US009108907B1 (12) United States Patent (10) Patent No.: US 9,108,907 B1 HL (45) Date of Patent: Aug. 18, 2015 (54) PROCESS FOR THE PRODUCTION OF (56) References Cited TAURINE FROMETHANOL U.S. PATENT DOCUMENTS (71) Applicant: Songzhou Hu, Princeton, NJ (US) 3,637.793 A * 1/1972 Lamberti ...................... 562/101 4,435,328 A * 3/1984 Lamberti et al. ................ 554.92 (72) Inventor: Songzhou Hu, Princeton, NJ (US) OTHER PUBLICATIONS Notice: Subject to any disclaimer, the term of this Manual of Patent Examining Procedure (MPEP) Ninth Edition, Mar. (*) 2014 section 714 "Amendments to the Claims’. patent is extended or adjusted under 35 Machine Translation of CN10148669 taken from espacnet.com.* U.S.C. 154(b) by 0 days. Breslow etal, Synthesis of Sodium Ethylenesulfonate from Ethanol J. Am..Chem.Soc., 1954, vol. 76, pp. 5361-5363. (21) Appl. No.: 13/999,203 * cited by examiner (22) Filed: Jan. 29, 2014 Primary Examiner — Karl J. Puttlitz (51) Int. C. (57) ABSTRACT C07C303/22 (2006.01) The present invention discloses a process for the preparation (52) U.S. C. of taurine from ethionic acid and ethanol by way of ethanol CPC .................................... C07C303/22 (2013.01) derived ethionic acid by the ammonolysis of ethionic acid and (58) Field of Classification Search by the ammonolysis of Sodium isethionate and Sodium vinyl None Sulfonate, key intermediates prepared from ethionic acid. See application file for complete search history. 2 Claims, 3 Drawing Sheets Production of Taurine via Ethionic Acid Ethanol Ethionic Acid Ammonia Evaporation Bleeding Fitration Solution Water Taurine & Ammonium Sulfate Filtration Annoniurn Sulfate Crystallization Filtration Filtration TAURINE Ammonium Sulfate U.S. Patent Aug. 18, 2015 Sheet 1 of 3 US 9,108,907 B1 Fig. 1. Production of Taurine via Ethionic Acid Ethanol 2SO3 Ammonia t Water Filtration Ammonium Sulfate Recrystallization Crystallization Filtration Filtration TAURINE Ammonium Sulfate U.S. Patent Aug. 18, 2015 Sheet 2 of 3 US 9,108,907 B1 Fig. 2. Production of Taurine via Sodium lsethionate Ethanol Ethionic Acid 2SO3 Water Sethionic Acid & Sulfuric Acid CaO or Sodium Sethionate di Sulfat Ca(OH)2 Calcium Sulfate Sodium Sulfate Filtration wavvannawawawa unawaw Calcium Sulfate Sodium sethionate Ammonia Sulfuric Acid Sodium Sulfate TAURINE U.S. Patent Aug. 18, 2015 Sheet 3 of 3 US 9,108,907 B1 Fig. 3. Production of Taurine via Sodium Vinyl Sulfonate Ethanol Ethionic Acid 2SO3 CaO or Sodium Vinyl Sulfonate f Ca(OH)2 Calcium Sulfate Sodium Sulfate Filtration WWMX101WWM Calcium Sulfate Sodium Vinyl Sulfonate Ammonia Sulfuric Acid Sodium Sulfate TAURINE US 9,108,907 B1 1. 2 PROCESS FOR THE PRODUCTION OF FIG.3 is a flow chart showing the third embodiment of the TAURINE FROMETHANOL present invention as a block diagram wherein taurine is pro duced by ammonolyis of sodium vinylsulfate intermediate TECHNICAL FIELD prepared from ethanol-derived ethionic acid. This invention relates generally to taurine and more par DESCRIPTION OF THE INVENTION ticularly to a process for the production of taurine from ethionic acid and ethanol by way of ethanol-derived ethionic In accordance with the present invention, there are dis acid. closed three preferred embodiments for producing taurine 10 from ethionic acid and more specifically from ethanol by way BACKGROUND OF THE INVENTION of ethanol-derived ethionic acid. These three embodiments are schematically illustrated in FIGS. 1 to 3 as a block dia Taurine can be referred to as 2-aminoethanesulfonic acid gram. and is one of the amino Sulfonic acids found in the tissues of In the first preferred embodiment of the present invention, many animals. Taurine is an extremely useful compound 15 because it has such pharmacological effects as detoxification ethionic acid is reacted with an aqueous solution of excess effect, fatigue-relieving effect and nourishing and tonifying ammonia to afford ammonium ethionate. The molar ratio of effect. As a result, taurine finds wide applications as an essen ammonia to ethionic acid can be in the range of 5 to 15, more tial ingredient for human and animal nutrition. preferably in the range of 8 to 10. Too little ammonia Taurine is currently produced in an amount of over 50,000 increases the formation of ditaurine, a byproduct, while more tons per year from ethylene oxide and monoethanolamine, ammonia is desirable for the reaction, too much ammonia both of which are petroleum derived chemicals. In addition to increases the process cost in the recovery of excess ammonia. their ever increasing cost, these two starting materials are The reactions are described as follows: toxic and for ethylene oxide difficult to handle. An alternate process for producing taurine from non-petroleum chemical 25 is, therefore, desirable. Such a process would be even more 1No + 2SOs —- Hos1 O N1)son valuable if taurine could be produced at a lower and more Ethionic Acid stable cost. O Ethanol is easily available