Pyrolysis
Pyrolysis is a conversion of biomass to liquid, solid and gas mixture by direct thermal decomposition of the biomass in the absence of oxygen at temperature range of 350–550 °C [37]. The pyrolysis processes under development are based on two different concepts namely slow pyrolysis and fast or flash pyrolysis. These differ from each other in terms of chemistry, yields and quality of products. Liquids produced from pyrolysis are called bio-oil; it is a complex mixture of aliphatic and aromatic compounds [38]. Pyrolysis reaction is an endothermic reaction as shown below: