United States Patent (19) - (11) 4,178,317 A. Horn et al. 45 Dec. 11, 1979 54 MANUFACTURE OF OLEFINICALLY (56) References Cited UNSATURATED ALPHATIC OR CYCLOALIPHATIC HYDROCARBONS U.S. PATENT DDOCUME MENT S 4,024,171 5/1977 McArthur ...... 260/666A 75) Inventors: Peter Horn, Hirschberg; Otto-Alfred FOREIGN PATENT DOCUMENTS Grosskinsky; Hugo Fuchs, both of Ludwigshafen, all of Fed. Rep. of 943745 12/1963 United Kingdom. Germany Primary Examiner-Veronica O'Keefe w Attorney, Agent, or Firm-Keil & Witherspoon 73) Assignee: BSAngelschall, Fed. Rep. 57 ABSTRACT Olefinically unsaturated aliphatic or cycloaliphatic hy 21) Appl. No.: 907,678 drocarbons are manufactured by bringing alkanecar boxylic acids of 3 to 20 carbon atoms, alkanedicarboxy ilar. lic acids of 4 to 20 carbon atoms or 5-membered or (22) Filed: May 19, 1978 6-membered cycloalkanecarboxylic acids or their alkyl, O 9 cycloalkyl, aralkyl or phenyl esters, in the gas phase, at 30. Foreign Application Priority Data from 250 to 800 C., into contact with catalysts in Jun. 10, 1977 (DE) Fed. Rep. of Germany. 2726106 which the active composition consists of boron trioxide, boric acid and/or boron nitride, together with one or 51) Int. C.’...... C07C3/00 more of the oxides of aluminum, silicon, tin, lead, tita 52 U.S. C...... 585/357; 585/638; nium and zirconium. 585/640 (58) Field of Search ...... 260/666 A 9 Claims, No Drawings 4,178,317 1. 2 ahydrobenzoate, cyclohexyl hexahydrobenzoate, MANUFACTURE OF OLEFINICALLY phenyl hexahydrobenzoate and benzyl hexahydroben UNSATURATED ALPHATIC OR ZOate. : .. 8 CYCLOALPHATIC HYDROCARBONS Of course the decarbonylation of monocarboxylic acids or their esters gives monoolefinically unsaturated The present invention relates to a process for the compounds with one carbon atom fewer, whilst the manufacture of olefinically unsaturated aliphatic or decarbonylation of dicarboxylic acids gives diolefins cycloaliphatic hydrocarbons by heating alkanecarboxy with 2 carbon atoms fewer. lic acids of 3 to 20 carbon atoms, alkanedicarboxylic The reaction is carried out in the gas phase. Advanta acids of 4 to 20 carbon atoms or 5-membered or 6-men 10 geously, the carboxylic acids, or their esters, used as bered cycloalkanecarboxylic acids or the alkyl, cycloal starting materials, are vaporized, but inert gases, such as kyl, aralkyl or phenyl esters of these at from 250 to nitrogen, noble gases, carbon dioxide, carbon monox 800 C. in the gas phase in the presence of a catalyst. ide, steam or flue gases may additionally be employed in There is a frequent requirement to convert carboxylic order to facilitate using the starting materials in the gas acids, obtained, for example, by oxidation processes, or 15 phase. The amount of such inert gas used is not critical, to convert carboxylic acids or their esters, obtained as since the gas merely serves as a carrier gas. by-products of carbonylation processes, into the corre The reaction is advantageously carried out under sponding olefins by decarbonylation. The decarbonyla atmospheric pressure, slightly superatmospheric pres tion of carboxylic acids of their esters is of particular sure, or reduced pressure, for example down to 20 mm interest if it permits olefins which are not readily acces 20 Hg. A pressure range from atmospheric pressure to 100 sible to be obtained from the more easily accessible mm Hg has proved particularly suitable. carboxylic acids or their esters. The reaction takes place at from 250 to 800. C., It is true that German Published Application DAS advantageously from 250 to 700° C. No. 1,158,050 has disclosed that carboxylic acids can be The reaction is carried out in the presence of cata converted into acid anhydrides and/or ketones by heat 25 lysts, of which the active composition consists of boron ing at from 250 to 800° C. in the gas phase in the pres trioxide, boric acid and/or boron nitride, together with ence of a catalyst comprising oxides, hydroxides and one or more of the oxides of aluminum, silicon, lead, phosphates of main groups 2 to 4 and sub-groups 3 to 8 titanium or zirconium. Preferred active compositions of the periodic table. However, the corresponding ole contain from 10 to 60, especially from 20 to 55, 7% by fins cannot be obtained by this method. 