A novel intensified approach for treating produced water from oil extraction using a multi-tube type falling-film distillation column equipped with a biphasic thermosiphon: a promising feasibility study

This study has the novel aim of experimentally examining the efficiency of a pilot-scale treatment plant, composed of a multi-tube type falling-film distillation column equipped with a biphasic thermosiphon, for treating a real sample of high-salinity produced water (electrical conductivity of 20,700 μS cm^-1). It investigates the influence of operational parameters, including feed temperature and steam chamber temperature of the biphasic thermosiphon, on distillate flow rate and reduction of conductivity. All experimental conditions tested achieved a reduction greater than 98% in terms of electrical conductivity. The production of treated water increased with increasing feed temperature; the flow rate increased from 20.8 L h^-1 to 28.2 L h^-1 as the feed temperature was increased from 80 °C to 90 °C, when the steam chamber temperature was fixed at 119 °C. Within the temperature range of the steam chamber, the specific energy consumption during the treatment process, with respect to the biphasic thermosiphon, remained practically unchanged between 0.58 kWh L^-1 and 0.60 kWh L^-1, when the feed temperature was 90 °C. The results proved the potential of the falling-film distillation technology assisted by heat pipes to be a promising proposal for removing salinity from produced water from oil extraction operations.