Publicação
Wood pellets combustion in a fixed bed combustor
| Resumo: | The development of biomass as a future sustainable energy resource, requires the continuous development of technologies that improve its efficiency of conversion and the reduction of harmful emissions to the environment. Biomass can be burned directly from the environmental state or processed through densification in the form of wood pellets. The combustion behavior of pine wood pellets was investigated in this study. The decomposition of wood particles under different heating and air flow rates were analyzed using the TGA device. The wood pellets burning in a small scale reactor were investigated under different temperatures and time. The wood pellets combustion in a fixed bed combustor with the boiler capacity of 20 kW were tested with several parameters including Power, excess air (EA), the split ratio (SR) and grate area (GA). In this work, the Taguchi method was applied to conduct the experiments. From these experiments, several parameters were evaluated including the mass loss and elemental analysis of wood pellets, kinetic parameters, gas emissions (CO), fuel bed temperature, efficiency, the ashes agglomeration, and the combustion instability. The results obtained from TGA showed that the heating rate affects the heat flow, ignition temperatures, burnout temperatures, and mass loss rate value and different kinetic parameters. But there was no significant influence of the air flow rates on the thermal decomposition of wood particles. The results of the experiment in a small scale reactor revealed that the mass losses increase for any specific temperature and the higher the temperature, the faster the pellets volatilize, and the mass loss occurs at a very slow rate for very low temperature. The reaction rate increased with the temperature and the higher the combustion temperature applied the higher the mass loss of all substances observed. The remaining mass as fixed carbon and ashes or unburned substances was about 3%. The residence time and temperature influenced the species concentration of wood pellets. The wood pellets combustion in a fixed combustor showed that the highest temperature in fuel bed was observed at 15 mm followed by 25 mm, 5 and 60 mm. The lower CO emission or higher efficiency was obtained at a medium thermal load. The results obtained from the ANOVA analysis showed that the SR and the Power are the most important parameters contributing to CO reduction and also the fuel bed temperature. In addition, the parameters that may change the temperature mean value in the core of fuel bed is Power, followed by GA. The combustion instability resulted from the accumulation of unburned wood pellets on the grate, which caused low combustion rate and generated the vortex and oscillation in the air flow rate, thus creating noise and disturbances, and increasing the CO emission. |
|---|---|
| Autores principais: | Fraga, Lelis Gonzaga |
| Assunto: | wood pellets combustion gas emission Taguchi method Thermogravimetric analysis heating rate devolatilization pellets de madeira combustão emissão de gases método de Taguchi análise Termogravimétrica taxa de aquecimento desvolatilização Engenharia e Tecnologia::Engenharia Mecânica |
| Ano: | 2019 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | português |
| Origem: | RepositóriUM - Universidade do Minho |
| _version_ | 1877775847467778048 |
|---|---|
| author | Fraga, Lelis Gonzaga |
| author_facet | Fraga, Lelis Gonzaga |
| author_role | author |
| contributor_name_str_mv | Teixeira, J. Carlos Ferreira, Manuel Eduardo Cardoso RepositóriUM - Universidade do Minho |
| country_str | PT |
| creators_json_txt | [{\"Person.name\":\"Fraga, Lelis Gonzaga\"}] |
| datacite.contributors.contributor.contributorName.fl_str_mv | Teixeira, J. Carlos Ferreira, Manuel Eduardo Cardoso RepositóriUM - Universidade do Minho |
| datacite.creators.creator.creatorName.fl_str_mv | Fraga, Lelis Gonzaga |
| datacite.date.Accepted.fl_str_mv | 2019-11-25T00:00:00Z |
| datacite.rights.fl_str_mv | http://purl.org/coar/access_right/c_abf2 |
| datacite.subjects.subject.fl_str_mv | wood pellets combustion gas emission Taguchi method Thermogravimetric analysis heating rate devolatilization pellets de madeira combustão emissão de gases método de Taguchi análise Termogravimétrica taxa de aquecimento desvolatilização Engenharia e Tecnologia::Engenharia Mecânica |
| datacite.titles.title.fl_str_mv | Wood pellets combustion in a fixed bed combustor |
| dc.contributor.none.fl_str_mv | Teixeira, J. Carlos Ferreira, Manuel Eduardo Cardoso RepositóriUM - Universidade do Minho |
| dc.creator.none.fl_str_mv | Fraga, Lelis Gonzaga |
| dc.date.Accepted.fl_str_mv | 2019-11-25T00:00:00Z |
| dc.format.none.fl_str_mv | application/pdf |
| dc.identifier.none.fl_str_mv | https://hdl.handle.net/1822/66106 |
| dc.language.none.fl_str_mv | por |
| dc.rights.cclincense.fl_str_mv | http://creativecommons.org/licenses/by/4.0/ |
| dc.rights.none.fl_str_mv | http://purl.org/coar/access_right/c_abf2 |
