Separation of components of hydrogen and hydrocarbon mixtures by plural distillation with heat exchange

Abstract

Abstract METHOD AND SYSTEM PARTICULARLY DESIGNED FOR SEPARATING HYDROGEN AND METHANE, AND ETHYLENE, FROM MIXTURES THEREOF, ALSO GENERALLY CONTAINING HEAVIER HYDROCARBONS, WHICH INVOLVES COOLING A COMPRESSED FEED MIXTURE, E.G., ONE CONTAINING HYDROGEN, METHANE, ETHYLENE, AND HEVIER HYDROCARBONS INCLUDING ETHANE AND PROPYLENE, PREFERABLY TO A SUBSTANTIALLY SATURATED VAPOR, BY HEAT EXCHANGE WITH COLD PRODUCT GAS STREAMS AND BY EXTERNAL REFRIGERATION PASING THE COOLED SUBSTANTIALLY SATURATED FEED VAPOR MIXTURE IN INDIRECT HEAT EXCHANGE RELATION WITH THE FLUID FROM THE LOWER PORTION OF A DISTILLATION COLUMN AT SEVERAL DIFFERENT TEMPERTURE LEVELS, SUCH FEED MIXTURE ALSO BEING SUBJECTED TO EXTERNAL REFRIGERATION AT SEVERAL DIFFERENT TEMPERATURE LEVELS AND EFFECTING A NON-ADIABATIC DISTILLATION IN THE COLUMN AND A PARTIAL CONDENSATION OF THE FEED VAPOR. THE EXITING PARTIALLY CONDENSED FEED MIXTURE FROM THE COLUMN IS PHASE SEPARATED INTO A VAPOR CONSISTING ESSENTIALLY OF HYDROGEN AND METHANE, AND A LIQUID CONSISTING ESSENTIALLY OF METHANE AND ETHYLENE. THE LIQUID IS INTRODUCED AS FEED INTO THE DISTILLATION COLUMN, AND A SEPARATION IS EFFECTED THEREIN INTO AN OVERHEAD VAPOR O METHANE AND A BOTTOM LIQUID PRODUCT OF ETHYLENE AND ANY HEAVIER HYDROCARBONS PRESENT IN THE FEED MIXTURE. THE OVERHEAD METHANE VAPOR IS PASSED IN HEAT EXCHANGE RELATION WITH AT LEAST A PORTION OF THE COMPRESSED FEED MIXTURE FOR COOLING SAME, IS FURTHER COOLED, AND CONDENSED, AND RECIRCULATED TO THE TOP OF THE DISTILLATION COLUMN AS REFLUX. THE COLD HYDROGEN AND METHANE STREAM FROM THE PHASE SEPARATOR IS PASSED IN HEAT EXCHANGE RELATION WITH COMPRESSED FEED MIXTURE AND RECIRCULATED OVERHEAD METHANE FOR COOLING SAME. THIS PROCESS AND SYSTEM ARE DESIGNED TO EFFECT AN EFFICIENT SEPARATION PARTICULARLY BY RECOVERING AND EFFECTIVELY UTILIZING REFRIGERATION IN A THERMODYNAMICALLY REVERSIBLE MANNER, RESULTING IN A REDUCTION OF COMPRESSOR POWER COST.

Inventors

• 👤 Michael L Hoffman

Bibliographic Details