Use of catalyst prepared with a subgroup VI element for the production of organic chemicals and fuels from lignin

Abstract

A process for the production of organic chemicals and fuels from lignin in the presence of a molybdenum or tungsten based catalyst, comprising mixing the lignin with the catalyst and a solvent in a sealed reactor, introducing an inert gas or hydrogen to the reactor to replace oxygen therein, and heating the sealed reactor to perform a depolymerization reaction at a reaction temperature of above 200° C. to obtain liquid products, which include aromatic compounds, esters, alcohols, monophenols and benzyl alcohols.

Claims

1. A process for the production of organic chemicals and fuels from lignin, comprising mixing the lignin with a molybdenum based catalyst and a solvent in a sealed reactor, introducing an inert gas to the reactor to replace oxygen therein, and heating the sealed reactor to perform a depolymerization reaction at a reaction temperature of 230-350° C. for 0.5-12 h to obtain liquid products comprising alcohols, esters, monophenols, benzyl alcohols and arenes; wherein the solvent is selected from the group consisting of deionized water, ethanol and a mixture of deionized water and ethanol; wherein the molybdenum based catalyst is a supported or an unsupported catalyst comprising molybdenum as an active metal; wherein the supported catalyst is expressed as A.sub.xB.sub.y/C, wherein A represents molybdenum which has a loading amount of 1-80 wt. % of the supported catalyst, B represents carbon, phosphorus or nitrogen, and C represents the support of the catalyst selected from the group consisting of aluminum oxide (Al.sub.2O.sub.3), activated carbon (AC), silicon dioxide (SiO.sub.2), silicon carbide (SiC), zeolites and nano-carbon fiber, 0<x≦2 and 0<y≦3; wherein the unsupported catalyst is expressed as A.sub.xB.sub.y, wherein A represents molybdenum, B represents carbon, phosphorus or nitrogen, 0<x≦2, and 0<y≦3; wherein the lignin includes alkali lignin, Klason lignin, milled wood lignin and organosolv lignin; wherein the inert gas is nitrogen, argon or helium; and wherein the mixture of deionized water and ethanol comprises 10-50% of ethanol by volume.

2. The process of claim 1, wherein the sealed reactor is adapted to receive both liquid and solid or slurry feeds, and continuous distillation is used to maintain continuous reaction.

3. The process of claim 1, wherein, a mass ratio of the lignin and solvent is 1:200-1:10; a mass ratio of the lignin and catalyst is between 1:1 and 200:1; the sealed reactor has an initial reaction pressure of 0-6 MPa at room temperature of 20-25° C., and the reaction proceeds at 260-300° C. for 2-6 h under a stirring rate of 100-1500 r/min.

4. The process of claim 3, wherein the mass ratio of the lignin and solvent is 1:100-1:80.

5. The process of claim 3, wherein the mass ratio of the lignin and catalyst is between 10:1 and 100:1.

6. The process of claim 1, wherein the catalyst further comprises a promoter Z which has a loading amount of 0.1-15 wt. % of the catalyst and is selected from the group consisting of Fe, Ni, Co, Ru, W, Cu, Cr and Pt.

Description

FIGURE LEGEND

(1) FIG. 1: Total ionic chromatogram of the liquid products obtained from the lignin depolymerization reaction at 280° C. for 6 h in pure ethanol over Mo.sub.2C/AC. (1)

(2) FIG. 2: Total ionic chromatogram of the liquid products obtained from the lignin depolymerization reaction at 280° C. for 6 h in water/ethanol (v:v=1:1) over W.sub.2P/AC. (2)

IMPLEMENTING CASES

The First Group of Examples: Depolymerization of Lignin with Molybdenum Based Catalyst

(3) The invention will be further introduced with the following examples. Ammonium paramolybdate was used as the source of molybdenum. Ammonia water was purchased from Guangfu Inc.

Example 1-1

(4) For a typical preparation, activated carbon (AC) was impregnated with the solution of ammonium molybdate with extra ammonia, then the material was dried at 120° C. for 12 h. The precursor was finally carburized using a temperature programmed reaction procedure. Specifically, 0.5 g sample was exposed to hydrogen, and heated to 350° C. and held at this temperature for 12 h. The gas was then switched to 15% CH.sub.4/H.sub.2, and the temperature was increased to 590° C. and then held at the temperature for 2 h. The sample was then cooled to room temperature (25° C.). The catalyst was represented as Mo.sub.2C/AC (30 wt. % Mo.sub.2C/AC).

