Answer:
1. Ethanol alcohol has lower content than lamp oil and candle wax because alcohol has a higher combustion heat than candle wax
2. And I think it is cheaper to produce and ship in bulk quantities
Here is the second one
1. It is due to the emissions that result from coal combustion like Sulfur dioxide (SO2), which contributes to acid rain and respiratory illnesses which is dangerous and many people want to avoid.
2.Second is that today in modern times many peope are using room heaters instead of old fashoined chimnney style or coal burning .
Hope this Answers your question