Produção e purificação de biogás utilizando biotecnologia de microalgas como alternativa energética renovável
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Data
2022-12
Autores
Orientador
Konrad, Odorico
Banca
Ethur, Eduardo Miranda
Hoehne, Lucelia
Silva, Maria Cristina Da Almeida
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Resumo
A fonte de energia renovável verde é uma promissora opção para superar a instabilidade energética, reduzir o lançamento na atmosfera de gases do efeito estufa e alcançar a sustentabilidade na produção de energia, e assim, cumprir os objetivos da Agenda 2030, que requer substituir as reservas de combustíveis fósseis por recursos renováveis. A geração de biogás a partir de microalgas por digestão anaeróbia é uma tecnologia que oferece vantagens sobre outras rotas de produção de biocombustíveis, como, por exemplo, a de apresentar elevada concentração de metano e baixas concentrações de enxofre quando comparado ao biogás oriundo de outros substratos. A aplicação de métodos biológicos tem se tornado uma alternativa atraente para o desenvolvimento sustentável na purificação do biogás. Suas principais vantagens são a facilidade e simplicidade de operação, baixo custo e preservação do meio ambiente. Esta pesquisa teve como objetivo avaliar o potencial de geração e de purificação biológica de biogás utilizando microalgas. A purificação biológica por processo fotossintético foi realizada em protótipo de purificador em escala piloto, composto por um sistema de dois estágios, constituído um por reator interligado a uma coluna de absorção, utilizando como microrganismos um consórcio de microalgas/bactérias. A avaliação da produção de biogás foi realizada por digestão anaeróbia em escala laboratorial, utilizando a microalga Euglena sanguinea. Para os ensaios de dessulfurização, as análises mostraram concentrações de H2S acima de 1.000 ppm no biogás bruto e sua remoção completa (eficiência de remoção de 100%) por meio do processo biológico com microalgas/bactérias aos 180 minutos de operação do sistema. Para os ensaios de verificação dos teores de CO2, CH4 e O2, o biogás bruto apresentou concentração de CO2 em torno de 32%; CH4 variando de 63,08% a 64,32 %; e O2 de 0,17% a 0,71%. Após a purificação biológica, o biogás apresentava concentrações de CO2 variando de 9,15% a 18,46%; CH4 de 71,4% a 76,2%; e de O2 entre 1,24% a 3,26%. Eficiências de remoção de CO2 de 42,46% a 72,02% foram registradas no biogás purificado. Na avaliação da produção de biogás, foi utilizada a biomassa da microalga Euglena sanguinea, que apresentou uma produção média acumulada de biogás de 1.619,63 ± 283,00 mL e o volume de metano de 746,27 ± 140,85 mL, atingindo o máximo de 65,54 ± 1,97% no 31° dia. O Potencial Bioquímico de Biogás obtido foi de 703,19 ± 127,31 mL.gVS -1 e o Potencial Bioquímico de Metano de 334,37 ± 63,35 mL.gVS -1 , o que representa um rendimento de 27,02 ± 4,89 m3 de biogás por tonelada de microalgas e 12,85 ± 2,43 m3 de metano. Assim, os resultados demonstraram que o processo biológico com microalgas se mostrou satisfatório e promissor para a purificação do biogás e que a microalga Euglena sanguinea apresentou potencial para uso como substrato para geração de biogás e metano.