Example 1-2

(5) With the exception of the Mo content, the same catalyst synthesis process was used as in example 1-1. The content of Mo in the Mo.sub.2C/AC catalyst was set as 1 wt. %, 5 wt. %, 10 wt. %, 15 wt. %, 20 wt. %, 30 wt. %, 50 wt. % and 80 wt. % with changing the concentration of ammonium molybdate or with repeated impregnation.

Example 1-3

(6) The same catalyst synthesis process was used as in example 1-1, except that the catalyst support was changed from AC to alumina (Al.sub.2O.sub.3), silicon carbide (SiC), silicon dioxide (SiO.sub.2). Therefore, molybdenum carbide catalysts with different support were obtained. For example: Mo.sub.2C/Al.sub.2O.sub.3, Mo.sub.2C/SiO.sub.2, Mo.sub.2C/SiC.

Example 1-4

(7) The same process of catalyst synthesis was used as in example 1-1, except that the final carbonization temperature was changed to 560° C., 620° C., 650° C., 680° C., 710° C., and 740° C. As a consequence, Mo.sub.xC.sub.y/AC samples with different crystal form are obtained, where 0<x≦2, 0≦y≦1, x is 1, 1, 2, 1, 2, 2; y is 1, 0, 0.5, 0.8, 0.2, 0.6.

Example 1-5

(8) The same process of catalyst synthesis was employed as in example 1-1, except that the sample was exposed to nitrogen, and heated to 500° C. and held at this temperature for 4 h. The catalyst was represented as MoO.sub.3/AC.

Example 1-6

(9) The same process of catalyst synthesis was employed as in example 1-1, except that the sample was exposed to hydrogen, and heated to 350° C. and held at this temperature for 12 h. The CH.sub.4/H.sub.2 was not needed in the preparation of this example. The catalyst was represented as MoO.sub.2/AC.

Example 1-7

(10) The same process of catalyst synthesis was employed as in example 1-1, except that the sample was exposed to hydrogen, and heated to 650° C. and held at this temperature for 4 h. The catalyst was represented as Mo/AC.

Example 1-8

(11) AC was impregnated with a solution of diammonium hydrogen phosphate and ammonium molybdate, then the mixtures were dried at 120° C. for 12 h and calcined at 500° C. for 4 h. The precursor was exposed to hydrogen, and heated to 650° C. and held at this temperature for 2 h. The catalyst was represented as MoP/AC.

Example 1-9

(12) The prepared catalysts were transferred into the batch reactor which was loaded with 1.0 g Kraft lignin (purchased from Sigma-Aldrich), 0.5 g catalyst and 100 mL ethanol. The initial gas pressure was 2 MPa of hydrogen. After reaction for 2 h at set 280° C., the system was cooled to room temperature. After releasing the gas, the reaction mixture was filtrated and analyzed. The liquid products were qualitatively analyzed with GC-MS (Agilent GC6890-MS5973), and quantitatively analyzed with GC (Agilent GC6890 with a FID) with internal standard method. The columns used with the FID and MS detector were both HP-5MS capillary columns (30 m×0.25 mm×0.25 μm). The yield of liquid products was expressed as mg/g lignin. The liquid product contains alcohols (monohydric alcohols such as butanol, butenol, hexyl alcohol, 2-hexenol, 2-ethyl butanol, 2-methyl pentenol), esters (ethyl acetate, butyl acetate, ethyl butyrate, ethyl hexanoate, ethyl 3-hexenoate, ethyl 2-hexenoate, ethyl 3-methylpentanoate, ethyl 4-octanoate, ethyl octanoate), phenols (guaiacol, 4-methyl guaiacol, 4-ethyl guaiacol, 4-propyl guaiacol), benzyl alcohols (benzyl alcohol, 2-methyl benzyl alcohol, 4-ethyl benzyl alcohol, 2,4,5-trimethyl benzyl alcohol) and arenes (toluene, xylene, 3-methyl ethylbenzene, 2,4-dimethyl ethylbenzene, 2,5-dimethyl ethylbenzene).

