Banca de QUALIFICAÇÃO: Maria dos Reis Santos Borges

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Maria dos Reis Santos Borges
DATE: 21/06/2023
TIME: 14:00
LOCAL: Plataforma Microsoft Teams
TITLE:

ANALYSIS OF THE ENVIRONMENTAL IMPACTS OF PRODUCTION AND DIFFERENT BIOGAS USE SCENARIOS

KEY WORDS:

Life Cycle Assessment; Biogas; Biomethane; life cycle scenarios; environmental impacts.

PAGES: 100
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

The feasibility of biofuel use, such as biogas, has become an advantageous alternative, given the energy potential and the various applications. In addition to having advantageous characteristics that guarantee the high performance of biogas as a renewable energy source, its sustainable production process is a consolidated way to reduce Greenhouse Gas (GHG) emissions. To evaluate the environmental impacts of the processes involved in biogas production and its various application possibilities, the present study uses the Life Cycle Assessment (LCA) tool in a cradle-to-gate approach, from production phases of 1 Nm3 of biogas obtained from dairy cattle manure, in a medium-sized Brazilian farm. Additionally, the study proposes the modeling of five scenarios related to the different possibilities of using the biogas produced, namely: Scenario 1 - Biogas for electricity (without reuse); Scenario 2 - Biogas for electricity (with reuse); Scenario 3 - Biogas to biomethane (Pressure Swing Adsorption - PSA); Scenario 4 - Biogas to biomethane (Membrane Separation - SM); Scenario 5 - Biogas to biomethane (Water Scrubbing - WS), where the functional unit was changed to 1 MJ. To propose the use of biogas as biomethane in evidence, given that this application is still little explored in Brazil, three scenarios with different upgrade techniques, were included. In this way, the mapping of the processes involved in each phase of the LCA aims to bring an overview of the possibilities that the production and use of biogas can provide in the Brazilian context. To design the LCA model, the GaBi software, version 9.2.1.68, was used, using the CML 2001 method, adopting the following impact categories: Global Warming Potential (GWP), Acidification Potential (AP), and Eutrophication Potential (EP). For the biogas production phase, the environmental impacts totaled 1.95 kg of CO2 Eq., which corresponds to 98.41% for the GWP category, where the manure production and management processes presented the main contributions. However, in AP and EP, electricity consumption at the plant was the principal emissions source. Regarding the use phase scenarios, significant reductions in environmental impacts were obtained, compared to the biogas production phase. For biogas to electricity scenarios (scenarios 1 and 2), average reductions of 73%, 79%, and 82% were obtained in GWP, AP, and EP, respectively. In the biogas to biomethane scenarios (scenarios 3, 4, and 5), reductions in environmental impacts were found, with an average of 90.8%, 95%, and 95% for GWP, AP, and EP. From an ambiental point of view, scenario 3 was the one that presented the lowest absolute impacts and the highest reductions when compared to the other scenarios and phases, confirming itself as a principal possibility of the environmentally friendly practical application for biogas.

BANKING MEMBERS:
Externo à Instituição - MARIO EDUARDO SANTOS MARTINS - UFSM
Interno - 2348930 - ARMANDO DE AZEVEDO CALDEIRA PIRES
Interno - 3138349 - EDGAR AMARAL SILVEIRA
Presidente - 1720225 - SANDRA MARIA DA LUZ
Externo à Instituição - THIAGO OLIVEIRA RODRIGUES - IBICT