Advancing Green Gasification─A Review on Biological Pretreatment, Syngas Purification, Machine Learning Technology, and Techno-economic Insights for Biofuel Production

The dependence on conventional fossils for energy and the ongoing utilization of carbonaceous resources significantly burden the environment. Consequently, researchers have strived to establish sustainable energy-generating methods that employ renewable resources to minimize environmental stress. Gasification of biomass is a potential route to harness the potential of biological reserves. This process strategically employs various agents to catalyze the desired reactions, facilitating the transformation of biomass feedstocks into fuels or alternative products. This article explores various gasification technologies, including catalytic gasification, steam gasification, and supercritical and subcritical water gasification, as a sustainable approach for converting lignocellulosic agricultural residues into biohydrogen. Additionally, comprehensive insights into syngas purification methodologies and carbon sequestration from the produced syngas are presented. One of the key highlights of this review is the utilization of machine learning models for enhancing the efficiency of gasification systems, showcasing the interdisciplinary nature of the research and its potential for future advancements. An economic evaluation is also presented. Implementing supercritical water gasification on lignocellulosic biomass has significantly increased the syngas production rate while decreasing the reaction time. Similarly, in catalytic gasification techniques that employ a variety of metallic and ceramic catalysts, a substantial increase in syngas output has been observed, featuring increased proportions of hydrogen and carbon oxides as well as a complete reduction in tar formation.