| dc.rights.rights.copyright.fl_str_mv | openAccess |
| dc.subject.none.fl_str_mv | wood pellets combustion gas emission Taguchi method Thermogravimetric analysis heating rate devolatilization pellets de madeira combustão emissão de gases método de Taguchi análise Termogravimétrica taxa de aquecimento desvolatilização Engenharia e Tecnologia::Engenharia Mecânica |
| dc.title.fl_str_mv | Wood pellets combustion in a fixed bed combustor |
| dc.type.none.fl_str_mv | http://purl.org/coar/resource_type/c_db06 |
| description | The development of biomass as a future sustainable energy resource, requires the continuous development of technologies that improve its efficiency of conversion and the reduction of harmful emissions to the environment. Biomass can be burned directly from the environmental state or processed through densification in the form of wood pellets. The combustion behavior of pine wood pellets was investigated in this study. The decomposition of wood particles under different heating and air flow rates were analyzed using the TGA device. The wood pellets burning in a small scale reactor were investigated under different temperatures and time. The wood pellets combustion in a fixed bed combustor with the boiler capacity of 20 kW were tested with several parameters including Power, excess air (EA), the split ratio (SR) and grate area (GA). In this work, the Taguchi method was applied to conduct the experiments. From these experiments, several parameters were evaluated including the mass loss and elemental analysis of wood pellets, kinetic parameters, gas emissions (CO), fuel bed temperature, efficiency, the ashes agglomeration, and the combustion instability. The results obtained from TGA showed that the heating rate affects the heat flow, ignition temperatures, burnout temperatures, and mass loss rate value and different kinetic parameters. But there was no significant influence of the air flow rates on the thermal decomposition of wood particles. The results of the experiment in a small scale reactor revealed that the mass losses increase for any specific temperature and the higher the temperature, the faster the pellets volatilize, and the mass loss occurs at a very slow rate for very low temperature. The reaction rate increased with the temperature and the higher the combustion temperature applied the higher the mass loss of all substances observed. The remaining mass as fixed carbon and ashes or unburned substances was about 3%. The residence time and temperature influenced the species concentration of wood pellets. The wood pellets combustion in a fixed combustor showed that the highest temperature in fuel bed was observed at 15 mm followed by 25 mm, 5 and 60 mm. The lower CO emission or higher efficiency was obtained at a medium thermal load. The results obtained from the ANOVA analysis showed that the SR and the Power are the most important parameters contributing to CO reduction and also the fuel bed temperature. In addition, the parameters that may change the temperature mean value in the core of fuel bed is Power, followed by GA. The combustion instability resulted from the accumulation of unburned wood pellets on the grate, which caused low combustion rate and generated the vortex and oscillation in the air flow rate, thus creating noise and disturbances, and increasing the CO emission. |
| dirty | 0 |
| eu_rights_str_mv | openAccess |
| format | doctoralThesis |
| id | rum_7d3eb4e7dde95b4819c98577975dddb5 |
| identifier.url.fl_str_mv | https://hdl.handle.net/1822/66106 |
| inst_facet_str | urn:organizationAcronym:repositorium{{{_:::_}}}Universidade do Minho |
| instacron_str | repositorium |
| institution | Universidade do Minho |
| instname_str | Universidade do Minho |
| language | por |
| network_acronym_str | rum |
| network_name_str | RepositóriUM - Universidade do Minho |
| oai_identifier_str | oai:repositorium.uminho.pt:1822/66106 |
| organization_str_mv | urn:organizationAcronym:repositorium |
| person_str_mv | Fraga, Lelis Gonzaga |
| publishDate | 2019 |
| repo_facet_str | urn:repositoryAcronym:rum{{{_:::_}}}RepositóriUM - Universidade do Minho |
| reponame_str | RepositóriUM - Universidade do Minho |
| repository_id_str | urn:repositoryAcronym:rum |
| service_str_mv | urn:repositoryAcronym:rum |
