Estimation of Bioethanol, Biohydrogen, and Chemicals Production from Biomass Wastes in Brazil

The aim of this study is to evaluate the potential of some selected biomass waste to be used as feedstock in the production of bioethanol and biohydrogen along with chemicals in Brazil. The substrates are rice bran (RB), rice husk (RH), brewer's spent grain (BSG), soybean waste (SW), and wheat waste (WW). These substrates are treated by diluted acid hydrolysis in an autoclave under different conditions of acid concentration, temperature, reaction time, and moisture. The highest concentration of reducing sugars (RS) of RH, RB, BSG, SW, and WW hydrolysates, measured by the 3,5‐dinitrosalicylic acid method (DNS), is 118.16 ± 2.85, 170.39 ± 20.47, 600.97 ± 23.05, 80.38 ± 2.39, and 228.04 ± 3.97 gRS kg−1substrate (dry basis), respectively. Total sugar concentration (cellobiose, glucose, xylose, arabinose) in the RH, RB, BSG, SW, and WW hydrolysates (with highest concentration of RS) is 56.54 ± 3.65, 42.99 ± 0.84, 72.18 ± 2.34, 42.48 ± 0.18, and 78.03 ± 3.06 gsugar kg−1substrate (dry basis). The total potential of bioethanol and biohydrogen production from the biomass assessed is 199.61 million L per year and 96.14 million m3 per year, respectively. Therefore, the assessed biomass is proved to be a potential biorefinery feedstock. The potential of bioethanol and biohydrogen production in Brazil from rice bran, rice husk, brewer´s spent grain, soybean waste, and wheat waste is 199.61 million L per year and 96.14 million m3 per year, respectively. Lignocellulosic biomass is proved to be a potential biorefinery feedstock, which can contribute to replace fossil feedstocks in the production of fuels and chemicals.