Green Solutions for Biogas Purification: Synergistic Use of Ionic Liquids and Orange peel Biochar

• Grant number: 25/11675-6
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2025
• End date: November 30, 2028
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal Investigator: Luis Alberto Follegatti Romero
• Grantee: Luis Alberto Follegatti Romero
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• City of the host institution: São Paulo
• Associated researchers: Bruna de Souza Moraes ; Murilo Leite Alcantara

Abstract

The growing demand for renewable energy sources has established biogas as a promising alternative. However, its raw composition-characterized by high concentrations of carbon dioxide (CO2) and hydrogen sulfide (H2S)compromises its calorific value and presents significant challenges related to equipment corrosion and emission control. Therefore, the removal of these impurities is essential to produce higher-quality biomethane and to expand its energy applications. This project aims to investigate the synergistic interaction between ionic liquids (ILs) and biochar derived from orange peels to develop novel hybrid materials for sustainable and efficient biogas upgrading. By combining the high surface area and porous structure of biochar with the tunable chemical environment and selectivity of ILs, the resulting hybrids are expected to exhibit enhanced adsorption capacities for key contaminants in biogas, particularly carbon dioxide (CO2) and hydrogen sulfide (H2S). This proposal seeks to support and expand the initiatives of the Paulista Center for Studies in Biogas and Bioproducts - CP2B (Grant 24/01112-1) by investigating strategies to intensify biogas and biomethane production. Initially, the project will focus on selecting ILs with high gas capture (CO2 and H2S) performance, using computational modeling based on the COSMO-SAC approach. The selected ILs will be synthetized and characterized in terms of their physicochemical properties to assess their suitability for biogas purification processes. Subsequently, these ILs will be incorporated into carbonaceous materials (biochar) derived from industrial citrus residues, resulting in low-cost, environmentally friendly hybrid materials. The hybrid adsorbents developed will undergo comprehensive characterization, including morphological analysis (SEM), chemical structure analysis (XRD), specific surface area (SSA/BET) determination, and thermal stability assessment (TGA). Finally, their adsorption efficiency for CO2 and H2S removal will be evaluated under simulated biogas conditions. The outcomes of this project are expected to contribute significantly to the advancement of clean technologies by improving biogas purification processes, promoting the valorization of agro-industrial residues, and strengthening the sustainability of renewable energy systems. (AU)