(12) Patent Application Publication (10) Pub. No.: US 2010/0193347 A1 Hulse Et Al
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US 2010.0193347A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2010/0193347 A1 Hulse et al. (43) Pub. Date: Aug. 5, 2010 (54) PROCESS FOR THE PURIFICATION OF Related U.S. Application Data HYDROFLUOROOLEFNS (60) Provisional application No. 61/148,505, filed on Jan. 30, 2009. (75) Inventors: Ryan Hulse, Getzville, NY (US); Publication Classification Rajiv Ratna Singh, Getzville, NY (US); Ian Shankland, Randolph, (51) Int. Cl. NY (US); Michael Van Der Puy, BOID 3/36 (2006.01) Amherst, NY (US) (52) U.S. Cl. .......................................................... 2O3A28 (57) ABSTRACT Correspondence Address: Processes for the preparation and purification of hydrofluo HONEYWELLAFOX ROTHSCHILD roolefins such as tetrafluorinated propenes. A process is pro Patent Services vided for separating a first hydrofluoroolefin from a second 101 Columbia Road hydrofluoroolefin by a) providing a mixture comprising a first Morristown, NJ 07962 (US) hydrofluoroolefin and a second hydrofluoroolefin, which first hydrofluoroolefin is preferentially more reactive with an amine than the second hydrofluoroolefin; b) adding a suffi (73) Assignee: HONEYWELL cient amount of an amine to the mixture to form a combina INTERNATIONAL INC., tion comprising the second hydrofluoroolefin and a reaction Morristown, NJ (US) product of the first hydrofluoroolefin and the amine; and then c) separating the reaction product from the combination. This is particularly useful for removing 1,2,3,3,3-pentafluoropro (21) Appl. No.: 12/696,613 pene (HFO-1225ye) impurities from the hydrofluoroolefin 2,3,3,3-tetrafluoropropene (HFO-1234yf). HFO-1234yf is a (22) Filed: Jan. 29, 2010 refrigerant with low global warming potential. Condenser Purified Amine Purified HFO Ammonium Salt and/or a higher boiling reaction product Amine with ammonium salt and/or a higher boiling HFO with Amine reaction product H reactive impurity YH -CH Patent Application Publication Aug. 5, 2010 US 2010/0193347 A1 Condenser Purified Amine Purified HFO Ammonium Salt and/or a higher boiling reaction product Amine with ammonium H reactionSalt and/or product a higher boiling H reactiveHFO with impurity Amine 1H FIG. 1 US 2010/0193347 A1 Aug. 5, 2010 PROCESS FOR THE PURIFICATION OF 0007 Although most HFC's will not deplete the ozone HYDROFLUOROOLEFNS layer, there is concern about the global warming potential (GWP) associated with these molecules. GWP is a measure of CROSS-REFERENCE TO RELATED the potential contribution to the green house effect of the APPLICATIONS chemical against a reference, the reference molecule in this case is CO which has a GWP-1. Regulation in the European 0001. This application claims the priority benefit of U.S. Union has already set limits of a GWP=150 for refrigerants to Provisional Application No. 61/148,505, filed Jan. 30, 2009, be used in Some applications such as automotive air condi which is incorporated herein by reference. tioning. 0008 Hydrofluorocarbons (HFCs), particularly hydrof BACKGROUND OF THE INVENTION luoroalkenes Such tetrafluoropropenes, have been disclosed to be effective refrigerants, fire extinguishants, heat transfer 0002 1. Field of the Invention media, propellants, foaming agents, blowing agents, gaseous 0003. The present invention relates to processes for pre dielectrics, sterilant carriers, polymerization media, particu paring hydrofluoroolefins such as tetrafluorinated propenes. late removal fluids, carrier fluids, buffing abrasive agents, 0004 2. Description of the Related Art displacement drying agents and power cycle working fluids. 0005 Fluorocarbon based fluids have found widespread Unlike chlorofluorocarbons (CFCs) and hydrochlorofluoro use in many commercial and industrial applications including carbons (HCFCs), both of which potentially damage the as refrigerants, aerosol propellants, blowing agents, heat Earth's ozone layer. HFCs do not contain chlorine and thus transfer media, gaseous dielectrics and as working fluids in pose no threat to the oZone layer. Tetrafluoropropenes, having air conditioning, heat pump and refrigeration systems. The Zero oZone depletion and low global warming potential, have vapor compression cycle is one of the most commonly used been identified as potentially filling this need. However, the type methods to accomplish cooling or heating in a refrigera toxicity, boiling point, and other physical properties in this tion system. The vapor compression cycle usually involves class of chemicals vary greatly from isomer to isomer. One the phase change of the refrigerant from the liquid to the vapor tetrafluoropropene having valuable properties is 2,3,3,3-tet phase through heat absorption at a relatively low pressure and rafluoropropene (HFO-1234yf). Thus, there is a need for new then from the vapor to the liquid phase through heat removal manufacturing processes for the production of tetrafluoropro at a relatively low pressure and temperature, compressing the penes and in particular 2,3,3,3-tetrafluoropropene. 