The integration of dilute acid hydrolysis of xylan and fast pyrolysis of glucan to obtain fermentable sugars

The enrichment of sugars and phenols from fast pyrolysis of bamboo via ethanol-Fenton pretreatment

The high-purity compounds (e.g., sugars and phenols) are important raw materials and chemicals, which can be produced by biomass pyrolysis. However, the direct biomass pyrolysis produces complex compounds and thus inhibiting its large-scale utilization. To increase the yield and enrichment of sugars and phenols, a green coupling process based on ethanol-Fenton pretreatment combined with fast pyrolysis is firstly proposed. The bamboo was effectively separated into the ethanol-Fenton pretreated bamboo (EF-bamboo), lignin-rich fractions, and hemicellulose-degradation intermixtures with the massive removal of inorganic metals via this process. Compared with the fast pyrolysis of raw bamboo, the levoglucosan yield of EF-bamboo increased 5.4 times and the enrichment of sugars improved from 7.6% to 59.7%. Similarly, the yield of monophenols from lignin-rich fractions increased around 0.6 times and the enrichment of monophenols increased from 25.7% to 63.5%. This work provides a green and efficient route to produce high-yield and high-enrichment sugars and phenols.

Effect of Glycerol Pretreatment on Levoglucosan Production from Corncobs by Fast Pyrolysis

In this manuscript, glycerol was used in corncobs' pretreatment to promote levoglucosan production by fast pyrolysis first and then was further utilized as raw material for chemicals production by microbial fermentation. The effects of glycerol pretreatment temperatures (220⁻240 °C), time (0.5⁻3 h) and solid-to-liquid ratios (5⁻20%) were investigated. Due to the accumulation of crystalline cellulose and the removal of minerals, the levoglucosan yield was as high as 35.8% from corncobs pretreated by glycerol at 240 for 3 h with a 5% solid-to-liquid ratio, which was obviously higher than that of the control (2.2%). After glycerol pretreatment, the fermentability of the recovered glycerol remaining in the liquid stream from glycerol pretreatment was evaluated by Klebsiella pneumoniae. The results showed that the recovered glycerol had no inhibitory effect on the growth and metabolism of the microbe, which was a promising substrate for fermentation. The value-added applications of glycerol could reduce the cost of biomass pretreatment. Correspondingly, this manuscript offers a green, sustainable, efficient and economic strategy for an integrated biorefinery process.

Quantitative characterization of enzyme adsorption and hydrolytic performance for ultrafine grinding pretreated corn stover

Quantitative analysis of enzyme adsorption and hydrolysis were performed for sieve-based grinding corn stover (SGCS) and ultrafine grinding corn stover (UGCS)¹ with different enzyme consumptions. The UGCS presented significantly higher enzyme adsorption quantity (5.15mg/g for UGCS, 1.33mg/g for SGCS), higher glucose yield (49.75% for UGCS, 28.75% for SGCS) under 20FPU/g and higher binding enzyme proportion (41.32% for UGCS, 10.64% for SGCS under 5FPU/g) which can be attributed to the more accessible microstructure properties. The relationship between enzyme adsorption and hydrolytic production was directly proportional for SGCS (GY₁=21.04×AQ₁+1.86 (R²=0.95)) while was exponential for UGCS (GY₂=49.42×(1-e^-0.57×AQ₂) (R²=0.99)),² indicating that overmuch enzyme consumption was not advisable for UGCS at economical aspect.