30 weight of boron trioxide, boric acid and/or boron ni It is an object of the present invention to provide a tride. The remainder of the active composition then process by means of which carboxylic acids or their consists of one of the above oxides. Active compositions esters can be converted by decarbonylation into the which contain boron trioxide or boric acid, especially corresponding olefins. the former, have proved particularly suitable. We have found that this object is achieved by a pro 35 The preferredoxides also present in the active com cess for the manufacture of olefinically unsaturated positions include alumina, e.g. in the form of hydrargil aliphatic or cycloaliphatic hydrocarbons by heating lite, boehmite or bayerite and their dehydration prod alkanecarboxylic acids of 3 to 20 carbon atoms, al ucts, e.g. y-, e- or 8-alumina, as well as tin dioxide, kanedicarboxylic acids of 4 to 20 carbon atoms or 5 titanium dioxide and silica gel. The use of alumina, or of membered or 6-membered cycloalkanecarboxylic acids 40 titanium dioxide in the anatase modification, is pre or their alkyl, cycloalkyl, aralkyl or phenyl esters at ferred. a-Alumina is industrially of particular impor from 250 to 800° C. in the gas phase in the presence of tance since it reduces the isomerization of the olefini a catalyst whereof the active composition consists of cally unsaturated hydrocarbons formed. baron trioxide, boric acid and/or boron nitride together Further catalysts according to the invention are those with one or more of the oxides of aluminum, silicon, tin, 45 resulting from mixed phase formation between one of lead, titanium or zirconium. the boron compounds used and the oxides mentioned The new process has the advantage that carboxylic above, e.g. boron trioxide and alumina, giving com acids or their esters can be converted in a simple manner pounds of the empirical formula 9 Al2O3. 2 B2O3 or 2 into olefins. It has the further advantage that it is easily Al2O3. B2O3. In such mixed phases, alumina is no scaled up to industrial operation and runs with good 50 longer detectable by X-ray crystallography. yields and good conversions. Advantageously, the active compositions addition It is preferred to start from an alkanecarboxylic acid ally contain one or more of the elements of group VIII of 3 to 16 carbon atoms, an alkanedicarboxylic acid of 4 of the periodic table, manganese, chromium, copper, to 12 carbon atoms or cyclohexanecarboxylic acid. zinc, cadmium, silver and/or gold. The said elements. Their alkyl, cycloalkyl, aralkyl and phenyl esters, espe 55 are preferably present in the active composition in an cially their alkyl esters, where alkyl is of 1 to 8 carbon amount of from 0.1 to 10% by weight (calculated as atoms, their cyclohexyl esters, their benzyl esters and metal), based on the active composition. their phenyl esters, are also suitable. The use of the free Suitable catalysts are prepared by, for example, mix carboxylic acids or of the corresponding methyl esters ing alumina and boron oxide or boric acid, or com as starting materials is preferred. The new process is of 60 pounds which form these on heating, e.g. ammonium particular industrial importance for the manufacture of borate, with or without the addition of compounds of cyclohexene from hexahydrobenzoic acid or its esters. the above heavy metals, e.g. manganese nitrate, manga Specific examples of suitable starting materials are pro nese acetate, cobalt nitrate, cobalt acetate, nickel ni pionic acid, methyl propionate, isobutyric acid, butyl trate, rhodium chloride, tris-(triphenylphosphine)- isobutyrate, caproic acid, methyl caproate, decanecar 65 rhodium