Integrated production of bacterial cellulose and biogas from agro-industrial wastewater: technical feasibility of implementing a biorefinery concept

Author(s)

Albanez, Roberta ; Paulinetti, Ana Paula ; Augusto, Isabela Mehi Gaspari ; Lovato, Giovanna ; Rodrigues, Jose Alberto Domingues ; Ratusznei, Suzana Maria

• Document type: Journal article
• Source: Brazilian Journal of Chemical Engineering; v. N/A, p. 12-pg., 2024-05-15.

Abstract

Bacterial cellulose (BC) is an organic substance produced by bacteria that has shown immense potential as an efficient biopolymer. BC has high potential for diverse applications, but low productivity and high production costs prevent widespread use. Several studies have been conducted recently to develop low-cost fermentation media, encouraging the use of residues and industrial by-products as substrates. Agro-industrial wastewaters can be used as substrates for BC production, including glycerol, vinasse, and whey. Therefore, this study initially aimed to produce BC from these wastewaters. BC was produced by Gluconacetobacter hansenii grown statically at room temperature. The BC media were the same as the Hestrin and Schramm medium, with only the original carbon source (glucose) replaced with agro-industrial residues: glycerol, vinasse, or 50% vinasse + 50% whey. After 28 days of growth, the glycerol medium achieved the highest BC per surface cultivation area and productivity. The second objective of the paper was to treat the effluent from the best condition of BC production (BCE) in an anaerobic sequencing batch reactor (ASBR) to produce biogas. Anaerobic digestion of BCE was carried out in bioreactors containing granular biomass operated at 100 rpm, 30 degrees C, and 24- hour cycle length. At 2.0 g-COD/L, BCE treatment resulted in 77% COD removal efficiency and 2.79 mmol-CH4/L. Experimental data using glycerol allowed the estimation of the maximum potential for BC production on an industrial scale, obtaining 63 tons-BC/month from 5,800 tons-glycerol/year generated by a Brazilian biodiesel industry. The ASBRs required for industrial biogas production from BCE treatment would be 2.8 x 104 m3, and the methane produced could be burned to generate 3.2 x 102 kW. (AU)

• FAPESP's process: 22/01425-4 - Two-stage hydrogen and methane production by the treatment of soybean processing waste (molasses and okara) in thermophilic and mesophilic condition
• Grantee: Isabela Mehi Gaspari Augusto
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 21/13810-7 - Biofuels production in mesophilic and thermophilic anaerobic conditions by soybean molasses treatment
• Grantee: Giovanna Lovato
• Support Opportunities: Regular Research Grants
• FAPESP's process: 22/10615-1 - Consolidation of the biorefinery concept applied to the biological treatment of wastewater and solid wastes
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 22/05522-4 - Operational viability of an AnSBBR in the treatment of sewage: diclofenac and ibuprofen removal
• Grantee: Ana Paula Paoli
• Support Opportunities: Scholarships in Brazil - Doctorate