Method and catalyst for producing methylbenzyl alcohol from ethanol by catalytic conversion

Abstract

Method and catalyst for producing methylbenzyl alcohol from ethanol by catalytic conversion. A route and corresponding catalysts for directly producing methylbenzyl alcohols through catalytic conversion starting from ethanol, providing an important alternative route for increasing the production of aromatic oxygenates. The selectivity of the methylbenzyl alcohols is up to 60%. At the same time, the prepared catalysts have excellent stability. Moreover, this innovative reaction route produces hydrogen as co-product without CO, thus can be directly used in chemical reactions and fuel cells. In addition, the route also produces high carbon number alcohols which can be used as fuels or oil additives to partially replace petroleum-based products, thus partly reducing the dependence on petroleum.

Claims

1. A method for producing methylbenzyl alcohol from ethanol by catalytic conversion, comprising the following steps: (1) preparing transition metals aqueous and/or alcohol solution; (2) using an incipient wetness impregnation method to prepare catalyst using the transition metals aqueous and/or alcohol solution prepared in step (1); after impregnation, stayed at room temperature for 0.5-2 h; (3) placing the mixture after staying in step (2) into a 50 C. oven for drying for 8-20 h; (4) conducting oxidation on the dried product in the step (3) at 350-450 C. for 1 to 5 h in an oxygen atmosphere, and then conducting reduction under hydrogen at 300-700 C. for 0.5-2 h to obtain transition metal-phosphate catalysts, wherein the transition metal-phosphate catalysts comprise two parts: transition metals and phosphate; a loading of the transition metals is 0.01-50 wt % of a weight of the phosphate; the transition metals are one or a combination of more than one of Co, Ni, Cu, Ag, Pd, Rh, Ru, Pt, Ir, Zn and Y; the phosphate is hydroxymetallic apatite and/or metal phosphate, wherein the hydroxymetallic apatite is A.sub.xB.sub.yC.sub.zD.sub.mE.sub.n(OH).sub.2(PO.sub.4).sub.6, x+y+z+m+n=9-10, 9-10x,y,z,m,n0; the metal phosphate is A.sub.xB.sub.yC.sub.zD.sub.mE.sub.n(PO.sub.4).sub.2, x+y+z+m+n=3, 3x,y,z,m,n0, wherein A, B, C, D and E are the same or different and are selected from one or a combination of more than one of Mg, Ca, Sr, Ba and Pb; the phosphate is one or a mechanical mixture of more than one; (5) at reaction temperature of 100-450 C. and reaction pressure of 1-50 atm, introducing ethanol into a reactor packed with the transition metal-phosphate catalysts to produce methylbenzyl alcohol by one-pot.

2. The method according to claim 1, wherein in the step (1), a concentration of the transition metals aqueous solution is 0.08 g/mL-1.0 g/mL; a concentration of the transition metals alcohol solution is 0.08-0.3 g/mL.

3. The method according to claim 1, wherein corresponding soluble salts of the transition metals are one or mixture of more than one of chloride, nitrate, diacetone, sulfate and acetate; the alcohol solvent is selected from methanol and/or ethanol.

4. The method according to claim 1, wherein in the step (4), a concentration of oxygen oxidation is one of 0.01-20 vol % O.sub.2/N.sub.2 (nitrogen), 0.01-20 vol % O.sub.2/He (helium) and 0.01-20 vol % O.sub.2/Ar (argon); a hydrogen concentration is one of 5-20 vol % H.sub.2/N.sub.2, 5-20 vol % H.sub.2/He and 5-20 vol % H.sub.2/Ar.

5. The method according to claim 3, wherein in the step (4), a concentration of oxygen oxidation is one of 0.01-20 vol % O.sub.2/N.sub.2 (nitrogen), 0.01-20 vol % O.sub.2/He (helium) and 0.01-20 vol % O.sub.2/Ar (argon); a hydrogen reduction concentration is one of 5-20 vol % H.sub.2/N.sub.2, 5-20 vol % H.sub.2/He and 5-20 vol % H.sub.2/Ar.

