United States Patent (19) 11) 4,219,685 Savini 45 Aug. 26, 1980 (54) IMPROVING ODOR OF ISOPROPANOL Attorney, Agent, or Firm-C. Leon Kim; Rebecca Yablonsky 75 Inventor: Charles Savini, Warren, N.J. 57 ABSTRACT 73 Assignee: Exxon Research & Engineering Co., Methods for deodorizing lower alcohols such as ethanol Florham Park, N.J. and isopropyl alcohol and their oxy derivatives such as ethers and esters are disclosed, including contacting 21 Appl. No.: 31,761 these compounds with a deodorizing contact mass com 22 Filed: Apr. 20, 1979 prising, on a support, metals and/or metal oxides, pref erably of the metals of Group IB, VIB and VIII of the Periodic Table, where the metal oxides are at least par Related U.S. Application Data tially reduced to metal and the deodorizing contact 63 Continuation-in-part of Ser. No. 908,910, May 24, mass has a minimum particle dimension of greater than 1978, abandoned, which is a continuation-in-part of about 0.254 mm so as to be in a form suitable for use in Ser. No. 834,240, Sep. 19, 1977, abandoned. a fixed bed contacting process. In a preferred embodi ment, isopropyl alcohol is deodorized employing such 51 Int. Cl’.............................................. CO7C 29/24 deodorizing contact masses, preferably comprising 52 U.S. Cl. .............. ... 568/917; 568/922 Group VIII metals such as nickel, iron, cobalt and the 58) Field of Search ................................ 568/917,922 like, on a support, so that the contact mass has a surface 56) References Cited area less than about 1,500 m2 per gram. Overall isopropyl alcohol finishing procedures are also U.S. PATENT DOCUMENTS disclosed employing such deodorizing methods in com 2,584,325 2/1952 Bowen et al......................... 568/922 2,585,816 2/1952 Mertzweiller ...... 568/922 bination with extractive distillation procedures to pro 2,857,436 0/1958 MacKinder et al. ... 568/917 duce a high grade, e.g., 91%, and/or anhydrous grade 3,624,165 11/1971 Dehn et al. ......... 568/922 isopropyl alcohol from a crude isopropyl alcohol 3,960,672 6/1976 Ester et al. ... ... 203/37 stream containing more than about 0.0005 percent wa 3,990,952 11/1976 Katzen et al. ........................ 568/921 ter. Primary Examiner-Joseph E. Evans 15 Claims, 3 Drawing Figures U.S. Patent Aug. 26, 1980 Sheet 1 of 2 4,219,685 U.S. Patent Aug. 26, 1980 Sheet 2 of 2 4,219,685 {} SN3, Ni Y O CO OHO) v Ad Old OSl 4,219,685 2 Thus, for example, U.S. Pat. No. 2,356,689 teaches a IMPROVING ODOR OF SOPROPANOL method for the purification of such alcohols employing solid cuprous chloride in specified amounts to stabilize CROSS-REFERENCE TO RELATED and improve the odor of these alcohols. This method is APPLICATIONS directed towards the removal of certain small quantities of odor causing impurities therefrom. In addition, this This application is a C.I.P. of Ser. No. 908,910, filed method employs the cuprous chloride as part of the May 24, 1978, now abandoned, which is a C.I.P. of Ser. alcohol finishing or purification procedure. No. 834,240, filed Sept. 19, 1977, now abandoned. Furthermore, U.S. Pat. No. 2,663,745 discloses a FIELD OF THE INVENTION 10 process whereby the quality of various alcohols is im proved by intimate contact with small sized glass parti The present invention relates to methods for deodor cles, i.e., having particle sizes of between about 4 and 20 izing lower alcohols and various oxygenated com mesh. pounds derived therefrom. Particularly, the present In another area, not concerned with alcohols made invention relates to methods for deodorizing C2 and C3 15 by hydration methods but rather with oxo alcohols of alcohols, e.g., ethanol and isopropyl alcohol, and their higher molecular weight, C4-C12, made by the hy ether and ester derivatives, e.g., diethyl ether. Still more droformylation of olefins followed by hydrogenation particularly, the present invention relates to method for with sulfided catalysts, the patentee in U.S. Pat. No. deodorizing isopropyl alcohol in connection with com 2,585,816 discloses the treatment of alcohols such as mercial isopropyl alcohol finishing processes. The 20 isooctanol of high sulfur content by metals such as mer C2-C3 alcohols are customarily manufactured industri cury, copper and nickel, viz., Raney nickel or nickel on ally by various methods of dehydration. a support, essentially for reducing the sulfur content BACKGROUND OF THE INVENTION thereof, e.g. from 58-83 ppm to 10–27 ppm, thereby improving color. However, such treatment is not capa The production and sale of various oxygenated com 25 ble of deodorizing isooctanol to produce a pleasant pounds, such as ethers and in particular lower alcohols smelling product, as demonstrated in Example 8 below. such as ethanol and isopropyl alcohol has been hindered In a more recent development, Japanese Pat. No. by the presence of highly undesirable odors in the com 51-1684 discloses another method for purifying isopro mercial products presently