250+ TOP MCQs on Thermal Processes – Combustion Technologies and Answers

Hazardous Waste Management Multiple Choice Questions on “Thermal Processes – Combustion Technologies”.

1. ____________ furnace uses forces of gravity to help in mixing of waste.
a) Bed plate
b) Fluidised bed
c) Incineration grate
d) Rotary
Answer: a
Clarification: Bed plate furnace uses forces of gravity to help in mixing of waste, as the waste is moved between series of metal plates.

2. Which of the following combustion technology is suitable for homogeneous and wet wastes?
a) Bed plate
b) Fluidised bed
c) Incineration grate
d) Rotary
Answer: a
Clarification: Bed plate furnace is suitable for homogeneous and wet wastes such as sludge cake, and pasty wastes.

3. In which of the following combustion technique waste is introduced to a bed of sand which is kept in suspension?
a) Bed plate
b) Fluidised bed
c) Incineration grate
d) Rotary
Answer: b
Clarification: In fluidised bed furnace waste is introduced into a bed of sand and heated several hundred degrees to provide inertia and sufficient combustion.

4. Which of the following waste combustion furnace is opted for waste of same size and density?
a) Bed plate
b) Fluidised bed
c) Incineration grate
d) Rotary
Answer: b
Clarification: Fluidised bed furnace is more suitable for waste of same size and density, and for wastes which have been pre-heated to reduce them in size.

5. Which of the waste combustion technique is opted for solid waste treatment?
a) Bed plate
b) Fluidised bed
c) Incineration grate
d) Rotary
Answer: c
Clarification: Incineration grates are used to treat solid waste such as municipal waste which do not comprise liquids, pastes or sludges that would run through gate.

6. Which of the following furnaces withstand high temperature?
a) Bed plate
b) Fluidised bed
c) Incineration grate
d) Rotary
Answer: d
Clarification: In rotary furnace wastes are placed in refractory-lined furnace which rotates itself and is designed to withstand high temperature and pressure.

7. Optimum temperature range for a furnace is ___________ degree Celsius.
a) 850-1200
b) 800-1200
c) 700-1250
d) 800-1250
Answer: a
Clarification: Optimum temperature range for a furnace is 800-1200 degree Celsius, to maintain the temperature mixing of low and high CV waste is carried out.

8. What is the average plant capacity of rotary kiln incinerator?
a) 20000-50000 tonnes per year
b) 25000-50000 tonnes per year
c) 200000-540222 tonnes per year
d) 457916-595263 tonnes per year
Answer: b
Clarification: The average plant capacity of rotary kiln incinerator is 25000-50000 tonnes per year and waste can be either solid, liquid or drummed wastes.

9. Complete destruction of hazardous components is done in first chamber of rotary kiln.
a) True
b) False
Answer: b
Clarification: The kiln is operated around 1200 degree Celsius and off-gas from first chamber is then combusted in secondary chamber to reduce particulates and to ensure complete destruction of hazardous components.

10. Which of the following combustion enables operator to control residence time and temperatures?
a) Rotary kiln
b) Fluidised bed
c) Pyrolysis
d) Rotary furnace
Answer: b
Clarification: Fluidised bed combustion technology enables operator to control residence time and sustain stable temperatures, and has good gas-to-solid contact characteristics.

11. Which of the following combustion technology destroys persistent chlorinated hydrocarbons?
a) Rotary kiln
b) Fluidised bed
c) Pyrolysis
d) Rotary furnace
Answer: b
Clarification: Fluidised bed combustion technology operates at temperature ranging from 650-775 degree Celsius and destroys highly persistent chlorinated hydrocarbons.

12. Manufacture of charcoal is example of pyrolysis.
a) True
b) False
Answer: a
Clarification: Pyrolysis is partial combustion in closed container in absence of oxygen, manufacture of charcoal is example of pyrolysis, which has been used for many years.

13. Which of the following combustion technology is used for pre-treatment of health care waste?
a) Rotary kiln
b) Fluidised bed
c) Pyrolysis
d) Rotary furnace
Answer: c
Clarification: Pyrolysis is used for pre-treatment of health care waste which consist of materials such as bandages, organic materials, plastics (safety clothes, syringes, tubes).

14. Which of the following combustion takes place in closed container in presence of oxygen?
a) Rotary kiln
b) Fluidised bed
c) Pyrolysis
d) Gasification
Answer: c
Clarification: Gasification is a partial combustion process that takes place in a closed container in the presence of oxygen and end products include hydrogen and methane.

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