Chemical Engineering - Fuels and Combustion

21. 

Pick out the wrong statement.

A. Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat.
B. Burning the fuel with theoretically required amount of pure oxygen results in attainment of maximum adiabatic flame temperature.
C. Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature.
D. Adiabatic flame temperatures of actual combustions are always less than the maximum values.

Answer: Option C

Explanation:

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22. 

Preheating of a gaseous fuel results in increased

A. flame length
B. flame temperature
C. quantity of flue gas
D. ignition temperature

Answer: Option B

Explanation:

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23. 

Eschka mixture, which is used for the determination of sulphur in coal, is a mixture of

A. MgO & Na2CO3
B. MgSO4 & BaCl2
C. BaSO4 & NaCl
D. MgCO3 & NaCl

Answer: Option A

Explanation:

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24. 

Fossil fuels mean

A. solid fuels
B. liquid fuels
C. those fuels which are found in the crust of earth.
D. premature fuels with low calorific value.

Answer: Option C

Explanation:

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25. 

Sometimes water is sprayed during coal charging in the coke oven, which helps in

A. prevention of clinker formation in the oven.
B. controlling the dust nuisance while charging the coal.
C. reducing the cracking of hydrocarbons in the gas and increasing the percentage of CO & H2 in the gas (due to the endothermic reaction represented by C + H2O = CO + H2)
D. all (a), (b) and (c).

Answer: Option D

Explanation:

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