Method for producing an olefin by catalytic conversion of at least one alcohol

Abstract

The invention relates to a method for preparing an olefine, a diene or a polyene, by catalytic conversion of at least one alcohol having a carbon chain of at least three carbon atoms and different from propan-2-ol, in the presence of at least one catalyst based of at least one phosphate of a metal or several metals M, M being chosen from among the 15 lanthanides (Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium), Yttrium, Scandium and Boron, and the applications of this method.

Claims

1. A method for preparing an olefine, a diene or a polyene, by catalytic conversion of at least one alcohol having a carbon chain of at least three carbon atoms different from propan-2-ol, in the presence of at least one catalyst of at least one phosphate of a metal M, M being chosen from Lanthanum, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Yttrium, and Scandium, wherein said olefine, diene or polyene is obtained by catalytic conversion of said alcohol or mixture of corresponding alcohols, having a carbon chain of the same number of carbon atoms.

2. The method according to claim 1, wherein the metal(s) are chosen from among Lanthanum, Neodymium, Gadolinium and Samarium.

3. The method according to claim 1, wherein said catalyst is doped by at least one alkali metal chosen from among Cesium, Rubidium and Potassium and/or a transition metal chosen from among groups 4 to 7.

4. The method according to claim 1, wherein the molar ratio P/M varies from 0.5 to 2, M representing the metal or the sum of the metals M which constitute said catalyst.

5. The method according to claim 4, wherein the molar ratio P/M varies from 0.9 to 1.5.

6. The method according to claim 1, wherein the catalyst is regenerated by air or by diluted air which has been enriched in situ or ex situ.

7. The method according to claim 1, wherein the catalyst comprises an active phase and a support and/or a binder and/or the catalyst is formed.

8. The method according to claim 7, wherein the support and/or the binder are constituted by pure silica (SiO.sub.2), a silica of an alkali metal, of an alkaline earth metal or of rare earth metals, titanium oxide (TiO.sub.2), boron oxide (B.sub.2O.sub.3) or resins (sulphonic resins, perfluorosulfonicresins) and their mixtures.

9. The method according to claim 1, wherein the conversion is carried out in a gas phase.

10. The method according to claim 9, wherein the conversion is carried out in a fixed bed reactor, a fluidized bed reactor or a circulating fluidized bed reactor with backup with an oxidant (O2, CO2, H2O, etc.) or a zone-type reactor TZFBR (two zone fluidized bed reactor).

11. The method according to claim 1, wherein the conversion is carried out in a liquid phase.

12. The method according to claim 1, wherein the alcohol or the alcohols are pure, partially purified, unpurified, or in the form of azeotropic compositions, and mixtures of these.

13. The method according to claim 1, wherein the alcohol or the alcohols are in an aqueous solution, at a concentration of at least 1% weight.

14. The method according to claim 1, wherein the alcohol or the alcohols are chosen from among propan-1-ol, butan-1-ol, butan-2-ol, isobutanol, but-3-ene-1-ol, but-2-ene-1-ol, but-3-ene-1,2-diol, butane-2,3-diol, butane-1,3-diol, butane-1,4-diol, propane-1,2-diol, propane-1,3-diol, erythritol, and their mixtures.

15. A method for selective preparation of but-2-ene from butan-1-ol, butan-2-ol, and their mixtures, according to claim 1.

16. A method for preparing isobutene from isobutanol, according to claim 1.

17. A method for preparing a mixture of olefines, dienes and/or polyenes, according to claim 1.

18. A method for preparing a mixture of at least two olefines, dienes and/or polyenes, characterized in that one of the olefines, dienes and/or polyenes is prepared by a method according to claim 1.

19. The method according to claim 18, wherein the at least other olefine(s), diene(s) and/or polyene(s) are obtained by catalytic conversion of an alcohol or a mixture of alcohols, in the presence of at least one catalyst based of at least one phosphate of at least one metal M, said metal M being chosen from among the 15 lanthanides (Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium), Yttrium, Scandium and Boron.

20. The method according to claim 19, wherein the catalysts are identical or different.

21. The method according to claim 19, wherein said catalyst used for the preparation of the other olefine(s), diene(s), polyene(s) comprises an active phase and a support and/or a binder and/or the catalyst is formed, possibly in the presence of a binder.

22. The method according to claim 18, wherein said catalyst used for the preparation of the other olefine(s), diene(s), polyene(s) is regenerated.

