Fuels and Combustion
Higher percentage of ash in coal meant for the production of metallurgical grade coke

Decreases the abrasion resistance of coke
Decreases the hardness of coke
None of these
Causes brittleness in steel

ANSWER DOWNLOAD EXAMIANS APP

Fuels and Combustion
Fuel gases containing hydrocarbons (ie.g. coke oven gas) are not preheated before burning, mainly because

It reduces its calorific value tremendously
The hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot
There are chances of explosion during preheating
It reduces its flame temperature tremendously

ANSWER DOWNLOAD EXAMIANS APP