Process intensification for the recovery of methane-rich biogas from dry anaerobic digestion of acai seeds

Author(s)

Sganzerla, William G. ; Ampese, Larissa C. ; Parisoto, Thuanny A. C. ; Forster-Carneiro, Tania

• Document type: Journal article
• Source: BIOMASS CONVERSION AND BIOREFINERY; v. N/A, p. 14-pg., 2021-07-06.

Abstract

Anaerobic digestion (AD) can be a suitable alternative for industrial waste treatment and energy recovery. In this study, the AD of acai seeds was evaluated under mesophilic temperature and dry regime. The stirred-tank reactor, composed of acai seeds (25%), inoculum (45%), and water (30%), was started up and operated in batch mode for 40 days. The results demonstrate that the total solids' biodegradation reached 59.38%, and the accumulated biogas produced was higher than 6 L. A stable methane content was obtained after 22 days of digestion, with a composition of around 60%. The experimental methane yield (156.65 mL-CH4-g(-1) TS) was higher than the theoretical methane yield (116.36 mL-CH4-g(-1) TS), demonstrating that the dry AD process was favorable to methane production. From the biogas combustion in a heat and power unit, 21.88 kWh of electricity and 98.48 MJ of heat could be produced from 1 ton of acai seeds submitted to dry AD, mitigating a total of 7.15 x 10(-3)-tCO(2eq). From the proposed industrial process intensification, the adoption of dry AD could supply 43.19% of the energy required by the acai processing industry. Hence, the AD can be a technological route for bioenergy recovery, contributing for reducing the acai industry's carbon footprint while promoting environmental, social, and economic benefits for the local sustainable development. (AU)

• FAPESP's process: 18/05999-0 - Waste2energy: integration of the supercritical and anaerobic digestion technologies for the management of water and food waste
• Grantee: Tânia Forster Carneiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/26925-7 - Development of an automated system for biofuel precursor production using sub-critical technology
• Grantee: William Gustavo Sganzerla
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 18/14938-4 - Waste2energy: integration of supercritical technologies and anaerobic digestion through an automated system for the production of biofuel precursors
• Grantee: Tânia Forster Carneiro
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2