23. The method according to claim 17, wherein the at least two olefines, dienes, polyenes are prepared in the same reactor or in different reactors.

24. A method for producing butadiene, characterized in that it implements a method according to claim 1, wherein the alcohol is chosen from among but-2-ene-1-ol, but-3-ene-1-ol, but-1-ene-3-ol, but-3-ene-1,2-diol, butane-2,4-diol, butane-1,3-diol, butane-2,3-diol, and butane-1,4-diol and their mixtures.

Description

(1) Hereinafter, the invention is illustrated through the following examples which show its details and its advantages in comparison with the prior art, and with reference to the figures according to which:

(2) FIG. 1 represents a comparison of the variation of the conversion of butan-1-ol, according to the temperature of the reaction, for three catalysts of the invention and for an alumina, under the conditions that are described in Example 1.

(3) FIG. 2 represents a comparison of the selectivity to but-2-ene according to the temperature of the reaction for the three same catalysts of the invention and for the same alumina, as FIG. 1, under the conditions that are described in Example 1.

(4) FIG. 3 represents a comparison of the conversion of butan-1-ol and the selectivity to but-2-ene, according to the temperature of the reaction, for a catalyst of the invention which has been prepared according to two different methods, under the conditions that are described in Example 2.

(5) FIG. 4 shows the effect of water on the dehydration of butane-2,3-ol into butadiene, under the conditions that are described in Example 15.

(6) The illustrated catalysts are characterized by the following parameters: The specific surface, expressed in m.sup.2/g and measured by the BET method, the phosphor content and the metal(s) M content, expressed by a molar ratio P/M, and measured by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectroscopy); in the following examples, this ratio varies within the preferred range that has been previously defined, from 0.9 to 1.5; more specifically, for the catalysts of the invention that are tested hereinafter, the molar ratio P/La is 1.10 for LaPO.sub.4, and the molar ratio P/Nd is 1.14 for NdPO.sub.4.

(7) The dehydration reaction of the alcohols has been carried out on the indicated catalysts, at atmospheric pressure or at a substantially higher pressure, in a fixed bed reactor. The reactor is placed in a furnace which allows keeping the catalyst at the temperature of reaction which varies between 130 and 390? C. The reactor is fed with alcohol by means of a saturator or a syringe pump in the presence of a flow of nitrogen. For each example, the relative molar ratio of alcohol to nitrogen is indicated. The weight hourly space velocity (WHSV) is expressed in grams of introduced alcohol by grams of catalyst and by hour.

EXAMPLE 1

(8) A series of orthophosphates of rare earth metals (Nd, Sm, Gd) has been tested in the dehydration reaction of butan-1-ol for the conversion of butan-1-ol into but-2-ene, and compared with gamma-alumina.

(9) The specific surface of each of the tested catalysts is 117 m.sup.2/g for NdPO.sub.4, 82 m.sup.2/g for SmPO.sub.4, 95 m.sup.2/g for GdPO.sub.4 and 270 m.sup.2/g for Al.sub.2O.sub.3.

(10) The reaction has been carried out at atmospheric pressure under the following conditions: WHSV=2.38 h.sup.?1; butan-1-ol/N.sub.2=1/82.6.

(11) In FIGS. 1 and 2, there are shown respectively the conversion of butan-1-ol and the selectivity to but-2-ene according to the temperature of the reaction with the following legend:

(12) ? NdPO.sub.4

(13) ? SmPO.sub.4

(14) .Math. GdPO.sub.4

(15) ? Al.sub.2O.sub.3

(16) It appears that the phosphates are active at a lower temperature than the reference alumina. Furthermore, a quite higher selectivity to but-2-ene has been measured.

EXAMPLE 2

(17) In this example, the lanthanum orthophosphate is prepared form two different precursors, respectively, Na.sub.2HPO.sub.4 in accordance with the production method described in J. A. Diaz-Guillen, A. F. Fuentes, S. Gallini, M. T. Colomer, J. All. and Comp. 427 (2007) 87-98, and (NH.sub.4)H.sub.2PO.sub.4 in accordance with the method of Pavel.

(18) The specific surface of each of the tested catalysts is 128 m.sup.2/g for LaPO.sub.4 that has been obtained from Na.sub.2HPO.sub.4, and 112 m.sup.2/g for LaPO.sub.4 that has been obtained from (NH.sub.4)H.sub.2PO.sub.4.

