MOE505 QUESTIONNAIRE

[L3-2]State which factors can affect the reactor design decisions

[L3-4] In the choice of the reaction path, state the available paths necessary to be evaluated

[L3-5] In order to produce vinyl chloride (C2H3Cl), we have the following three choices of paths:

a) C2H2 + HCl -> C2H3Cl

acetylene hydrogen chloride vinyl chloride

b) C2H4 + Cl2 -> C2H4Cl2 and C2H4Cl2 -> C2H3Cl2 + HCl

ethylene chlorine dichloroethane dichloroethane vinyl chloride hydrogen chloride

c) C2H4 + 1/2O2 + 2HCL -> C2H4Cl2 + H2O

ethylene oxygen hydrogen chloride dichloroethane water

C2H4Cl2 -> C2H3Cl2 + HCl

dichloroethane vinyl chloride hydrogen chloride

Given the following table and assuming that raw material costs and product and byproduct values dominate the cost of the process, state which reaction path looks most promising by using Economic Potential to compare options.

Material / Molecular Weight / Value ($/kg)
Acetylene / 26 / 0.94
Chloride / 71 / 0.21
Ethylene / 28 / 0.53
HCl / 36 / 0.35
Vinyl chloride / 62 / 0.42

b) Considering the 3 reaction paths for the production of vinyl chloride, devise a process based on these reaction paths which uses ethylene and chlorine as the raw materials and produces minimal byproducts

c) Discuss whether this process can be economically attractive

[L3-S12]Give examples of single reaction systems of the following type:

a) FEED->PRODUCT

b) FEEED->PRODUCT + BYPRODUCT

[L3-S13]Give examples of multiple reaction systems in parallel of the following type:

a) FEED1 + FEED2->PRODUCT and FEED1 + FEED2->BYPRODUCT

[L3-S14]Give examples of multiple reaction systems in series of the following type:

a) FEED1 + FEED2->PRODUCT and PRODUCT->BYPRODUCT1 + BYPRODUCT2

[L3-S17] Provide definitions regarding the reactor performance for the following terms:

a) Conversion

b) Selectivity

c) Reactor yield

[L3-S18] To produce benzene from toluene in a multiple series reaction:

C6H5CH3 + H2 -> C6H6 + CH4

toluene hydrogen benzene methane

with a secondary series reaction:

2C6H6 ↔ C12H10 + H2

benzene diphenyl hydrogen

we have the following inputs and outputs into and out of the reactor respectively:

COMPONENT / FLOWRATE (kmol/hr)
H2 / 1858
CH4 / 804
C6H6 / 13
C6H5CH3 / 372
C12H10 / 0
COMPONENT / FLOWRATE (kmol/hr)
H2 / 1583
CH4 / 1083
C6H6 / 282
C6H5CH3 / 93
C12H10 / 4

Calculate the conversion, selectivity and reactor yield with respect to the following:

a) The toluene feed

b) The hydrogen feed

[L3-S29] Draw and explain the general characteristics of the following idealized reactor models:

a) Ideal batch model

b) Continuous well mixed model

c) Plug flow reactor model

d) Continuous well-mixed model for Plug-flow reactor (PFR)

[L3-S37] Fill in the table below showing how to choose an ideal reactor in multiple reactions in parallel

Reaction
System / FEED->PRODUCT
FEED->BYPRODUCT / FEED1+FEED2->PRODUCT
FEED1+FEED2->BYPRODUCT
Rate
Expression
Ratio to maximize
a1 < a2 / b1 < b2
b1 > b2
a1 > a2 / b1 < b2
b1 > b2

[L4-S3-5]

a) What is a homogeneous mixture?

b) What is heterogeneous mixture?

c) In the case of heterogeneous mixtures, define which physical properties can be used to separate the various materials

d) For the separation of homogeneous mixtures, one needs to create or add another phase to the mixture. Give 5 examples of such phase additions

e) For the separation of heterogeneous mixtures, state 4 principal separation techniques

[L4-S20] With an aid of a diagram, explain the following separation processes of homogeneous mixtures by creation of another phase:

a)Distillation

b) Evaporation

c) Multistage evaporation by:

c1) Forward feed operation

c2) Backward feed operation

c3) Parallel feed operation

d) Crystallization

[L4-S20] With an aid of a diagram, explain the following separation processes of homogeneous mixtures by using mass separating agents:

a)Drying

b) Stripping

c) Adsorption

d) Liquid-Liquid extraction

[L6]

[L6-S2]a) Define the three major hazards in the process industry

[L6-S4]b) Provide definition for flash point

[L6-S4]c) Provide definition for autoignition temperature

[L6-S5-7]d) Discuss flammability limits dependence on temperature and pressure

[L6-S9]e) When does combustion of a flammable mixture occur?

