PRODUCTION OF ALLYL ALCOHOL FROM GLYCEROL USING A REUSABLE CATALYST MADE FROM RHENIUM

Abstract

The present invention relates to the use of a catalyst made of rhenium oxide supported by cerium oxide, with formula ReO.sub.x/CeO.sub.2 (I), for catalyzing the deoxydehydration of glycerol to allyl alcohol, the reaction being carried out under heterogeneous conditions in the presence of at least one aliphatic alcohol; and to a method for producing allyl alcohol from glycerol in the presence of the catalyst.

Claims

1. A process for catalyzing the deoxydehydration of glycerol into allyl alcohol, comprising reacting glycerol and a catalyst containing rhenium oxide supported by cerium, with the formula ReO.sub.x/CeO.sub.2 (I), said reaction being carried out under heterogeneous conditions in the presence of at least one aliphatic alcohol.

2. The process according to claim 1, wherein said at least one aliphatic alcohol is used as a solvent.

3. The process according to claim 1, wherein said catalyst with the formula (I) is selected from the catalysts in which the amount of ReO.sub.x ranges from 2 to 20% by weight with respect to the total weight of catalyst with the formula (I).

4. A process for producing allyl alcohol from glycerol in the presence of a catalyst, said process comprising only one step of deoxydehydration of glycerol, said reaction being carried out under heterogeneous conditions, in the presence of i) a catalyst containing rhenium oxide supported on cerium oxide, with the formula ReO.sub.x/CeO.sub.2 (I) and (ii) at least one aliphatic alcohol.

5. The process according to claim 4, wherein the catalyst with the formula (I) is selected from catalysts in which the amount of ReO.sub.x ranges from 2 to 20% by weight based on the total weight of catalyst with the formula (I).

6. The process according to claim 4, wherein the catalyst with the formula (I) is selected from catalysts in which the amount of ReO.sub.x ranges from 3% to 15% by weight, and preferentially from 4% to 12% by weight with respect to the total mass of catalyst with the formula (I).

7. The process according to claim 4, wherein the aliphatic alcohol is a monohydric alcohol having from 6 to 10 carbon atoms.

8. The process according to claim 4, wherein the aliphatic alcohol is a monohydric alcohol having from 6 to 8 carbon atoms.

9. The process according to claim 4, wherein the aliphatic alcohol is a monohydric secondary alcohol.

10. The process according to claim 4, wherein the aliphatic alcohol is 2-hexanol or 3-octanol.

11. The process according to claim 4, wherein the deoxydehydration reaction is carried out at a temperature greater than or equal to 140° C.

12. The method according to claim 4, wherein the specific surface area of the cerium oxide used for supporting ReO.sub.x ranges from about 100 m.sup.2/g to 300 m.sup.2/g as determined by the BET method.

13. The process according to claim 6, wherein the catalyst with the formula (I) is selected from catalysts in which the amount of ReO.sub.x ranges from 4% to 12% by weight with respect to the total mass of catalyst with the formula (I).

14. The method according to claim 4, wherein the specific surface area of the cerium oxide used for supporting ReO.sub.x ranges from 150 m.sup.2/g to 250 m.sup.2/g as determined by the BET method.

Description

EXAMPLE 1

Preparation of a Cerium-Supported Rhenium Oxide Catalyst (ReO.SUB.x./CeO.SUB.2.) According to the Invention

[0031] Rhenium catalysts supported on cerium (HAS-5, marketed by SOLVAY) were prepared by the incipient wetness impregnation method. The BET surface area of HAS-5 is 246 m.sup.2/g. For the preparation of 10% by weight of ReO.sub.x/CeO.sub.2 (i.e. comprising 10% by weight of ReO.sub.x with respect to the total weight of catalyst), first, CeO.sub.2 (HAS-5, 2 g) was washed with distilled water using vacuum filtration, then was dried and calcined in static air at 110° C. (12 h) and 500° C. (3 h), respectively. After that, same was added to a dilute aqueous solution of HReO.sub.4 solution, which was obtained by mixing 400 mg of the aqueous solution containing 75% by weight of HReO.sub.4 (Aldrich) with water (0.75 ml). The impregnated catalyst was dried at 110° C. for 12 h and calcined in static air at 500° C. for 3 hours using a heating rate of 5° C./min.

