specific heat capacity = 0.58 Btu/lb. of

Physical propcrtics of water at avg. T
Viscosity = 1.57 lb/ft.hr
Thermal conductivity = 0.078 Btulhr.ft. of

Specific heat capacity = 1 Btu/lb. of

(a) Decide tube and shell side fluids and explain the reason of your decision. (4)
(b) Find the required surface area, number of tubes and shelllD. (12)
(c) Check if the velocity of tube side flow is in acceptable range or not. (5)
(d) Check the heat exchanger is suitable for this use or not. (14)
Self-study/ChE Date: 19/10/2019

BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA

B. Sc. Engineering Examinations

Sub: CHE 411 (Economics and Managemcnt of Chemical Process Industries)

Full Marks: 280 Time: 3 Hours
USE SEPARATE SCRIPTS FOR EACH SECTION
Thc figurcs in the margin indicate full marks.
SECTION-A

There are FOUR questions in this section. Answer any THREE.

1. (a) Transform the cash flows on the left-hand side of the accompanying diagram (see figure)

to their equivalent amount, F, shown on the right-hand side. The interest rate is 8% per year. (l6K
~" --
---~"""'_----~--------~--------------'l
100 100 100 100 100 100 .,I
I

F.
I
j .

!
I

,
.. 1

o .I 234 5
I

6 7 <=> o
I
1
!
2 3 4 5
I I

J. End of Year End of Year .

._-_._----
'----~-------------------~- -~

(b) A company is considering constructing a plant to manufacture a proposed new product.

The land costs $300,000, the building costs $600,000, the equipment costs $250,000, and
$100,000 additional working capital is required. It is expected that the product will result in
sales of $750,000 per year for 10 years, at which time the land can be sold for $400,000, the
building for $350,000 and the equipment for $50,000. All of the working capital would be
recovered at the EOY 10. The annual expense for labor, materials, and all other items are
estimated to total $475,000. If the company requires a MARR of 15% per year on projects of
comparable risk, determine if it should invest in the new product line. Use the AW method. (25)
(c) Differentiate between nominal and effective interest rate. (5)

2. (a) What are the difficulties associated with the IRR method? How does the ERR method
overcomes the difficulties ofIRR method in project feasibility study? (16%)
(b) In the Rawhide Company (a leather products distributor), decisions regarding approval of
proposals for capital investment are based upon a stipulated MARR of 18% per year. The
four packaging devices listed in the Table were compared, assuming a 10-year life and zero
market value for each at that time. Which one (if any) should be selected? Make any
additional calculations that you think are needed to make a comparison, using the ERR
method. (External reinvestment rate, E = 18%) (30)

Packaging EauiDment
A B C D
CaDital Investment $38000 $50000 $55000 $60000
Annual revenues less exoenses 11000 14100 16300 16800
ERR 21.1% 20.8% 21.4% 20.7%

Contd P/2
 =2=

CHE411
3. (a) What are the major sources of uncertainty that arise while undertaking economic analysis

of engineering projects? Explain them briefly. (16 %)

(b) The managers of a company are considering an investment with the following estimated

cash flows. MARR is 15% per year. (Useful life = 5 years) (30)
Capital investment=$30000
Annual revenues=$20000
Annual expense=$5000
Market value=$1 000
The company is inclined to make the investment; however, the managers are nervous because
all of the cash flows and the useful life are approximate values. The capital investment is
known to be within I5%. Annual expenses are known to be within IIO%. The annual

revenue, market value, and useful life estimates are known to be within :t20%.
Analyze the sensitivity of PW to changes in each estimate individually. Based on your
results, make a recommendation regarding whether or not they should proceed with this
project. Graph your results for presentation to management.

4. (a) List the difficulties associated in evaluating public sector projects. (8 %)

(b) A retrofitted space-heating system is being considered for a small office building. The
system can be purchased and installed for $120,000, and it will save an estimated 300,000
kilowatt-hours (kWh) of electric power each year a six-year period. A kilowatt-hour of
electricity costs $0.1 and the company uses a MARR of 15% per year in its economic
evaluations of refurbished systems. The market value of the system will be $8,000 at the end
of six years, and additional annual operating and maintenance expense are negligible. Use the

benefit-cost method to make a recommendation. (15)

(c) An area can be irrigated by pumping water from a nearby river. Two competing

installations are being considered. (23)

o erating load on motor

Efficienc of urn motor
Cost of installation
Market value
Useful life

The MARR is 12% per year and electric power for the pumps costs $0.06 per kWh. Recall
that I horsepower (hp) equals 0.746 kilowatts. At what level of operation (hours per year)
would you be indifferent between the two pumping systems? If the pumping system IS

expected to operate 2,000 hours per year, which system should be recommended?

Conld P/3
 =3=

CHE 411
SECTION-B

There are FOUR questions in this Section. Answer any THREE.

5. (a) This question is compulsory.

Choose the correct answer and provide concise reason for your choice. If you Do not defend

your choice you will receive only 40% marks. (lOx5=50)

i. The statement "No smoking in the factory" is an example of
A. an objective
B. a strategy
C. a policy
D. a rule
ii. The situation which leads to the greatest difficulty in planning is the one in which
prices in an industry are:
A. slowly increasing
B. slowly decreasing
C. subject to change in unanticipated ways
D. subject to no change
iii. Which level of management would be most involved in the function of directing and
controlling?
A. top
B. middle
C. first level
D. all of these
iv. According to "Scalar Principle of Organization?
A. A manager can directly supervise a limited number of people
B. the line of authority must be clearly defined
C. exceptionally complex problems are referred to higher levels of management
. D. each subordinate should have one superior.
v. The best statement of a goal is:
A. increase our sales by 22 percent
B. change our method of assembly by June17
C. reduce the scrap rate 35% before year end
D. do a better job than we did previously
vi. Centralization is a system of:
A. planning
B. organization
C. staffing
D. directing
Contd P/3
 -,-
_/1-

CHE411
Contd .... Q. NO.5
vii. An advantage of centralization is:
A. it reduces the workload of overburdened executives
B. it helps develop managerial talent
C. it achieve more confonnity and coordination
D. decision can be made more quickly
viii. The emphasis of the informal organization is on:
A. the positions
B. role
C. status
D. people and their relationships.
ix. Which of the following statements concerning grapevine is not correct?
A. Grapevine is generally used irregularity in organizations
B. Grapevine is used largely to serve the self-interests of people within it
C. Some managers use grapevine to their advantage
D. In time, and with proper pressure, grapevine ean be eliminated
x. When Mark the manager communicates his department's resource needs to company
headquarters, which interpersonal role is he fulfilling?
A. liaison
B. Disseminator
C. Figurehead
D. Leader

