Pyrolysis is a process where biomass is combusted at high temperatures and decomposed in the absence of oxygen. However, some difficulties arises when trying to create a totally oxygen free atmosphere. Often a little oxyidation does occur which may create undesireable byproducts and also it is highly energy intensive and expensive at the moment. The burning creates pyrolysis oil, char or syngas which can then be used like petroleum to generate electricity. It does not create ash or energy directly. Instead it morphs the biomass into higher quality fuel. The process begins with a drying process in order to maximize burning potential from the biomass, similar to the direct combustion process above. When cooled, the brown liquidy pyrolysis oil can be used in a gasifier.