EXAMPLE 2

Reaction of Glycerol for Obtaining Allyl Alcohol Using 10% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention (1st Use of the Catalyst)

[0032] A pressure-resistant glass tube equipped with a magnetic stirring bar was filled with glycerol (92 mg, 1 mmol, purity in water>99%), 10% by weight of ReO.sub.x/CeO.sub.2 (100 mg; obtained in the Example 1) and 2-hexanol (3.3 ml). The container was hermetically closed by a screw cap and the mixture was stirred (1300 rpm) in an oil bath maintained at 175° C. for 2 h so that the reaction medium was maintained at a reaction temperature of 145° C. Although 2-hexanol has, at atmospheric pressure, a boiling point of 136° C., the preferred reaction temperature is above 136° C. After reaction, the solution was cooled to room temperature and then recovered; 1 ml was collected for analysis by gas chromatography. Benzene (9 mg, 0.115 mmol) was added to the solution, and the mixture was then well mixed in an ultrasonic bath for 10 min at 60° C. The conversion and selectivity were determined by GC analysis using benzene as the internal standard.

[0033] The results are shown in Table 1. The allyl alcohol yield was 54%, the glycerol conversion was 74% and the allyl alcohol selectivity was 73%.

[0034] Table 1. Results of the Reaction of Glycerol in Allyl Alcohol Using 10% by Weight of ReO.sub.x/CeO.sub.2 in 2-Hexanol [a]

TABLE-US-00001 TABLE 1 Experi- Yield Conversion Selectivity ment Catalyst (%) (d) (%) (c) (%) (c) Comment 1 10%* by 54 74 73 1.sup.st use weight of ReO.sub.x/CeO.sub.2 2 10%* by 54 77 70 2.sup.nd use weight of ReO.sub.x/CeO.sub.2 3 10%* by 58 80 74 3.sup.rd use weight of ReO.sub.x/CeO.sub.2 [a] Reaction conditions: glycerol (92 mg, 1 mmol), catalyst (100 mg) and 2-hexanol (3.3 ml), oil bath at 175° C., 1300 rpm, 2 h, unless otherwise indicated (c) Selectivity and conversion determined by GC analysis (d) Yield = Selectivity * Conversion/100 *Comprising 10% by weight of ReO.sub.x with respect to the total weight of catalyst.

EXAMPLE 3

Reaction of Glycerol for Obtaining Allyl Alcohol Using 10% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention (2.SUP.nd .Use of Catalyst) (Experiment 2)

[0035] The reaction was carried out as in the Example 2, but using the 10% by weight of ReO.sub.x/CeO.sub.2 from experiment 1 with a new quantity of glycerol. The 10% by weight of ReO.sub.x/CeO.sub.2 used was reused without prior washing, drying or calcination.

[0036] The allyl alcohol yield was 54%, the glycerol conversion was 77% and the allyl alcohol selectivity was 70%.

EXAMPLE 4

Reaction of Glycerol for Obtaining Allyl Alcohol Using 10% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention (3.SUP.rd .Use of Catalyst) (Experiment 3)

[0037] The reaction was carried out as in the Example 3, but using the 10% by weight of ReO.sub.x/CeO.sub.2 from experiment 2 with a new quantity of glycerol. The 10% by weight of ReO.sub.x/CeO.sub.2 used was reused without prior washing, drying or calcination.

[0038] The allyl alcohol yield was 58%, the glycerol conversion was 80% and the allyl alcohol selectivity was 74%.

