Co‐production of biobutanol and biomethane from distillers' grain waste by an integrated process

Abstract

BackgroundDistillers' grain waste (DGW) is the main by‐product in the Baijiu‐making process and its management remains a great challenge for the Baijiu industry. To address this issue, an integrated biobutanol and biomethane production process was established to obtain valuable products from DGW and reduce environmental pollution.ResultsIn the integrated process, DGW was hydrolyzed and detoxified to produce biobutanol, while the distillery waste derived from solvent extraction process was used for biomethane fermentation. After the optimization of overliming detoxification of DGW hydrolysate by artificial neural network and genetic algorithm, totals of 10.65 ± 0.07 g L−1 butanol and 4.51 ± 0.21 g L−1 isopropanol were attained with negligible amounts of acetone and ethanol (i.e. 0.14 ± 0.00 and 0.52 ± 0.06 g L−1, respectively). Anaerobic digestion of the distillery waste was efficient, and the chemical oxygen demand removal rate approached 92.3 ± 0.1% with a methane yield of 167.8 ± 1.2 mL g−1 TCODremoved. Moreover, the anaerobic digestion effluent could be recycled as a potential substitute for process water in biobutanol fermentation without having any negative effect on enzymatic hydrolysis of DGW, and the butanol production also reached 8.19 ± 0.29 g L−1.ConclusionThe present study provides a new idea for comprehensive utilization of DGW towards energy and resource recovery, without secondary pollution. © 2023 Society of Chemical Industry.

Recent Advances in Resource Utilization of Huangshui from Baijiu Production

“…The high concentration of organics of Huangshui with some microorganisms can be used as a substrate or inoculum to treat certain types of organic wastewater for organic pollutant degradation and biofuel production. Wang et al [66] utilized the DSG containing Huangshui to co-produce biobutanol and bioCH 4 , having relatively high costs. Ling et al [11] observed that the antimicrobial activity of Huangshui could promote the oleaginous yeast to become the dominant microbes over undesirable microbes for treating mixed wastewater to produce lipids.…”

“…Using abundant organic substances to synthesize products with high value can obtain the material virtuous cycle in the Baijiu industry [11]. Through innovating food products, optimizing fertilization structure, and paying attention to healthy foods and integrated water and fertilizer, along with eco-friendly management and reutilization strategies, the full utilization of Huangshui can be achieved, with its maximum value, ultimately impelling the sustainable developments and prosperities of the food industry and agriculture fields [10,66]. With the intensification of energy and food crises and water shortages, as well as the increasing demand for environmental protection, the full utilization of high-strength organic wastewater can alleviate the above difficulties.…”