being produced. These un pyl alcohol comprising contacting the alcohol with desirable odors have been found to be particularly in 30 various Raney metals, including Raney nickel. This tense and to have caused considerable difficulty in the method includes contacting with the Raney metal, pref marketing of these products, which presently have a erably in the presence of a reducing gas such as hydro wide variety of commercial uses. In particular, these gen. The Raney metals are present in amounts of from commercial uses have included use as solvents, disinfec about 0.01 to 5 parts per hundred parts of alcohol. This tants, spray products, and in many areas where the 35 procedure is not commercially feasible, however, par presence of such odors is of extreme significance, par ticularly due to the fact that the Raney metals are ex ticularly is cosmetics and medicinal formulations. tremely unstable and potentially dangerous to use. This problem is particularly significant with respect The removal of odor from lower alcohols is difficult, to the commercial production of isopropyl alcohol, inasmuch as the contaminants responsible are present in which in view of its excellent solubility, low toxicity, very small amounts and one doesn't know just which and cost, has become widely used in such areas as cos contaminants are causing the odor. Although the refer metic products, disinfectants, etc. There has thus been ences cited date back to the early 50's, the problem of considerable need for commercial processes to deodor deodorizing isopropanol has persisted up to present ize these types of products without unnecessarily hin times. Thus, the problem is a difficult one, the solution dering the commercial production thereof. These ef. 45 to which has a high degree of unpredictability so that forts have generally been centered upon processes such this is an area where there is little obviousness. as extractive distillation processes, use of ion exchange The search has therefore continued for new methods resins, adsorption on compounds such as activated char for deodorizing lower alcohols, i.e. C2 and C3 alcohols, coal, activated alumina, sand, and the like. In many of such as isopropyl alcohol, and their ether and ester these cases the patentees have attempted to analyze the 50 derivatives such as diethyl ether in a commercially various possible causes of negative odor characteristics acceptable and simple manner. in these materials, such as in U.S. Pat. No. 2,729,682, assigned to the assignee of the present invention. In the SUMMARY OF THE INVENTION latter patent, however, the patentee attempts to over It has now been unexpectedly discovered that said come the problems of "recycle' odor by incorporating 55 lower alcohols and their oxygenated compounds can be into the propylene stream a C4 to C6 mono-olefin, foll deodorized to a highly sufficient extent in a simple, lowed by water extractive distillation. highly economical, and highly adaptable manner by In addition, U.S. Pat. No. 2,857,436 teaches the odor contacting these compounds with a deodorizing contact improvement of lower alcohols with successive passage mass comprising a metal and/or a metal oxide which is of these materials through two different contact masses, at least partially reduced to metal and where the de a bed of unglazed porcelain and a bed of iron metal such odorizing contact mass has a suitable dimension, e.g., a as steel wool, so that the process is inherently uneco minimum particle dimension of greater than about one nomic. The patentee also teaches that other metals such hundredth of an inch (1/100"), so that it can be effec as copper, nickel and zinc have no effect. tively employed in a fixed bed contacting process. That None of these prior methods have, however, resulted 65 is, these particle sizes permit the deodorizing contact in a commercially acceptable method for arriving at mass to be used in a column and to support itself suffi products having acceptable odor levels with economi ciently therein to be useful in such fixed bed contacting cally and commercially acceptable utility. processes. 3 4,219,685 4. It is therefore necessary that the deodorizing contact FIG. 3 is a graph showing isopropyl alcohol odor mass have such a minimum particle dimension of intensity plotted against sulfur therein in parts per bil greater than about 0.254 mm (1/100 inches), but prefer lion. ably a minimum particle dimension of greater than about 0.794 mm (1/32 inches), and most preferably less DETAILED DESCRIPTION than about 6.352 mm ( inches). One aspect of the significance of the present inven In a preferred embodiment, the deodorizing contact tion is the fact that it represents a simple, economically mass thus has an effective surface area of less than about desirable, efficient method for incorporation into con 1,500 m2 per gram, and most preferably the deodorizing ventional processing techniques for the production of contact mass comprises.