Liquid hot water pretreatment of multi feedstocks and enzymatic hydrolysis of solids obtained thereof

Abstract

Agricultural feedstocks (brewers' spent grain - BSG, corncob - CC, corn husk - CH, wheat straw - WS and Luffa sponge - LS) were pretreated by liquid hot water (LHW) in order to increase cellulose recovery and enzymatic saccharification. LHW-pretreatment resulted in hemicellulose solubilization, and solids enriched in cellulose. Chemical analysis showed different susceptibilities of the feedstocks to LHW-pretreatment and enzymatic hydrolysis. Pretreated feedstocks presented higher crystallinity (determined through X-ray diffraction) and thermal stability (determined through thermogravimetric analysis) than untreated feedstocks. SEM images confirmed the effect of LHW-pretreatment on structural changes. Moreover, enzymatic hydrolysis and cellulose conversion to glucose (CCG) were improved for pretreated feedstocks, with exception of LS. CCG (in relation to glucose potential on solids) followed the order: BSG>CH>WS>CC>LS. LHW-pretreatment showed to be a good technology to pretreat multi feedstocks and for improving the enzymatic hydrolysis of recalcitrant agricultural feedstocks to sugars, which can be further converted to ethanol-fuel and other value-added chemicals.

Biorefinery cascade processing for creating added value on tomato industrial by-products from Tunisia

“…Generally, LHW treatment is known to solubilize mainly the hemicellulose fraction of biomass [4]. Therefore, TS which contained much more hemicellulose tended to submit more hydrolysis as compared to TP.…”

“…Importantly, a compromise should be made between carotenoid, oil, and protein extractions and sugars hydrolysis. A supplementary enzymatic hydrolysis step might be efficient for improving the hydrolysis of sugars from cellulose and hemicellulose fractions of PT-TP and PT-TS [4, 37, 48]. Moreover, a flow-through method can be investigated for the hydrolysis of tomato industrial by-products, as this reactor configuration had been considered superior to batch methods for the solubilization of biomass in LHW treatment [27].…”

“…Being available in large quantities and non-competitive with the food industry, the agro-industrial by-products become more and more interesting as raw materials for such refineries [4]. In the context of tomato agriculture, worldwide, million tons are industrially processed yearly resulting in large amounts of residues that are estimated around 4% of the total processed tomatoes [5, 6].…”

“…Interestingly, the hydrolysis with liquid hot water (LHW) , a physicochemical process using pressurized water, is picking up an expanding consideration as an environmentally friendly technique. Effectively, LHW has an extensive variety of applications, such as extraction, hydrolysis, and wet oxidation of organic compounds [4, 25, 27]. …”

Factors Affecting Enzymatic Hydrolysis from Pretreated Fibre Pressed Oil Palm Frond Using Sacchariseb C6

“…Different geographic locations, climate, and soil conditions can also be the reasons for the variations in the chemical composition among them. 5,6 In this study, fibre pressed oil palm frond (FPOPF) was introduced as a raw material where the hemicellulose and cellulose were converted into simple sugars. In order to improve the accessibility of cellulase enzyme on FPOPF, the structure of the lignocellulose must be broken down, i.e., by alkaline pretreatment.…”