Question

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

• A. the hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot
• B. it reduces its calorific value tremendously
• C. it reduces its flame temperature tremendously
• D. there are chances of explosion during preheating

Answer 1

The correct option is A the hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot

Hydrocarbon gases should not be preheated because at high temperature, they form soot. Heat salvage by preheating impure carbon particles of the hydrocarbons crack, thereby, choking and fouling the heat transfer surface by carbon soot.