[0039] Results:

[0040] The catalyst was easily reused for producing allyl alcohol with yields of 54% and 58% for a second and a third use, respectively (Table 1, experiments 1 to 3). No peak attributed to acrolein or acrylic acid was observed.

EXAMPLE 5

Reaction of Glycerol for Obtaining Allyl Alcohol Using CeO.SUB.2 .(HAS-5) (Comparative)

[0041] The reaction was carried out as in the Example 2, but using CeO.sub.2 (HAS-5, 100 mg) and 2.5 h of reaction time.

[0042] The allyl alcohol yield was 0%, the glycerol conversion was 3% and the allyl alcohol selectivity was 0%.

EXAMPLE 6

Reaction of Glycerol for Obtaining Allyl Alcohol Using 2.5% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention (i.e. Comprising 2.5% by Weight of ReO.SUB.x .with Respect to the Total Weight of Catalyst)

[0043] The reaction was carried out as in the Example 2, but using 2.5% by weight of ReO.sub.x/CeO.sub.2 (100 mg) and 2.5 h of reaction time.

[0044] The conditions for preparing the catalyst were as in the Example 2, but using a dilute aqueous solution of HReO.sub.4, which was obtained by mixing 93 mg of the aqueous solution containing 75% by weight of HReO.sub.4 (Aldrich) with water (0.75 ml).

[0045] The allyl alcohol yield was 77%, the glycerol conversion was 91% and the allyl alcohol selectivity was 84%.

EXAMPLE 7

Reaction of Glycerol for Obtaining Allyl Alcohol Using 5% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention (i.e. Comprising 5% by Weight of ReO.SUB.x .with Respect to the Total Weight of Catalyst)

[0046] The reaction was carried out as in the Example 2, but using 5% by weight of ReO.sub.x/CeO.sub.2 (100 mg) and 2.5 h of reaction time.

[0047] The conditions for preparing the catalyst were as in the Example 2, but using a dilute aqueous solution of HReO.sub.4, which was obtained by mixing 190 mg of the aqueous solution containing 75% by weight of HReO.sub.4 (Aldrich) with water (0.75 ml).

[0048] The allyl alcohol yield was 84%, the glycerol conversion was >99% and the allyl alcohol selectivity was 84%.

EXAMPLE 8

Reaction of Glycerol for Obtaining Allyl Alcohol Using 10% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention (i.e. Comprising 10% by Weight of ReO.SUB.x .with Respect to the Total Weight of Catalyst) at an Increased Reaction Time

[0049] The reaction was carried out as in the Example 2 using 10% by weight of ReO.sub.x/CeO.sub.2 (100 mg) but with 2.5 h of reaction time.

[0050] The preparation conditions for the catalyst were as in the Example 2. The allyl alcohol yield was 86%, the glycerol conversion was >99%, the allyl alcohol selectivity was 86%.

EXAMPLE 9

Reaction of Glycerol for Obtaining Allyl Alcohol Using 15% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention (i.e. Comprising 15% by Weight of ReO.SUB.x .with Respect to the Total Weight of Catalyst)

[0051] The reaction was carried out as in the Example 2, but using 15% by weight of ReO.sub.x/CeO.sub.2 (100 mg) and 2.5 h of reaction time.

[0052] The conditions for preparing the catalyst were as in the Example 2, but using a dilute aqueous solution of HReO.sub.4, which was obtained by mixing 635 mg of the aqueous solution containing 75% by weight of HReO.sub.4 (Aldrich) with water (0.75 ml).

[0053] The allyl alcohol yield was 81%, the glycerol conversion was >99%, the allyl alcohol selectivity was 81%.

[0054] Results:

[0055] Experiments for optimizing the ReO.sub.x load were carried out (Table 2): the yield from the CeO.sub.2 bare support was 0%, the yields increased with the increase in the ReO.sub.x load up to 10% by weight (77%, 84% and 86% for 2.5% by weight, 5% by weight and 10% by weight of ReO.sub.x, respectively), but the yield slightly decreased for 15% by weight of ReO.sub.x/CeO.sub.2 (yield of 81%).

