Sustainable bioprocess combining subcritical water pretreatment followed by anaerobic digestion for the valorization of jabuticaba (Myrciaria cauliflora) agro-industrial by-product in bioenergy and biofertilizer

Author(s)

da Rosa, Rafael Gabriel ; Sganzerla, William Gustavo ; Barroso, Tiago Linhares Cruz Tabosa ; Castro, Luiz Eduardo Nochi ; Berni, Mauro Donizetti ; Forster-Carneiro, Tania

• Document type: Journal article
• Source: FUEL; v. 334, p. 15-pg., 2023-02-15.

Abstract

The management of agri-food by-products has received worldwide attention due to concerns about the environmental impacts caused by incorrect deposition. This study presented a sustainable bioprocess combining subcritical water pretreatment (SWP) followed by semi-continuous anaerobic digestion (AD) for the valorization of jabuticaba (Myrciaria cauliflora) agro-industrial by-product in bioenergy and agricultural fertilizer. The SWP was conducted at 180 degrees C, 15 MPa, water flow rate of 10 mL min-1, solvent to feed of 22.5 g g-1, and a kinetic time of 45 min. The AD process was operated in semi-continuous mode under mesophilic and methanogenic conditions. The results demonstrated that the hydrolysate presented glucose (5.78 g L-1), fructose (3.63 g L-1), arabinose (1.82 g L-1), and cellobiose (1.28 g L-1) as major compounds. The use of pretreated jabuticaca byproduct increased the methane yield (239.04 L CH4 kg-1 TVS) in the designed bioprocess combining SWP and AD when compared to the AD without pretreatment (42.31 L CH4 kg-1 TVS). The methane produced in the bioprocess with SWP followed by AD can generate 543 kWh t-1 of electricity and 2,243.17 MJ t-1 of heat, avoiding a total of 177.54 kg CO2-eq t-1. The digestate generated after AD can be used as a biofertilizer up to a concentration of 0.3 g L-1, without toxic effects on the germination of Lactuca sativa. Finally, the sustainable bioprocess designed could be an alternative to the management of jabuticaba by-product within a circular economy framework, producing bioenergy and agricultural fertilizer that can reduce greenhouse gas emissions and environmental pollution in the food industry. (AU)

• 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: 20/16248-5 - Purification of jabuticaba waste extracts by adsorbents and biochar using supercritical technology
• Grantee: Tiago Linhares Cruz Tabosa Barroso
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 21/04096-9 - Integration of the extraction/hydrolysis processes in subcritical water and purification for the valuation of grape bagasse in a biorrefinery concept
• Grantee: Luiz Eduardo Nochi de Castro
• Support Opportunities: Scholarships in Brazil - Doctorate