Adsorção de compostos nitrogenados utilizando carvão ativado

• Ano de defesa: 2017
• Autor(a) principal: Ferreira, Maria Eugênia de Oliveira
• Orientador(a): Ostroski, Indianara Conceição
• Banca de defesa: Oliveira, Sérgio Botelho de, Vaz, Boniek Gontijo, Alonso, Christian Gonçalves
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Engenharia Química (IQ)
• Departamento: Instituto de Química - IQ (RG)
• País: Brasil
• Palavras-chave em Português: Adsorção; Compostos nitrogenados; Resíduo de vácuo; Carvão ativado; Quinolina
• Palavras-chave em Inglês: Adsorption; Nitrogen compounds; Vacuum residue; Activated carbon; Quinoline
• Área do conhecimento CNPq: ENGENHARIAS::ENGENHARIA QUIMICA
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/8749

Heavy petroleum fractions, especially the vacuum residue, concentrate the largest amounts of nitrogen compounds. Such compounds are considered contaminants of the refining process, and interfere in the conversion steps to obtain lighter derivatives from the heavy fractions. In this study, the aim was to evaluate the removal of nitrogen compounds by adsorption process. Quinoline solution solubilized in toluene was used as a synthetic filler. Commercial activated carbons from coconut shell of babaçu and dendê in their original form and chemically modified with concentrated solutions of nitric and sulfuric acid, as well as sulfonated carbon developed from the rice husk, were evaluated for the adsorption capacity against compounds nitrogen residues present in the vacuum residue and synthetic charge. The textural characteristics of the adsorbents were also evaluated, in which it was observed that the modification with acid reduces the specific area of the activated carbons, but it promotes an increase in the removal of quinoline from the medium. From the preliminary batch adsorption test, the activated carbon from dendê treated with sulfuric acid (CDAS) was able to remove 67.08% of the quinoline present in the solution and was selected for kinetic and equilibrium study. The adsorption kinetics of quinoline were relatively fast for the three concentrations studied (500, 2000, 5000 mg L-1), reaching equilibrium after 240, 120 and 60 minutes of contact, respectively. The kinetic data for the three systems fit the pseudo-second order model better. The equilibrium data were better adjusted to the Freundlich model, revealing the physisorption character of adsorptive process. The maximum adsorption capacity obtained by Langmuir model was 56.63 mg g-1. The results show that CDAS is a promising adsorbent for the removal of quinoline in organic medium. In relation to the vacuum residue sample, batch adsorption tests were conducted in such a way to ascertain the efficiency in class N removal. The results of Mass Spectrometry, ESI (±) Orbitrap MS, showed that the adsorbents CBB and CBAN were more selective in the removal of the non-basic nitrogen compounds, while the basic nitrogenous ones were more persistent and were not removed by any of the adsorbents tested.