[0056] Table 2. Screening of the Rhenium Load on the Catalyst According to the Invention ReO.sub.x/CeO.sub.2 [a]

TABLE-US-00002 TABLE 2 Yield Conversion Selectivity Example Catalyst (%) (c) (%) (b) (%) (b) 5 CeO.sub.2 0 3 0 (comparative) 6 2.5% by 77 91 84 weight* of ReO.sub.x/CeO.sub.2 7 5% by 84 >99 84 weight* of ReO.sub.x/CeO.sub.2 8 10% by 86 >99 86 weight* of ReO.sub.x/CeO.sub.2 9 15% by 81 >99 81 weight* of ReO.sub.x/CeO.sub.2 [a] Reaction conditions: glycerol (92 mg, 1 mmol), catalyst (100 mg) and 2-hexanol (3.3 ml), oil bath at 175° C., 1300 rpm, 2.5 h, unless otherwise indicated (b) Selectivity for allyl alcohol and glycerol conversion determined by GC analysis (c) Yield = Selectivity * Conversion/100 *by weight of ReO.sub.x with respect to the total weight of catalyst.

EXAMPLE 10

Reaction of Glycerol for Obtaining Allyl Alcohol Using 3-Octanol

[0057] The reaction was carried out as in the Example 2, but using 3-octanol (3.3 ml) and 2.5 h of reaction time.

[0058] The allyl alcohol yield was 80%, the glycerol conversion was >99% and the allyl alcohol selectivity was 80%.

EXAMPLE 11

Reaction of Glycerol for Obtaining Allyl Alcohol Using 2-Pentanol

[0059] The reaction was carried out as in the Example 2, but using 2-pentanol (3.3 ml) and 2.5 h reaction time.

[0060] The allyl alcohol yield was 65%, the glycerol conversion was 82% and the allyl alcohol selectivity was 79%.

EXAMPLE 12

Reaction of Glycerol for Obtaining Allyl Alcohol Using 1-Heptanol

[0061] The reaction was carried out as in the Example 2, but using 1-heptanol (3.3 ml) and 2.5 h of reaction time.

[0062] The allyl alcohol yield was 22%, the glycerol conversion was 45% and the allyl alcohol selectivity was 48%.

EXAMPLE 13

Reaction of Glycerol for Obtaining Allyl Alcohol Using 2-Butanol

[0063] The reaction was carried out as in the Example 2, but using 2-butanol (3.3 ml) and 2.5 h of reaction time.

[0064] The allyl alcohol yield was 24%, the glycerol conversion was 37% and the allyl alcohol selectivity was 65%.

EXAMPLE 14

Reaction of Glycerol for Obtaining Allyl Alcohol Using Cyclohexanol

[0065] The reaction was carried out as in the Example 2, but using cyclohexanol (3.3 ml) and 2.5 h of reaction time.

[0066] The allyl alcohol yield was 21%, the glycerol conversion was 35% and the allyl alcohol selectivity (yield/conversion) was 59%.

[0067] Results:

[0068] Various alcohols were tested with the catalyst containing 10% by weight of ReO.sub.x/CeO.sub.2 (Table 3). Secondary alcohols showed higher yields than primary alcohols (Table 3, Examples 8, 10-13). The aliphatic alcohol having longer chains also showed good reactivity leading to obtaining allyl alcohol with a yield of 80% (Table 3, Example 10). Short-chain aliphatic alcohols are good candidates if one is concerned about the cost, but the reactivity is lower than in the case of 2-hexanol (Table 3, Example 13, yield 24% in the case of 2-butanol). The cyclic alcohol showed a moderate yield (Table 3, Example 14).

