Biomass Energy Questions on “Usable Forms of Biomass, their Composition and Fuel Properties – 1″.
1. What is cellulose made up of?
a) Polysaccharide
b) Steel
c) Carbon nano fibre
d) Silicon
Answer: a
Clarification: Cellulose is a complex polymer, or polysaccharide. Polysaccharide is made up of glucose, a six carbon sugar. Steel is used in industries to manufacture various things like automobile bodies, etc. Silicon is used in manufacturing glass and in semiconductor industry.
2. Why is cellulose resistant to hydrolysis?
a) Because it consists of polysaccharides
b) Because it has a crystalline structure
c) Because it is hydrophobic
d) Because it is a polymer
Answer: b
Clarification: Cellulose is resistant to hydrolysis because of its crystalline made up of polysaccharide. Hydrolysis the chemical reaction that releases simple, fermentable sugars from polysaccharide.
3. Hemicellulose is a source of biomass accounting from 20% to 40% by ________
a) volume
b) moles
c) weight
d) molarity
Answer: c
Clarification: Hemicellulose is another major source of biomass. It accounts from 20 – 40% by weight and is the next best source after cellulose. It is a complex polysaccharide made from 5 to 6 carbon sugars.
4. Why does burning biomass not add to greenhouse gas emissions?
a) Because it is a clean source
b) Because it absorbs greenhouse gases to burn
c) Because it releases the same amount of greenhouses gas as burning fossil fuel does
d) Because it releases greenhouse gas that was captured and converted into other forms during its growth
Answer: d
Clarification: Burning biomass does not add to greenhouse gas emissions because it does not release any additional amount. Instead, it released the same amount of gas that was captured and converted to other forms during its growth.
5. What are the two types of moisture content in biomass?
a) Intrinsic and extrinsic
b) Higher heating value and lower heating value
c) Lower heating value and extrinsic
d) Higher heating value and intrinsic
Answer: a
Clarification: Moisture content is one of the main properties of biomass. The two types of moisture content are intrinsic moisture content and extrinsic moisture content. Heating value talks about the total amount of energy available in the fuel.
6. What is intrinsic moisture content in biomass?
a) Moisture content of the material with the moisture content in atmosphere
b) Moisture content of the material without the influence of weather effects
c) Moisture content of the material with the influence of weather effects
d) Moisture content of the material without the moisture content in atmosphere
Answer: b
Clarification: Intrinsic moisture content is the moisture content in biomass without the influence of weather effects. It does not depend on the amount of moisture content present in the atmosphere.
7. What is extrinsic moisture content?
a) Moisture content of the material with the moisture content in atmosphere
b) Moisture content of the material without the influence of weather effects
c) Moisture content of the material with the influence of weather effects
d) Moisture content evaporated to the atmosphere
Answer: c
Clarification: Extrinsic moisture content of biomass is the moisture content due to influence of weather conditions. It is essentially the amount of moisture absorbed from the atmosphere due to changes in weather.
8. Which of the following is a problem for using biomass as a source of energy?
a) Less moisture content in the atmosphere during time of harvesting
b) Low calorific value
c) Low intrinsic silica content
d) High moisture content in the surroundings
Answer: d
Clarification: High moisture content or an increase in moisture content is a problem for biomass combustion. This is because, the amount of energy that can be used for applications is significantly reduced due to absorption of moisture. The heat used to burn the fuel will first be used to evaporate the water vapour thereby leading to excess use of resources.
9. What is calorific value (CV) of a material?
a) Amount of energy content or heat value released by the material when burnt in air
b) Amount of energy content or heat value released by the material when burnt in water
c) Amount of energy content or heat value absorbed by the material when burnt in air
d) Amount of energy content or heat value absorbed by the material when burnt in water
Answer: a
Clarification: Calorific value is another important property that indicates how good is the biomass. It is the amount of energy content or heat value released by the material when burnt in air. Burning or combustion is usually not done in water.
10. What is the volatile matter in biomass?
a) The content in biomass that remains after heating
b) The content in biomass that is driven off as gas by heating
c) The biomass that is being heated
d) The moisture content in biomass
Answer: b
Clarification: Volatile matter is that content in biomass which is driven off as gad by heating. It also includes the water vapour. Moisture content present in biomass is not volatile matter by itself. When it turns into water vapour, it can be called as volatile matter.
11. What is fixed carbon content in biomass?
a) The carbon content in biomass
b) The carbon content that is fixed in biomass and cannot be changed
c) The content in biomass that is driven off as gas by heating
d) The mass that remains after the releases of volatile matter on heating the biomass
Answer: d
Clarification: Fixed carbon content is the mass that remains after the releases of volatile matter on heating the biomass. Since it is fixed and not released as gas, it is called fixed carbon content.
12. A biomass feedstock with a high cellulose/hemi-cellulose is needed to produce ethanol.
a) True
b) False
Answer: a
Clarification: For the production of ethanol, a biomass feedstock with a high cellulose/hemi-cellulose content is chosen. This is because it provides a high l/t yield.
13. Ash is the residue content is the solid residue after chemical breakdown of biomass.
a) True
b) False
Answer: b
Clarification: The chemical breakdown either by thermo-chemical or bio-chemical processes of biomass produces a solid residue. When the residue is produced by combustion in air, it is called ash.
14. In a bio-chemical process, the solid residue represents ________ present in biomass.
a) the quantity of biodegradable carbon
b) the quantity of biodegradable potassium
c) the quantity of non-biodegradable carbon
d) the quantity of biodegradable sodium
Answer: c
Clarification: In a bio-chemical process, the solid residue represents the quantity of non-biodegradable carbon present in biomass. It specifically talks about carbon and not any other element.
15. Which of the following is most impacted by the bulk-density of the biomass as-produced?
a) Calorific value
b) Storage of the fuel after processing
c) Heating value
d) Transportation and fuel storage costs
Answer: d
Clarification: Transportation and fuel storage costs are most impacted by the bulk density or volume of the biomass as-produced. These costs are before processing the fuel to produce energy. Calorific and heating value are not affected by bulk density.