chloride, iridium chloride, palladium nitrate, boxylic acid, palmitic acid, methyl palmitate, dimethyl platinum chloride, zinc nitrate, cadmium nitrate, copper adipate, dimethyl methylglutarate, methyl cyclopen nitrate, silver nitrate or gold chloride, if appropriate tanecarboxylate, hexahydrobenzoic acid, methylhex working the mixture into a paste with water and knead 4, 178,317 3 4. ing the paste, and molding the material into shapes, e.g. pills, tablets or extrudates. Advantageously, the mate EXAMPLE 1. rial is then dried and heated at up to 400 C. If the active 200 g of hexahydrobenzoic acid per hour were passed composition is to be used as a fluidized bed catalyst, it is from a vaporizer into a fluidized bed reactor at 550 C., advisable to comminute the moldings to the desired 5 the reactor being charged with 630g of a catalyst which size, e.g. to an average particle size of from 0.01 to 2 consisted of 52.3 percent by weight of y-Al2O3 and 45.5 mm, especially from 0.2 to 1 mm. The catalyst composi percent by weight of B2O3, and had a particle size of tion is then heated at from 600 to 1,500 C., preferably from 0.1 to 0.3 mm and a bulk density of 0.63 kg per from 700 to 1,300° C. and especially from 1,000 to liter. The catalyst was fluidized by means of the hexahy 1,200 C. for a period of from 15 minutes to 20 hours, O drobenzoic acid vapor and a slight stream of nitrogen, especially from 30 minutes to 5 hours. as well as by maintaining a reduced pressure of 360 mm In another advantageous embodiment, the active Hg. The resulting reaction vapors were condensed. The compositions according to the invention are obtained following products were isolated after 3 hours' opera by impregnating, for example, alumina or one of the tion: 86 g of water and 384 g of an organic phase. The other oxides mentioned, which already have a particle 15 organic phase was washed with aqueous sodium bicar size of from 0.1 to 2 mm, with boron trioxide or boron bonate solution in order to remove traces of uncon compounds which under the conditions of manufacture verted hexahydrobenzoic acid and was then distilled. of the catalyst are converted into boron trioxide or Examination of the distillate by gas chromatography boric acid, at an elevated temperature, under pressure, showed the following composition: 63% by weight of in the presence of a solvating agent. Suitable materials, 20 cyclohexene, 29% by weight of 1-methylcyclopent in addition to boron trioxide and boric acid, are boron 1-ene, 4% by weight of 3-methylcyclopent-l-ene and trichloride, boron triflouride and ammonium borate. An 4% by weight of 4-methylcyclopent-1-ene. advantageous solvating agent is water, with or without EXAMPLE 2 the addition of small amounts of ammonia or mineral 25 The procedure followed was as described in Example acids, e.g. hydrochloric acid or perchloric acid; other except that before use the catalyst employed in Exam suitable solvating agents are alcohols, e.g. methanol, ple 1 was heated for 4 hours at 1,150 C. After 7 hours' ethanol and glycerol. Advantageously, the oxides are operation, 61 g of water and 356 g of an organic phase, impregnated under superatomospheric pressure, e.g. at consisting, after working up as described in Example 1, from 1.1 to 20 bars, at an elevated temperature, e.g. at 30 of 72% by weight of cyclohexene and 23% by weight of from 50 to 250 C. The weight ratio of solvent to start 1-methylcyclopent-1-ene, were obtained. ing materials used is advantageously from 1:1 to 10:1. In particular, equal parts by weight of solvent and starting EXAMPLE 3 materials are used. Such an impregnated catalyst is then The procedure followed was as described in Example dried at from 50' to 200 C. and subsequently heated at 35 1, except that the catalyst additionally, contained 1.3% from 600 to 1,500 C. The catalysts may be used unsup by weight of rhodium. After 3 hours' operation, 69 g of ported or on carriers. water and 366 g of an organic phase, consisting, after