Modelagem matemática do processo de lavagem alcalina do gás natural

• Ano de defesa: 2015
• Autor(a) principal: Lima Sobrinho, Raimundo Alves
• Orientador(a): Marques, José Jailton
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Engenharia Química
• Palavras-chave em Português: Engenharia química; Gás natural; Química; Absorção; Dessulfuração; Absorção química; Dessulfurização; Natural gas; Chemical absorption; Desulphurization
• Área do conhecimento CNPq: ENGENHARIAS::ENGENHARIA QUIMICA
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/17087

The use of natural gas is growing worldwide due to its low pollution potential. Although it is composed by light hydrocarbons, besides contaminants as CO2 (carbon dioxide) and H2S (hydrogen sulfide). These compounds are corrosive to steel (in the presence of moisture) and H2S has an additional trouble of being a toxic substance. Therefore, the removal of this natural gas contaminant is crucial to reduce operating costs and the environmental impacts associated with its use. Various processes for removing H2S are used in industry mainly those ones using alkyl amines, widely used in continuous processes in most processing plants along the world. Motivated by the existence of stranded natural gas fields having high H2S concentrations, similar to the situation in associated gas from sub-salt oilfields, this theoretical work based on a previous experimental study by the same authors, aims the mathematical modeling of hydrogen sulfide removal from natural gas through chemical absorption in a bubble column containing an aqueous solution of sodium hydroxide as absorbent, operating in a semi-continuous fashion. At the gas outlet, a device measured H2S concentration over time and recorded the medium saturation. Mathematical modeling of this process led to the solution of an equation system derived from the phenomenological treatment of the chemical absorption process, validated against available experimental data. Global volumetric mass transfer coefficient (KGa) and kinetics parameters were estimated. The simulations were performed using the computational package EMSO - Environment for Modeling, Simulation and Optimization, which is an environment with capabilities similar to the classic structured languages, with the advantage of having a friendlier interface. The results supported the determination of the controlling step, predicted values of the parameters of the absorption process with satisfactory adjustment level, and allowed the study of system behavior in situations other than those ones studied experimentally.