[0069] Table 3. Screening of Alcohols with 10% by Weight of ReO.sub.x/CeO.sub.2 Catalyst According to the Invention (i.e. Comprising 10% by Weight of ReO.sub.x with Respect to the Total Weight of Catalyst) [a]

TABLE-US-00003 TABLE 3 Yield Conversion Selectivity Example Alcohol (%) (c) (%) (b) (%) (b) 8 2-hexanol 86 >99 86 10 3-octanol 80 >99 80 11 2-pentanol 65 82 79 12 1-heptanol 22 45 48 13 2-butanol 24 37 65 14 cyclohexanol 21 35 59 [a] Reaction conditions: glycerol (92 mg, 1 mmol), 10% by weight of ReO.sub.x/CeO.sub.2 (100 mg) and alcohol (3.3 ml), oil bath at 175° C., 1300 rpm, 2.5 h, unless otherwise indicated (b) Selectivity for allyl alcohol and glycerol conversion determined by GC analysis (c) Yield = Selectivity * Conversion/100.

EXAMPLE 15

Reaction of Glycerol for Obtaining Allyl Alcohol in an Oil Bath with a Temperature of 165° C.

[0070] The reaction was carried out as in the Example 2, but using 165° C. as the oil bath temperature and 2.5 h reaction time.

[0071] The allyl alcohol yield was 62%, the glycerol conversion was 88% and the allyl alcohol selectivity was 71%.

EXAMPLE 16

Reaction of Glycerol for Obtaining Allyl Alcohol in an Oil Bath with a Temperature of 185° C.

[0072] The reaction was carried out as in the Example 2, but using 185° C. as the oil bath temperature and 2.5 h reaction time.

[0073] The allyl alcohol yield was 81%, the glycerol conversion was >99% and the allyl alcohol selectivity was 81%.

[0074] Results:

[0075] Experiments for optimizing the reaction temperature were carried out with 10% by weight of ReO.sub.x/CeO.sub.2 catalyst according to the invention (Table 4). The yields increased with the increase in temperature up to 175° C. (oil bath) (yields 62% and 86% for 165° C. and 175° C. temperatures, respectively, of the oil bath), but the yield decreased slightly using a temperature of 185° C. (81% Yield).

[0076] Table 4. Screening of the Reaction Temperature with 10% by Weight of Catalyst According to the Invention ReO.sub.x/CeO.sub.2 (i.e. Comprising 10% by Weight of ReO.sub.x with Respect to the Total Weight of Catalyst) [a]

TABLE-US-00004 TABLE 4 Oil bath Reaction Conver- temperature temperature Yield sion Selectivity Example (° C.) (° C.) (%) (c) (%) (b) (%) (b) 15 165 140 62 88 71 8 175 145 86 >99 86 16 185 150 81 >99 81 [a] reaction conditions: glycerol (92 mg, 1 mmol), 10% by weight of ReO.sub.x/CeO.sub.2 (100 mg) and 2-hexanol (3.3 ml), 1300 rpm, 2.5 h, unless otherwise indicated (b) Selectivity for allyl alcohol and glycerol conversion determined by GC analysis (c) Yield = Selectivity * Conversion/100.

EXAMPLE 17

Reaction of Glycerol for Obtaining Allyl Alcohol Using 10% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention with Glycerol with 95% Purity in Water

[0077] The reaction took place as in the Example 2, but with a glycerol with a 95% purity in water and 2.5 h reaction time. Glycerol (92 mg) and water (5 mg) were mixed beforehand in order to obtain a homogeneous mixture with 2-hexanol. The allyl alcohol yield was 81%, the glycerol conversion was >99%, the allyl alcohol selectivity was 81%.

EXAMPLE 18

Reaction of Glycerol for Obtaining Allyl Alcohol Using 10% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention with Glycerol of 85% Purity

[0078] The reaction was carried out as in the Example 2, but with a glycerol with 85% purity and 2.5 h reaction time. Glycerol (92 mg) and water (16 mg) were mixed beforehand in order to obtain a homogeneous mixture with 2-hexanol.

