FUELS AND COMBUSTION QUIZ

Thick fire bed and preheated primary air

Low forced draught and fuel bed temperature

Low reactivity of carbonised residue containing high proportions of iron & sulphur

All of these

Coke oven gas

Pitch

Tar

Pulverised coke

All of these

Free carbon in tar is more

Aliphatic tar is produced

Ammonia yield is more

More carbon

All of these

Less volatile matter

Greater percentage of ash

Soft coke

Very low calorific value coke oven gas

Metallurgical coke

No by-products

Has poor strength and abrasion resistance

None of these

Produces more slag when used in the blast furnace

Is desirable in producer gas manufacture

The ratio of its percentage of fixed carbon to that of volatile matter

Helpful in estimation of its rank

Neither A nor B

Both A and B

Low fusion point of ash

Very low ash content (8-10%)

High volatile matter content

High caking index

CH₄ (upto 90%)

H₂

C₃H₈

C₂H₆

Lower ignition temperature

Lower theoretical flame temperature

Higher calorific value

Narrower limit of inflammability