Modelagem e simulação do processo de adsorção de compostos orgânicos em xisto, catalisador exaurido de FCC e carvão ativado em pó

Abstract

The high cost of the activated carbon has motivated the search of low cost adsorbents such as industrial by-products. In this sense, the use of industrial by-products of oil shale: Oil Shale (XC), Pirolized Oil Shale (XR) and Pirolized Oil Shale with Tires (XRP), from PETROSIX/PETROBRAS, and the spent catalyst (CAT), from FCC (Fluid Catalytic Cracking) unit were characterized and used in this work in the adsorption of organics compounds of industrial liquid effluent. The main contribution of this thesis is to propose a mathematical model to the adsorption process of organic compounds in oil shale, spent catalyst of FCC and powdered activated carbon. This model is based on HSDM (Homogeneous Surface Diffusion Model) model and on the hydraulic behavior of the adsorbent system. Other contribution is the structural and chemical characterization of several samples of oil shale (oil shale, Pirolized oil shale and Pirolized oil shale with Tires) and of the spent catalyst of FCC. A computational model to simulate the adsorption process of these materials is also developed and can be considered an additional contribution of this work. Experimental and simulated results allow characterization of the oil shale adsorbent as basically macroporous and with superficial area about 0.51 to 3.36 m2.g-1. In addition, they present the same crystal structures and clay micrografies characteristics. The adsorbent CAT is composed basically by Faujasite, silica and alumina. They present spherical beads, irregular forms and micropores, with superficial area characteristics of zeolitic materials (148 and 155 m2.g-1). The adsorption tests realized in the synthetic and industrial effluents (Phenolic and Petrochemical) showed the potential of application of the industrial by-products of oil shale and CAT in the removal of organics compounds (dyes, Phenol and COT) of these effluents. In respect of environmental standards to effluents disposal (CONAMA resolution 357), simulations results, obtained with the proposed model, has demonstrated that the use of only oil shale or CAT is not viable, because the high quantity of adsorbents required. However, such adsorbents can be used in the reduction of organic loads in both effluents, when combined with other processes. Each adsorbent showed be used where it is produced because of transportation cost. The CAT is indicated for the treatment of Petrochemical effluent while the others adsorbents may be applied in the phenolic effluent treatment.