6. (a) Draw an ORGANOGRAM of a manufacturing company that has production facilities in

two locations. In one location it produces foodstuffs, and in the other location it produces
toiletries products. The company has an active research program to develop new toiletries
products. Staff spport is available for all managers. Show at least 4 (four) levels of

management. (20)

(b) Describe the types ofleadership. (13)

(c) What is Theory Y in the organizing function of management? How applicable is it in

modern day context? (12)

7. (a) What is the "S" Curve of Technology Management? Explain your answer with a real-life

example. (IS)
(b) Communication Barriers can prevent managers from discharging their management
functions. What are these barriers and how do these prevent managers from discharging their

duties properly? (15)

Contd P/4
CHE 411
Contd .... Q. NO.7

(c) Write briefly on the 7 (seven) basic ideas that are useful in the development of a control

system? (15)

8. (a) For the problem below- (37)

(i) Draw the active diagram for this process.
(ii) Calculate the early start and finish time, late start and finish time and total float for
each event. Identify the CRITICAL PATH with an arrow diagram.
Activitv IMMEDIATE Predecessor Activity Times Estimate (weeks)
A - 4
B - 7
C - 3
D A 6
E B 4
F B 7
G C 6
H E 10
I D 3
J F,G 4
K H, I 2

(b) What is an MIS? Why is it important for a modem company to have an MIS? (8)
 •
"

L-4/T -l/ChE Date: 0211112019

BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA

L-4rr-1 B. Sc. Engincering Examinations 2018-2019

Sub: CHE 453 (Transport Phenomena)

Full Marks: 210 Time: 3 Hours

The figures in the margin indicate full marks.
USE SEPARATE SCIUPTS FOR EACH SECTION

SECTION -A

There are FOUR questions in this Section. Answer any THREE.

I. (a) A viscous fluid is in laminar flow in a slit formed by two parallel walls at a distance 2B
(B = 0.1 inch) apart. as shown in Fig. 1. Make a differential momentum balance and obtain

the expression for the distribution of momentum flux and velocity. State all the assumptions. (20)
(b) For pressure drop of 40 psi, determine the flow rate through the slit (Fig. 1).
-.-~~~ --cc--
Given data: (15)
Length of the slit (L) : 1 ft
Width of the slit (W) : 0.5 ft
Fluid viscosity ~ : 250 Ibm ft-1h-1 I .~ /
t '"t-:--,.
Z '''•.•

~ 28 ~

I I
..

, , Fluid out 'I

~g.l: Flowthroughaslil I
2. (a) What are the transport phenomena? How are they related? Why should transport

phenomena be studied together? (10)

(b) What is Hages - 'Posieuille law? Why is it important in transport process? (5)
(c) What are the conditions required to be maintained between two systems to make it

dynamically similar? (6)

(d) Explain the following terms: (9)

(')1 P artla. I' tIme d'envatIve,-

. ae
at
de
(ii) Total time derivative, -
dt

(iii) Substantial time derivative, De

Dt
(e) Equation of motion can be written in vector form as: (5)

£ pV = -[V'liiv]- Vp - [V.f]+ pg
8t ,
Write down the physical significances of all the terms in the above equation.
Contd P/2
 =2=

CHE 453
3. (a) Explain Reynold's Analogy for heat and momentum transport and show that S,,10 = Yz!

Where/is the fanning friction factor. Extend the Reynold's analogy in case of mass transfer. (17)
(b) Detennine the velocity and shear stress distributions for the tangential laminar flow of an
incompressible fluid between two vertical coaxial cylinders, the outer one of which is

rotating with an angular velocity no' Draw a neat sketch of the system. Use equation of

continuity and equation of motion as attached. (18)

4. (a) Define the term "time smooth velocity" and "eddy viscosity" for turbulent flow. (6)
(b) For annular flow, is the surface zero momentum flux closer to the inner or the outer wall?

Why? (4)
(c) Determine the ratio 1l(1)/1l at s = R/2 for water flowing at a steady rate in a long smooth

round tube under the following conditions: (25)

R = tube radius = 3 in
To = wall shear stress = 2.36xI0-5Ibjin-2
p = density = 62.4 Ibm. ft-)
v = kinematic viscosity = 1.1xl 0-5 ft2sec-1
Given: time - smoothed equation of motion:

D~ __
p DI =-\lP - \l.r
(Il] [_ ....(Il] + pg
[_ ...•
- \l.r

SECTION -B

There are FOUR questions in this Section. Answer any THREE.

5. (a) Define thermal conductivity. What is the thennal conductivity of a material panel area of
10 ft2 and thickness 0.5 in if the heat flow is 5 watts at steady state with temperature

difference between two main surfaces of 2°C. (10)

(b) Compare the temperature dependence of thcrmal conductivities for gases, Liquid and

solids. (7)
(c) An incompressible Newtonian fluid between two coaxial cylinders where the outcr
cylinder rotates and mechanical energy degraded into thermal energy. If the surface of inner
and outer cylinders are maintained at T = To and T = T b, find the expression for temperature

distribution profile. Make necessary assumptions. (18)

6. (a) Two concentric porous spherical shells of radii kR and R as shown in figure 6(a) where
dry air at temperature, Tk is blown outward radially from the inner shell into the intervening
space and out through the outer shell. \ind an expression for the required rate of heat
removal from the inner surface as a function of mass rate of flow of gas. Assume steady
laminar flow and low gas velocity.
Contd P/3
 =3=

CHE 453
Contd .... Q.No.6

(b) For dimensional analysis ofthe equation of change, show that

DT' =_I_'V"T' +~t/;' (10)

Dt' ReP,. ReP,. •

Symbols have their usual meanings.

7. (a) How are the fluxes J; and N; related in an n-component system? (5)

(b) Show that the sum of the fluxes J;' is zero. (5)

(c) The mass flux relative to stationary co-ordinates, show that (5)
I1A = wAnA +l1o)-cDAO'VWA

(d) Consider a gas A dissolves in liquid B and undergoes an irreversible first order chemical
(---'--

I
~..;

reaction: A + B ~ AB, rA = k)CA

Show that,
~-~-4
~_;o;_O_
-
L' - - --
!t I .-_..
- ,
The molar flux of A at plane z = 0, N Az I =c ~tanh
AO-V1l1UAB
-'-
D (20)
z=O
AB
- :TtP~[Q,
-l:,~.-b-

8. The rate of leaching of a substrate A from solid particles by a solvent B, the rate controlling
step is the diffusion of A from the particle surface through a liquid film out into the main
liquid stream.
(a) Obtain a differential equation for CA as a function of z. Make necessary assumptions.

