Fuels and Combustion

391.Washing of coal

1. Reduces its ash & sulphur content
2. Improves its coking properties
3. Increase the fusion point of its ash by removing chlorine compounds
4. All (A), (B) and (C)

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392.Washing of coal decreases its

1. Caking index
2. Mineral matter content
3. Ash content
4. Both (B) and (C)

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393.Washing of coal does not reduce its

1. S & P content
2. Heating value
3. Fusion point of ash
4. None of these

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394.Washing of coal is done to reduce the

1. Inherent impurities
2. Adhering impurities
3. Mineral matter
4. Both (B) and (C)

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395.Water gas constitutes mainly of

1. CO & H₂
2. CO & N₂
3. CO₂ & H₂
4. CH₄ & H₂

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396.Weathering of coal during storage causes

1. Reduction in coal size
2. Increase in its friability
3. Decrease in its caking capacity
4. All (A), (B) and (C)

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397.When incomplete combustion loss is high, the flue gas analysis shows large amount of

1. CO₂
2. CO
3. O₂
4. C

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398.When steam is passed over coal resulting in the endothermic reaction represent by, C + H₂O = CO + H₂, it is called the _________ of coal.

1. Carbonisation
2. Oxidation
3. Coalification
4. Gasification

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399.When the coal is heated in absence of air, it is called its

1. Deoxidation
2. Gasification
3. Coalification
4. Carbonisation

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400.Which adsorbent is used for removing sulphur compounds (S Q, H₂S, RSH etc.) removal from coke oven gas in by-products recovery plant?

1. Silica gel
2. Diatomaceous earth
3. Basalt
4. Bog iron (i.e., moist ferric hydroxide)

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