The self-heating of lignocellulosic biomass, when degraded under anaerobic conditions, has been reportedly observed. Such a phenomenon would cause substrate to show exothermic characteristics which are in contrast to the current thermodynamic or microbiological knowledge. Rice straw (RS), when undergone anaerobic digestion, is prone to self-heating which can increase the reactor temperature according to heat-releasing characteristics, thus improve the net energy production. In the present study, the relationship of biogas production and self-heating release as well as the synergistic effects of two energy production pathways was investigated. Moreover, the optimal process for maximizing the biogas production under self-heating phenomenon was scrutinized. Compared to control assays, a 0.48 °C increase in average temperature was noticed among experimental trials due to RS self-heating phenomenon. The results showed that the self-heating was even improved simultaneous with increased methane production rate. Hydrolysis rate and total solid content were found to be possible promising options to control the self-heating release.
Bibliographical noteFunding Information:
The authors gratefully acknowledge financial support from Fundamental Research Funds for Central Non-profit Scientific Institution (No. G202002-33 ), Open Fund of Key Laboratory of Development and Application of Rural Renewable Energy , Ministry of Agriculture and Rural Affairs, China (No. 2019013 ), Special Fund for Agro-scientific Research in the Public Interest from the Ministry of Agriculture, China (No. 201303089 ), Comprehensive Construction Project on Rural Energy of Ministry of Agriculture and Rural Affairs (No. 2013012619016 ), Comprehensive methods of agricultural non-point source pollution control in typical watershed (No. 13200276 , 13200275 ), the International Clean Energy Talent Program of China Scholarship Council (No. 201802180094 ) and the Agricultural Science and Technology Innovation Program (ASTIP) of the Chinese Academy of Agricultural Sciences.
© 2020 Elsevier Ltd
- Anaerobic digestion
- Hydrolysis rate