Efeitos da alteração de combustíveis nas emissões e dispersão atmosférica de SO2 de caldeiras em refinaria de bauxita.

Abstract

Sulfur dioxide (SO2) in the atmosphere has several harmful effects on human health, vegetation and the environment. Sulfur dioxide emission is mainly combustion of fossil fuels such as coal and sulfur-containing petroleum derivatives in both automobiles and installations industrial Steam and electricity generation boilers represent significant S02 emissions in the industrial environment. Changing fuels of these Equipment consists of one of the main pollution control methods. The evaluation of the effects of this method on the dispersion and concentration of SO2 at ground level through Computer simulations provide less time, lower cost and greater security in decisions related to changes in the energy matrix of equipment. The purpose of this work and use computational fluid dynamics to simulate the atmospheric dispersion of SO2 emissions from the three Babcock & Wilcox boilers by assessing the concentrations of pollutant level in order to guide technical studies aimed at changes in the matrix fossil energy of the equipment. ANSYS Computational Fluid Dynamics Software Workbench - FluidFlow (CFX) was used for the development of the geometry of the domain, computational mesh, boundary conditions, computational solution and evaluation of results from six scenarios. In all simulated scenarios the convergence occurred after the process reached the residue target of le "4 for Moment, Mass, Heat Transfer, Turbulence and Mass Fraction of S02 in the domain. The results Scenario 1 (default) approached the Calpuff model developed in the Environmental Impact of Project Expansion. Simulation Results indicated that under neutral atmosphere conditions the complete atmospheric dispersion of SO2 plume from the boilers achieved optimal ground-level performance at from the partial or total replacement of fuel capable of reducing sulfur by 25% in the emissions. Thus, the use of eucalyptus or babacu biomass, materials abundant in the region, in addition to the use of mineral coal with a lower concentration of sulfur, presents itself as an alternative that should have its technical and economic viability studied.