A Study on the Valorization of Rice Straw into Different Value-Added Products and Biofuels
Date
2024-04
Journal Title
Journal ISSN
Volume Title
Type
Article
Publisher
Hindawi Publishing Corporation
Series Info
International Journal of Chemical Engineering;Volume 2024, Article ID 9185870, 22 pages
Scientific Journal Rankings
Abstract
Tis work depicts that rice straw (RS), which is one of the major lignocellulosic wastes all over the world and causing many
environmental problems, has considerable amounts of protein, ash, macronutrients, and micronutrients of approximately 11.38%,
16.77%, 2.27 mg/kg, and 771.9 mg/kg, respectively; besides, a C/N ratio of 15.18, a total N, P2O5, and K2O content of 1.85%, and
a considerably low concentration of undesirable heavy metals and silica of approximately 77.69 mg/kg and 109 mg/kg are also
present, which recommends its applicability as a precursor feedstock for the production of organic fertilizer and animal fodder.
Te batch solid-state fermentation (SSF) of RS by Trichoderma longibrachiatum DSMZ 16517 produced considerable amount of
total reducing sugars (TRS) of approximately 339.2 mg TRS/g RS under the optimum operatic conditions of 20% (w:v) substrate
concentration, pH 7, 1% inoculum size, a 9-day incubation period, and 30°C incubation temperature. Te readily available and
cost-efective agroindustrial waste, sugarcane molasses, proved to enhance the fungal biomass growth and (hemi) cellulolytic
enzymes activities. Te inoculated RS-SSF batch process with T. longibrachiatum precultured on 10% molasses enhanced the
(hemi) cellulolytic enzymatic activities and TRS production rate by approximately 5.82 and 3.8 folds, respectively, relative to that
inoculated by T. longibrachiatum precultured in the conventional potato dextrose broth medium. Te separate hydrolysis and
fermentation processes by diferent yeast strains Candida tropicalis DSM 70156, C. shehatae ATCC 58779, and Saccharomyces
cerevisiae ATCC 64712 revealed an efcient bioethanol yield and productivity that ranged between 0.36 and 0.38 g/g sugars and
0.22 and 0.23 g/L/h, respectively, with concomitant competent fermentation efciencies that ranged between 48.35% and 51.25%.
Te proximate analysis of rice straw before and after fungal hydrolysis proved calorifc values of approximately 15.8 MJ/kg and
16.05 MJ/kg, respectively, recommending their applicability as primary and secondary solid biofuels. Tus, this study proved the
waste prosperity of RS for environmental opulence and sustainability.