INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPURMid-Spring Semester Examination, 2017-2018
Subject: Chemical Process Technology. Subject No.: CH 30014. No. of Students: 96
Date: 19.0;.2018 (AN) Time), Hrs Full Marks;>y GoLj- ~
-----------------------------------------------------------------------------------------------------------------------Instructions: Answer any 4 questions. State and assume any missing data.
Q I. (i) Identify the product from the plant shown in the flowsheet shown below. (ii) Prepare abrief write up describing the process steps shown in the flowsheet. (i ii) State the chern ical reacionsoccuring in different sections of the process and (iv) provide the process details not included in theflow sheet. [1+3+6+5=15]
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Q2a) A mixed stream of benzene, toulene and zylene is available from a naphtha catalyticreformer. Suggest to the company the four possible downstream petrochemicals that can bemanufactured from this BTX stream. Your suggestion should be in the form of block flowdiagram(s) and the accompanying write up must include justification for your choice of eachproduct and its manufacturing process you include in your flowsheet. [4+4+4=12]
2b) Provide a scheme for manufacturing chloromethanes starting from natural gas and salt(NaCI). [3]
Q3a) Outline the process of manufacture of viscose rayon with a flow diagram and itsdescription. What are the pollutants from rayon industry and how are the effluents treated in thisindustry? [4+2=6]
3b) What is Portland cement? Suggest the flow sheet of a cement plant with its processdescription to an enterpreneur who plans to put up the plant at Kharagpur. Justify the process yousuggest. Provide (i) a list of major equipment, (ii) raw materials required. [5+2+2=9]
Q4a) In a plant for catalytic synthe is of I mt methanol, the raw material requirements arereported to be 0.127 mt H2 and 0.89 mt CO. Verify if these figures are realistic. The raw materialstotal up to more than 1 mt. What happens to the extra amount? [4+ 1=5]
4b) Following reactions relate to gasification of coal/coke to produce producer / water gas.Reaction /).]f, k cal/mol of C(s), CO(g) or
H2O(l)A C(s)+02(g)[Excess air] ~ CO2(g) -96.5B C(S)+(1/2)02(g)[Limiting air] ~ 2CO(g) -57.8C C( s)+C02(g) ~ 2CO(g) +38.7D C(s)+H20(l) ~CO(g)+H2(g) +38.9E CO(g)+ H20(l) ~ CO2(g)+H2(g) +0.4
F H20(I) ~ H2O(g) +29.8Water gas production in a continuous plant involves passmg of a mixture of steam [H20(g)] andoxygen [02(g)] through the coke/coal bed. The steam to oxygen ratio is set such that the bedtemperature remains constant. Estimate the composition of the gas exiting the plant. Clearly stateall assumptions [4+ 1=5]
4c) Explain why the caustic chlorine industry often have a hydrochloric acid plant as a part ofthe complex. [2]
4d) In a mixed fertil izer grade 5-10-5, what is the weight fraction of the elemental phosphoruspresent in it? [3]
Q5) Answer in brief the following (5 x3 = 15 marks)
(a) Explain why for production of BTX by catalytic reforming of naphtha the feedstock ischosen to be lighter (lower boiling range) than that for producing high octane reformate?
(b) Explain the difference between the membrane and the diaphragm cells in chloro-causticplants.
(c) What's 'black liquor'? How is it disposed off?
(d) What are the specific differences between a 'block flow diagram' and a 'process flowdiagram' - explain with example.
(e) Show the calculation to find the % H2S04 in 35% Oleum?
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