Estudo de caso de sobrenadante da indústria petroquímica

Abstract

In the oil extraction process, fluids flow from the reservoir to the well, then pass through the production column and flow at the surface through pipelines, valves, fittings and pipe fittings until they reach the primary processing plants where substances such as water, inorganic components and dissolved gases are separated from the crude oil. During this course, the dispersion of water into the oil may occur as tiny droplets, resulting in the appearance of water-oil (W/O) or oil-water (O/W) emulsions. In this case, the water-oil separation of the emulsions is a process which generally requires the use of chemical, thermal and physical treatments. The objective of this work is to characterize the inorganic components of the oil-water interface of samples obtained from a treatment unit and decantation tanks of a crude oil processing plant located in the state of Rio Grande do Norte, using techniques of Soxhlet extraction, X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD). Samples from oil-water interface of three tanks located at the oil processing unit and two tanks from the wastewater treatment plant were collected and taken to the Núcleo de Processamento Primário e Reuso de Água Produzida e Resíduos (NUPPRAR / UFRN). In laboratory, these samples were taken to a centrifuge where, after centrifugation, four phases named here as: oil, interface, water and sedimented solid were obtained. Water and oil were discarded. The Soxhlet extraction process was used to remove all the organic volatiles from the interface and from the sedimented solid. The inorganic part, then, was prepared and taken for analysis in XRF and XRD. Analyzing the results, it was possible to conclude that the greatest mass percentage of the samples was organic matter, however, regarding to the inorganic matter obtained, the major chemical elements were Sulfur, Iron, Silicon and Calcium and the most common chemical compounds were sulfates and carbonates, suggesting that in our samples we had many products of fouling from the pipelines.