A review on biomass and pyrolysis technique

Dependence on fossil fuels causes pollution, climate change, and energy insecurity. Biomass is a carbon-neutral, abundant, and versatile energy source. Pyrolysis is one of the most prominent thermochemical pathways for producing bio-oil, biochar, and biogas from a variety of feedstocks. This review critically evaluates biomass pyrolysis with emphasis on feedstock characterisation, pre-treatment methods, process parameters, and applications of the resulting products. Comparative analysis shows that while fixed-bed and tubular reactors continue to be useful for laboratory research and the synthesis of biochar, fluidised bed reactors produce greater bio-oil yields appropriate for industrial uses. Biochar improves soil fertility, helps remove pollutants, and supports long-term carbon sequestration. Biogas helps recover direct energy through combustion, combined heat and power, and the production of synthetic fuels. Bio-oil shows promise as a renewable liquid fuel, but it needs to be upgraded to overcome instability for widespread use. The United Nations Sustainable Development Goals (SDGs) are also highlighted in the review, with particular attention paid to SDGs 7 (Affordable and Clean Energy), 12 (Responsible Consumption and Production), and 13 (Climate Action). Stabilisation of bio-oil, techno-economic analysis, reactor scalability, and life cycle environmental impacts are still areas with significant research gaps.