Chemical Engineering

Question: For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3 ), while the C.V. is same on weight basis (i.e., kcal/kg) ?
[A].

Propane and acetylene

[B].

Propane and LPG

[C].

Sewage gas and gobar gas

[D].

B.F. gas and coke oven gas

Answer: Option A

Explanation:

No answer description available for this question.

Question: During coking of coal, the ash content (percentage)
[A].

increases

[B].

decreases

[C].

remains constant

[D].

–

Answer: Option A

Explanation:

No answer description available for this question.

Question: For the case of a fuel gas undergoing combustion with air, if the air/fuel ratio is increased, the adiabatic flame temperature will
[A].

increase

[B].

decrease

[C].

increase or decrease depending on the fuel type

[D].

not change

Answer: Option B

Explanation:

No answer description available for this question.

Question: Gross & net calorific value is the same for
[A].

blast furnace gas

[B].

coke oven gas

[C].

L.D. converter gas

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: Low temperature carbonisation of coal produces
[A].

metallurgical coke

[B].

soft coke

[C].

very low calorific value coke oven gas

[D].

no by-products

Answer: Option B

Explanation:

No answer description available for this question.

Question: Incomplete combustion of fuel in the furnace is judged by high __________ of the flue gases.
[A].

CO content

[B].

dew point

[C].

CO2 content

[D].

O2 content

Answer: Option A

Explanation:

No answer description available for this question.

Question: Dust content in raw blast furnace gas is about __________ gm/Nm3 , hence it is cleaned to the dust level of about < 10 mg /Nm3 before use.
[A].

15-30

[B].

1-2

[C].

70-100

[D].

150-200

Answer: Option A

Explanation:

No answer description available for this question.

Question: Blast furnace coke is made from coal by
[A].

low temperature carbonisation.

[B].

high temperature carbonisation.

[C].

medium temperature carbonisation.

[D].

heating the coal in an oven in presence of air.

Answer: Option B

Explanation:

No answer description available for this question.

Question: __________ prohibits the use of alcohols directly in petrol engines.
[A].

Low octane number

[B].

High cost & availability

[C].

Low flash point

[D].

Low calorific value

Answer: Option B

Explanation:

No answer description available for this question.

Question: Coal tar fuels (CTF) as compared to petroleum based fuel oils have higher
[A].

calorific value

[B].

higher C/H ratio

[C].

sulphur content

[D].

difference in gross & net calorific value

Answer: Option B

Explanation:

No answer description available for this question.