Simultaneous pretreatment and enzymatic hydrolysis of sugarcane bagasse in a hydrodynamic cavitation reactor in the presence of surfactants for second-generation ethanol production

• Grant number: 25/15603-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal Investigator: Júlio César dos Santos
• Grantee: Murilo Henrique Zampaulo
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil
• Associated research grant: 23/09789-8 - Decarbonization of transport for the benefit of society: enhancing sustainability with the integration of biochemical and thermal routes in the integral use of biomass, AP.TEM

Abstract

The extensive use of non-renewable carbon and energy sources has led to several environmental issues, such as climate change driven by the increase in the planet's average temperature, which has been mainly attributed to the accumulation of greenhouse gases in the atmosphere as a result of carbon dioxide emissions from fossil fuel combustion. In this context, scientific and technological research efforts have been directed toward the development of biofuels and other environmentally compatible products aligned with a sustainable economy, with solutions based on renewable resources. Among the alternatives, second-generation ethanol stands out, whose production in Brazil can be favored by the abundance of agro-industrial residues and byproducts, such as sugarcane bagasse. To make use of the carbohydrates present in this material, however, it is essential to perform a pretreatment step, which improves the accessibility of cellulose to enzymatic action in the subsequent hydrolysis stage. Despite significant advances over recent decades, this step still represents a technical and economic challenge for the process. Hydrodynamic cavitation is a promising approach for the pretreatment of lignocellulosic materials, as it modifies the material's composition and structure through processes that require low chemical input and short processing times. After pretreatment, the material undergoes enzymatic hydrolysis, generating a liquor rich in fermentable sugars, which can then be converted into ethanol through fermentation. One strategy to optimize costs in biorefineries is the integration of simultaneous processes, reducing overall operation time. Although there have been advances in combining biological steps, studies on the simultaneous implementation of pretreatment and enzymatic hydrolysis are still scarce. In this context, the present project proposes the evaluation of a system that integrates the pretreatment and enzymatic hydrolysis of sugarcane bagasse into a single process assisted by hydrodynamic cavitation, using surfactants to reduce issues related to the non-productive adsorption of enzymes onto the lignin present in the material. Initially, the process will be assessed in simple batch mode using different concentrations of non-ionic surfactants. Subsequently, the system will be operated in fed-batch mode, with the addition of sugarcane bagasse at different processing times. The fermentable sugars produced will be used for ethanol production by the yeast Scheffersomyces shehatae. The implementation of this study may contribute to innovative alternatives for lignocellulosic biomass biorefineries, fostering the development of sustainable technologies in Brazil.