Effective ethanol production by reutilizing waste distillage anaerobic digestion effluent in an integrated fermentation process coupled with both ethanol and methane fermentations.
An integrated ethanol-methane fermentation coupled system characterized with full wastewater reutilization was proposed. The waste distillage originated from ethanol distillation was treated with anaerobic digestion and then recycled for medium preparation in the next ethanol fermentation run. This process could enhance wastewater reutilization, save fresh water and reduce energy consumption in the cassava-based ethanol production. The results indicated that, when using anaerobic effluents from the digestion process with only one tank, an ethanol concentration of 10.5% (v/v) compatible with that of conventional one could be achieved, but ethanol fermentation was partially inhibited and operation time gradually prolonged from 48 to 105 h. Using anaerobic effluents from the digestion process with two subsequently connected tanks, ethanol fermentation performance could be largely improved, and the fermentation lag could be completely eliminated. The performance enhancement was due to the concentrations reduction in organic acids, such as acetic and propionic acids in the digestion effluents using two digestion tanks in-series.
Zhang
Cheng Ming
CM
The Key Laboratory of Industrial Biotechnology, Ministry of Education, Fermentation and Ecological Engineering Laboratory, School of Biotechnology, Jiangnan University, Wuxi, China.
Mao
Zhong Gui
ZG
Wang
Xin
X
Zhang
Jian Hua
JH
Sun
Fu Bao
FB
Tang
Lei
L
Zhang
Hong Jian
HJ
D019342:Acetic Acid / Q000737:chemistry; D000693:Anaerobiosis; D002241:Carbohydrates / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry*; D005285:Fermentation; D002365:Manihot / Q000378:metabolism; D008697:Methane / Q000737:chemistry*; D011422:Propionates / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
D002241:Carbohydrates; D011422:Propionates; D014874:Water Pollutants, Chemical; D000431:Ethanol; C029658:propionic acid; D008697:Methane; D019342:Acetic Acid