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Sept. 5, 1967 R. B. DUKE. J.R., ETAL 3,340,312 MANUFACTURE OF NEOPENTYL GLY COL AND ISOBUTANOL Fied Oct. 2, 1964 m 2 Sheets-Sheet 2 N w//77OO /77/Og Ae/Ay 29 -MM/77Oo 13/7GOyed 29 s APOY A. DUAE, JR. M/1. TOW A. AAAAY A/OWAAPA AV. WARIGHT, WA INVENTORS 77OAMEYS 3,340,312 United States Patent Office Patented Sept. 5, 1967 1. 2 culation through line 5, pump 6, line 7, heat exchanger 3,340,312 11, line 12, conduit 13 while another portion of the mix MANUEFACTURE OF NEOPENTYL GLYCOL ture is withdrawn from reactor 15 by line 16 and passed AND SOBUTANOL Roy B. Duke, Jr., Smyrna, Ga., and Milton A. Perry and to decanter 17 where the aqueous and organic phases are Howard N. Wright, Jr., Longview, Tex., assignors to separated. The aqueous phase is withdrawn from decanter Eastman Kodak Company, Rochester, N.Y., a corpo 17 by line 21 and discarded via line 22 or recycled to line ration of New Jersey 5 via line 23. The organic phase containing hydroxy Filed Oct. 21, 1964, Ser. No. 405,525 pivaldehyde and isobutyraldehyde is removed from de 5 Claims. (C. 260-635) canter 17 and passed into hydrogenation reactor 25 by O line 24. Hydrogen is introduced into hydrogenation re This invention relates to a novel chemical process and actor 25 via line 26 and is contacted with hydroxy more particularly to a novel process for the simultaneous pivaldehyde and isobutyraldehyde in the presence of a production of neopentyl glycol and isobutanol. copper-chromium oxide hydrogenation catalyst, e.g., a Neopenty glycol is a valuable chemical compound Supported barium activated copper chromite catalyst. The which has heretofore been prepared by various expensive 5 hydrogenation product containing neopentyl glycol and and inefficient processes. We have now discovered a isobutanol is removed from hydrogenation reactor 25 process for the simultaneous production of neopenty and passed into isobutanol column 31 via line 27. Iso glycol and isobutanol by which it is possible to manu butanol column 31 is operated at subatmospheric pres facture neopentyl glycol and isobutanol in large quan Sure and isobutanol and lower boiling components are tities at a reasonable cost. 20 removed overhead via line 32. The components of the The process of our invention is made possible by our hydrogenation product having a boiling point above that discovery of a novel combination of reaction conditions of isobutanol are removed from the bottom of column 31 and purification procedures by which the efficient pro and passed into salts column 34 via line 33. Salts column duction of neopentyl glycol and isobutanol can be 34 is operated at subatmospheric pressure, e.g., a pressure achieved. In particular, the process of our invention is 25 of about 5 to about 200 mm. Hg, and any metal salts of made possible by our discovery that mixtures of hydroxy organic acids (formed, for example (by the Cannizzaro pivaldehyde and isobutyraldehyde can be hydrogenated reaction of aldehydes with the aldol catalyst) and any in the presence of copper-chromium oxide hydrogenation hydrogenation catalyst residues are removed from the catalysts to give high yields of isobutanol and neopenityl bottom of salts column 34 and discarded via line 36. The glycol and by our discovery that mixtures of isobutyr 30 overhead stream from salts column 34 is removed via aldehyde and hydroxypivaldehyde suitable for hydro line 35 and introduced into low boilers column 37. genation in the presence of a copper-chromium oxide Low boilers column 37 is operated so that the overhead hydrogenation catalyst can be prepared by employing a stream which is removed via line 41 is composed of mate stoichiometric excess of isobutyraldehyde in the aldol rial having a boiling point below that of neopentylglycol condensation of isobutyraldehyde and formaldehyde to 35 and the bottoms stream which is removed via line 42 is hydroxypivaldehyde. composed of neopenty glycol and higher boiling material. The process of our invention thus involves three chem The overhead stream is passed via line 41 into line 52 ical reactions which can be represented by the following and recycled to hydrogenation reactor 25 by line 24. The equations: 'bottoms stream is passed via line 42 into neopentylglycol 40 column 43 where it is separated into an overhead stream () O CE O CE. O. comprising Substantially pure neopentyl glycol and a bot H&H -- CH-bH-6H --> HO-CH-6-5A toms stream composed of material having a boiling point above that of neopentyl glycol. The substantially pure &H, neopentylglycol is removed overhead from neopenty gly (II) CH O CH 45 col column 43 via line 