Modelagem de cristalizador por evaporação para tratamento de efluentes líquidos de refinarias de petróleo

• Ano de defesa: 2014
• Autor(a) principal: Hugo Montalvao Gontijo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Cloreto de; Cristalização; Reúso de água; Modelos dinâmicos; sódio; Engenharia metalúrgica; Tecnologia mineral; Água Reutilização; Cristalização Métodos de simulação
• Link de acesso: http://hdl.handle.net/1843/BUOS-9KGUET

Water is an essential component in most industrial process and its responsible and correct use is important in order to minimize environmental impacts. Reduction in water consumption may be achieved by improving industrial effluent treatment processes, allowing water and other valuable raw materials to be recycled and reused. In Gabriel Passos oil refinery, owned and operated by Petrobras, a recovery up to 68% of water by conventional methods has been practiced. Effluent treatment by electrodialysis raises that number by 14% totaling 82% of water recovery. Aiming at a maximum water recovery, studies have been conducted to implement a crystallization stage, thus allowing the remaining 18% of remaining water to be recovered. The effluent treated by crystallization consists of an aqueous solution with 0.5% of inorganic salts that feed a crystallization pilot plant. This work consisted in the development of a dynamic model for the crystallizer by continuous vacuum evaporation with forced recirculation, present in the pilot plant, from the population mass and energy balances. The simulation was developed using Matlab software for simultaneously solve the differential equations. Laboratory tests using a batch evaporative crystallizer and simulation were carried out simultaneously in order to compare the results and to adjust the kinetic parameters. The pilot plant simulation was developed according the crystallization unit flowchart, theoretical mass and energy balances as well as the effluent chemical composition. The effects in crystal properties caused by variations in feed rate, feed concentration and recycle rate were simulated and discussed. From the simulation results, it was possible to understand how the variability of the feed concentration, the purge flow and temperature control recirculation affect the stabilization of the pilot plant.