[0079] The allyl alcohol yield was 72%, the glycerol conversion was 91%, the allyl alcohol selectivity was 79%.

EXAMPLE 19

Reaction of Glycerol for Obtaining Allyl Alcohol Using 10% by Weight of ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention with Glycerol of 80% Purity

[0080] The reaction was carried out as in the Example 2, but with a glycerol with 80% purity and 2.5 h reaction time. Glycerol (92 mg) and water (23 mg) were mixed beforehand in order to obtain a homogeneous mixture with 2-hexanol.

[0081] The allyl alcohol yield was 63%, the glycerol conversion was 79%, the allyl alcohol selectivity was 79%.

[0082] Results:

[0083] Glycerol at 95%, 85% and 80% purity in water was studied as starting material for the catalytic reaction in order to determine the effect of water (Table 5). The yield decreased slightly when glycerol with a purity of 95% (Example 17) was used to give the corresponding allyl alcohol with a yield of 81% with a complete conversion (>99%). When glycerol of 85% and 80% purity was used (Examples 18 and 19), yields of 72% and 63% were obtained, respectively. Such effect could be related to the decrease in the boiling point of the liquid mixture when water is added to the glycerol.

[0084] Table 5. Reaction of Glycerol with 80 to 99% Purity in Water Using 10% by Weight of ReO.sub.x/CeO.sub.2 Catalyst According to the Invention (i.e. Comprising 10% by Weight of ReO.sub.x with Respect to the Total Weight of Catalyst) [a]

TABLE-US-00005 TABLE 5 Glycerol purity in Yield Conversion Selectivity Example water (%) (%) (c) (%) (b) (%) (b) 8 >99 86 >99 86 17 95 81 >99 81 18 85 72 91 79 19 80 63 79 79 [a] Reaction conditions: glycerol (92 mg, 1 mmol), water (0, 5, 16, 23 mg for the Examples 8, 17-19 respectively), 10% by weight of ReO.sub.x/CEO.sub.2 (100 mg) and 2-hexanol (3.3 ml), oil bath at 175° C., 1300 rpm, 2.5 h, unless otherwise indicated (b) Selectivity for allyl alcohol and glycerol conversion determined by GC analysis (c) Yield = Selectivity * Conversion/100.

EXAMPLE 20

Comparison of the Results Obtained Between the ReO.SUB.x./CeO.SUB.2 .Catalyst According to the Invention and the Comparative ReO.SUB.3./Al.SUB.2.O.SUB.3 .Catalyst According to EP3124462

[0085] Compared with the prior application EP3124462, the catalysts according to the invention have comparable performances in terms of allyl alcohol yield (conversion of glycerol * selectivity toward allyl alcohol). However, when considering the productivity of the catalysts, a much higher productivity can be indicated for the ReO.sub.x/CeO.sub.2 catalyst according to the invention, as can be seen in Table 6 below:

TABLE-US-00006 TABLE 6 Comparative Catalyst catalyst REO.sub.3/Al.sub.2O.sub.3 ReO.sub.x/CeO.sub.2 according to according to Parameters EP3124462 the invention % by weight of rhenium 8 5 Quantity of catalyst 100 100 (mg) Isoltaed allyl alcohol (mg) 52.2 48.7 Reaction time (h) 2.5 2.5 Productivity (= (g of allyl 2.6 3.9 alcohol/g rhenium)/h

[0086] From the results, it can be seen that a comparable amount of allyl alcohol was produced (48.7 mg versus 52.2 mg), but using a catalyst containing less reactive phase (5% by weight versus 8% by weight), whereby the productivity increased by 50% (3.9 g compared to 2.6 g of allyl alcohol per gram of Re per hour) was obtained.

[0087] The ReOx/CeO 2 Catalyst According to the Invention Can Thus be Used for Obtaining Allyl Alcohol from Glycerol with a Greatly Increased Productivity.