Neglect the curvature of the particle. (15)

(b) Show that in the absence of chemical reaction in the liquid phase, the concentration

profile is linear. (12)

(c) Show that the rate ofleaching is given by NA/j (8)

L~~ __ "

:._,---~
 }

CitE ~S3

TABLE 3.4-1
THE EQUATION OF CONTINUITY IN SEVERAL
COORDINATE SYSTEMS

Rectangular coordinnle.r (x, Y. z):

iJpiJ a a
at + a;; (pvz) + Oy (pv,) + ~ (pv,) =0 (A)

Cylindrical coordinates (r, 8, z):

01.• riJ Ii) a

- -:- - -
al j" a." (prv,) + r- -ao (pv,) + -iJz, (pI',) =0 . (B)

Spherical coordinates (r, 0, t/J):

;
\
.l.

f--]
-KR
'I

t
J.jr flow out
 ',./ 7
'. ,}endix B Fluxes and the Equations of C~an~e.
.,
'',j
,
.J
NEWTON'S LAW OF VISCOSITY (continued)

Cylindrical coordinates (r, 8, z):

(B.1-8)'

(B.1-9)'

f (B.I-I0)'

(B.l-11)

(B.1-13)

in which
1a 1av• av, (B.1-14)
(9 .v) =--(rv)
rar' +--+-
rao az

~When the fl~idis assumed to hi ','~constant density, the term containing (V. v) may' be omitt(,.'<i.For
monatomic gases at low density, ~!H~dilatational viscosity K is zero.

Spherical coordinates (r, 0,t/»:

(ll.i-15)'
T" = -1-'[2 ~:] + (~I-'- K)(V• v)
r
(B.1-16), 1
TOO = -I-' [ 2(1-- av. + -v,)], + (-I-' - K)( V • v) I
r ao r 3

T ••
[(
= -I-' 2 ~-
1 av~ v,+v. cot
+ 0)] + <51-', - K)(V.v) (1l.1-17l'
rsmOat/> r

ToO = To.
[ a (v.)
= -I-' r ar r + r1 av,]
ao
(B.1-18) ,
I,
[ sin 0 aoa ( sin'O
v.) 1!
0 av.] (B.1-19)
T.~ = TOO = -I-' -r- + r sin at/> ,i
,
T~, = T,~ =-1-'
[ 1
r sin 0av, a(V~)]
at/>+ r ar r
(B.1-20)
,
in which
I. -
1 a a.
1 1 av.
(V . v) = .,r or (r'v,) -'-0
+ r sm ao (v. sm 8) + r sm at/>
I
-'-0 (B,l-21)

• When the lluid is assumed to have constant density, the term containing (V . v) may be omitted. For
monatomic gases at low density, the dilatational viscosity Ie is zero. .
 Sil.S The Equation of Ivlotion in Terms nf i 847-

[HE EQUATION OF MOTION IN TERMS OF T

(fiOV / Ot = - VI' - IV .. r] + fig]

Cartesian coordinates (x, y, z):1J

,!.v-,-+ v '!lJ.!. + v 'lv, + v av,) = _ ap - [iL 7 ' + iL 7 + 1, 7 ] +

P ( ,at x ax Y By : iJz ax ax :r.1 Jy y.r iJz U" Pg:z. (13.5,] )

P
av, av,
( at + Vy; ax + vy
av,
By + Vz
av,)
az =
ap
-ay - [ a
iJx T.ty + ay
a
Tyy +
a
vZ T~y
J+ Pgy (5.5-2)

,/~ P(
~--;jf + v.1' ax
a~ + vy ~By + v," az
~) ~
= - iJz -
[aJx Tn + Bya T.1Jz + iJza ] + Pgz
Tzz (B.5-3)

, ,J,.
I': \ "These equations-have been \\'ritten without making the assumption thal 'T is symmetric. This means, for
il
"
example, that when the usual assumption is made that the stress tensor is symmct~ic, 'T,,!, and Tyr may be
interchanged.
,i
I
i Cylilldrical coordillates (r, 0, z):'

av, + v -av, + -Voav, av, vi) ap []- -a ] a a 7HOJ'

I' ( -at ar r r --ao + v z -az - -
r = --
a, -
r ar " + -r -ao 7tJT + -iJz 7l'
(r7 ) - -
r + pg r (1),5-4)

al'O avo Voavo av" v,vo) ] ap [] a r' ] a a

I' ( ~ + v, ar + r ali + v, az + -r- = -1' ao - ;:> ar ( 7'0) + l' ao 700 + az 7,o +
70, -
r
7,oJ + pg" (5.5-5)

av, av, v, av, av,) ~p [] a ] a a ]

; I' ( aT+ v'ar + raij + v'ai: =-az- rar(r7')+ra070'+ ~Z7= +pg, (B.5-6)

~These <--"Iuations
have been written without making the as~umption that T is .synunetric. 'illis means, for example, that when the usual
assumption is made that the stress tensor is sy~metric, 'r,o - "0, :::::"
O.
I
Spllerical coordinates (r, 0, q,J:'
p(~v, + v av, + Voav, + ~ '!.':o: _ if, + V~) = _ ap
at ' ar r ao r sin 0 a4> r ar
] a ] ~, ] a 700+7""J
- [ ;:> ar (r'7,,) + r sin Ii ao (7°' sm 0) + r sin 0 a4>7., - r + fJg, (B.5-7)

p(avo + v avo + v. avo + -.!..~_avo + v,vo - v;, cot 0) = _2 ap

at ' ar r ao r sin 0 a4> r r ao ,
] a ] a, ] a (70, - 7,0) - 7"" cot 0)
- [ ;:> ar (r'7",) + r sin 0 ao (700 sm 0) + r sin Ii a4>r•• + r + pgo (B.5-H)

IJ(cJV,J. + v aVt/> + v8 aVf/j +~ ()v.:- + Vol', + vuv.:,. cot 0) = ]_ ap

at 'ar r ao r sin 0 a4> r r sin 0 acP
] a ] a , ] a (7., - 7,,~)+ 7•• cot OJ
- [ ;:> ar (r'r,.) + r sin 0 ao (7•• sm 0) + r sin 0 acPT•• + r + pg. (135-9)