The catalysts may be used as a fixed bed, but are working up as described in Example 1, of 74% by preferably used in a fluidized bed, in which they un weight of cyclohexene, 19.6% by weight of 1-methyl-1- dergo a rising and falling movement. Residence times of 40 cyclopent-1-ene and 5.5% by weight of benzene, were from 0.01 to 50 seconds over the catalyst have proved obtained. advantageous for the reaction. By way of example, the process may be carried out EXAMPLE 4 by fluidizing a finely divided supported catalyst, for 300 g of hexahydrobenzoic acid per hour were passed example aluminum oxide containing boron trioxide, in 45 from a vaporizer into a fluidized bed reactor at the an apparatus suitable for producing a fluidized bed, reaction temperature of 480 C., the reactor being heating the catalyst to the stated temperature and pass charged with 795 g of a catalyst which consisted of 35 ing the carboxylic acid ester or carboxylic acid in the percent by weight of y-Al2O3, 45 percent by weight of gaseous form, with or without a carrier gas, through the B2O3 and 20 percent by weight of SnO2, and had a catalyst bed from below. Of course, it is also possible to 50 particle size of from 0.1 to 0.3 mm and a bulk density of pass the liquid carboxylic acid or liquid ester into the 0.795 kg per liter. The catalyst was fluidized by means heated catalyst bed. The gas mixture obtained is cooled of the hexahydrobenzoic acid vapor and a slight stream and in doing so the olefins, unconverted starting materi of nitrogen, as well as by maintaining a reduced pres als and, when using esters, the corresponding alcohols, sure of 360 mm Hg. The resulting reaction vapors were are condensed out. The inert gaseous constituents can 55 condensed. After 4 hours' operation, 186 g of water and be re-used as the carrier gas. Equally, unconverted 813 g of an organic phase consisting, after working up starting materials can be recycled to the reaction. It as described in Example 1, of 68.3% by weight of cyclo may or may not be necessary to separate the olefins hexene and 19.2% by weight of 1-methyl-cyclopent formed from the alcohol by-products, for example by 1-ene, were isolated. distillation. Olefinically unsaturated hydrocarbons manufactured EXAMPLE 5 by the process of the invention may be used, for exam 200 g of methyl hexahydrobenzoate per hour were ple, to manufacture aldehydes by the oxo reaction. Cy passed from a vaporizer into a fluidized bed reactor at clohexene obtained by the process of the invention may the reaction temperature of 550 C., the reactor being be used for the manufacture of cyclohexanol, for exam 65 charged with 630 g of a catalyst which consisted of 52.3 ple as described in British Pat. No. 339,592. percent by weight of y-Al2O3 and 45.5 percent by The Examples which follow illustrate the process of weight of B2O3, and had a particle size of from 0.1 to 0.3 the invention. mm and a bulk density of 0.63 kg per liter. The catalyst 4,178,317 5 6 was fluidized by means of the methylhexahydrobenzo ate vapor and a slight stream of nitrogen, as well as by EXAMPLE 10 maintaining a reduced pressure of 360 mm Hg. The 200 g of caproic acid per hour were passed from a resulting reaction vapors were condensed. After 3 vaporizer into a fluidized bed reactor at the reaction hours' operation of the installation, 184g of an organic 5 temperature of 550° C., the reactor being charged with phase, consisting, after washing with water and distilla 630 g of a catalyst which consisted of 50% by weight of tion, of 82.3% by weight of cyclohexene and 17.7% by B2O3 and 50% by weight of y-Al2O3, and had a particle weight of 1-methylcyclopent-1-ene, were isolated. size of from 0.1 to 0.3 mm and a bulk density of 0.63g per liter. The catalyst was fluidized by means of the EXAMPLE 6 10 caproic acid vapor and a slight stream of nitrogen, as well as by maintaining a reduced pressure of 360 mm The procedure followed was as described in Example Hg. The resulting reaction vapors were condensed. 