Pervaporation technology for regeneration of diethylene glycol at Russian complex gas treatment plants with the use of ceramic membranes HybSi

Conventional methods of regeneration of diethylene glycol used as an absorbent for natural gas dehydration at complex gas treatment plants in the Russian gas fields are analyzed. An alternative method of regeneration by pervaporation using tubular ceramic membranes coated on the inside with the HybSi material is proposed. Experimental study of pervaporation dehydration of diethylene glycol in concentration ranges 97-99.5 wt% and 93.5-99.5 wt% corresponding to saturation levels 2.5 wt% and 6.0 wt%, respectively, is carried out in the temperature range 70-90 °C and vacuum pressure range 5-30 mm Hg. Increase in saturation level from 2.5 wt% to 6.0 wt% leads to inessential increase in the required surface area of HybSi membranes. Results of the experimental study are compared with experimental results obtained by other researchers for SepraTek hollow-fiber polymer membranes. Losses of diethylene glycol through HybSi membranes are shown not to exceed losses at conventional stripping and to be lower by two orders of magnitude than losses through SepraTek membranes. Use of pervaporation instead of stripping for diethylene glycol regeneration leads to more than two-fold energy saving.