Lignocellulosic biomass can be thermally converted into biofuels by various technologies. One of such most effective and lucrative technology is pyrolysis. Pyrolysis of lignocellulosic biomass convert it into bio-oil, bio-char and pyrolysis gas, these all have high energy content and potential in them. Two main types of processes for production of bio-oils from biomass are flash pyrolysis and hydrothermal liquefaction (HTL). Flash pyrolysis involves the rapid thermal decomposition of organic compounds by heat in the absence of oxygen, which results in the production of charcoal, bio-oil, and gaseous products.