Co-gasification of rice husk and waste crumb rubber in a semi-industrial gasifier: Experimental insights into enhanced performance and operational stability

Abstract

The challenges in converting less dense biomass through more efficient technologies, such as gasification, have made such fuels unsuitable for the power and thermal generation sectors. This work aims to enhance the gasification of less dense rice husk (RH) by adding discarded tire rubber waste material called as crumb rubber (CR) in a semi-industrial gasifier, and its performance has been investigated through the variation in feedstock consumption, char generation, syngas concentration, gas calorific value (CV), syngas yield, and hot gas efficiency, along with the practical challenges. The thermogravimetric analyses of the blended feedstock showed a positive shift in the thermal degradation rate, which confirms the potential for the enhancement of gasification efficiency. Among the various blended feedstock compositions, BR40 has demonstrated better gasification performance at 0.3 ER. The gasifier is capable of producing gas with a CV of 7.29 MJ/m³ and achieving 80.14 % hot gas efficiency, even when using air as gasifying medium. The optimal producer gas (PG) compositions are 23.94 vol% CO, 19.08 vol% H₂, and 4.64 vol% CH₄, with H₂ evidencing a 57.3 % increase in comparison to RH alone. By combining CR with RH, the risk of operational challenges has been mitigated, and the gasification process has been achieved in a smooth and stable manner, without any clogging. Therefore, it is desirable to combine CR with less dense biomass in order to improve its gasification performance, including sawdust, coir pith, peanut shell, corn stover, and other herbaceous biomasses.