2,3,3,3- vapor to a relatively elevated pressure, condensing the vapor Tetrafluoropropene (HFO-1234yf) is a refrigerant that has to the liquid phase through heat removal at this relatively been designed to meet the EU regulations for automotive air elevated pressure and temperature, and then reducing the conditioning. pressure to start the cycle over again. Certain fluorocarbons 0009 U.S. patent application publication US2007/ have been a preferred component in many heat exchange 0179324 discloses a synthesis process involving the dehy fluids. For, example, fluoroalkanes. Such as chlorofluo drofluorination of 1,1,1,2,3-pentafluoropropane (HFC romethane and chlorofluoroethane derivatives, have gained 245eb) to form HFO-1234yf. Also disclosed is the widespread use as refrigerants in applications including air dehydrofluorination of 1,1,1,2,3,3-hexafluoropropane (HFC conditioning and heat pump applications owing to their 236ea) under similar conditions to form 1.2.3,3,3-pentafluo unique combination of chemical and physical properties. ropropene (HFO-1225ye(Z)). Accordingly, the presence of Many of the refrigerants commonly utilized in vapor com HFC-236ea impurities in this reaction could produce HFO pression systems are either single components fluids oraZeo 1225ye(Z) as an unwanted byproduct. To overcome this issue, tropic mixtures. US2007/0179324 also discloses that HFO-1225ye(Z) can be 0006. However, suspected environmental problems asso reacted with hydrogen to form HFC-245eb, which can be ciated with the use of some of these fluids, including the dehydrofluorinated to form HFO-1234yf. However, any relatively high global warming potentials associated there HFO-1225ye(Z) which is not fully hydrogenated in the first with, it is desirable to use fluids having the lowest possible step will end up as an impurity if the final product stream of greenhouse warming potential in addition to Zero oZone HFO-1234yf. depletion potential. Thus there is considerable interest in 0010 Distillation is a conventional purification method developing environmentally friendlier materials for the appli for commercial processes. Distillation takes advantage of the cations mentioned above. Concern has increased in recent fact that the liquid and vapor of a chemical mixture are at years about potential damage to the earth's atmosphere and different compositions. However, distillation becomes inef climate, and certain chlorine-based compounds have been ficient and then impossible as the chemical mixture identified as particularly problematic in this regard. The use approaches a pinch point and an azeotropic composition, of chlorine-containing compositions (such as chlorofluoro respectively. The closer the composition is to a pinch point the carbons (CFCs), hydrochlorofluorocarbons (HCF's) and the more yield loss there will be in the distillation. This phenom like) as refrigerants in air-conditioning and refrigeration sys ena renders the separation of HFO-1225ye(Z) from a HFO tems has become disfavored because of the ozone-depleting 1234yf product stream using standard distillation techniques properties associated with many of Such compounds. Thus, very difficult. More particularly, it is very difficult to remove there is an increased need for new fluorocarbon and hydrof HFO-1225ye(Z) from HFO-1234yfby conventional distilla luorocarbon compounds and compositions that offer alterna tion at very low levels of HFO-1225ye(Z) without large yield tives for refrigeration and heat pump applications. For losses due to the fact that HFO-1225ye(Z) and HFO-1234yf example, it has become desirable to retrofit chlorine-contain ing refrigeration systems by replacing chlorine-containing form an azeotrope (see U.S. Pat. No. 7,098,176). refrigerants with non-chlorine-containing refrigerant com SUMMARY OF THE INVENTION pounds that will not deplete the ozone layer, such as hydrof 0011. This invention provides a method for preparing high luorocarbons (HFCs). purity hydrofluoroolefin by reacting certain undesirable US 2010/0193347 A1 Aug. 5, 2010 hydrofluoroolefin impurities and/or byproducts with an pentafluoropropene and the second hydrofluoroolefin com amine to produce a reaction product having a relatively high prises 2,3,3,3-tetrafluoropropene. boiling point and/or an ammonium salt. The amine reactive 0017. A sufficient amount of an amine is added to the impurity can then be removed from the desired composition mixture to form a combination comprising the second hydrof without significant yield loss. This method is particularly luoroolefin