Reduction in environmental impact of sulfuric acid hydrolysis of bamboo for production of fuel ethanol.

Zhao-Yong Sun, Yue-Qin Tang, Shigeru Morimura, Kenji Kida

Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto City, Kumamoto 860-8555, Japan.

Bioresource technology 2013 Jan

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Fuel ethanol can be produced from bamboo by concentrated sulfuric acid hydrolysis followed by continuous ethanol fermentation. To reduce the environmental impact of this process, treatment of the stillage, reuse of the sulfuric acid and reduction of the process water used were studied. The total organic carbon (TOC) concentration of stillage decreased from 29,688 to 269 mg/l by thermophilic methane fermentation followed by aerobic treatment. Washing the solid residue from acid hydrolysis with effluent from the biological treatment increased the sugar recovery from 69.3% to 79.3%. Sulfuric acid recovered during the acid-sugar separation process was condensed and reused for hydrolysis, resulting in a sugar recovery efficiency of 76.8%, compared to 80.1% when fresh sulfuric acid was used. After acetate removal, the condensate could be reused as elution water in the acid-sugar separation process. As much as 86.3% of the process water and 77.6% of the sulfuric acid could be recycled. Copyright © 2012 Elsevier Ltd. All rights reserved.

Citation

Zhao-Yong Sun, Yue-Qin Tang, Shigeru Morimura, Kenji Kida. Reduction in environmental impact of sulfuric acid hydrolysis of bamboo for production of fuel ethanol. Bioresource technology. 2013 Jan;128:87-93