How exothermic characteristics of rice straw during anaerobic digestion affects net energy production. (1st December 2020)

• Record Type: Journal Article
• Authors: Luo, Tao; Khoshnevisan, Benyamin; Pan, Junting; Ge, Yihong; Mei, Zili; Xue, Jian; Fu, Yanran; Liu, Hongbin
• Is Part Of: Energy. Volume 212(2020)
• Publication Date: 2020-12-01
• Subjects: Anaerobic digestion -- Hydrolysis rate -- Self-heating -- Straw; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2020.118772
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: 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. Highlights: Main self-heating occurred between first biogas production peak and disappearance of second peak. Self-heating and CH4 production exhibited a negative correlation. TS content could play an essential role on energy production capacity improvement. Particle size and TS content were found to be possible promising options to control self-heating.