I
I C These t'quations have been written without making thl.!assumption that T is symmetric. This means, for example, that when the usual

( assumption is made that the stn"Ss tensor is symmetric, "'0 - "0, == 0,

 ,pendix 13 Fluxes and the Equations of Change

EQUATION OF MOTION FOR A NEWTONIAN RUm

WITH CONSTANT p AND /.l.
,• I
[pOv/OI = -'i1p + J1.'i1'v + pgl

l
I Carlesian coordinates (x, y, z): '
,
;

P(av,
-at + v -av, av, av,)
ax + v' -,ay + v, -az
I
= --
ap + [a'v, + a'v" a'v,]
ax' ~ al~ -ai + -az" + f'g
1/ - (13.6-1)

avy av, avy av,) ap [a'vy a'v, a'vyJ

p ( -al + v, -a.x + v, -aY + v, -az = -a-Y + J1. -:2
ax + -,ay + -,az + Pg..
(13.6-2)

av, av, av, av,) ap [a'v, a'v, a'v,]

".'! " P( at + v, ax + vy ay + v, "a1." = -az + J1. aX' + ai + ai' + pg, (13.6-3)

Cylindrical coordinates (r, 0, z):

P(av,
-al + v ' av,
-ar + -v,r -'-
av, + v av, vl) ap [a a(1 ) a'v, a'v,1 2 av,]
ao ' -az - -r = --a, + J1. -ar -r -ar (rv)' + -~ -ao' + -az' - -~ - + pg (1l.6-4)
ao '
\
av, + v -avo + -v, -av, + v -ilv, + -v,v') = --1 -ap + J1.[a- (1- -a (Tl',) ) + -----
1 a'v, a'v, + -2 -av,] + pg,
P(-
ill 'ar r ao ' az' r , r ao a, r ar ~ ao' + -a,' ~ ao (1l.6-5)

av, av, v, av,'

p-+v-+--+v.---
( al
av,)
' a, r ao . az =--+J.L--
ap
az
[1
a (av,)
r ar
r-
a, +--+-
1
a'v, a'v,]
~ ao' az' +pg , (1l.6-6)

Spherical coordinales (r, 0, q,):

av, av, v, av, v. av, vi + vi) ap
p ( at + v, ar + r ao + , sin 0 aq, - -,- = - a,
+ J.L[l_a'_ (,'v) + __ 1 _.1.. (sin 0 _av,) + __ I a_,,_,,]+ p (13.6-7)'
" a,' ' " sin 0 ao ao,' sin' 0 aq,' g,
av, + v av, + v, av, + ~ av, + v,vo - vi COlO) = _! ap
p ( al ' ar , ao , sin 0 ilq, , , ao
+ J.L [1- - a ( , ,av,)
- + -1 -a ( -.-1 -a (v, Sin
.) 0) + ---. 1 -- a'v, + -2 av, 2 cot 0 av,]
- - ---- + pgo (!J.6-B)
r' a, a, " iJO Sin 0 iJO " sin' 0 iJ</>' ,'iJO ,'sin 0 a</>
av. + v av~ + v, av~ + ~ av. + v.v, + v,V. COlO) = __ 1_ iJp ,
(
Pal 'a, 'ao ,sinOa</> r rsinOa</>
+ J.L[.!..L (r' av.) + l.1.. (_._1_.1.. (v sin 0»)+ 1 a'v~ + 2 av, + 2 cot 0 av,] + pg (13.6-9)
" a, a, ,'iJO Sin 0 ao • " sin' 0 iJ</>' ,'sin 0 a</> T' sin 0 tJ</> •

• The quantity in the brackels in Eq. B.6-7 is nol what one would expect from Eq. (M) for IV. VvJ in Table A.7-3, because we have added
lo Eq. (M) the expression for (2/r)(V. v). which is zero for fluids with conslanl p. This gives a much simpler equation.
 j

•
. o 'Appendix B Fluxes and the Equations of Change
••
! 9B.9 THE EQUAnON OF ENERGY FOR PURE NEWTONIAN
FLUIDS WITH CONSTANT" p AND k
[pC,DT /Ot = kV'T + 1-'<1>.1
urlesum coordinates fx, y, z);

pC (aT + v aT + v aT + vaT) = k[a'T + a'T + a'T] + <I> (8,9-1)'

'at 'ax,' ay , az ax' al az' I-' ,
Cylindria>/ coordinates fr, 8. z);

pC (aT
p af
+ v aT + v, aT + v aT)
ar r ao
r az 1
= k[U. (r aT) + l a'T + a'T]
r aT ar ,2 a02 az2
+ <I>
J.L I' (8.9-2)'

Spherical coordinales fr, 8, </»;

pC, ( at ' ar r a8 r sin 8 aq,

T)
• VaT + v aT +:'! aT + __ ' _ L = k [ ll. (),J aT +
r' ar ar r'
1 ,
sin 8
a ()sin 8 aT +
a8 a8 r'
1
sin' 8
a, T] + <I>
aq,' I-' ,. (B.9-3)'

• This form of the energy equation is also valid under the less stringent assumptions k constant and (c1lnp/rJ In n"DplDt
Cl c: O. The
assumption p = constant is gh'en in, the table heading because it is the assumption more often made. .
b The function 4>11 is given in ~B.7.The term JJ.4>1' is usually negligible, except In systems with large velocity gradien'ts.
'i
i
~B.I0 THE EQUAnON OF CONTINUITY FOR SPECIES a
IN TERMS' OF j.
[PDw.IDf =. -(V - l.) + r.1
urfesilln coordinates (x, y, z);

aw, aw.
-+t'-+V-+V-
aw. aw,) =-
[aj" aj., ai.,]
-+-+- (B.10-1)
~ at • ax Y ay • az ' ax ay az +r '
Cy/indria>1 coordinates fr, 8, z);
aw.
at
aWn v, aWn
( -+v-+--+v-
P ' ar r a8 1
aw.)
oZ
[1 a.
=- --(rl )+--+-.-'+r
r ar ot r a8 tiz
1 aj.. aj.,]
(l
(8.10-2)

Spheria>1coordinates fr. 8. </»;

jaw.
'\at + v, ar
aw,
+
v, aw, ,v. aw,) _
r a8 + r sin 8 aq, -
[1r' ara (r ,.I.,) + r sin'1 8.a8a (I••" Sin 8) + r sin1 8 aj,,] ,
aq, T r v
(8.10-3)

• To obtain the corresponding equations in terms of J: make the following replacements:

Replace P w. i.. y r
II

by c
 •
"

L-4ff -lIChE Date: 02/11/2019

BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA

L-4ff-l B.Sc. Engineering Examinations 2018-2019

Sub: CHE 455 (Mathematical Models in Chemical Engineering)

Full Marks: 2 I0 Time: 3 Hours
USE SEPARATE SCRIPTS FOR EACH SECTION
The figures in the margin indicate full marks,
SECTION-A

There are FOUR questions in this section. Answer any THREE.

