Techno-economic and life cycle assessments for bioenergy recovery from acid-hydrolyzed residues of sugarcane bagasse in the biobased xylose production platform

The acid-hydrolyzed residues of lignocellulosic biomass are the primary organic solid wastes during xylose production, while their management and/or valorization have often been overlooked. Here, based on the xylose production platform, four scenarios were established for techno-economic and life cycle assessments (TEA-LCA) of sugarcane bagasse-derived hydrolysis residue obtained from H2SO4 pretreatment, including landfill (baseline), incineration with cogeneration system, bioethanol production, and biomethane production. According to the TEA results, the landfill scenario exhibited the lowest economic benefits, with an internal rate of return (IRR) 18.8% and a net present value (NPV) of 23,270,090 $. In contrast, the incineration scenario showed the best economic results, with IRR and NPV improving by 4.7% and 68.8%, respectively. The bioethanol and bio-methane scenarios exhibited an IRR of 0.2% and 2.2% higher than the IRR of the landfill, respectively. Furthermore, the economics of all four scenarios were sensitive to plant capacity, hemicellulose to xylose con-version rate, and xylose price. The LCA showed that landfill was the worst option, followed by bioethanol and incineration, while the biomethane scenario reduced 39.3% of the adverse impacts using the ReCiPe single score, as it avoided a higher amount of production of synthetic fertilizer and natural gas. The environmental perfor-mance was sensitive to the conversion rate of hemicellulose to xylose as per the sensitivity analysis. This study indicated that the valorization of acid-hydrolyzed residues into bioenergy was attractive for the xylose plant, and give the decision-makers a clear perspective for developing a sustainable disposal policy for acid-hydrolyzed residues.