Hydrothermal Liquefaction and Methanogenesis in the Valorization of Solid Waste from Orange Juice Production

• Grant number: 23/17827-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2025
• End date: March 31, 2026
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Giovana Tommaso
• Grantee: Isac Antonio Alcantara Queiroz
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 22/10615-1 - Consolidation of the biorefinery concept applied to the biological treatment of wastewater and solid wastes, AP.TEM

Abstract

Oil is used in the manufacturing of numerous products worldwide, causing direct impacts on fauna, flora, and contributing to global warming. Due to the dependence on the use of this input and the possibility of scarcity, public policies for investment in the production of biofuels are being developed in the search for high-yield inputs and processes. Hydrothermal liquefaction (HTL) can be used for the conversion of agro-industrial waste into bio-oil; however, the wastewater (HTLW) from this process is produced abundantly and with characteristics that complicate its treatment. The objective of this project is to combine the hydrothermal liquefaction of solid waste from orange juice production (OSW) and anaerobic digestion of wastewater for the valorization of this waste and bioenergy production. The project will have the following steps: 1. Characterization of orange industrial waste; 2. Implementation of HTL by Experimental Design to define the best process conditions; 3. Characterization of HTLW; 4. Implementation of AD for HTLW treatment. The parameters tested for hydrothermal liquefaction during the experimental design will be solid concentration (1:5; 1:12.5; 1:20 (v/m)), reaction time (10, 20, and 30 min), and temperature (260, 280, and 300 ºC), with 8 trials and triplicate at the central point. The response variables will be the yield of bio-oil, wastewater, and bio-char, and the concentration of organic matter and total phenolics in wastewater. All generated wastewater will be evaluated in terms of organic matter concentration, total phenolic compounds, Nitrogen Series, and Anaerobic Biodegradability. Process stability will also be assessed in relation to the production of metabolites (short-chain volatile acids). Finally, an energy balance will be constructed to understand the energy flow in the coupling of the two processes. It is believed that this work has the potential to offer an alternative for the use of orange pulp without the need for drying or pelleting to meet the production of two important fuels that will contribute to diversifying the country's energy matrix.