I. (a) Describe the advantages of hierarchical structure of model development for chemical

processes. Classify the different types of mathematical models. (12)

(b) Discuss the roles of different mathematical models in chemical engineering field. (8)
(c) Benzene (1), toluene (2), styrene (3) and xylene (4) are to be separated in the sequence of
distillation columns shown in Figure bellow. Determine molar flow rates of streams D), B),

D2 and B2 by solving material balance equations using Gauss Elimination method. (15)
-------- r.o-..., __ --~---~----~-~

I~t.X':\kne
. :l.51.9Nf'<1\"-
'/Of Tofi,.~e
6l.of Be~t.~
F:::. 100 "'tol j,.,in

_____ ~ ••..•.
_. _==""" -=-.--..L...,>

2. (a) Acetone can be removed from acetone air mixture by simple counter-current cascades, by
adsorption onto charcoal. We wish to find the required number of equilibrium stages to
reduce a gas stream carrying 0.222 kg acetone per kg air to 0.0202 kg acetone per kg air.
Clean charcoal (Xo = 0) enters the system at 2.5 kg/sec, and air rate is constant at 3.5 kg/sec.
Equilibrium betwecn the solid and gas can bc taken to obey the Langmuir-type relationship

KX
Y = n.K =0.5
n l+KXn'

where Y n = kg acetone I kg air

Xn = kg acetone I kg charcoal.
Arrange the material balance between the first stage and n'h stage so that, Ricatti equation

arises. Find the values of A, Band C. When A, B, C have the usual meanings. (15)

(b) Briefly discuss one of strategies for simplifying mathematical model using an example. (10)
(c) In many cases the model development becomes an iterative procedure-Explain and

elaborate on this statement. (10)

Contd P/2
 =2=

CHE 455
3. (a) Using the Newtons interpolation formula, derive the Explicit Euler method. (17)
(b) Prove that Backward Euler Method is always stable. (10)
(c) Briefly describe the effect of stiffness on the numerical solution of ODE systems. (8)

4. (a) Derive the following equation form,l Q= -I Notification indicate their usual meanings. (12)

(b) Using Taylor series expansion solve the nonlinear equations below: (15)

.t;(xJ,xJ= 2Xl2 -3X1X2 +5 =0 and J;(XI,X2)=-X~ -x2 +2 =0

Start with initial assumption around XI(I) = 3;x~J) = 3

(c) Discuss the role of step size control in numerical integration method. (8)

SECTION -B
There are FOUR questions in this section. Answer any THREE.

5. (a) Find the volume of the largest right circular cylinder that can be inscribed inside a sphere

of radius R. (10)
(b) Examine the reactor inthe following Figure. The objective function,j(c,7) = (c - Cr)2 + t-
T
is subject to the constraint C = Co + e and also Co < K, where, Cr is the set point for the outlet
concentration, a constant, and K is a constant. Find the minimum valuc of the objective

function using Lagrange multipliers for the case in which K ':- Cr - 2 (25)

Reactor
, Control
valves

T
c '
I
6. A chemical plant makes three products and uses three raw materials in limited supply as
shown in following Figure. Each of the three products is produced in a separate process

(1,2,3) according to the schematic shown in Figure Q. 6. (35)

The available A, B, and C, do not have to be totally consumed.
--------------- -_._------
Monomer
A , 1

-2 F
Monolner
B

3 G

-Inhibitor Contd P/3

C
 =3=

CHE 455 Process data

Conld .... O.No.6 Raw Material Maximum available Cost ($/IOOlb)

(Ib/day)
A '4000 1.50
.1
I
B 3000 2.00 >

i
.,'j, C 2500 2.50

Process Product Reactants Operating Selling price

I
I

Needed (Ib11b cost ($) of product i

oroduct) . -($) .
I E ~A !.B 1.00/100lb 4/100 Ib E
3 ., 3
A (consumed .
in l) .
2 F ~A !.B 0.50/100Ib 3.30/100 Ib F
3 ' 3 A (consumed
in 2) i
3 G !.A !.B'3!.C 1.00/1001b 3.80/100 lb' :
2 '6
G (produced G
in 3) I

"-J
Set up the linear profit funetion and linear constraints to find the optimum product
distribution, and apply the simplex technique to obtain numerical answers.

7. (a) A chemical manufacturing finn has discontinued production of a certain unprofitable

product line. This has created considerable excess production capacity on the three existing
batch production facilities. Management is considering devoting this excess capacity to one
or more of three new products: Call them products I, 2, and 3. The available capacity on the

existing units that might limit output is summarized in the following table: (10)
Unit Available Time (h/week)
A . 20
B 10
C 5
Each of the three new products requires the following processing time for completion:
Productivity (hlbatch)
Unit Product I Product 2 Product 3
A 0.8 0.2 0.3
B 0.4 0.3
C 0.2 0.1
The sales department indicates that the sales potential for products I and 2 exceed the
maximum production rate and that the sales potential for product 3 is 20 batches per week.
The profit per batch is $20, $6, and $8, respectively, on products I, 2, and 3. Formulate a
linear programming model for determining how much of each product the firm should
produce to maximize profit.

(b) Consider the objective function, f = 6X1

2
+ x; + 6x1 x2 + 3x; (15)

Find the stationary points and clarify them using the Hessian matrix.
Contd P/4
 =4=

CHE 455
Contd .... Q.No.7

(C) A shell-and-tube heat exchanger has a total cost of C = $7000 + $250 D2.5L + $200 DL,

where D is the diameter (ft) and L is the length (ft). (10)

What is the absolute and the relative sensitivity of the total cost with respect to the diameter?

If an inequality constraint exists for the heat exchanger 20( 7r~2};:: 300, (12)

how much the sensitivity calculation be modified?