3 except that the reaction temperature was 700 C. After 3 hours' operation of the installation, 229 g of an After 3 hours' operation of the installation, 265 g of an organic phase consisting of 1.5% by weight of 3 organic phase consisting, after washing with water and 15 methylbut-1-ene, 14.3% by weight of pent-1-ene, 10% distillation, of 74% by weight of cyclohexene and 25% by weight of 2-methylbut-1-ene, 30% by weight of by weight of 1-methyl-cyclopent-1-ene, were isolated. trans-pent-2-ene, 17.2% by weight of cis-pent-2-ene and EXAMPLE 7 21% by weight of 2-methylbut-2-ene were isolated. We claim: 200 g of cyclohexyl hexahydrobenzoate per hour 1. A process for the manufacture of olefinically unsat were passed from a vaporizer into a fluidized bed reac urated aliphatic or cycloaliphatic hydrocarbons which tor at the reaction temperature of 600 C, the reactor comprises: being charged with 630 g of a catalyst which consisted contacting at least one member of the group consist of 52.3 per cent by weight of y-Al2O3 and 45.5 percent ing of (a) alkanecarboxylic acids of 3 to 20 carbon by weight of B2O3, and had a particle size of from 0.1 to atoms, (b) 5-membered or 6-membered cycloalk 0.3 mm and a bulk density of 0.63 kg per liter. The anecarboxylic acids and (c) alkyl, cycloalkyl, aral catalyst was fluidized by means of the cyclohexylhex kyl or phenyl esters of (a) or (b), ahydrobenzoate vapor and a slight stream of nitrogen, in the gas phase, as well as by maintaining a reduced pressure of 360 mm at a temperature of from about 250 to 800 C., Hg. The resulting reaction vapors were condensed. 30 with a catalyst in which the active material is a com After 3 hours' operation of the installation, 440 g of an bination of a compound selected from the group organic phase were obtained, which, after washing with consisting of boron trioxide, boric acid and boron water and distillation, consisted of 54% by weight of nitride and a compound selected from the group 1-methylcyclopent-1-ene and 42.6% by weight of cy consisting of aluminum oxide, silicon dioxide, tita clohexene. 35 nium dioxide and zirconium dioxide. 2. The process of claim 1, wherein the temperature is EXAMPLE 8 maintained at from 250' to 700 C. 3. The process of claim 1, wherein the catalyst con The procedure followed was as described in Example tains from 10 to 60% by weight of boron trioxide, boric 4, except that phenyl hexahydrobenzoate was used as 40 acid and/or boron nitride, based on the active composi the ester and that the reaction temperature was 700 C. tion. After 3 hours' operation of the installation, 243 g of 4. The process of claim 1, wherein boron trioxide is phenol and 266 g of an organic phase consisting, after used. washing with water and distillation, of 62% by weight 5. The process of claim 1, wherein the active compo of 1-methylcyclopent-1-ene and 32% by weight of cy 45 sition additionally contains one or more of the elements clohexene, were isolated. of group VIII of the periodic table, manganese, chro EXAMPLE 9 mium, copper, zinc, cadmium, silver or gold. 6. The process of claim 1, wherein alumina is used. The procedure followed was as described in Example 7. The process of claim 1, wherein a-alumina is used. 4, except that the ester employed was benzyl hexahy 50 8. The process of claim 1, wherein hexahydrobenzoic drobenzoate and the reaction temperature was 700 C. acid or one of its alkyl, cycloalkyl, aralkyl or phenyl After 3 hours' operation, 77 g of toluene, 31 g of benzal esters is used as the starting material. dehyde, 51 g of benzyl alcohol and 122 g of an organic 9. The process of claim 1, wherein the catalyst corre phase consisting, after washing with water and distilla sponds to the composition 9 Al2O3. 2 B2O3 or 2 Al2O3 tion, of 44% by weight of 1-methylcyclopent-1-ene and 55 . B2O3. y 36% by weight of cyclohexene, were isolated. as at . .

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