CATALYTIC OXIDATION OF EMISSION GAS FROM A REFINERY 01L-WATER SEPARATION

Abstract

The emission of trace volatile organic compounds (VOCs) from various industrial and commercial processes is of considerable concern due to their harmful environmental effects. The uncontrolled emission of these VOCs from oil-water separator of petroleum refineries generally contains 50-5000 mg/m3 of light aliphatic and aromatic hydrocarbons. There are large numbers of technologies in use for the control of these volatile emissions into the atmosphere. Most of the control devices does not destroy these VOCs but just transfer them from one phase to another. Catalytic oxidation offers the advantages of lower operating temperature, shorter space-time and high destruction efficiencies at a very economical cost compared to other methods. of VOC emission control. A refinery wastewater sample was collected from the oil-water separator inlet for analysis and the concentrations of the commonly found VOCs were determined. Benzene and n-hexane, representing the aromatics and the aliphatic compounds emitted from the oil water separator, were selected for the further investigation as the control devices are designed on the basis of most carcinogen compound or the one, which is most volatile. Next, a theoretical estimate of the emissions of these VOCs from the refinery oil-water separator was done by using software developed by United States environmental protection agency. In order to find the proper reaction condition and design data for oxidation of VOCs from oil water separator specific reaction kinetics should be known. Kinetic data related to the catalytic oxidation of these VOCs over Pt/Al2O3 catalyst was collected from the literature. Different oxidation mechanisms were tested for explaining the kinetic results observed. Using the rate expression from the best model and the emissions calculated, estimation and effect of the operating conditions on catalytic oxidation system performance was determined.