6. The method according to claim 1, wherein the transition metals are in an oxidation state or a metal state; nitrate, chloride, diacetone, sulfate or acetate of the transition metals is adopted as a precursor.

7. The method according to claim 6, wherein the transition metal is Co with a loading of 0.01-50 wt % of phosphate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The sole FIGURE is data of specific product distributions at reaction temperature of 325 C. in embodiment 4.

DETAILED DESCRIPTION

(2) The present invention is described below in detail through some embodiments. However, the present invention is not limited to these embodiments.

(3) The phosphate is represented by HAP-M and PO-M, wherein HAP represents hydroxymetallic apatite; PO represents metal phosphate; and M refers to metal and is one or more of Ca, Mg, Ba, Sr, Pb, etc.

(4) The catalysts are represented by xMetal-HAP-M and xMetal-PO-M supports, wherein x=weight percent of metal loading in total weight of the catalysts100.

Embodiment 1

(5) Synthesis of Co-HAP-Ca Catalyst:

(6) (1) HAP-Ca is dried at 120 C. for 2 h to remove physical adsorption water on its surface;

(7) (2) Catalyst mixture were prepared via an incipient wetness impregnation method via treating the HAP-Ca dried in the step (1) at 25 C. using Co(NO.sub.3).sub.2.6H.sub.2O aqueous solution prepared in entry 5 in Table 1;

(8) (3) the obtained mixture after staying for 2 h at room temperature is then dried at 50 C. for 10 h to obtain corresponding catalyst precursors;

(9) (4) the catalyst precursor obtained in the step (3) is further oxidized at 350 C. for 2 h in an oxygen-included atmosphere, and then subjected reduction treatment at 400 C. for 2 h (10 vol % H.sub.2/N.sub.2) to obtain Co-HAP-Ca, which was denoted as Co-HAP-Ca (entry 5 in Table 1);

(10) (5) the loading of Co can be changed by controlling metal salt concentration and impregnation time, corresponding to entry 2, entry 3, entry 5, entry 7, entry 8 and entry 9 in Table 1.

(11) The preparation conditions of other catalysts are the same as these in embodiment 1. The corresponding relationship between the sample number and the preparation conditions are shown in Table 1.