(19) These catalysts have been tested in the dehydration of butan-1-ol under the following test conditions: WHSV=2.38 h.sup.?1; butan-1-ol/N.sub.2=1/82.6.

(20) FIG. 3 shows the variation of the conversion of the alcohol and the selectivity to but-1-ene according to the temperature, with the following legend:

(21) ? (conversion) and ? (selectivity): LaPO.sub.4 obtained from Na.sub.2HPO.sub.4

(22) ? (conversion) and ? (selectivity): LaPO.sub.4 obtained from (NH.sub.4)H.sub.2PO.sub.4

(23) It is observed that the catalytic properties of the catalysts of the invention do not depend on the used precursors.

EXAMPLE 3

(24) In this example, the neodymium orthophosphate in two different polymorphic forms (rhabdophane and monazite), has been tested in the dehydration reaction of butan-1-ol.

(25) The test conditions are as follows: WHSV=2.38 h.sup.?1; butan-1-ol/N.sub.2=1/82.6.

(26) Table 1 shows the conversion of the alcohol and the selectivity to but-2-ene at 320? C.:

(27) TABLE-US-00001 TABLE 1 Conversion of Selectivity to but- Selectivity to but- Catalyst butan-1-ol (%) 2-ene (%) 1-ene (%) NdPO.sub.4 99.8 73 27 rhabdophane NdPO.sub.4 monazite 99.9 72 28

EXAMPLE 4

(28) A 50/50 molar mixture of ethanol and butan-1-ol has been dehydrated on a catalyst GdPO.sub.4 of the invention and on a gamma-alumina. The catalytic results, obtained at 360? C., are shown in Table 2 below.

(29) The specific surface of the catalyst GdPO.sub.4 of the invention is 95 m.sup.2/g and the specific surface of alumina is 270 m.sup.2/g.

(30) The test conditions are as follows: WHSV=2.34 h.sup.?1; N.sub.2=100 ml.

(31) Both alcohols have been completely transformed on the phosphate catalyst. This transformation results in an ethylene/but-2-ene mixture which is characterized by a molar ratio of 1.4 and which may be used directly in a metathesis reaction in order to form propene. It is also observed that the phosphate catalyst is very stable.

(32) TABLE-US-00002 TABLE 2 Conversion Conversion Selectivity Selectivity Time of of to ethylene to but-2- Catalyst (h) ethanol (%) butan-1-ol (%) (%) ene (%) GdPO.sub.4 1 100 100 100 74 60 99 100 100 71 Al.sub.2O.sub.3 1 100 100 99 16

EXAMPLE 5

(33) The catalysts LaPO.sub.4 and NdPO.sub.4 have been compared with alumina in the dehydration of but-3-ene-1-ol.

(34) The specific surface of the catalysts NdPO.sub.4 and LaPO.sub.4 of the invention are 117 m.sup.2/g and 124 m.sup.2/g, respectively, and the specific surface of alumina is 270 m.sup.2/g.

(35) The reaction conditions are as follows: WHSV=2.49 h.sup.?1; 3-but-1-ene-ol/N.sub.2=1/76.8.

(36) Table 3 below shows the conversion of the alcohol and the selectivity to butadiene at 286? C.

(37) TABLE-US-00003 TABLE 3 Catalyst Conversion of 3-but-1-ene-ol (%) Selectivity to butadiene (%) NdPO.sub.4 100 99 LaPO.sub.4 92 98 Al.sub.2O.sub.3 34 12

EXAMPLE 6

(38) NdPO.sub.4 has been tested and compared with alumina in the dehydration of isobutanol.

(39) The specific surface of the catalyst NdPO.sub.4 of the invention is 117 m.sup.2/g and the specific surface of alumina is 270 m.sup.2/g.

(40) The reaction conditions are as follows: WHSV=2.38 h.sup.?1; isobutanol/N.sub.2=1/82.6.

(41) The conversion of isobutanol and the selectivity to isobutene and to but-2-ene at 245? C., are given in the following Table 4.

(42) TABLE-US-00004 TABLE 4 Conversion of Selectivity to isobutanol isobutene Selectivity to Catalyst (%) (%) but-2-ene (%) NdPO.sub.4 52 91 9 Al.sub.2O.sub.3 20 98 2

EXAMPLE 7

(43) NdPO.sub.4 has been tested in the dehydration reaction of butan-2-ol and compared with alumina.

(44) The specific surface of the catalyst NdPO.sub.4 of the invention is 117 m.sup.2/g and the specific surface of alumina is 270 m.sup.2/g.

