Understanding and technological approach of acid hydrolysis processing for lignocellulose biorefinery: Panorama and perspectives

Lignocellulose is the most abundant biomass resource on Earth and the cheapest raw material to produce biofuels and biochemicals. Even today, acid hydrolysis still shows significant advantages. This paper reviews the representative products of different acids in the bio-refining system of wood fiber raw materials. The advantages and disadvantages of inorganic acid, organic acid and solid acid are compared. The kinetic model of acid hydrolysis process and the mathematical model of integration strategy will also be discussed. Although inorganic acids have been used in the production of commercial cellulosic ethanol, sugar hydrolysis needs to be controlled. Organic acids are beneficial to the production of functional oligosaccharides due to their mildness. Solid acid is a promising pretreatment method with low corrosion, less wastewater, and ease of storage and reuse, but practical applications are still a long way off. Combined pretreatment based on acid hydrolysis can synthesize the advantages of different pretreatment, which may be the focus of future research.