Production of value added products from biomass waste by pyrolysis: An updated review

Fossil fuels resources are continually running out due to the rapid rise in industrialization and outgrowth. Moreover, the excessive utilization of fossil fuel has resulted in release of various toxic gases and global warming. Hence, it necessitates the demand to explore for an inexhaustible, renewable and eco-friendly energy sources. In this review, various waste biomasses which are abundantly available throughout the world have been reviewed as a feedstock for obtaining various value added products i.e. bio-oil, gases and biochar etc., using various pyrolysis techniques. The pyrolysis is considered to be the most effective conversion technique in which three stage degradation mechanism is observed leading to the production of valuable hydrocarbons from decomposition of hemicelluloses, cellulose and lignin. The bio-oil obtained if upgraded properly, is served as fuel for commercial use. The study also reviews the composition of lignocellulosic biomass, conversion techniques, and mechanism of conversion to various pyrolytic products, upgradation of bio-oil and effective utilization of biomass for energy generation. This review suggests utilization of lignocellulosic biomass waste as energy resource by converting it to value-added products by low-cost conversion methods which would ultimately lead to overcome the energy crises to some extent.