Improvement of the separation process of oil-water mixtures in laboratory conditions

An improved process for separating water-oil mixtures in laboratory conditions using a specially developed device is presented in the article. To assess the efficiency of the device, samples of two types of water-oil emulsions were studied: three samples of the inverse type (water in oil) based on high-viscosity oils and six samples of the multiple type (water in oil in water) based on light oils. Comparison with standard laboratory separation methods based on physical, chemical and physicochemical effects was made. Analysis of the results revealed a number of disadvantages of the standard methods, which consist in a significant duration of the process, the need to use several laboratory tools, leading to increasing the time costs for preparing a dehydrated hydrocarbon phase. To separate particularly stable emulsions, especially based on high-viscosity oils, it was necessary to consequently use several methods. A developed laboratory device is proposed as an alternative. It consists of two main modules: 1) a 3.5 dm³ metal vessel made of stainless steel and equipped with a ceramic heating ring, an adapter, and a reflux condenser with a tank for collecting low-boiling fractions; 2) a 400 cm³ vessel with a drying agent (calcium chloride) having a drain hole. The modules are connected via a peristaltic pump, which provides the transfer of the hydrocarbon phase between them at a controlled rate. Separated hydrocarbon phase undergoes additional purification from residual water in the vessel with the drying agent and is collected in the receiving tank. The optimal operating parameters were established: heating temperature of 50–60 °C for light oils and 90–100 °C for high-viscosity oils; peristaltic pump pumping rate of 3 l/h. The efficiency of the device was assessed by passing each sample through the device nine times. In all cases the dehydration degree of 99% was achieved. The use of the device accelerates and simplifies preparation of samples, which are represented by emulsions of various types.