8. (a) Carry out the initial and an additional stage of the numerical search for minimizing the
J
function f(x) = 2x - 5x2 - 8, x ~ 1by (i) Newton's method (start at x = 1), (ii) the quasi-
Newton (secant) method (pick a starting point of your choice) (iii) polynomial approximation

(pick starting points including x = 1). (25)

(b) The objective function for the work requirement for a three-stage compressor can be

expressed as (p is pressure) J = ~:
0.286 + ( ;: )0.286 + ( ;: )0,'' PI atm and P4 = 10 atm. The
( )

minimum occurs at a pressure ratio for each stage of V10 . (12)

Is/convex for 15, P2 5, JO, 15, PJ 5, 10?
L-4/T -1/ChE Date: 06/11/2019
BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA
L-4/T -1 B. Sc. Engineering Examinations 20 18-20I9
Sub: CHE 475 (Biochemical Engineering II)
Full Marks: 2I0 Timc : 3 Hours
USE SEPARATE SCRIPTS FOR EACH SECTION
The figures in the margin indicate full marks.
SECTION-A

There are FOUR questions in this section. Answer any THREE.

I. (a) A schematic of the vector p475 is shown in Figure I (a). The restriction enzymes
listed cut only where indicated; they do not cut anywhere else in the vector or insert.
A schematic diagram of gene W is below. You want to clone all of gene W DNA into
the p475 vector. Give two different strategies that you could use to clone gene W into

p475, and obtain colonies that contain a recombinant plasmid. (15)

EcoR I

Kl'llIB ,HI BamH!

VI 1f!~III,II$l\,~;;~~~~rG~te'lw.~~~M~~!illill \

(b) Design two 12-nucleotide long primers for the following gene of interest. List the
amino acids that can be expressed from this gene of interest. (8)

,
. GCTACTG A TGCGCACGA TCGTACA TACGGTTCACATCTAA TTCGACG

(c) What are the major steps 111 signal propagation process? With the help of a
hypothetical signal transduction network,. explain the different aspects of signal
transduction network. (12)

2. (a) What is the difference between regular and fluorescence microscopy? Briefly
explain the main types of regular microscopy techniques. (12)
(b) What is a phosphodiester bond? Explain with schematics the formation of a
phosphodiester bond. (6)
(c) What are endotoxins and exotoxins? Discuss the mechanism of exotoxin activity
in the body. (9)
(d) What is.the principle of similarity? What are the major similarity stages important
for bioprocess engineering? (8)
Contd P/2
 =2=

CHE 475
3. (a) What is aeration capacity? Derive the equation required to measure the aeration
capacity experimentally. Explain the measurement method with relevant plots. (13)
(b) Determine the power requirement to agitate a 5,000 litre tank filled with water.
The tank diameter is 2 m in diameter and is agitated at 200 rpm by a 6-blade disk type

agitator. The agitator is one-half the tank diameter with 20 cm blade width. (12)

(c) Explain the bioethanol production process using a neat schematic. (10)

4. (a) From the substrate balance equation, drive the generalized equation of batch
reaction time. A fungi is used to convert glucose to ethanol in a batch fenl1enter under
anaerobic conditions. The yield of biomass from substance is 0.06 g g-I; Ypx is 7.7

g g-I. The maintenance coefficient is 2.2 g. g-l. h-I; the specific rate of product

fonnation is 3.4 h-1• The maximum specific growth rate of the fungi is approximately

0.4 h-1. 5 g bacteria are inoculated into 5litres of medium containing 12 g I-I glucose.

Detenl1ine batch culture times required to: (8+9=17)

(i) produce 35 g biomass;
(ii) achieve 90% substrate conversion
Assume that, ethanol synthesis is directly coupled to energy metabolism in the cell.

(b) Write short notes on the followings: (6x3=18)

(i) Gasification
(ii) Bubble column reactor
(iii) Restriction Endonucleases.

S.ECTION-B
There are FOUR questions in this Section. Answer any THREE.

5. (a) Mention some sectors where biosensors have applications. Discuss their
applications in criminology and civil defense. (4+6=10)
(b) What are surface plasmons? Descirbe the working procedure of an optical
biosensor based on surface Plasmon resonance along with its advantages and
disadvantages. (2+8+4=14)
(c) What is the purpose of detection probe immobilization? Differentiate between
cross linking and covalent bonding techniques along with examples and mention
where they should be used. (4+7=11)

Contd P/3
 =3=

CHE 475
6. (a) Define false positive and false negative. Explain how they might occur in case of a
pregnancy test kit. (4+7=11)
(b) In ten Italian centres-hospitals and geriatric institutions-130 outpatients and
inpatients with a diagnosis of Alzheimer's disease were recruited for a randomized,

double blind, placebo controlled clinical trial with I-acetylcamitine. (4+ 11=15)
(i) Define placebo and Double blinded study.
(ii) Describe the procedure sequentially that is required to carry out this study and
finally obtain the result for this case.
(c) What is interlocked door system? Graphically represent how differential pressure

is maintained between classifications of clean rooms using interlocked doors. (3+6=9)

7. (a) Give definitions of the following: (4x2=8)

API, ACPH, Parenteral products, cGMP
(b) Describe the working procedure ofHPLC along with suitable diagrams. (15)

(c) Briefly discuss common chromatographic resins that are available. (12)

8. (a) What is downstream processing? Draw downstream processmg flowsheet for

intracellular and extracellular product recovery. (2+8=10)
(b) How is protein precipitation done? Write down the similarities and dissimilarities
between Crystallization and Precipitation. (6+9~15)
(c) Define partition coefficient and explain its significance. Aqueous two phase
extraction is used to recover a amylase from solution. A polyethylene glycol-dextran
mixture is added and the solution separates into two phases. Maximum possible
enzyme recovery is 95% when the volume ratio of upper to lower phase is 5.
Calculate the partition coefficient. (5+5=10)
 Nde 1: Sal I: feaR I:
5' CJfrATG 5' G"CGAC 5' JAATTC
3' GTATAC 3'CAGCTG 3' CTTAAG
t 'to t
Bamill: Kpn I: Xha I:

5' JGATCC 5' GGTA& 5' JrCGAG

3' CCTAGG 3' C{ATGG 3' GAGCTC
t - .t
'iI
i;
,.,.
I

I
'j

Figure for Question 1(a)

- ... - -- ..
-------------+._--~--.
------, -----. _.
 I;~

l'
q
- "

second base In codon

T c A G

c:
0

"0
-
::r
::;
c.
0 C C"

.=., OJ

'"
<D
:;-
'"
-
'"
S>

'~
" A
;:
n
0
c.
.0
".

