What is the cheapest fuel for boilers in liquid form?(otherthan FO,LDO)?
If FO stands for Fuel Oil it is actually one of the more expensive ways of heating a boiler. It is used because oil contains more calories than something like alcohol would. This means one could use far less oil than alcohol. However, alcohol is a renewable fuel and fuel oil is not. This is why the price of oil will continue to rise indefinetly. However, another source of oil is vegetable oil. Many bio-diesel engines run on recycled cooking oil very cheaply. Vegetable oil is renewable, but a boiler would need more of it than a bio-diesel engine. This is because in the engine, the fuel is turned directly into mechanical energy. A boiler is a two step process, and because of entropy, some energy is going to be lost. Most of the entropy in a boiler is associalted with the amount of energy it takes to turn the water into steam. One other possibility is plastic. Oil refineries have things known as cracking towers. The oil is heated to high temperatures and exposed to an alumina catylist. This breaks the oil down into lighter hydrocarbons, such as LP gas. Plastic could concievably be recycled and cracked, especially material such as polyethylene which is a pure hydrocarbon and would be easy to turn into either a liquid or gaseous fuel with the proper catylist.
