Effects of Physical Pretreatment by a Continuous Twin Screw-driven Reactor (CTSR) on the Enzymatic Hydrolysis of Miscanthus sinensis var. purpurascens

Pretreatment techniques have generally been divided into three distinct categories: physical (mechanical), chemical, and biological pretreatment. The objective of a mechanical pretreatment is to reduce the particle size and crystallinity. Mechanical comminution primarily disrupts cellulose crystallinity, decreases the degree of polymerization (DP), and increases the specific surface area of the cellulosic biomass by breaking down the biomass into smaller particles, which renders the substrate more amenable to subsequent enzymatic hydrolysis. Continuous pretreatment process with a continuous twin screw-driven reactor (CTSR) is a novel and promising pretreatment method which can provide a unique and efficient reaction environment for the fractionation of lignocellulosic biomass. The thermo-mechanical energy provided by the continuously stirred screws in CTSR, which causes the shear forces, can be applied to the continuous pulverization of biomass, thus improving the overall rate of biomass conversion. Miscanthus was pretreated by a CTSR with process variables such as barrel temperature, screw rotational speed, and screw configuration that will enable to optimize the overall process. Size reduction through CTSR process effectively promoted the enzymatic hydrolysis of pretreated Miscanthus. Meanwhile, the crystallinity of the physically pretreated Miscanthus was not a greater factor affecting the enzymatic digestibility.