Maximizing the energy recovery from rice straw through two-step conversion using eggshell-catalytic pyrolysis followed by enhanced anaerobic digestion using calcium-rich biochar

Shah Faisal; Reham Ebaid; Min Xiong; Jin Huang; Qingyuan Wang; Mohamed El-Hefnawy; Abdelfatah Abomohra

doi:10.1016/j.scitotenv.2022.159984

Maximizing the energy recovery from rice straw through two-step conversion using eggshell-catalytic pyrolysis followed by enhanced anaerobic digestion using calcium-rich biochar

Sci Total Environ. 2023 Feb 1;858(Pt 3):159984. doi: 10.1016/j.scitotenv.2022.159984. Epub 2022 Nov 8.

Authors

Shah Faisal¹, Reham Ebaid², Min Xiong³, Jin Huang³, Qingyuan Wang⁴, Mohamed El-Hefnawy⁵, Abdelfatah Abomohra⁶

Affiliations

¹ Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, PR China; Institute of New Energy and Low-carbon Technology, Sichuan University, Chengdu 610065, PR China.
² Institute of New Energy and Low-carbon Technology, Sichuan University, Chengdu 610065, PR China.
³ Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, PR China.
⁴ Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, PR China; Institute of New Energy and Low-carbon Technology, Sichuan University, Chengdu 610065, PR China. Electronic address: wangqy@scu.edu.cn.
⁵ Department of Chemistry, Rabigh College of Science and Arts, King Abdulaziz University, Rabigh 21911, Saudi Arabia; Chemistry Department, Faculty of Science, Tanta University, Tanta 31527, Egypt.
⁶ Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, PR China. Electronic address: abomohra@cdu.edu.cn.

PMID: 36356751
DOI: 10.1016/j.scitotenv.2022.159984

Abstract

Anaerobic digestion of lignocelluloses for biogas production is greatly restricted by the poor biomass degradability. Herein, a novel approach is suggested to enhance the energy recovery from rice straw through a two-step conversion using eggshell-based catalytic pyrolysis followed by biochar-based anaerobic co-digestion. Pyrolysis with eggshell significantly enhanced the crude bio-oil yield by 4.6 %. Anaerobic digestion of rice straw using 4 g L^-1 of rice straw biochar (RB) showed the highest recorded biogas yield of 503.7 L kg^-1 VS, with 268.6 L kg^-1 VS biomethane yield. However, 4 g L^-1 of calcium-enriched eggshell rice straw biochar (ERB) enhanced the biomethane yield to 281.8 L kg^-1 VS, which represented 95.6 % higher than the control. It was attributed to enhancement of biomethanation, which resulted in 74.5 % maximum recorded biomethane content at the 7th day of anaerobic digestion. Microbial analysis confirmed that Methanosarciniales was the most dominant Archael group in the control (14.84 %), which increased sharply to 73.91 % and 91.66 % after addition of 4 g L^-1 RB and ERB, respectively. The suggested route enhanced the energy recovery in the form of bio-oil and biomethane by 41.6 %.

Keywords: Biocrude; Biomethane; Biorefinery; Green energy; Integrated approaches.

MeSH terms

Calcium*
Oryza*

Substances

Bio-Oil
Calcium