Compositional Analysis of Lignocellulosic Feedstocks. 1. Review and Description of Methods

TL;DR: In this paper, the chemical composition of pretreated sugarcane bagasse (SCB), in terms of cellulose, hemicellulose and lignin, was analyzed using a fast near-infrared spectroscopy (NIR) technique.

TL;DR: In this article, a combination of approaches was used to characterize the structural and compositional features of wild-type Arabidopsis and mutants with distinct lignin monomer compositions: fah1-2 (Guaiacyl, G-lignin dominant), C4H-F5H (Syringyl, S-lIGNin dominant).

TL;DR: Gamma-valerolactone (GVL) was found to be an effective, sustainable alternative in the lignocellulose defragmentation for carbohydrate isolation and, more specifically, for lignin dissolution as mentioned in this paper.

Abstract: Tertiary cellulose, obtained from wastewater treatment plants, is described herein as an attractive and renewable feedstock for producing bio-based chemicals. It is composed of ca. 57 wt% cellulose and a cellulose-to-hemicellulose weight ratio of approximately 4 (comparable to toilet paper). The enzymatic hydrolysis of tertiary cellulose into glucose over a commercial cellulase enzyme catalyst was studied. At a tertiary cellulose loading of 5 % w/v, the yield of glucose could reach 94 mol% after 72 h of hydrolysis using 30 FPU/g substrate enzyme concentration. The hydrolysis rate was enhanced at higher enzyme dosages. However, the glucose yield tended to decrease at increased solid loadings especially at the late stage of hydrolysis, which is ascribed to high solids effect (e.g., liquid-solid mass transfer limitation and enzyme inhibition). Compared with other cellulosic sources including pulp and Avicel, tertiary cellulose is easily depolymerized and exhibited the highest glucose yield given its lowest crystallinity index. The work further explored the alkaline pretreatment of tertiary cellulose and the use of a fed-batch hydrolysis strategy to enhance the enzymatic saccharification. Pretreated tertiary cellulose using 1 M KOH at 90 °C for 1 h could provide a higher hydrolysis yield (84.6 mol% in 48 h compared with 79.4 mol% for untreated raw materials; using 10 % w/v substrate loading and 30 FPU/g dry substrate enzyme), though at the cost of a concomitant cellulose loss to some degree during the pretreatment. Despite the presence of scale-up effects, the advantages of fed-batch operation could be seen from the more or less constant glucose production rate maintained between consecutive batches, possibly due to the mitigated high solids effect and improved enzyme performance.

TL;DR: Here, the natural resistance of plant cell walls to microbial and enzymatic deconstruction is considered, collectively known as “biomass recalcitrance,” which is largely responsible for the high cost of lignocellulose conversion.

TL;DR: In this paper, a simple and rapid method for the preparation of alditol acetates from monosaccharides is described, which can be performed in a single tube without transfers or evaporations.

TL;DR: In this paper, an update of NREL's ongoing process design and economic analyses of processes related to developing ethanol from lignocellulosic feedstocks is presented, along with a cost basis for the process using a corn stover feedstock.