Análise termodinâmica da gaseificação do licor negro em água supercrítica

• Autor(a) principal: Araújo, Beatriz Mendes Mazon de
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/11926
• topic: Licor negro; Gaseificação; Minimização de Gibbs; Equilíbrio químico e de fases; Otimização; Black liquor; Gasification; Gibbs minimization; Chemical and phases equilibrium; Optimization; ENGENHARIAS::ENGENHARIA QUIMICA

Black liquor (BL) is a by-product of the pulp and paper industry process. Its composition is full of organic and inorganic matter and products of lignin’s solubilisation. Nowadays, black liquor has been used as a burning source for the boilers and generates the biggest part of the electricity in the industry where it’s produced. However, the actual process has low efficiency, reduced flexibility, besides promoting the emission of harmful gases and corrosion in boilers. The supercritical water gasification (SCWG) introduces many advantages when compared to current recovery process of black liquor, making possible the generation of high added value gases such as hydrogen and methane and contributing to energetic efficiency of the plants. In this work, a thermodynamic analysis of supercritical water gasification was conducted in a black liquor representative compound, from the Kraft process and eucalyptus wood. The chemical-and-phase equilibrium calculations were performed using Gibbs minimization method, with a non-stoichiometric approach, that is, the direct Gibbs minimization. To simulate the gas phase behaviour, two different models were compared: the ideal gas mixture model and the Peng Robinson state equation with the van der Waals mixing rule. The solid phase was considered as pure graphite carbon. From the simulations performed, a sensitivity analysis of of pressure and temperature influence on the balance composition of the reactive system was conducted, what makes possible to predict behaviors and so, makes easier decision making, saving time and resources. The Results indicate that besides generate value added gases, BLSCWG could also produce more thermal energy when compared to conventional BL recovery process.