at reasonable cost from natural HOs1 N-1Nson -- 3NH He Sources by fermentation as it is produced in large quantity as 30 HN a fuel additive and as an industrially important chemical. Y1NSOH (NH);so, Furthermore, an industrially applicable process for the con Taurine version of ethanol into ethionic acid is already known (U.S. Pat. No. 3,637.793, incorporated herein, by reference). This When the aqueous ammonia Solution of ammonium invention discloses novel methods for the conversion of etha 35 ethionate is Subjected to the ammonolysis reaction at a tem nol-derived ethionic acid into taurine. perature of 100 to 250° C., preferably from 130 to 220° C., at The disclosed process can also be applied to the production a pressure from the autogenous to 250 bar, preferably from of taurine from ethionic acid prepared from other materials 100 to 150 bar, ammonium ethionate is converted to taurine Such as ethylene and carbyl Sulfate. and ammonium sulfate, along with the formation of some It is, therefore, an object of this invention to provide a 40 ammonium isethionate. The ammonolysis can also be carried process for producing taurine from ethanol via ethanol-de out in the presence of catalyst Such as the alkaline salts of rived ethionic acid, which is economical and more competi Sodium, potassium and lithium. Such salts are sodium tive than current industrial processes using ethylene oxide hydroxide, potassium hydroxide, lithium hydroxide, Sodium and monoethanolamine as starting materials. carbonate, potassium carbonate, lithium carbonate, sodium It is another object of the present invention to disclose a 45 Sulfate, Sodium sulfite, potassium sulfate, potassium sulfite. process for the conversion of ethionic acid into sodium Any one or a combination of two or more these salts can be isethionate and Sodium vinyl Sulfonate, key intermediates for used as catalyst to influence the reaction. producing taurine from ethionic acid by a combined use of It is Surprising to disclose in the present invention that no calcium oxide/calcium hydroxide and Sodium Sulfate as alka acid neutralization of the aqueous Solution is needed when line media. 50 excess ammonia is removed first by flash distillation, then by It is a further object of the present invention to disclose a evaporation under vacuum. The concentrated Solution shows process for the cyclic use of alkali metal ions, more specifi a pH of 5-6, and upon cooling, taurine is crystallized and can cally, Sodium ion in the form of sodium sulfate, sodium be separated by filtration. Further concentration of the mother isethionate, and sodium ethionate, in the production of tau liquor results in the crystallization of a mixture of taurine and rine from ethionic acid via key intermediates of sodium 55 ammonium sulfate. The separation of taurine and ammonium isethionate and sodium vinyl Sulfonate. Sulfate can be accomplished according to a process disclosed in the Co-pending application, titled Cyclic Process for the DESCRIPTION OF THE DRAWINGS Production of Taurine from Monoethanolamine, incorpo rated herein in FIG.1. Crude taurine is upgraded to a product FIG. 1 is a flow chart showing the first embodiment of the 60 of pharmaceutical grade after one or more recrystallization in present invention as a block diagram wherein taurine is pro deionized water. duced by direct ammonolysis of ethanol-derived ethionic In the second preferred embodiment, ethionic acid, more acid. specifically, ethanol-derived ethionic acid, is first converted FIG. 2 is a flow chart showing the second embodiment of to sodium isethionate, which is then subjected to the the present invention as a block diagram wherein taurine is 65 ammonolysis reaction to yield Sodium taurinate. The process produced by ammonolyis of sodium isethionate intermediate is schematically illustrated in FIG. 2 and the reaction schemes prepared from ethanol-derived ethionic acid. are as follows: US 9,108,907 B1 4 invention is operationally simpler, and more economical. The O process requires only the monitoring of the pH in the reaction Hos1 Y1, YSOH Ho - system. Moreover, the costly base of sodium hydroxide is HON1 Nson + H2SO ->Ca(OH)2 + Na2SO4 replaced with the inexpensive calcium oxide or calcium 5 hydroxide, and sodium is introduced into the product in the "N1)-son, + CaSO4 form of sodium sulfate, which by itself is a byproduct in the production of taurine. "N1)-son, + NH3 -> "n-1\son, It is apparent from FIG. 2 that sodium sulfate is recycled "N-1\son, + H2SO4 -> continuously in the production of taurine from ethionic acid 10 by way of intermediate sodium isethionate, thus eliminating "N-1so + Na2SO4 an otherwise waste discharge. An added advantage is the increased recovery yield of taurine, since sodium Sulfate Production of alkali isethionate from ethionic acid is separated from its mixture with taurine invariably contains a 15 Small amount of taurine. This cyclic use of sodium sulfate in already known (U.S. Pat.