(45) The reaction has been carried out at atmospheric pressure under the following conditions: WHSV=2.38 h.sup.?1; butan-2-ol/N.sub.2=1/82.6; temperature of the reactor=200? C.

(46) TABLE-US-00005 TABLE 5 Catalyst Conversion of butane-2-ol (%) Selectivity to but-2-ene (%) NdPO.sub.4 76 84 Al.sub.2O.sub.3 52 81

EXAMPLE 8

(47) In this example, the neodymium phosphate has been tested in the dehydration of propan-1-ol.

(48) The specific surface of the catalyst NdPO.sub.4 of the invention is 117 m.sup.2/g.

(49) The reaction has been carried out at atmospheric pressure under the following conditions: WHSV=3.04 h.sup.?1; propan-1-ol/N.sub.2=1/49.5; temperature of the reactor=330? C.

(50) The conversion of propan-1-ol and the selectivity to propene are shown in the following Table 6.

(51) TABLE-US-00006 TABLE 6 Catalyst Conversion of propan-1-ol (%) Selectivity to propene (%) NdPO.sub.4 99 99

EXAMPLE 9

(52) The neodymium phosphate has been tested as a catalyst in the dehydration of butane-2,3-diol.

(53) The specific surface of the catalyst NdPO.sub.4 of the invention is 117 m.sup.2/g.

(54) The reaction has been carried out under the following conditions:

(55) WHSV=2.95 h.sup.?1; butane-2,3-ol/N.sub.2=1/80.3; temperature of the reactor=320? C.

(56) The catalytic results that have been obtained are shown in the following Table 7.

(57) TABLE-US-00007 TABLE 7 Catalyst Conversion of butane-2,3-diol (%) Selectivity to butadiene (%) NdPO.sub.4 99 60

(58) The catalyst is very active and selective to butadiene.

EXAMPLE 10

(59) The phosphates of Lanthanum, Neodymium and Gadolinium have been tested as catalysts in the dehydration of butane-2,3-ol (2,3-BDO).

(60) The reaction conditions are as follows: WHSV=2.98 h.sup.?1; m.sub.cata=101 mg; contact time (W/F)=30.28 g.sub.cata.Math.h.Math.mol.sub.2,3-BDO.sup.?1; N.sub.2=100 ml.Math.min.sup.?1 and a gaseous mixture butane-2,3-ol/N.sub.2=1/80.3.

(61) The catalytic results that have been obtained are shown in the following Table 8.

(62) TABLE-US-00008 TABLE 8 Conversion Selectivity Selectivity Selectivity Temperature of 2,3- to butadiene to MEK to MPA Catalyst (? C.) BDO (%) (%) (%) (%) LaPO.sub.4 300 95.4 56 7 37 NdPO.sub.4 320 100 58 7 35 GdPO.sub.4 300 100 60 7 33

(63) The catalysts are very active and selective to butadiene.

EXAMPLE 11

(64) The catalyst GdPO.sub.4 has been tested in the dehydration of 3-butene-2-ol.

(65) The reaction conditions are as follows: m.sub.cata=101 mg; contact time (W/F)=28.97 g.sub.cata.Math.h.Math.mol.sup.?1; 3-butene-2-ol/N.sub.2=1/76.8.

(66) Table 9 shows the conversion of 3-butene-2-ol and the selectivity to butadiene at 230? C.

(67) TABLE-US-00009 TABLE 9 Catalyst Conversion of 3-butene-2-ol (%) Selectivity to butadiene (%) GdPO.sub.4 100 99

(68) The catalyst is very active and selective to butadiene.

EXAMPLE 12

(69) The catalyst GdPO.sub.4 has been tested as a catalyst for the dehydration of but-3-ene-1,2-diol.

(70) The reaction conditions are as follows: m.sub.cata=118 mg; contact time (W/F)=30.3 g.sub.cata.Math.h.Math.mol.sup.?1; Alcohol/N.sub.2=1/68; T=310? C.

(71) The catalytic results that have been obtained are shown in the following Table 10.

(72) TABLE-US-00010 TABLE 10 Conversion of Selectivity Selectivity to Selectivity to 3-butene-1,2-ol to butenal butadiene other products* Catalyst (%) (%) (%) (%) GdPO.sub.4 96 98 1 1 *Other products: methyl vinyl ketone, 1,3-butadienol, 2,5-dihydrofurane

EXAMPLE 13

(73) SmPO.sub.4 has been tested in the reaction of the joint dehydration of ethanol, propanol and butanol.

