Salt drying process

A method for removing water from a liquid hydrocarbon, which comprises the steps of:

• (i) contacting a feed stream of the liquid hydrocarbon with a stream of a treating agent of an aqueous salt solution of a drying salt having an affinity for water, to remove water from the hydrocarbon and form a mixture of (i) the hydrocarbon and (ii) the treating agent with water removed from the hydrocarbon,
• (ii) subjecting the mixture of hydrocarbon and treating agent to coalescence/separation by first coalescing the finely divided droplets of the discontinuous aqueous phase of the mixture into larger, coarser droplets by adsorption of droplets on a packing of a coalescence material having a critical wetting surface energy intermediate the surface tensions of the hydrocarbon and of the water in the mixture to coalesce the non-hydrocarbon components of the hydrocarbon/treating agent mixture to form larger size coalesced liquid droplets of the treating agent with water removed from the hydrocarbon,
• (iii) separating the coalesced liquid droplets comprising water and dissolved drying salt by passing the coalesced water droplets and hydrocarbon to a separating element having a surface energy which permits transfer of the hydrocarbon through the pores of the separator material while precluding passage of the coalesced water droplets to form a partly dried hydrocarbon stream and a second salt solution stream,
• (iv) contacting the partly dried hydrocarbon product with a solid drying salt having an affinity for water to form a dried hydrocarbon product and a third salt solution stream,
• (v) circulating the second salt solution stream (from step (iii) to contact the feed stream of the liquid hydrocarbon in step (i).

A method for removing water from a gaseous hydrocarbon, which comprises the steps of:

• (i) contacting a feed stream of the gaseous hydrocarbon with a stream of a treating agent comprising an aqueous salt solution of a drying salt having an affinity for water, to form a stream of a mixture of the hydrocarbon and the salt solution,
• (ii) subjecting the mixture of hydrocarbon and the salt solution to coalescence/separation by first coalescing the finely divided droplets of the discontinuous aqueous phase of the mixture into larger, coarser droplets by adsorption of droplets on a packing of a coalescence material having a critical wetting surface energy intermediate the surface tensions of the hydrocarbon and of the water in the mixture to coalesce the non-hydrocarbon components of the mixture to form larger size coalesced liquid droplets of the salt solution with water removed from the hydrocarbon,
• (iii) separating the coalesced liquid droplets comprising dissolved drying salt and water by passing the coalesced water droplets and hydrocarbon to a separating element having a surface energy which permits transfer of the hydrocarbon through the pores of the separator material while precluding passage of the coalesced water droplets to form a partly dried gaseous hydrocarbon stream and a second salt solution stream,
• (iv) contacting the partly dried gaseous hydrocarbon product stream in countercurrent with a third salt solution of the drying salt to form a gaseous hydrocarbon product stream having a reduced content of water and a fourth salt solution stream comprising an aqueous solution of the drying salt and water removed from the partly dried hydrocarbon product stream,
• (v) contacting the gaseous hydrocarbon product stream having the reduced content of water with solid drying salt to further dry the gaseous hydrocarbon product stream and form a fifth salt solution from removal of water from the hydrocarbon product stream by the solid drying salt, and
• (vi) circulating the fourth salt solution stream of step (iv) to contact the feed stream of the gaseous hydrocarbon in step (i).