Biomass Energy Multiple Choice Questions on “Biomass Conversion Technologies – 1”.
1. Which of the following technologies are used to convert biomass into useful energy forms?
a) Bio-chemical process
b) Galvanization
c) Doping
d) Photoelectric effect
Answer: a
Clarification: The three main technologies used to convert biomass into useful forms of energy are bio-chemical, thermo-chemical and physio-chemical processes. Galvanization is a process used to prevent corrosion of metals. Doping and photoelectric effect are not related to biomass conversion technologies.
2. What are the four main types of thermo-chemical processes?
a) Galvanization, photovoltaic effect, chemo-mechanical effect, pyrolysis
b) Pyrolysis, gasification, combustion, hydrothermal processing
c) Pyrolysis, gasification, combustion, doping
d) Photovoltaic effect, gasification, combustion, hydrothermal processing
Answer: b
Clarification: The four main types of thermo-chemical processes are pyrolysis, gasification, combustion and hydrothermal processing. Photovoltaic effect, doping, chemo-mechanical effect and galvanization are not related to biomass conversion technologies.
3. What are the two primary processes under bio-chemical conversion?
a) Photosynthesis and respiration
b) Photosynthesis and photovoltaic
c) Anaerobic digestion and fermentation
d) Anaerobic digestion and photosynthesis
Answer: c
Clarification: Anaerobic digestion and fermentation are two primary processes under bio-chemical conversion. Photosynthesis, photovoltaic and respiration are not related to biomass conversion technologies.
4. Which of the following is an example of physio-chemical conversion technique to convert biomass into usable forms of energy?
a) Pyrolysis
b) Gasification
c) Anaerobic Digestion
d) Extraction with esterification
Answer: d
Clarification: Physio-chemical process mainly consists of extraction with esterification. Pyrolysis and gasification are thermo-chemical conversion. Anaerobic digestion is a bio-chemical conversion process.
5. Which of the following is a product of pyrolysis of biomass?
a) Producer gas
b) Steel
c) Agricultural residue
d) Sodium
Answer: a
Clarification: The output is producer gas. Steel and sodium are not the outputs of any pyrolysis process. Agricultural residue is a type of biomass.
6. Pyrolysis occurs in the presence of _______ oxygen.
a) large amounts of
b) absence of
c) extremely large amount of
d) low amounts of
Answer: b
Clarification: In pyrolysis, the biomass is subjected to high temperatures in the absence of oxygen. The output of pyrolysis is producer gas which is a mixture of flammable gases (primarily CO and H2) and non-flammable gases (primarily nitrogen and carbon dioxide).
7. Which of the following best indicates the process of gasification?
a) Biomass → carbon dioxide and water → producer gas and charcoal → carbon monoxide and hydrogen
b) Biomass → carbon monoxide and hydrogen → carbon dioxide and water → producer gas and charcoal
c) Biomass → producer gas and charcoal → carbon dioxide and water → carbon monoxide and hydrogen
d) Producer gas and charcoal → carbon dioxide and water → carbon monoxide and hydrogen → biomass
Answer: c
Clarification: Gasification basically converts all the available biomass to “gas”. In the first stage, the biomass is partially combusted to form producer gas and charcoal which is then sent to the second stage. In the second stage, the carbon dioxide and water produced in the first stage is chemically reduced by charcoal to form carbon monoxide and hydrogen.
8. Which of the following is best suited for hydrothermal processing?
a) Forestry byproducts
b) Wheat
c) Corn
d) Sewage sludge
Answer: d
Clarification: Feedstocks with high moisture content like sewage sludge are suitable for hydrothermal processing. Agricultural residue like wheat and corn and forestry byproducts are not best suited for hydrothermal processing.
9. What is hydrothermal processing?
a) Heating aqueous slurries of biomass at high pressures to produce products of greater energy density
b) Heating aqueous slurries of biomass at high temperatures to produce products of lower energy density
c) Heating aqueous slurries of biomass at low pressures to produce products of greater energy density
d) Heating aqueous slurries of biomass at low temperatures to produce products of lower energy density
Answer: a
Clarification: Hydrothermal processing is a biomass conversion technique that involves heating of aqueous slurries of biomass at high pressures to produce products of greater energy density. Feedstocks with high moisture content like manures are best suited for this process.
10. What is anaerobic digestion?
a) Produces biogas by heating the biomass
b) Produces biogas using micro-organisms operating in anaerobic conditions
c) Produces biogas by subjecting the biomass to high pressures
d) Produces biogas using micro-organisms operating in aerobic conditions
Answer: b
Clarification: Anaerobic digestion is a biological process of breaking down the biomass to produce products with high energy density – biogas. It occurs in anaerobic conditions. Waste water treatment plants commonly use anaerobic conditions to treat the influent.
11. Catalytic liquefaction occurs at _________
a) low temperature, low pressure
b) high temperature, high pressure
c) low temperature, high pressure
d) high temperature, low pressure
Answer: c
Clarification: Catalytic liquefaction is a thermo-chemical biomass conversion process. It requires low temperature and high pressure and the process is carried out in liquid phase under the presence of a catalyst.
12. Sugarcane is used to produce ethanol.
a) True
b) False
Answer: a
Clarification: One of the most commonly used feedstocks to produce ethanol is sugarcane. This is very popular in developing due to the high productivity of sugarcane when supplied with sufficient water.
13. Which of the following are used to produce ethanol when water is not available in plenty?
a) Sugarcane
b) Wheat
c) Corn
d) Sorghum
Answer: d
Clarification: Cassava or sorghum is commonly used to produce ethanol when water is not available in plenty. Sugarcane is used when there is no limitation on water content. Wheat and corn do not produce ethanol.
14. Which of the following are commonly used in fermentation process?
a) Yeast
b) Bacteria
c) Mushrooms
d) Virus
Answer: a
Clarification: Yeast is commonly used in fermentation process. Fermentation is the process converting biomass to alcohol and carbon dioxide.
15. Fermentation is aerobic process.
a) True
b) False
Answer: b
Clarification: Fermentation is an anaerobic process. It is another commonly used bio-chemical process of converting feedstock (biomass) to energy in the presence of micro-organisms.