(74) The reaction has been carried out at atmospheric pressure under the following conditions:

(75) contact time (W/F)=28.33 g.sub.cata.Math.h.Math.mol.sup.?1;

(76) Ethanol/1-propanol/2-propanol/2-butanol=10/15/15/60;

(77) N.sub.2=100 ml.Math.min.sup.?1;

(78) temperature of the reactor=330? C.

(79) As indicated in the following Table 11, it is observed, at this temperature, a 100% conversion of all alcohols and practically a 100% selectivity to the corresponding alkenes.

(80) TABLE-US-00011 TABLE 11 Con- Selec- Con- Selec- Con- Selec- version tivity version tivity version tivity of to of 1- et 2- to of 2- to 1-/2- ethanol ethylene propanol propene butanol butene Catalyst (%) (%) (%) (%) (%) (%) NdPO.sub.4 99.1 100 100 99.5 100 27/73 SmPO.sub.4 100 100 100 100 100 24/76

EXAMPLE 14

(81) The catalysts SmPO.sub.4 and NdPO.sub.4 have been studied in the dehydration of an ABE mixture (acetone/butanol/ethanol) which has been obtained by fermentation.

(82) The test has been carried out at atmospheric pressure under the following conditions:

(83) m.sub.cata=101 mg;

(84) contact time (W/F)=28.1 g.sub.cata.Math.h.Math.mol.sup.?1;

(85) Acetone/1-butanol/ethanol=3/6/1;

(86) N.sub.2=100 ml.Math.min.sup.?1;

(87) temperature of the reactor=330? C.

(88) The following Table 12 shows the results.

(89) TABLE-US-00012 TABLE 12 Conversion Conversion Selectivity Conversion Selectivity to of acetone of ethanol to ethylene of 1-butanol 1-/2-butene Catalyst (%) (%) (%) (%) (%) NdPO.sub.4 0 100 100 100 34/66 SmPO.sub.4 0 100 100 100 30/70

EXAMPLE 15

(90) When produced by fermentation, the butane-2,3-ol (2,3-BDO) is mixed with a significant quantity of water which has to be eliminated by evaporation. If this separation could be completely or partially avoided prior to the step of dehydration into butadiene, this would surely be interesting from an economic point of view.

(91) The Gadolinium phosphate has been tested in the presence of water.

(92) The reaction has been carried out under the following conditions:

(93) Temperature=300? C.; m.sub.cata=101 mg; contact time (W/F)=30.28 g.sub.cata.Math.h.Math.mol.sub.2,3-BDO.sup.?1; N.sub.2=100 ml.Math.min.sup.?1

(94) The results are shown in the following Table 13 and illustrated in FIG. 4.

(95) TABLE-US-00013 TABLE 13 Water Conversion of Selectivity to Selectivity Selectivity (% butane-2,3-ol butadiene to to Catalyst mol) (%) (%) MEK (%) MPA (%) GdPO.sub.4 0 100 60 7 33 50 100 50 10 40 90 100 43 13 44

(96) It is observed that an increase of the quantity of water does not significantly modify the catalytic properties but slightly lowers the selectivity to butadiene.

(97) The effect of water on the stability of the catalyst under the reaction conditions has also been studied. Water has a quite positive effect on this stabilization.

EXAMPLE 16

(98) A 50/50 molar mixture of ethanol and 1-butanol has been dehydrated on phosphates of Gadolinium, Samarium and Neodymium.

(99) The catalytic reaction conditions are as follows:

(100) m.sub.cata=101 mg; contact time (W/F)=25 g.sub.cata.Math.h.Math.mol.sup.?1; N.sub.2=100 ml.Math.min.sup.?1

(101) The catalytic results that have been obtained are shown in Table 14 below.

(102) TABLE-US-00014 TABLE 14 Conversion Conversion Selectivity Selectivity Temperature of ethanol of 1-butanol to ethylene to 2-butene Catalyst (? C.) (%) (%) (%) (%) GdPO.sub.4 360 100 100 100 74 SmPO.sub.4 360 99.8 100 100 75 NdPO.sub.4 350 97.8 100 100 73

(103) Both alcohols have been completely transformed on the catalysts. For both dehydration reactions, the catalysts are very active and selective. The catalyst SmPO.sub.4 is more selective to 2-butene.