[L6-S10-11]f) Compare flammable liquids to flammable gases

[L6-S14-15]g) State and explain the two types of chemical explosions and the two different conditions in which they can occur

[L6-S18-19]h) Write down equations for the sensible heat of the superheat and for the vapour fraction (VF)

[L6-S21-25]i) State the 3 different ways of contact with toxic material and provide definitions regarding the time weighted, short-term and ceiling exposure from toxic materials

[L7 and L11-S4]

a)Use the problem table algorithm to identify the QHmin and QCmin as well as the pinch location without the use of any graphs of the following streams given that the ΔTmin is 10 oC

Stream
No / Stream / Type / Supply Temperature
Ts(oC) / Target Temperature
TT(oC) / Enthalpy
Change ΔΗ(MW) / Heat Capacity Flowrate CP
(MW/oC)
1 / Reactor 1 feed / Cold / 20 / 180 / 32 / 0.2
2 / Reactor 1 product / Hot / 250 / 40 / -31.5 / 0.15
3 / Reactor 2 feed / Cold / 140 / 230 / 27 / 0.3
4 / Reactor 2 product / Hot / 200 / 80 / -30 / 0.25

b) Use the results of the problem table algorithm to plot the composite curves for the above table.

c) By using the pinch design method, draw the heat exchanger network design for the above example for maximum energy recovery.

[L10-S6] State the rules for the construction of a typical grid diagram of heat transfer operations

[WS-7-8]

a) Given the following flowsheet, construct the heat exchanger diagram below with ΔTmin= 10 oC

Stream
No / Type / Supply Temperature
Ts(oC) / Target Temperature
TT(oC) / Heat Capacity Flowrate CP
(kW/oC)
1 / Hot
2 / Hot
3 / Cold
4 / Cold

b) Use the problem table algorithm to calculate the minimum hot and cold utility requirements and the location of the pinch

[WS-9-10] Given the following heat exchanger diagram, perform the following:

a) Explain why the above design does not achieve the targets shown on the composite curves?

b) Draw the grid diagram representation of this network

c) Redraw the network, separating the “Above” and “Below” pinch designs

[WS-11] Given the following stream data with ΔTmin = 10 oC and QHmin = 960 kW and QCmin = 120 kW and that the pinch occurs at 65 oC, perform the following:

Stream
No / Type / Supply Temperature
Ts(oC) / Target Temperature
TT(oC) / Heat Capacity Flowrate CP
(kW/oC)
1 / Hot / 180 / 80 / 20
2 / Hot / 130 / 40 / 40
3 / Cold / 60 / 100 / 80
4 / Cold / 30 / 120 / 36

a) Draw the composite curves

b) Design a heat exchanger network for maximum energy recovery

[WS-12] Given the following stream datawith ΔTmin = 50 oC and QHmin = 9.2 MW and QCmin = 6.4 MW, design a heat exchanger network for maximum energy recovery by using stream splitting if necessary

Stream
No / Type / Supply Temperature
Ts(oC) / Target Temperature
TT(oC) / Heat Capacity Flowrate CP
(MW/oC)
1 / Hot / 750 / 350 / 0.045
2 / Hot / 550 / 250 / 0.04
3 / Cold / 300 / 900 / 0.043
4 / Cold / 200 / 550 / 0.02

[WS-13] In the case of multiple utilities, one has the following problem table algorithm for a ΔTmin= 20 oC.

T* (oC) / Cascade Heat Flow (MW)
540 / 21
510 / 42
490 / 44
390 / 24
310 / 0
190 / 60
150 / 52
90 / 64
50 / 56

a) Draw the Grand Composite curve

b) Determine how much steam can be produced at a saturation temperature of 210 oC from boiler feedwater with temperature of 100 oC (For steam: ΔH=2000 kJ/kg, For boiler feedwater: Cp = 4.2 kJ/kgoC)

c) If flue gas is available (TTFT = 1800 oC), determine the flue gas duty