Catalysts and their role in biomass gasification and tar abetment: a review

Abstract

Biomass gasification is a promising technology for the transformation of biomass into a gaseous product. However, it suffers from a major drawback of tar generation which affects the downstream application and operation to a larger extent becoming a big hurdle in the commercialization of the technology. Catalytic tar reduction by using a different catalyst as the in situ mode or as a secondary catalyst is an attractive technique to achieve a clean and tar-free gaseous product. Besides this, catalysts are used for altering the gas distribution as per the requirement for a specific application like FT synthesis or methanol synthesis. However, few shortcomings persist in using a different type of catalyst and their economic viability; there is a need to develop low cost and effective catalysts. The present paper provides a review on the role of catalysts in biomass gasification and tar reduction, and different catalysts used in biomass gasification. The paper discusses the challenges and prospects for developing the novel catalyst.

A comprehensive review of primary strategies for tar removal in biomass gasification

“…the surface [57,242,[258][259][260]. Thus, the catalytic activity of those natural catalysts in the biomass gasification seems to be related to CaO-MgO in the dolomite, MgO and Fe 2 O 3 phases in the olivine and CaO in the limestone.…”

“…These catalysts may be used as primary catalysts directly in the gasifier, or as secondary catalysts in downstream catalytic processes. The use of in situ primary catalysts is a promising method to reduce the tar concentration in comparison with the use of a more expensive secondary catalytic cracking reactor downstream [58,242,243]. A large number of materials with significant activity for tar cracking and reforming have been examined as primary catalysts.…”

Prospective of Response Surface Methodology as an Optimization Tool for Biomass Gasification Process

“…On the other hand, in steam gasification, catalysts increase the production of hydrogen-rich gas. However, methane content can decrease slightly [35].…”

A review of the thermochemistries of biomass gasification and utilisation of gas products

“…Catalysts help to decrease the required temperature and time for the biomass gasication process for efficient production of high-quality syngas (or producer gas). There are several excellent reviews 27,65,70,75,[125][126][127][128][129][130] and experimental research published on the various catalysts used in biomass gasication. 126,[131][132][133][134][135][136][137][138][139][140][141][142] Biomass gasication catalysts are considered successful if they can lower the required activation energy for gasication reactions to achieve high carbon conversions that positively inuence the gasication process.…”

“…In some cases, a combination of catalytic systems for primary gasication and secondary reforming of tar has been report. 121,128,173 5.1.1. Catalysts for ex situ tar reduction and elimination during biomass gasication.…”