chemical engineering fuels and combustion MCQs – Page 8

Practise multiple-choice questions from chemical engineering fuels and combustion for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering fuels and combustion Mcqs
141. Calorific value of coke even gas produced by low temperature carbonisation of coal is about ____________ Kcal/Nm3?
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A. 10000

B. 6500

C. 4000

D. 2500

142. The difference between total carbon and fixed carbon of coal will be minimum in case of___________________?
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A. Anthracite

B. High temperature coke (V.M < 0.5%)

C. Lignite

D. Bituminous coal

143. The fuel ratio of a coal is__________________?
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A. The ratio of its percentage of fixed carbon to that of volatile matter

B. Helpful in estimation of its rank

C. Both A. and B.

D. Neither A. nor B.

144. Laboratory gas is obtained by the cracking of____________________?
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A. Fuel oil

B. Kerosene

C. Diesel

D. Gasoline

145. Flue gas discharge velocity through chimney of a big thermal power plant may be around ________________ m/sec?
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A. 500

B. 0.5

C. 50

D. 10
146. Dry air required to burn 1 kg of carbon completely may be around ______________ kg?
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A. 2

B. 11

C. 38

D. 20

147. Micum Index of a coke is a measure of its___________________?
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A. Reactivity

B. Porosity

C. Hardness & strength

D. Bulk density

148. Overfire burning in a furnace is a phenomenon characterised by the __________________?
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A. Supply of excess air

B. None of these

C. Burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying

D. Supply of excess fuel

E. e air</strong>

149. With increase in moisture content of coal, its___________________?
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A. None of these

B. Calorific value increases

C. Swelling during carbonisation becomes excessive

D. Caking properties diminish
150. During combustion of coal on grate, clinker formation is increased by the___________________?
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A. Use of thick fire bed

B. Low fusion point of ash (< 1100 C)

C. Use of preheated primary air

D. All A., B. & C.
151. The calorific value of LPG (50% propane + 50% butane) is about ______________ kcal/Nm3?
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A. 15,000

B. 10,000

C. 5000

D. 25,000
152. High pressure coal gasification is employed in ________________ process?
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A. None of these

B. Kopper-Totzek

C. Lurgi

D. Winkler

153. Bulk density of pulverised coal may be about ______________ kg/m3?
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A. 1500

B. 100

C. 1000

D. 500
154. Gross calorific value will be equal to the net calorific value for __________________?
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A. C2H2

B. H2

C. CO

D. C2H6

155. Presence of phosphorous in metallurgical coal__________________?
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A. Badly affects the quality of steel

B. Increases its caking power

C. Is not undesirable

D. Reduces its calorific value

156. Which is the most matured coal ?
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A. Bituminous

B. Anthracite

C. Semi-anthracite

D. Lignite

157. Theoretical flame temperature of a fuel is that temperature which is attained, when the fuel is completely burnt using theoretical amount of air in___________________?
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A. Air

B. Either A. or B.

C. Oxygen

D. Either A. or B. without gain or loss of heat
158. Which of the following combustibles is absent in blast furnace gas ?
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A. H2

B. CO

C. None of these

D. CH4
159. Which of the following is called blue gas?
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A. Producer gas

B. Water gas

C. Coke oven gas

D. Natural gas

160. High sulphur content in a fuel ______________ of the flue gases?
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A. Decreases the dew point

B. Increases the dew point

C. Reduces the combustion efficiency by limiting the permissible temperature reduction

D. Both B. and C.