Optimization of Hemicellulose Recovery from Rice Straw for Biorefinery: Dilute Acid Pretreatment at Reduced Temperatures

Sustainable application of rice-waste for fuels and valuable chemicals-a mini review

“…In general, the rice waste mainly includes the rice husk and the rice straw. As reported in previous studies, 1 kg of harvested rice grain is accompanied by 1-1.5 kg of rice straw, and an ideal milling process can produce around 20% of rice husk (Abraham et al, 2016;Wanninayake et al, 2021;Shaheen et al, 2022). That means over 750-1,125 million tons of rice straw and around 150 million tons of rice husk are produced as rice waste every year around the world.…”

“…Moreover, the sodium hydroxide pretreated rice straw was found to provide higher yields of levulinic acid (65.5%) and formic acid (75.8%) than untreated rice straw (levulinic acid: 49.8%; formic acid: 50.5%) (Ukarde and Pawar, 2022). Typically, these organic acids are produced along with the furan derivatives (Wanninayake et al, 2021). To convert these derivatives into acids, Peng et al developed a one-pot chemo-enzymatic reaction system utilizing Snsepiolite catalyst and immobilized E. coli TS whole-cell biocatalyst for the efficient synthesis of furoic acids from alkali pretreated rice straw (Peng et al, 2019).…”

“…Agricultural waste, including corn stoves (leaves, stalk, and cobs), wheat straw, rice straw, rice husk, and bagasse (sugarcane), etc., is abundant with a world production of 5.1 billion tons per year in dry weight (Ho et al, 2014;Biswas et al, 2017). Particularly, the utilization of rice waste (Oryza sativa) is highly desired in many Asia countries such as China, India, Indonesia, Vietnam, etc., where rice is the main food crop (Wanninayake et al, 2021). In general, the rice waste mainly includes the rice husk and the rice straw.…”