SEPARATION OF WATER FROM HYDROCARBONS

摘要

A method for the removal of dissolved water or water and ice from hydrocarbon liquids such as petroleum refinery fuels or natural gas liquids in a manner which enables the fuels to be readily treated by the coalescence/separation technique while reducing the potential for plugging filters and other equipment with ice crystals. Free water or water/ice is removed from the liquid hydrocarbons by contacting the hydrocarbon feed with a treating agent which as an affinity for water prior to subjecting the mixture to coalescence/separation. The treating agent is preferably a co-solvent for the water and the hydrocarbon such as an alcohol e.g. methanol. The treating agent and water are separated from the hydrocarbon component during the coalescence/separation and recirculated to the feed with the composition of the recycle aqueous phase being controlled to achieve the desired level of water removal to meet relevant product specifications. Consistent with the removal of the water during the coalescence/separation, the water concentration of the recycle loop containing the co-solvent/water blend gradually increases with removal of the water from the feed. This progressive increase in water level can be compensated by controlled addition of pure co-solvent to the recycle coupled with continuous or periodic dumping of excess mixture. Alternatively, the circulating mixture may be subjected to continuous or batch regeneration or disposed of in any other way which is convenient and economical.