A review of the thermal pretreatment of lignocellulosic biomass towards glucose production: Autohydrolysis with DIC technology

Abstract

There is increasing demand for the production of biofuels from lignocellulosic biomass. Lignocellulosic biomass consists mainly of three polymeric components: cellulose, hemicelluloses, and lignin. The separation of these components requires an effective pretreatment process to ensure high quality glucose production, and is highly influenced by several factors, including moisture content, cellulose crystallinity, lignin content, and available surface area. Over time, numerous pretreatment methods have been utilized to change the lignocellulosic fiber structure and to enhance the enzymatic saccharification of cellulose to polysaccharides. This article reviews thermal-based pretreatment of lignocellulosic fiber used for glucose production. Based on the reviewed studies, autohydrolysis of lignocellusic biomass, followed by the “Instant pressure drop (DIC),” method can be regarded as an effective pretreatment process of lignocellusic biomass.

An Overview of Lignocellulose and Its Biotechnological Importance in High-Value Product Production

“…Different processes used in chemical pretreatment methods include dilute acid, alkaline, ionic liquid, organosolv process, ozonolysis, and deep eutectic solvents [60]. In the dilute acid pretreatments, inorganic or organic acids, such as HCl, H 2 SO 4 , HNO 3 , and formic acid, break down the hydrogen and glycosidic bonds in cellulose/hemicellulose [61,62]. Bases such as NaOH, NH 4 OH, Ca(OH) 2 , and KOH are always used in alkaline pretreatment methods to solubilize lignin [3].…”

Investigation of Microwave Irradiation and Ethanol Pre-Treatment toward Bioproducts Fractionation from Oil Palm Empty Fruit Bunch

“…Lignin is synthesized through the polymerization of these three major phenolic compounds, where their ratio within the polymer varies according to the different parts of the plants, such as the wood tissues and cell wall layers [2]. The linkage between lignin and polysaccharides is regarded as a lignin-polysaccharide complex due to the composite links that connect lignin to the polyoses side groups of arabinose, galactose, and 4-O-methylglucoronic acid, as depicted in Figure 7 [22]. Hence, the difficulty in achieving a complete separation of lignin from lignocellulosic materials resulted from the sterically structured component of lignin.…”

“…Hence, the difficulty in achieving a complete separation of lignin from lignocellulosic materials resulted from the sterically structured component of lignin. Thus, a combination of methods, such as a physicochemical method, is typically employed in order for the separation of lignin from lignocellulosic biomass material to be accomplished [22]. The cellulose, hemicellulose, and lignin components form structures known as microfibrils, which are then structurally organized into macrofibrils that are responsible for mediating the structural ability in the cell wall of plants.…”

Cellulose Nanocrystals (CNCs) and Cellulose Nanofibers (CNFs) as Adsorbents of Heavy Metal Ions

“…Hemicellulose is unstable when compared to cellulose and lignin, making it more difcult to hydrolyze [85,86]. Hemicellulose is a compound with an amorphous structure that makes hemicellulose easy to convert into simple sugars through enzymatic and hydrothermal methods [87,88]. Meanwhile, lignin is a complex polymer compound that acts as a barrier that coats cellulose and hemicellulose so that lignin is more difcult to remove.…”