Efficient chain elongation synthesis of n-caproate from shunting fermentation of food waste

Food waste was used to produce ethanol by yeast fermentation and volatile fatty acids (VFAs) by hydrolytic acidogenesis for chain elongation. Effectiveness of mole ratio of ethanol in yeast fermentation effluent (YFE) to VFAs in hydrolytic acidification effluent (HAE) on chain elongation was examined. The ideal YFE to HAE ratio for chain elongation was 2:1, the highest n-caproate production was 169.76 mg COD/g vS and the food waste utilization was 65.43 %. Electron transfer and carbon distribution did not completely correspond to n-caproate production, suggesting timely product extraction. The abundance of Romboutsia and Clostridium_sensu_stricto_12 increased as chain elongation progressed, which was critical for the chain elongation to n-caproate. The food waste shunting ratio of yeast fermentation to hydrolytic acidogenesis was 6:5, and 572.6 CNY can be created through chain elongation from shunting fermentation of 1 t food waste. This study proposed a new approach for efficient producing n-caproate from food waste.

Automated summary

Yeast fermentation and hydrolytic acidogenesis were used to produce ethanol and volatile fatty acids for chain elongation from food waste. The ideal ratio of ethanol to VFAs for chain elongation was found to be 2:1, with a highest n-caproate production of 169.76 mg COD/g vS and a food waste utilization rate of 65.43%. Electron transfer and carbon distribution did not fully align with n-caproate production, suggesting the need for timely product extraction. The abundance of Romboutsia and Clostridium_sensu_stricto_12 increased as chain elongation progressed, playing a critical role in n-caproate production.