Combined Approaches to Xylose Production from Corn Stover by Dilute Acid Hydrolysis

Abstract

Corn stover is a lignocellulosic biomass, an agricultural by-product, a possible raw material for xylose production. In this study corn stover was hydrolyzed with sulfuric and hydrochloric acid. In the presented work, hydrochloric acid resulted in the highest, 88.8 % xylose yield of theoretical under the conditions of 2 % (w/w) hydrochloric acid concentration, 40-minute reaction time, 10 % (w/w) dry matter, at 120 °C. Sulfuric acid experiments resulted in 81.9 % xylose yield of theoretical by using 1.5 % (w/w) sulfuric acid, 60-minute reaction time, at 140 °C, 7 % (w/w) dry matter. Acid hydrolysis at low dry matter content resulted in relatively low sugar concentrations. Hydrolyzate recycling concentrated xylose to three-times, while the recycling does not decrease the xylose yields. It is also shown that the pseudo first-order and biphasic kinetic models can be based on total sugar concentrations.

Hydrolyzed corn stover as a promising feedstock for 2‐phenylethanol production by nonconventional yeast

“…This increased after pretreatment, thus making this material a promising renewable substrate for the manufacture of value‐added bioproducts. The composition of the raw corn stover was in accordance with previous reports …”

Treatments of Lignocellulosic Hydrolysates and Continuous‐Flow Hydrogenation of Xylose to Xylitol

“…To convert the xylan in the corn stover to xylose, sulfuric acid hydrolysis was performed at 140°C in an autoclave using 7 % dry matter content [14]. The acid concentration and reaction time were 1.5 wt % and 40 min, respectively.…”

“…The concentrated hydrolysate had the following composition: 91 g L -1 glucose, 175 g L -1 xylose, 77 g L -1 arabinose, and 20.2 g L -1 acetic acid. This concentrated hydrolysate was diluted 8.5-fold (experiments 1-12) or 4.5-fold (experiments [13][14][15][16][17][18][19][20] prior to the hydrogenation experiments. In experiments 21-30, the bio-purified hydrolysate was hydrogenated directly without prior concentration, and the hydrolysate had the following composition: 0.23 g L -1 glucose, 12.6 g L -1 xylose, and 1.9 g L -1 arabinose.…”

“…Corn stover is a type of lignocellulosic biomass, an agricultural by-product, and can serve as a possible raw material for xylose production. The main components of corn stover are glucan and xylan, which represent 37 % and 25 %, respectively, of the dry matter [14].…”

“…Besides xylose, considerable amounts of arabinose and glucose can also be found in corn stover [14]. Owing to their susceptibility to hydrogenation, these sugars may influence the yield of xylitol during the hydrogenation and increase the hydrogen consumption.…”