Engineering Questions with Answers - Multiple Choice Questions
Chemical Technology MCQ’s – C3 Compounds – Acrylonitrile
1 - Question
Which method is used for the manufacture of industrial acrylonitrile?
a) Propylene-ammonia-air oxidation process
b) Catalytic dehydrogenation of isopropanol
c) Propylene alkylation of benzene
d) Contact process
View Answer
Explanation: A C3 refinery is introduced along with ammonia and air via sprangers into a fluidized bed catalytic reactor. Acetone is manufactured by Catalytic dehydrogenation of isopropanol. Cumene is manufactured by propylene alkylation of benzene. Contact process is to produce sulfuric acid.
2 - Question
Reaction kinetics is the major engineering problem in the manufacture of acrylonitrile.
a) True
b) False
View Answer
Explanation: This chemical reaction is one of the few commercialized where three reactants and a solid catalytic surface are all necessary involved in producing only a single major product.
3 - Question
Which catalyst is used in the manufacture of acrylonitrile from propylene-ammonia-air oxidation process?
a) Molybdenum-bismuth
b) Molybdenum
c) Silver
d) Iron
View Answer
Explanation: Molybdenum-bismuth is used because it has excellent attrition resistance. Also, it provides more than an adsorptive surface in furnishing oxygen by surface reaction and transfer.
4 - Question
What are the by products produced in the manufacture of acrylonitrile from Propylene-ammonia-air oxidation process?
a) Cumene and acetone
b) Cumene and acetonitrile
c) Acetonitrile and hydrogen cyanide
d) Cumene and hydrogen cyanide
View Answer
Explanation: Hydrogen cyanide and acetonitrile are produced in the product stripper reactor which further goes into a purifying column. For one ton as basis around 0.09 and 0.08 tons of acetonitrile and hydrogen cyanide is produced respectively.
5 - Question
What are the impurities present in the acrylonitrile column in the manufacture of acrylonitrile from propylene-ammonia-air oxidation process?
a) Saturated alcohol
b) Saturated carboxylic isocyanide
c) Saturated carboxylic cyanohydrin
d) Dust particles
View Answer
Explanation: Impurities in the final acrylonitrile column which give trouble are saturated carboxylic cyanohydrins (HO-R-CN). These dissociate to form volatile contaminants.