Preparação e caracterização de membranas compósitas tubulares aplicadas a separação de emulsão óleo/água.

Abstract

The separation of emulsion oil water using membranes is a very important and very used process, in this sense the search for new materials and new techniques for the production of membranes is a source of industrial interest. The innovation of this study is the synthesis of composite membranes based on ultra-high molar mass polyethylene (UHMWPE) by sintering and organophilic Brasgel or nanocomposite for oil / water emulsion separation. The objective of this work is to: (i) prepare ultra-high molar mass polyethylene tubular polymer membranes (UHMWPE) under different experimental conditions and their internal surfaces were modified by impregnation with a solution of HDPE in toluene; (Ii) prepare PEUAPM-based tubular composite membranes by adding organophilic Brasgel or nanocomposite clay; (Iii) investigate process parameters for membrane synthesis, such as sintering time and percentage of material (organophilic clay or nanocomposite) that will influence the performance of the membranes in the process; (Iv) evaluate this membranes in the water-oil emulsion process. The characterization techniques used to evaluate the organophilic clay composition were X-ray diffraction (XRD), Spectroscopy and X-ray Fluorescence (FRX-ED), Physical Nitrogen Adsorption, Cation Exchange Capacity (CTC) Fourier Transform Infrared Spectroscopy (FTIR), Differential and Thermogravimetric Thermal Analysis (ATD/TG) and Scanning Electron Microscopy (SEM). All membranes were characterized by DRX, MEV, water absorption capacity, porosity and chemical resistance. All membranes were evaluated in the oil/water emulsion separation process. The tests were carried out at the initial concentration of 100 mg.L-1 oil, temperature at 25ºC, atmospheric pressure, which allowed to observe the flows (m3.m-2.h-1) and the percentage of rejection. The organophilization of Brasgel clay was evidenced by XRD, FTIR and ATD/TG. Composite membranes were successfully obtained from the polymer PEUAPM and organophilic Brasgel or nanocomposite. It was observed from XRD analyzes that the composite membranes presented exfoliated structures. The characterization by SEM showed that the surfaces of the membranes were modified with the deposition of the LDPE film, leading to the reduction in pore size. Based on studies on the effect of the parameters, such as sintering time (60, 90 and 120 minutes) and percentage of the material (organophilic Brasgel or nanocomposite clay) in the synthesis of the composite membranes, it was concluded that these two factors are important This fact was evidenced by tests of water absorption capacity and porosity tests. Based on the results obtained by membrane separation process (PSM) of the oil/water emulsion, it can be concluded that the insertion of the materials (organophilic Brasgel or nanocomposite) to the polymer membranes improved their performances, consequently increasing the percentage of rejection. These results corroborate with the water absorption and porosity tests of the respective membranes. As a general conclusion, the performances of the composite membranes were superior to the results of the polymer membranes, evidencing that the incorporation of the organophilic clay or the nanocomposite affects positively.