| spelling | porporThe development of biomass as a future sustainable energy resource, requires the continuous development of technologies that improve its efficiency of conversion and the reduction of harmful emissions to the environment. Biomass can be burned directly from the environmental state or processed through densification in the form of wood pellets. The combustion behavior of pine wood pellets was investigated in this study. The decomposition of wood particles under different heating and air flow rates were analyzed using the TGA device. The wood pellets burning in a small scale reactor were investigated under different temperatures and time. The wood pellets combustion in a fixed bed combustor with the boiler capacity of 20 kW were tested with several parameters including Power, excess air (EA), the split ratio (SR) and grate area (GA). In this work, the Taguchi method was applied to conduct the experiments. From these experiments, several parameters were evaluated including the mass loss and elemental analysis of wood pellets, kinetic parameters, gas emissions (CO), fuel bed temperature, efficiency, the ashes agglomeration, and the combustion instability. The results obtained from TGA showed that the heating rate affects the heat flow, ignition temperatures, burnout temperatures, and mass loss rate value and different kinetic parameters. But there was no significant influence of the air flow rates on the thermal decomposition of wood particles. The results of the experiment in a small scale reactor revealed that the mass losses increase for any specific temperature and the higher the temperature, the faster the pellets volatilize, and the mass loss occurs at a very slow rate for very low temperature. The reaction rate increased with the temperature and the higher the combustion temperature applied the higher the mass loss of all substances observed. The remaining mass as fixed carbon and ashes or unburned substances was about 3%. The residence time and temperature influenced the species concentration of wood pellets. The wood pellets combustion in a fixed combustor showed that the highest temperature in fuel bed was observed at 15 mm followed by 25 mm, 5 and 60 mm. The lower CO emission or higher efficiency was obtained at a medium thermal load. The results obtained from the ANOVA analysis showed that the SR and the Power are the most important parameters contributing to CO reduction and also the fuel bed temperature. In addition, the parameters that may change the temperature mean value in the core of fuel bed is Power, followed by GA. The combustion instability resulted from the accumulation of unburned wood pellets on the grate, which caused low combustion rate and generated the vortex and oscillation in the air flow rate, thus creating noise and disturbances, and increasing the CO emission.application/pdfporWood pellets combustion in a fixed bed combustorFraga, Lelis GonzagaTeixeira, J. CarlosFerreira, Manuel Eduardo CardosoHostingInstitutionOrganizationalRepositóriUM - Universidade do Minhoe-mailmailto:repositorium@usdb.uminho.ptrepositorium@usdb.uminho.ptTID1015429502019-11-252019-11-25T00:00:00ZHandlehttps://hdl.handle.net/1822/66106http://purl.org/coar/access_right/c_abf2open accesswood pelletscombustiongas emissionTaguchi methodThermogravimetric analysisheating ratedevolatilizationpellets de madeiracombustãoemissão de gasesmétodo de Taguchianálise Termogravimétricataxa de aquecimentodesvolatilizaçãohttp://www.oecd.org/science/inno/38235147.pdfFields of Science and Technology (FOS)Engenharia e Tecnologia::Engenharia Mecânica31432047 bytesliteraturehttp://purl.org/coar/resource_type/c_db06doctoral thesis2019-11-25http://creativecommons.org/licenses/by/4.0/openAccesshttp://purl.org/coar/access_right/c_abf2application/pdfhttps://repositorium.uminho.pt/bitstreams/217061e5-37d8-4e84-91c6-7ffad1a0df77/download |
| spellingShingle | Wood pellets combustion in a fixed bed combustor Fraga, Lelis Gonzaga wood pellets combustion gas emission Taguchi method Thermogravimetric analysis heating rate devolatilization pellets de madeira combustão emissão de gases método de Taguchi análise Termogravimétrica taxa de aquecimento desvolatilização Engenharia e Tecnologia::Engenharia Mecânica |
| status | SINGLETON |
| subject.fl_str_mv | wood pellets combustion gas emission Taguchi method Thermogravimetric analysis heating rate devolatilization pellets de madeira combustão emissão de gases método de Taguchi análise Termogravimétrica taxa de aquecimento desvolatilização |
| subject.other.fl_str_mv | Engenharia e Tecnologia::Engenharia Mecânica |
| title | Wood pellets combustion in a fixed bed combustor |
| title_full | Wood pellets combustion in a fixed bed combustor |
| title_fullStr | Wood pellets combustion in a fixed bed combustor |
| title_full_unstemmed | Wood pellets combustion in a fixed bed combustor |
| title_short | Wood pellets combustion in a fixed bed combustor |
| title_sort | Wood pellets combustion in a fixed bed combustor |
| topic | wood pellets combustion gas emission Taguchi method Thermogravimetric analysis heating rate devolatilization pellets de madeira combustão emissão de gases método de Taguchi análise Termogravimétrica taxa de aquecimento desvolatilização Engenharia e Tecnologia::Engenharia Mecânica |
| topic_facet | wood pellets combustion gas emission Taguchi method Thermogravimetric analysis heating rate devolatilization pellets de madeira combustão emissão de gases método de Taguchi análise Termogravimétrica taxa de aquecimento desvolatilização Engenharia e Tecnologia::Engenharia Mecânica |
| url | https://hdl.handle.net/1822/66106 |
| visible | 1 |
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