Alkaline delignification of lignocellulosic biomass for the production of fermentable sugar syrups

Abstract

The objective of this study to analyze the effect of alkaline pretreatment on the structure, composition, and subsequent hydrolysis of agricultural wastes. An increase in the content of reducing sugars after the pretreatment is achieved. Its effectiveness is confirmed, offering a practical procedure to produce alternative energy. Factors such as the calcium hydroxide concentration (0.1 and 0.5g Ca(OH)2/g-dry matter), liquid to solid ratio (12 and 28ml/g-dry matter), temperature (40 and 70°C), stirring rate (0 and 200rpm), an average particle size (0.45 and 1.015mm) were assessed using an experimental design. On average, kikuyo grass had the highest lignin removal (28.31%) while the African oil palm fiber had the lowest value (14.10%). The average particle size was a statistically significant factor for the pretreatment of African oil palm fiber, the stirring rate was an important factor during the pretreatment of kikuyo grass. The Ca(OH)2 concentration had a major effect on the pretreatment of sugarcane bagasse and coffee pulp waste.

Optimization of pretreatment in delignification of hyacinth biomass for ethanol production

“…Alkali application is able to alter the structure of lignin by degrading ester and glycosidic side chains, cellulose swelling, and partial cellulose recrystallization (Kim et al 2014). Previous studies on alkaline pretreatment have shown its effectiveness in a variety of modes and conditions with treatment times on the order of hours and days rather than minutes or seconds (Fuertez-Córdoba et al 2021). In this work, sodium hydroxide pretreatment showed the highest performance in delignification process, followed by calcium hypochlorite, and sulfuric acid pretreatments.…”

“…Size reduction may provide better results but very fine particle size may impose negative effects on the subsequent processing such as enzymatic hydrolysis. Effectiveness of pretreatment was determined the substrate structure and composition of lignocellulosic biomass as well as pretreatment conditions (Fuertez-Córdoba et al 2021). Pyrolysis is an endothermic process where less input of energy is required.…”

Comparative Analysis of Acidic and Alkaline Pretreatment Techniques for Bioethanol Production from Perennial Grasses

“…Alkaline pretreatment involves the utilization of alkaline bases such as sodium hydroxide (NaOH), potassium (KOH), calcium hydroxide (Ca( OH) 2 ) , and ammonia hydroxide (NH 4 OH), among others. A notable feature is its operation under mild temperature and pressure conditions, minimizing sugar degradation and inhibitory compounds formation [12,95]. The primary outcome of alkaline pretreatment is disintegration of the cell wall, which is achieved by dissolving polysaccharides and inducing chemical swelling, leading to the disruption of linkages between lignin and carbohydrates, ultimately removing lignin.…”

Bottle Gourd (Lagenaria vulgaris) Shell as a Natural, Biodegradable, Highly Available, Cheap, Agricultural by-Product, Miscellaneous Biomass, Ion Exchanger, Biosorbent and Fertilizer

“…Pretreatment of lignocellulosic biomass involves partial delignification, and then depolymerization of hemicellulose, using appropriate reagents and optimal pretreatment conditions [33]. Delignification and depolymerization of hemicellulose increases biomass porosity, which during sorbent synthesis will enable better accessibility of agents for more efficient conversion of cellulose to the desired product.…”