Publicação
Production of biogas from crude glycerol using ultrasound as pretreatment in a batch reactor
| Resumo: | Global energy supply is based on petroleum derivative. Scarcity of natural sources and environmental concerns are problems associated to the energy supply as well as its increasing demand. These problems can be solved by using more renewable sources. Biofuels as biogas have the potential to provide energy and decrease environmental emissions. Studies made before, says that crude glycerol from biodiesel production process can be used to produce biogas by anaerobic digestion process. In order to improve biogas volume and its quality, pretreatments to the substrate are being studied. The aim of this work is to study the effect of ultrasound, a mechanical pretreatment, in crude glycerol to produce biogas. The volume of biogas and methane produced was measured, the last to evaluate the quality of biogas, to assess the main effect of pretreatment on anaerobic digestion. They were carried out in batch reactors under mesophilic conditions (37 ° C). Different pretreatment times with ultrasound (15 and 30 minutes) of glycerol treatment were tested and compared with untreated glycerol. For biogas production, measurement was made by moving with its pressure the plunger of a syringe. Methane production by washing the biogas in sodium hydroxide (3%). Characterization tests were also performed on the inoculum and the substrate. As an inoculum, the activated sludge from septic tanks in the rural area of Bragança was used. Substrate was the crude glycerol from biodiesel production process of the Biofuels Laboratory of the School of Technology and Management of IPB. Results shows the maximum production of biogas of 2012 ml that was produced by the crude glycerol pretreated with 30 minutes of ultrasound. It was followed by the one that had 15 minutes of pretreatment with a performance of 1356.6 ml of biogas against the untreated one that presented 1010.5 ml. Measurements of methane volume showed that the 30 minutes treatment had the maximum performance of 13184.7 ml of methane. With this time of pretreatment was performed the mesoscale, in a system with a 7 l reactor built under mesophilic conditions. A mixing and a heating system were connected to the reactor and pH adjusted. Biogas was washed in sodium hydroxide and methane production was daily measured. It achieved 16224 ml of methane. Therefore, it can be concluded that ultrasound treatment improves biogas production. |
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| Autores principais: | Zschach, Lis Geraldine |
| Assunto: | Biogas Crude glycerol Ultrasound pretreatment Anaerobic digestion |
| Ano: | 2020 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Instituto Politécnico de Bragança |
| Idioma: | inglês |
| Origem: | Biblioteca Digital do IPB |
| Resumo: | Global energy supply is based on petroleum derivative. Scarcity of natural sources and environmental concerns are problems associated to the energy supply as well as its increasing demand. These problems can be solved by using more renewable sources. Biofuels as biogas have the potential to provide energy and decrease environmental emissions. Studies made before, says that crude glycerol from biodiesel production process can be used to produce biogas by anaerobic digestion process. In order to improve biogas volume and its quality, pretreatments to the substrate are being studied. The aim of this work is to study the effect of ultrasound, a mechanical pretreatment, in crude glycerol to produce biogas. The volume of biogas and methane produced was measured, the last to evaluate the quality of biogas, to assess the main effect of pretreatment on anaerobic digestion. They were carried out in batch reactors under mesophilic conditions (37 ° C). Different pretreatment times with ultrasound (15 and 30 minutes) of glycerol treatment were tested and compared with untreated glycerol. For biogas production, measurement was made by moving with its pressure the plunger of a syringe. Methane production by washing the biogas in sodium hydroxide (3%). Characterization tests were also performed on the inoculum and the substrate. As an inoculum, the activated sludge from septic tanks in the rural area of Bragança was used. Substrate was the crude glycerol from biodiesel production process of the Biofuels Laboratory of the School of Technology and Management of IPB. Results shows the maximum production of biogas of 2012 ml that was produced by the crude glycerol pretreated with 30 minutes of ultrasound. It was followed by the one that had 15 minutes of pretreatment with a performance of 1356.6 ml of biogas against the untreated one that presented 1010.5 ml. Measurements of methane volume showed that the 30 minutes treatment had the maximum performance of 13184.7 ml of methane. With this time of pretreatment was performed the mesoscale, in a system with a 7 l reactor built under mesophilic conditions. A mixing and a heating system were connected to the reactor and pH adjusted. Biogas was washed in sodium hydroxide and methane production was daily measured. It achieved 16224 ml of methane. Therefore, it can be concluded that ultrasound treatment improves biogas production. |
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