Liquid hot water as sustainable biomass pretreatment technique for bioenergy production: A review

In recent years, lignocellulosic biomass has emerged as one of the most versatile energy sources among the research community for the production of biofuels and value-added chemicals. However, biomass pretreatment plays an important role in reducing the recalcitrant properties of lignocellulose, leading to superior quality of target products in bioenergy production. Among existing pretreatment techniques, liquid hot water (LHW) pretreatment has several outstanding advantages compared to others including minimum formation of monomeric sugars, significant removal of hemicellulose, and positive environmental impacts; however, several constraints of LHW pretreatment should be clarified. This contribution aims to provide a comprehensive analysis of reaction mechanism, reactor characteristics, influencing factors, techno-economic aspects, challenges, and prospects for LHW-based biomass pretreatment. Generally, LHW pretreatment could be widely employed in bioenergy processing from biomass, but circular economy-based advanced pretreatment techniques should be further studied in the future to achieve maximum efficiency, and minimum cost and drawbacks.

Automated summary

In recent years, lignocellulosic biomass has gained attention as a versatile energy source for biofuels and chemicals production, with biomass pretreatment playing a crucial role in enhancing product quality. Liquid hot water (LHW) pretreatment offers advantages such as minimal monomeric sugar formation and significant hemicellulose removal, but constraints need to be addressed for optimal efficiency. Future research should focus on advanced pretreatment techniques based on circular economy principles to maximize efficiency and minimize costs.