Simulação do sistema de evaporação do licor negro da Klabin - KPMA

Abstract

The pulp and paper industry contributes significantly to the development of Brazil. Currently, Brazil is fourth and tenth largest producer of pulp and paper in the world, respectively. Cellulose is obtained by cooking wood in a pressurized vessel, with white liquor, which is composed of sodium hydroxide and sodium sulfide. During the digestion process the black liquor is generated. This liquor is considered weak and is composed of organic compounds derived from wood and inorganic compounds derived mainly from the cooking liquor. The black liquor is sent to the chemical recovery process where it enters in a system of multiple effect evaporators. In this system, the black liquor concentration increases from 22% to 75%. This work aims to simulate the black liquor evaporation system of Klabin - KPMA, using the simulator HYSYS by using the resources available in the simulator or by emulating the necessary operations. The HYSYS does not have a compound that represents the black liquor in his database. Thus, a molecule for this purpose was created using the UNIFAC method. The molecule developed presented good results, because their physical properties showed similar patterns to those found in the literature for the black liquor. The result of the created model was validated according to the output concentration of the evaporators. In this case, the error obtained was less than 8% in the most cases, showing that the simulation was relatively close to the real process.