The green renewable energy source is a promising option to overcome energy instability, reduce the release of greenhouse gases into the atmosphere and achieve sustainability in energy production, and thus fulfill the goals of the 2030 Agenda, which requires replacing reserves from fossil fuels to renewable resources. The generation of biogas from microalgae by anaerobic digestion is a technology that offers advantages over other biofuel production routes, such as having a high concentration of methane and low concentrations of sulfur when compared to biogas from other substrates. The application of biological methods has become an attractive alternative for sustainable development in biogas purification. Its main advantages are the ease and simplicity of operation, low cost and preservation of the environment. This research aimed to evaluate the potential of generation and biological purification of biogas using microalgae. Biological purification by photosynthetic process was carried out in a prototype purifier on a pilot scale, consisting of a two-stage system, consisting of one per reactor connected to an absorption column, using a consortium of microalgae/bacterium as microorganisms. For the desulphurization tests, the analyzes showed H2S concentrations above 1,000 ppm in the raw biogas and its complete removal (100% removal efficiency) through the biological process with microalgae/bacterium after 180 minutes of system operation. For the verification tests of the CO2, CH4 and O2 contents, the raw biogas presented a CO2 concentration around 32%; CH4 ranging from 63.08% to 64.32%; and O2 from 0.17% to 0.71%. After biological purification with microalgae, the biogas presented CO2 concentrations ranging from 9.15% to 18.46%; CH4 from 71.4% to 76.2%; and O2 between 1.24% to 3.26%. CO2 removal efficiencies of 42.46% to 72.02% were recorded in the purified biogas. In the evaluation of biogas production, the biomass of the microalgae Euglena sanguinea was used, which presented an average accumulated production of biogas of 1,619.63 ± 283.00 mL and the methane volume of 746.27 ± 140.85 mL, reaching a maximum of 65, 54 ± 1.97% on the 31st day. The Biochemical Potential of Biogas obtained was 703.19 ± 127.31 mL.gVS -1 and the Biochemical Potential of Methane was 334.37 ± 63.35 mL.gVS -1 , which represents a yield of 27.02 ± 4.89 m3 of biogas per ton of microalgae and 12.85 ± 2.43 m3 of methane. Thus, the results demonstrated that the biological process with microalgae was satisfactory and promising for the purification of biogas and that the microalgae Euglena sanguinea showed potential for use as a substrate for the generation of biogas and methane.
The green renewable energy source is a promising option to overcome energy instability, reduce the release of greenhouse gases into the atmosphere and achieve sustainability in energy production, and thus fulfill the goals of the 2030 Agenda, which requires replacing reserves from fossil fuels to renewable resources. The generation of biogas from microalgae by anaerobic digestion is a technology that offers advantages over other biofuel production routes, such as having a high concentration of methane and low concentrations of sulfur when compared to biogas from other substrates. The application of biological methods has become an attractive alternative for sustainable development in biogas purification. Its main advantages are the ease and simplicity of operation, low cost and preservation of the environment. This research aimed to evaluate the potential of generation and biological purification of biogas using microalgae. Biological purification by photosynthetic process was carried out in a prototype purifier on a pilot scale, consisting of a two-stage system, consisting of one per reactor connected to an absorption column, using a consortium of microalgae/bacterium as microorganisms. For the desulphurization tests, the analyzes showed H2S concentrations above 1,000 ppm in the raw biogas and its complete removal (100% removal efficiency) through the biological process with microalgae/bacterium after 180 minutes of system operation. For the verification tests of the CO2, CH4 and O2 contents, the raw biogas presented a CO2 concentration around 32%; CH4 ranging from 63.08% to 64.32%; and O2 from 0.17% to 0.71%. After biological purification with microalgae, the biogas presented CO2 concentrations ranging from 9.15% to 18.46%; CH4 from 71.4% to 76.2%; and O2 between 1.24% to 3.26%. CO2 removal efficiencies of 42.46% to 72.02% were recorded in the purified biogas. In the evaluation of biogas production, the biomass of the microalgae Euglena sanguinea was used, which presented an average accumulated production of biogas of 1,619.63 ± 283.00 mL and the methane volume of 746.27 ± 140.85 mL, reaching a maximum of 65, 54 ± 1.97% on the 31st day. The Biochemical Potential of Biogas obtained was 703.19 ± 127.31 mL.gVS -1 and the Biochemical Potential of Methane was 334.37 ± 63.35 mL.gVS -1 , which represents a yield of 27.02 ± 4.89 m3 of biogas per ton of microalgae and 12.85 ± 2.43 m3 of methane. Thus, the results demonstrated that the biological process with microalgae was satisfactory and promising for the purification of biogas and that the microalgae Euglena sanguinea showed potential for use as a substrate for the generation of biogas and methane.
Descrição
Palavras-chave
Purifação de biogás; Microalga; Biofixação; Sustentabilidade energética.; Biogas purification; Microalgae; Biofixation; Energy sustainability
Citação
CASTRO, Aline Antonia. Produção e purificação de biogás utilizando biotecnologia de microalgas como alternativa energética renovável. 2022. Tese (Doutorado) – Curso de Ambiente e Desenvolvimento, Universidade do Vale do Taquari - Univates, Lajeado, 12 dez. 2022. Disponível em: http://hdl.handle.net/10737/3454.