Biofuel production from straw hydrolysates: current achievements and perspectives

Abstract

Straw is an agricultural residue of the production of e.g. cereals, rapeseed or sunflowers. It includes dried stalks, leaves, and empty ears and corncobs, which are separated from the grains during harvest. Straw is a promising lignocellulosic feedstock with a beneficial greenhouse gas balance for the production of biofuels and chemicals. Like all lignocellulosic materials, straw is recalcitrant and requires thermochemical and enzymatic pretreatment to enable access to the three major biopolymers of straw—the polysaccharides cellulose and hemicellulose and the polyaromatic compound lignin. Straw is used for commercial ethanol and biogas production. Considerable research has also been conducted to produce biobutanol, biodiesel and biochemicals from this raw material, but more research is required to establish them on a commercial scale. The major hindrance for launching industrial biofuel and chemicals’ production from straw is the high cost necessitated by pretreatment of the material. Improvements of microbial strains, production and extraction technologies, as well as co-production of high-value compounds represent ways of establishing straw as feedstock for the production of biofuels, chemicals and food.

Recent progress in the conversion of biomass wastes into functional materials for value-added applications

“…Crop straw is promising lignocellulosic raw materials to produce biofuel and some chemicals, but physico-chemical, bio and enzymatic pretreatments are needed due to its chemical constituents and the structure of lignocellulose. For example, biodiesel can be obtained by fast pyrolysis and catalytic liquefaction followed by hydrolysis, fermentation, and alkali catalysis processes [20].…”

Animal Biopolymer-Plant Biomass Composites: Synergism and Improved Sorption Efficiency

“…Major components of biomass often derived from plants or animals include polysaccharides and lignins, where straw and chitosan are common biomaterials derived from plant and animal sources, respectively. Wheat straw is a multicomponent biomass that contains cellulose, hemicellulose, and lignins; whereas chitosan is a single component polysaccharide comprised of β-(1→4)-2-amino-2-deoxy-D-glucopyranose units [3,4]. Studies have shown that valorization of straw [5] often requires energy intensive conversion to yield fuels, along with chemical modification strategies for enhanced utilization as an adsorbent [6,7].…”

Enzymatic Hydrolysis of Sugarcane Bagasse in Aqueous Two-Phase Systems (ATPS): Exploration and Conceptual Process Design

“…The search for alternatives to replace fossil fuels by renewable energy has been seen as a major necessity in modern times (Passoth and Sandgren, 2019 ). In order to reach the requirements established by the Paris Agreement in 2017, net zero greenhouse gases emission must be achieved by 2050 (Pye et al, 2017 ).…”