Open AccessEffect of Dilute-acid Hydrolysis Conditions on Sugar and Productions from Paragrass
Author(s) -
Vipa Thongtus,
Sasikarn Nuchdang,
Papin Chirathivat,
Elvin J. Moore,
Chantaraporn Phalakornkule
Publication year - 2019
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/265/1/012010
Subject(s) - furfural , chemistry , xylose , hydrolysate , hydrolysis , hemicellulose , hydroxymethylfurfural , sugar , enzymatic hydrolysis , reducing sugar , yield (engineering) , nuclear chemistry , organic chemistry , chromatography , fermentation , catalysis , materials science , metallurgy
In this study, the productions of sugars as well as inhibitory compounds, e.g hydroxymethylfurfural (HMF) and furfural, from paragrass ( Brachiaria mutica ) were investigated using dilute acid hydrolysis. Sulphuric acid concentration of 1.0, 1.2, 1.5 and 2.0 wt% and reaction temperature of 120, 130, 140 and 150 °C for either 30 or 60 min were investigated. Xylose was found to be the major product at a maximum yield of 99±3 mg/g grass using 1.2 wt% H 2 SO 4 and reaction temperature of 140 °C for 30 min. Analysis of variance (ANOVA) showed that for the reaction temperature between 120-140 °C, sulphuric acid concentration was the most important factor affecting the yields of hemicellulose sugars from paragrass. However, the temperature ≥ 150 °C caused the marked drop in all sugar compounds. At the optimal condition, the concentration of HMF was 0.16 g/l and furfural 0.09 g/l. The formation of HMF and furfural was almost linearly increased with increasing hydrolysis temperature between 120 and 150 °C. Furthermore, longer reaction times led to higher levels of HMF and furfural. The dilute acid hydrolysis in series with enzyme saccharification of paragrass yielded 122 mg total reducing sugar (TRS) per g grass in the enzyme hydrolysate.