Chemical Process Technology Multiple Choice Questions on “Natural Products – Fermentation”.
1. Which of the following statements are wrong?
a) Micro-organism cell wall rupture takes place under high shear stress
b) Escape velocity decreases with increase in tank size
c) Heat sterilization avoids contamination of pure cultures in fermenters
d) Rapid fermentation rates is a pre-requisite for successful fermentation process
Answer: b
Clarification: Escape velocity = V*v/A, where A is the unused gas escape area, V is total volume; v is the volume of air per unit volume of liquid per unit time. V varies as D3, A varies as D2. Hence escape velocity is linearly proportional to D, which means escape velocity increases with increase in tank size.
2. Which of the following is not a design principle for sterile operations?
a) Continued use of steam for labile zones
b) Dependent sterilization of each part of system
c) Usage of Kel-F diaphragm valves
d) All welded smooth inside construction
Answer: b
Clarification: Continued use of steam for labile zones, Usage of Kel-F diaphragm valves, all welded smooth inside construction, and we need to independently sterilize each part of system.
3. Science of fermentation is called zymology.
a) True
b) False
Answer: a
Clarification: The statement is true as the science of fermentation is called zymology. It is a metabolic process and it is of 2 types: aerobic and anaerobic fermentation.
4. Percentage of alcohol in beer is ______
a) 8-10% alcohol
b) 95% alcohol
c) 10-15% alcohol
d) 50% alcohol
Answer: a
Clarification: 8-10% alcohol in fermented liquor is called beer. Azeotropic alcohol-water mixture contains 95% ethanol. 50-60% alcohol is taken from the beer still.
5. Bottoms from the beer still are known as _____________
a) Mash
b) Denatured spirits
c) Slops
d) Bagasse
Answer: c
Clarification: While top product from beer still is sent to aldehyde column, the bottoms known as slops are concentrated so that they can be used as cattle feed or can be discharged as waste.
6. Ethyl alcohol can be produced by oxidation of petroleum.
a) False
b) True
Answer: b
Clarification: Fermentation from sucrose substrate, catalytic hydration of ethylene, fermentation from starch substrate, oxidation of petroleum are some of the possible processes for manufacturing alcohol. Out of which only some are economical.
7. Which of the following operation is not involved in petroleum fermentation process?
a) Evaporation
b) Distillation
c) Leaching
d) Condensation
Answer: b
Clarification: Petroleum fermentation process involves separation, condensation, fermentation, evaporation, drying, leaching, and recovery.