44 and the bottoms stream is re Ho-CH-d-dri -- E --> Ho-CH-)-CH-OH moved via line 45 and recycled to hydrogenation reactor 25 via valved line 49, line 52 and line 24. Alternatively, &H, &H, the bottoms stream from neopentylglycol column 43 is (II) C O C3 introduced into high boilers column 46 by line 45 and 50 valved line 48. High boilers column 46 is preferably op CH-CH-CH -- H - CEs-CE-CH-OH erated So that the bottoms stream which is removed via The process of our invention can be carried out in a line 47 contains 2,2,4-trimethylpentane-1,3-diol and com batch or continuous manner. However, the process is ponents having a boiling point above that of 2,2,4-tri preferably conducted in a continuous manner. methylpentane-1,3-diol and the overhead stream which is The following description of the process of our inven 55 removed via line 51 and recirculated to hydrogena tion has reference to FIG. 1 which is a schematic flow tion reactor 25 via lines 52 and 24 is composed of ma diagram of one embodiment of our process. terial having a boiling point below that of 2,2,4-trimethyl Isobutyraldehyde is continuously fed into line 4 via pentane-1,3-diol. line 1 and formaldehyde, e.g., an aqueous solution of An alternate procedure for purifying the neopentylgly formaldehyde, is continuously fed into line 4 via line 2. 60 col produced by the process of our invention is illustrated An aqueous alkali metal hydroxide aldol catalyst, e.g., by the schematic flow diagram of FIG. 2. A fraction of a 0.25 percent solution of sodium hydroxide, is continu the reaction product having a boiling point above that of ously fed into line 4 via line 3. The mixture of iso isobutanol is obtained by removing isobutanol by frac butyraldehyde, formaldehyde, and aqueous aldol catalyst tional distillation from the product obtained by hydrogen is drawn through line 5 by pump 6 and forced through 65 ating the product of the aldol condensation of isobutyral line 7. The mixture passes through heat exchanger 11 dehyde and formaldehyde, as illustrated in FIG. 1. This where the temperature of the mixture is adjusted to the fraction, boiling above isobutanol, is then introduced into desired reaction temperature, e.g., about 15° C. The mix salts column 34 via line 33. Salts column 34 is operated at ture is then passed into aldo1 reactor 15 via line 12 and Subatmospheric pressure, e.g., a pressure of about 5 to passes through conduit 13 from which it is directed O about 200 mm. Hg, and any metal salts of organic acids against concave baffle plate 14. A portion of the mixture and any hydrogenation catalyst residues are removed from is withdrawn from aldol reactor 15 by line 4 for recir the bottom of salts column 34 and discarded via line 36. 3,340,312 3 4 The overhead from salts column 34 is removed and passed The organic phase containing hydroxypivaldehyde and to residue column 61 via line 35. isobutyraldehyde is hydrogenated in the presence of a Residue column 61 is operated so as to remove neopen- copper-chromium oxide hydrogenation catalyst. The hy tyl glycol and all lower boiling components overhead and drogenation reaction can be conducted at a temperature to remove all components having a boiling point above 5 of about 175 C. to about 220 C. and a hydrogen pres that of neopentyl glycol as a bottoms fraction. The over- sure of about 900 to about 6000 pounds per square inch, head from residue column 61 containing neopentyl glycol gage (hereinafter referred to as p.s.i.g.). The hydrogen and lower boiling components is removed and passed to ation reaction is preferably carried out at a temperature product column 64 via line 62. Product column 64 is of about 190° C. to about 200° C. and a hydrogen pres operated so that the bottoms fraction comprises substan- 10 sure of about 2100 to about 4600 p.s.i.g. tially pure neopentylglycol. The substantially pure neo- The copper-chromium oxide hydrogenation catalysts pentyl glycol is removed from product column 64 via line which are useful in the process of our invention are com 66. The overhead from product column 64, having a boil- mercially available catalysts of known composition. These ing point below that of neopentyl glycol, is removed via catalysts are often referred to as copper chromite catalysts line 65 and introduced into line 52 for recycle to the hy- 15 though they do not necessarily contain the compound cop drogenation reactor. (the hydrogenation reactor is shown per chromite. Among the useful catalysts are those dis as hydrogenation reactor 25 of FIG. 1). closed in U.S. Patents 2,137,407; 2,091,800; 2,782,243; The bottoms fraction from residue column 61, having and 2,544,771.