Recent approaches on the optimization of biomass gasification process parameters for product H2 and syngas ratio: a review

Biomass gasification technology has an ancient and well-established background. The technology has widely been used to produce H2 and syngas which is subsequently upgraded to obtain valuable biofuels, Fischer–Tropsch chemicals and used in combined heat and power (CHP) plants. Abatement of tar-related complexes with an improved hydrogen content and syngas ratio (H2/CO) via biomass gasification is a critical challenge. In this review, an attempt has been made to evaluate the critical parameters affecting biomass gasification process. It is revealed that each parameter (i.e., biomass feedstock particle size, moisture content, gasifying agent, residence time, equivalence ratio, steam to biomass ratio, and gasification temperature) has significant impact of H2 and syngas production. Fluidized bed gasifiers have been quite efficient for small to medium scale applications to produce optimal syngas ratios. Use of catalyst greatly influenced the H2 and syngas yields. Impregnated catalysts were found to have more pronounced effect on the water–gas shift reaction resulting in improved gas yields. Although, the parametric optimization could be achieved; notwithstanding, economic feasibility and industrial viability are to be considered too.