(12) TABLE-US-00001 TABLE 1 Corresponding Relationship between Sample Number and Preparation Conditions in Embodiment 1 Loading/ Concentration/ Temperature/ Entry Catalyst wt % Support Metals Solvent g/mL C. 1 HAP-Ca 0 HAP-Ca Cobalt nitrate Water 0 400 2 0.1Co-HAP-Ca 0.1 HAP-Ca Cobalt nitrate Water 0.1 400 3 0.5Co-HAP-Ca 0.5 HAP-Ca Cobalt nitrate Water 0.3 400 4 0.8Co-HAP-Ca 0.8 HAP-Ca Cobalt nitrate Water 0.5 300 5 0.8Co-HAP-Ca 0.8 HAP-Ca Cobalt nitrate Water 0.5 400 6 0.8Co-HAP-Ca 0.8 HAP-Ca Cobalt nitrate Water 0.5 550 7 1.6Co-HAP-Ca 1.6 HAP-Ca Cobalt nitrate Water 1.0 400 8 3.3Co-HAP-Ca 3.3 HAP-Ca Cobalt nitrate Water 1.0 400 9 8.9Co-HAP-Ca 8.9 HAP-Ca Cobalt nitrate Water 0.75 400 10 0.8Co-HAP-Sr 0.8 HAP-Sr Cobalt nitrate Water 0.5 400 11 0.8Co-HAP-Mg 0.8 HAP-Mg Cobalt nitrate Water 0.5 400 12 0.8Co-HAP-Ba 0.8 HAP-Ba Cobalt nitrate Water 0.75 400 13 0.8Co-HAP-Pb 0.8 HAP-Pb Cobalt nitrate Water 0.5 400 14 0.8Co-HAP-Ca/ 0.8 HAP-Ca/ Cobalt nitrate Water 0.5 400 Sr Sr 15 0.8Co-HAP-Ca/ 0.8 HAP-Ca/ Cobalt nitrate Water 0.5 400 Sr/Ba Sr/Ba 16 0.8Co-HAP-Ca + 0.8 HAP-Ca Cobalt nitrate Water 0.5 400 0.8Ni-HAP-Ca 17 0.8Co-HAP-Ca 0.8 HAP-Ca Cobalt Water 0.5 400 chloride 18 0.8Co-HAP-Ca 0.8 HAP-Ca Cobalt acetate Water 0.5 400 19 0.8Ni-HAP-Ca 0.8 HAP-Ca Nickel nitrate Water 0.5 500 20 0.8Cu-HAP-Ca 0.8 HAP-Ca Copper Water 0.5 400 nitrate 21 0.8Ag-HAP-Ca 0.8 HAP-Ca Silver nitrate Water 0.5 400 22 0.8Rh-HAP-Ca 0.8 HAP-Ca Rhodium Water 0.5 400 chloride 23 0.8ZnO-HAP-CA 0.8 HAP-Ca Zinc nitrate Water 0.5 400 24 0.5Co0.5Ni-HAP- 0.8 HAP-Ca Cobalt nitrate + Water 0.3 400 Ca Nickel nitrate 25 0.5Co-HAP-Ca 0.8 HAP-Ca Cobalt nitrate Ethanol 0.3 400 26 0.5Co-HAP-Ca 0.8 HAP-Ca Cobalt nitrate Methanol 0.3 400 27 0.8Co-PO-Ca 0.8 PO-Ca Cobalt nitrate Water 0.5 400 28 0.8Ni-PO-Ca 0.8 PO-Ca Cobalt nitrate Water 0.5 400

Embodiment 2

(13) Synthesis of Co and Ni Bimetallic HAP-Ca-Based Catalyst:

(14) (1) HAP-Ca is dried at 120 C. for 2 h to remove physical adsorption water on its surface;

(15) (2) at 25 C., the Co(NO.sub.3).sub.2.6H.sub.2O aqueous solution prepared in entry 5 in Table 1 and the Ni(NO.sub.3).sub.2.6H.sub.2O aqueous solution prepared in entry 19 are mixed at equal volume; and then, an incipient wetness impregnation method is used to treat the HAP-Ca dried in the step (1) to stand for 2 h;

(16) (3) the obtained mixture after staying for 2 h at room temperature is then dried at 50 C. for 10 h to obtain catalyst precursors;

(17) (4) the catalyst precursor obtained in the step (3) is oxidized at 350 C. for 2 h in an oxygen-included atmosphere, and then subjected reduction at 400 C. for 2 h (10 vol % H.sub.2/N.sub.2) to obtain Ni and Co-HAP-Ca catalyst, which is denoted as CoNi-HAP-Ca (entry 24 in Table 1).

Embodiment 3

(18) Different transition metal-phosphates are used to catalyze the conversion of ethanol to methylbenzyl alcohol.

(19) Ethanol upgrading is studied in a fix-bed, atmosphere pressure reactor by feeding ethanol as reactant. Reaction conditions are as follows: the catalyst is first packed in the fix-bed reactor with an inner diameter of 8 mm and kept at 325 C. Then, ethanol liquid is fed in a rate of 0.3 mL/h. After steady, ethanol conversion and products distribution were analyzed by an on-line gas chromatography (GC). The corresponding relationship between samples number and ethanol upgrading activity are shown in Table 2.

