Banca de DEFESA: RAPHAEL RODRIGUES DA SILVA SERPA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RAPHAEL RODRIGUES DA SILVA SERPA
DATE: 24/02/2026
TIME: 14:00
LOCAL: Sala de Aula 01 do PPEAMB, 1º andar do Prédio Antônio Coelho, do Departamento de Tecnologia Rural
TITLE:

Thermochemical pretreatments to optimize the anaerobic digestion of vinasse co-digested with sugarcane bagasse for biogas production.

KEY WORDS:

Scientometric analysis; Biomass; hydrolysis; lignocellulosic residues; methane production.

PAGES: 120
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUMMARY:

The sugar-energy industries play a strategic role in the global economy, particularly in sugar and ethanol production. However, these activities generate high volumes of agro-industrial wastes, such as filter cake, straw, molasses, sugarcane bagasse, and vinasse. Among these byproducts, bagasse and vinasse present the greatest quantitative relevance, with approximately 140 kg of bagasse generated per ton of processed cane and between 12 and 15 m³ of vinasse per cubic meter of ethanol produced. Despite Brazil’s significant role in the global scenario, challenges persist regarding the valorization and environmentally adequate management of these residues, especially bagasse. Several technological routes have been proposed for bagasse utilization; however, many are associated with significant environmental impacts. In this context, anaerobic digestion stands out as a sustainable alternative, aligned with circular economy principles, enabling the energy valorization of the residue through biogas and methane production. Nevertheless, the high structural complexity of sugarcane bagasse requires the application of efficient pretreatments to increase its biodegradability and make its energy conversion viable. This study adopted an integrated approach, comprising a scientometric analysis and experimental investigation. Initially, a scientometric analysis was performed based on 52 scientific articles indexed in the Web of Science database, accessed via the CapesCafe platform, aiming to identify global trends related to bagasse pretreatments. Data were analyzed using VOSviewer software and Microsoft Excel for result organization and graph preparation. Results indicated that Brazil accounts for 33% of the analyzed publications, followed by the United States and Pakistan, with a predominance of studies focused on physicochemical pretreatment methods. In the experimental stage, aiming at bagasse pretreatment and methane production improvement in the anaerobic digestion step, thermo-acidic hydrolysis (using raw vinasse) was used, followed by alkaline hydrolysis (3% NaOH). The anaerobic stage trials were conducted via Biochemical Methane Potential (BMP) tests, using anaerobic inoculum (sludge) in 250 mL batch reactors, operated for 30 days under mesophilic conditions. The optimized configuration, post-pretreatments, containing 5 g of bagasse and 45 mL of vinasse, presented the highest yield, reaching 147.80 ± 50.11 NmL CH₄·gVS⁻¹. Experimental data were fitted to first-order, modified Gompertz, and Cone kinetic models, with the latter showing the best fit (R² = 0.9981). It was concluded that the use of vinasse as a thermo-acidic hydrolysis agent constitutes an innovative alternative, associated with alkaline hydrolysis, contributing to the low-cost energy valorization of bagasse and strengthening the sustainability of the sugar-energy chain. The byproducts generated after the pretreatment and anaerobic digestion stages can still be used for soil incorporation in sugarcane cultivation, adding value to the production chain.

COMMITTEE MEMBERS:
Presidente - ANDRE FELIPE DE MELO SALES SANTOS
Externo à Instituição - JORGE VINICIUS FERNANDES LIMA CAVALCANTI - UFPE
Externa à Instituição - LILIANA ANDREA DOS SANTOS