Figure for Question 1(b)

1,000

500
Flat.blade Pitched.bl«ie

>00

•Cl 100
~
~ -
•.]'" 50

I
"-
E
c
, 70

i Curve 1 Curve 2 Curvt 3 . Curve 4

~ 10

5
-.... 1

3
1
,
, s<~"•• ;Il.I. J

1~ 1~ 10' 10'
1 '0
Revnolds number, 01Np/s:.

Figure for Question 3(b)

--------_._-- ,--
---_._----_ .. - .. ..

..,/,~.-

'.
,~
'

L-4/T -lIChE Date: 06/11/2019

BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA

L-4/T -1 B. Sc. Engineering Examinations 2018-2019
Sub: PMRE 413 (Natural Gas Engineering)
Full Marks: 210 Time: 3 Hours
USE SEPARATE SCRIPTS FOR EACH SECTION
The figures in the margin indicate full marks.
SECTION -A

There are FOUR questions in this section. Answer any THREE.

Log-log paper will be provided.

I. (a) Draw a multi component P-T diagram and illustrate the behavior of each type of

reservOIr. (10)

(b) Draw phase diagram of volatile oil. (5)

(c) Draw a phase diagram of a reservoir with gas cap. (5)

(d) Explain Gas Cycling with appropriate diagrams. Why can't we blow down the

reserVoir? (7+3)
(e) Write down the main features of two component P-V diagram. (5)

2. (a) List the methods of preventing hydrate formation at the well sites. (5)
(b) Find the water content of a 1.3 gravity gas at 1500 psia and 71°C. (5)
(c) An isochronal test is shown in Figure 2(c). Assume the well stabilize after 3 hours.
Detennine the following: (10+10)
(i) n, C"ab and AoF
(ii) Construct inflow perfonnance curve.
(d) Define 'Deliverability test'. What is the purpose of this test? (2+3)

3. (a) Name three types of deliverability test method and explain how are perfonned
with appropriate sketches. (10)

(b) ,What is absorption dehydration? Write down the advantage of using glycol. (2+3)
(c) Estimate the AOF of this well for an isochronal test. The following table
summarizes the isochronal test data. (20)

Pb:-14.7 psia.
is'= Ps = 352.4 psia
Pp(i')'=Pp(ps)=9.9715 X 106psia2/cp
Pp(Pb) = 2099psia2/cp

Contd P/2
 =2=

PMRE413
Contd ... Q. No. 3(c)

.'Time ..... :;,~<-l;4;

: (ljoul's}:'::
':'~"l<}.~~,,~:.>~tp?:~f.'-
., (MM~cfIDL,'(p.slaj,.:.4P~I)I~~Cp))
...:j
'~'.,_-_" ~::~-~'~" '. __.c..;\" - '''';' 1., .'.;._i' .B..:_,::-....,~I
0.5 0.983 344.7 9.6386 X 10'
1 0.977 342.4 9.5406 X 10'
2 0.970 339.5 9.4179 X 10'
3 0.965 337.6 9.3381 X 10'
0.5 2.631 329.5 9.0027 X 10'
I 2.588 322.9 8.7351 X 10'
2 2.533 315,4 8,4371 X 10'
3 2.5 310.5 8..2458 X 10'
0.5 3.654 318.7 8.5674 X 10''''
1 3.565 -'309.5 8.2071 X 10'
2 3.453 298.6 7.7922X 10'
3 3.390 291.9 7.5435 X 10'
0.5 4.782 305.5 8.0534 X 10'
I 4.625 293.6 7.6136 X 10'
2 4.438 279.6 7.099 X 10'
3 4.318 270.5 6.7797 X 10'
214 1.156 291.6 7.5285 X 10'
(Extended
flow point)

4. (a) Explain compressibility and compressibility factor. (5)

(b) Write down the behavior of real gas. (5)
(c) Draw the phase equilibrium diagram for gas-water hydrate system. (8)
(d) In an analysis of a sweet gas sample, the following compositional data has been
obtained. Please find the gas gravity and compressibility factor at 2000 pSla and
200°F. Assume the C7+ fraction to exhibit the same properties as n-Cg. (5+12)

--'.1,
....... ..., l', .' "-'0
i,Comp-:
f", ' .. ~ ~
li.j
. .
.
. .. ;

..
'.~9:e~f :jMole~ula)' ":".~~,~l)ci":'
-0 -. '-,.

-o:~:"~:.'.:.':..,-W~fo:ht,,..:"': ".~
d' ••..

;.'r'.->i;'~<~_~-',> \~):::,7.:.>}:;T;-i,
-._,,'-:.
'",
':>:~,,_,:~~!~~
CH, 94.4 16.043 667.8 343.1
C,H, 3.29 30.07.0 707.8 549.8 ,, .
C1H, 1.36 44.097 616.3 665.7
n-C,HIO 0.37 58.124 550.7 765,4
i-C,HIO 0.23 58.124 .529.1 734.7
n-C,H12 0.10 72.151 488.6 845.4
i-C,H12 0.12 72.151 490.4 828.8
C,H14 0.08 86.178 436.9 91:1.4
,
C,H18+ 0.05 128.259 332.0 1070,4
-~. ------ --------.----- -- - - -- -- _. - ~-----~

Contd P/3
 ~3~

PMRE413
SECTION -B

There are FOUR questions in this Section. Answer any THREE.

5. (a) What is the purpose of doing perforations in a wellbore? Name the equipment used

to perforate a reservoir. (2+3)

(b) Draw a detail diagram of Christmas tree. (10)
(c) Detennine the Size of a Vertical separator for the following conditions: (20)
Gas flow rate: 10 MMscfd at 0.4 mole fraction
Oil flow rate: 2,000 BOrD at 40° API
Operating pressure: 1000 psia
Operating temperature: 60°F
Droplet size removal: 140 microns
Retention time: 3 minutes
CD: 0.854
Gas Compressibility: 0.84
Gas Viscosity: 0.013 cp
Gas Molecular weight = 17.5 gm/mole

6. (a) Write down the reactions 111 an Iron sponge unit (Both for the reaction. and

regeneration unit). (5)

(b) To design an Amine process for Gas sweetening using DEA as solvent below
infonnation is available: (15)
Qg = 100 x 106 scfd
S.G = 0.6
H2S inlet = 10 ppm
H2S outlet = 4 ppm
C02 inlet = 4%
C02 outlet = 2%
CO = 0.689
Droplet diameter = 140 micron
Gas Compressibility factor = 0.84
P = 1000 psig
T = 100°F
(i) Determine DEA circulation rate using 35% DEA and an acid gas loading of
0.5 mole acid gas/mole DEA.
(ii) Determine preliminary height and diameter of DEA contact tower.
(iii) Calculate approximate reboiler duty with 250°F reboiler temperature.

