CO-DIGESTION OF SUGARCANE, CITRUS WASTE, AND CATTLE DUNG IN LEACH BED REACTORS: PROCESS OPTIMIZATION FOR LARGE-SCALE APPLICATION

• Grant number: 24/18476-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2025
• End date: May 31, 2028
• Field of knowledge: Engineering - Sanitary Engineering - Environmental Sanitation
• Principal Investigator: Sandra Imaculada Maintinguer
• Grantee: Vitor Alves Lourenço
• Host Institution: Instituto de Pesquisa em Bioenergia (IPBEN). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Associated research grant: 17/22401-8 - Fruit-refinery: obtention processes, characterization methods and generation of products derived from residues of the fruitculture, AP.TEM

Abstract

The use of leach bed reactors (LBRs) is a promising alternative for dry anaerobic digestion, as they can be installed on farms or in agricultural regions to valorize organic waste generated for bioenergy production. However, there is a limited number of experimental studies published on the use of agro-industrial waste in LBRs for biogas production, with most of these being conducted in Europe, North America, and Asia. Therefore, there is a notable need for investigating the use of domestic agro-industrial waste in this type of reactor configuration. Due to the presence of farms with cattle farming and the cultivation of sugarcane and oranges in the interior of São Paulo state, as well as industries processing these products, the present project aims to investigate the co-digestion of organic solid waste generated from some of these activities. First, the best inoculation strategy for LBRs fed with sugarcane straw and cattle dung will be investigated. Then, in batch assays, the ratio between substrates and inoculum, along with the addition of sugarcane bagasse, orange peel, and bagasse, will be evaluated. After optimization via a central rotational composite design two optimized conditions will be used for LBR operations. The best condition will be applied in sequential LBRs with one leachate tanks and other with two. Thus, the central objective of this project is to investigate the anaerobic co-digestion of cattle dung and solid waste from the sugarcane and orange processing industries in LBRs, with an emphasis on methane production and the potential for large-scale adoption. To this end, the influence of different strategies and conditions on methane yield and production kinetics, microbial community, metabolic pathways involved in the process, and the energy and economic feasibility for its future large-scale application will be evaluated.