Impact of operational parameters on the yield of biochar, bio-oil, and pyrolytic gas in lignocellulosic biomass pyrolysis: A systematic review

Lignocellulosic biomass represents a promising renewable energy source, particularly when converted via pyrolysis, which produces biochar, bio-oil, and gas. This study consolidates current knowledge through a systematic review analyzing the effects of operating parameters on product yields. The structured methodology included three steps: planning, selection/classification, and summary/reporting. Findings indicate that biochar yield is favored by lower temperatures, slower heating rates, shorter residence times, and larger particle sizes. Gas production increases with higher temperatures, faster heating rates, longer times, and smaller particles. Bio-oil yield exhibits a more complex pattern, with optimal production at temperatures near 500 °C, faster heating rates, longer times, and particles below 2.0 mm. Variables such as carrier gas flow, humidity, and reactor type also influence pyrolysis outcomes. Despite identified trends, inconsistencies in experimental results, often due to feedstock variability, highlight the need for more controlled, comparative studies. Addressing these gaps is essential for optimizing pyrolysis for sustainable energy production.