Contd 1'/3
PMRE413
Contd ... Q. NO.6

(c) Write down the reasons for removing H2S and CO2: (7)
(d) Draw a multistage separator flow diagram with three separator system that is

operating in constant pressure and increasing temperature. (8)

7. (a) Write down the process of LNG liquefaction. Name the four major components of

"LNG Value Chain". (3+5)

(b) What does FSRU stand for? Draw typical regasification process diagram labeling

the major components. (2+7)

(c) Write down the functions of the following separator Vessel internals (2+7)
(i) Vortex Breaker
(ii) De-foaming Plates
(iii) Mist extractor
(e) How do you solve the following problems of separator (9)
(i) Accumulation of paraffin
(ii) Liquid escaping with gas
(iii) C02 is creating foam inside the separator.

8. (a) Give five examples of both Drilling and Produced Water wastes. (8)
(b) Draw a typical NGL, processes diagram labeling all the major components. (10)
(c) For the following data given for a horizontal pipeline, predict gas flow rate in
,
ft3/hr through the pipeline by applying Weymouth Equation with trial and error

method. (17)
Given:
Diameter of pipeline = 16 in
Length = 190 miles
Average temperature = 80°F
Specific gravity of gas = 0.63
Upstream pressure = 1050 psia
Downstream pressure = 430 psia
Standard temperature = 60°F
Standard pressure = 14.7 psia
Average gas compressibility factor = 0.8533
Viscosity of gas = 0.0097 cp
Tolerance limit = 1500
 i i
•
I
80,000
,
60.000 f=
- "~a
,
C ••••~~~ •• __ ltv

• ~ :c:~<o.1
40,000
:::: c.:
0.•
I ~~1-~~
/ /
V
._"v . 'fr-,
V V
..,... /

.,.
0.•
20.000
'T v
10,000 ...!..
=
0.>

.,i l
20
o.°JG .~~
""
GM

','
Mo~I.r_~'
'.2
•• =
3. io
j ~.15 1 1.8
1/ / V/ /

8,000
6,000

.,000
.! Coo'r-edDn 1ew ••• " •.••
ltv / /
'.00
/ / / ///t 0/
2,000 ~Jo=
! j O.OG "
Co ~ 0.0.
.;,ce/ ..: / V /V-/~~
'E:
~
,.
:t. ',000
800
~-. : 0."2
0.:90 0 ,
To, ••1 _':m
2 2
In twl •••• ""
•
/

~
600
7 7 7'
/ ~X#
ii: .00
! I
/ / .# ./
~
~ 'y
V

,.
lI,
/': V ~
-
/,
,. /
.'
200
;li
'"}
w.,....,....., •• l'!:
D~l'w!od IlnC"S nrct
equilibriu",.
tT'H'!U'rSl.8bte
A.c:;'tVal
equllibriu," Is Jo_r /"
/
/,", V / ~
'l. ~
./
..,.:9'
__ nter conte ....•. Angle h: e
'00 = function of con'tOos;t:ion "
~
~ 80
~
60

.<.- '"
-l>
/ / /IE: /.
. ,." "
"

V /
;Sf "
20
i // VII' .' // ~
~ Lf
/
'i;}/;~Z
-"
,~ • .I::! PJ,SitiO,"" thl. linc.
-' ./ /

I
is II function of gus
'0 COn1t'>O$.tion.
8
~~
6

• ~7#/J(.?'/ 1
V /,
/~
'//7/#
l,.~~ •••
V! /
--r::-;
/, / I:~;/~i I
2

,// l//~
VII' 77f7.
y/~/ -:/ l
I

• GO 00 20 o 20 40 GO 80 '00 120 140160"'180200 240 280

I
Fig for Question - 2(b)
Here Pressure is in psia and Temperature is in OF
 pM RE: LtI:>
------------_.::=;;{:;~~---------------~

eompressibilityFactors for Natural Gases as a ~t

Functlon of Pseu.doreduced .Pressure and Temperature.

Ii'
1.1
0 1 - --
7
~'

I :.'
~, i,
i

1.0 1.0
.OS
1.2
0.9 0.9S
I
,!

0.6 1.7 I!
l'
~.0.7
N

~
1.6
I
«l
u.
~
:i5
0.6 1.5
i~. !
.~
0.5 1.4
0. ~i
E
8 0.4 " I,

0.3 "'. I
f;
0.25
1.1

1.0

0.9
7 6

. ~
.-
Figure for Question 4"(d)

I~
,
~..
..
}i:or Pipeline Design
".,1':
I
.{.... Jam Equation:.
11~'
I
I

1 .
= 1.14 '-. 2 log (.eV+ 21.25
0.9.
J I

fif .. NRe
. . .
Reynolds. Number for Gas flow thro~gh pipelines:

. OA8q~YK
N Re =---~
f-lD
. I
i
I
,
Weymouth Equation:
II
I
I,
I
,

--_:.-._------------'
 /
•. ....... , r'-

v
.;:1' ..

"... . i
,-;~i:.•
,

~Appendix;

For Vertical Separator Design

d2 ,
~ 5; 040 . [TZQ ] [(
g ,~. .
) ,-2-C ]1/2, .
.' p. PI Pg dm ,

d2h _ trQI .
.0.12

h+76 (for diameters < 36 in.)

Lss == --- 12
. ,
I

h +d+40 .(for diameters > 36in.)

Lss == -, --1-2-

. (141.5" ,)
PI = P",a'u B 1.5 + API Gravity .
I
I . Sf
.' P =2.7-
1 " .n
For Amine process' Design .

. .. 192Q Mf'
Lo];' ",---"-- fi
'" cp AI>
20% MBA '":"8.41 lb/gal :~.028 mple MEA/gal
35 ,%DEh;=8.71Iblgnl ::{).W9 mole DBA/gal

)'ypic~nyfon stnpW(With 20ltays, the reboiler d~lieswill be as'

follows:' : .'. ,.... . .
. . . .... '

I',
.'MEA,~ystem""':1;OOOtot200atulgal h~al)solution
, b£Asystem+900 iot;OOoBtulglltle~nsbiution

1 !
!,
L-- . 'f .-