(20) TABLE-US-00002 TABLE 2 Corresponding Relationship between Sample Number and Ethanol Conversion and Methylbenzyl Alcohol Selectivity in Embodiment 3 Conversion Selectivity Entry Catalyst (%) (%) 1 HAP-Ca 27.7 0.4 2 0.1Co-HAP-Ca 30.3 10.3 3 0.5Co-HAP-Ca 38.5 40.2 4 0.8Co-HAP-Ca 35.9 59.5 5 0.8Co-HAP-Ca 34.9 60.1 6 0.8Co-HAP-Ca 30.2 30.8 7 1.6Co-HAP-Ca 36.6 64.0 8 3.3Co-HAP-Ca 38.6 62.5 9 8.9Co-HAP-Ca 35.5 60.5 10 0.8Co-HAP-Sr 35.5 60.2 11 0.8Co-HAP-Mg 34.1 55.0 12 0.8Co-HAP-Ba 30.1 56.2 13 0.8Co-HAP-Pb 29.8 55.2 14 0.8Co-HAP-Ca/Sr 32.2 50.1 15 0.8Co-HAP-Ca/Sr/Ba 35.0 59.8 16 0.8Co-HAP-Ca+0.8Ni-HAP-Ca 36.0 60.8 17 0.8Co-HAP-Ca 36.2 62.0 18 0.8Co-HAP-Ca 10 5.2 19 0.8Ni-HAP-Ca 27.2 50.5 20 0.8Cu-HAP-Ca 32.1 51.0 21 0.8Ag-HAP-Ca 47.1 65.4 22 0.8Rh-HAP-Ca 48.0 45.2 23 0.8ZnO-HAP-Ca 30.1 15.1 24 0.5Co0.5Ni-HAP-Ca 41.2 65.1 25 0.5Co-HAP-Ca 32.5 41.2 26 0.5Co-HAP-Ca 33.1 40.2 27 0.8Co-PO-Ca 24.6 25.2 28 0.8Ni-PO-Ca 18.0 17.2

Embodiment 4

(21) Co-HAP-Ca is used to catalyze the upgrading of ethanol to methylbenzyl alcohol at different reaction temperature.

(22) Ethanol upgrading is studied in a fix-bed, atmosphere pressure reactor by feeding ethanol as reactant. Reaction conditions are as follows: the catalyst is first packed in the fix-bed reactor with an inner diameter of 8 mm and kept at different reaction temperature (100-450 C.). Then, ethanol liquid is fed in a rate of 0.3 mL/h with WHSV of 1.0 h.sup.1. After steady, ethanol conversion and products distribution were analyzed by an on-line gas chromatography (GC). Reaction results are shown in Table 3.

(23) The products distribution at 325 C. is shown in the FIGURE.

(24) TABLE-US-00003 TABLE 3 Ethanol Conversion and Methylbenzyl Alcohol Selectivity on Co-HAP-Ca in Embodiment 4 Temperature Conversion (%) Selectivity (%) 100 0.5 0.5 250 6.9 12.8 275 11.4 34.7 300 19.2 49.2 325 34.9 60.1 350 53.1 65.1 400 85.1 65.8 450 >99 50.5

Embodiment 5

(25) At 325 C., the effect of ethanol feeding rate on methylbenzyl alcohol selectivity is studied.

(26) Ethanol upgrading is studied in a fix-bed, atmosphere pressure reactor by feeding ethanol as reactant. Reaction conditions are as follows: the catalyst is first packed in the fix-bed reactor with an inner diameter of 8 mm and kept at 325 C. Then, ethanol liquid is fed in a rate of 0.05-2.7 mL/h (milliliter per hour). After steady, ethanol conversion and products distribution were analyzed by an on-line gas chromatography (GC). Reaction results are shown in Table 4.

(27) TABLE-US-00004 TABLE 4 Study of Effect of Ethanol Feeding rate on Methylbenzyl Alcohol Selectivity in Embodiment 5 Feeding Conversion Selectivity (mL/h) (%) (%) 0.05 69.7 42.1 0.1 55 47.8 0.15 41.2 52.1 0.2 37.3 54.2 0.27 33.5 57.4 0.32 25.8 58.0 2.7 5.2 18.9