Example 1-10

(13) The yields (mg/g lignin) of grouped compounds obtained with different Mo-based catalysts (Mo.sub.2C/AC, Mo/AC, MoO.sub.2/AC, MoO.sub.3/AC) are listed as follows. The reaction conditions were the same as in Example 1-9. High yield of liquid products were obtained from Mo-based catalysts, among which Mo.sub.2C/AC showed the highest activity.

(14) TABLE-US-00002 Yield of Yield of Yield of Yield of benzyl Yield of Catalyst alcohols esters phenols alcohols arenes Mo.sub.2C/AC 139 215 44 34 14 MoP/AC 54 122 32 33 7 Mo/AC 44 126 26 31 5 MoO.sub.2/AC 12 85 21 20 5 MoO.sub.3/AC 14 63 21 10 4 No catalyst 5 31 18 none none

Example 1-11

(15) The effect of the supports (Mo.sub.2C/AC, Mo.sub.2C/Al.sub.2O.sub.3, Mo.sub.2C/SiO.sub.2, Mo.sub.2C/SiC, Mo.sub.2C) on the yields (mg/g lignin) of the grouped compounds are shown as follows. The reaction conditions were the same as in Example 1-9. High yield of liquid products were obtained from Mo-based catalysts with different supports, among which Mo.sub.2C/AC shows the highest activity.

(16) TABLE-US-00003 Yield of Yield of Yield of Yield of benzyl Yield of Catalyst alcohols esters phenols alcohols arenes Mo.sub.2C/AC 133 215 44 34 14 Mo.sub.2C/Al.sub.2O.sub.3 112 162 43 22 8 Mo.sub.2C/SiO.sub.2 103 186 41 32 9 Mo.sub.2C/SiC 99 174 46 27 9 Mo.sub.2C 86 133 40 23 8

Example 1-12

(17) The effect of Mo loading (30 wt. % Mo.sub.2C/AC, 20 wt. % Mo.sub.2C/AC, 10 wt. % Mo.sub.2C/AC) on the yields (mg/g lignin) of the grouped compounds are shown as follows. The reaction conditions were the same as in Example 1-9. High yields of liquid products were obtained from Mo-based catalysts with different Mo loading, among which 30 wt. % Mo.sub.2C/AC showed the highest activity.

(18) TABLE-US-00004 Yield of Yield of Yield of Yield of benzyl Yield of Catalyst alcohols esters phenols alcohols arenes 30 wt. % 133 215 44 34 14 20 wt. % 132 204 31 35 17 10 wt. % 82 163 32 35 12  5 wt. % 82 139 32 38 12

Example 1-13

(19) The effect of different carbonization temperature on the yields (mg/g lignin) of the grouped products are shown as follows. The reaction conditions were the same as in Example 1-9. High yields of liquid products were obtained with Mo-based catalysts with different carbonization temperatures, among which the highest yield of liquid was obtained at 590° C.

(20) TABLE-US-00005 Carbonization Yield of Yield of Yield of Yield of benzyl Yield of temperature (° C.) alcohols esters phenols alcohols arenes 560 84 71 40 11 10 590 133 215 44 34 14 650 96 143 42 27 11 710 67 165 42 14 10

Example 1-14

(21) The effect of solvent on the yields (mg/g lignin) of the grouped products are shown as follows. The reaction conditions were the same as in Example 1-9, with the exception of the solvent used. Only phenols were obtained in the water solvent and the highest overall yield of liquid product was obtained with ethanol as the solvent.

(22) TABLE-US-00006 Yield of Yield of Yield of Yield of benzyl Yield of Solvent alcohols esters phenols alcohols arenes Water no no 49 no No Water/ethanol  21  37 44 no no Ethanol 133 215 44 34 14

Example 1-15

(23) The effect of the initial hydrogen pressure on the yields (mg/g lignin) of the grouped products are shown as follows. The reaction conditions were the same as in Example 1-9, with the exception of the initial hydrogen pressure.

(24) TABLE-US-00007 Initial hydrogen Yield of Yield of Yield of Yield of benzyl Yield of pressure (MPa) alcohols esters phenols alcohols arenes 0 63 251 40 39 22 1 119 213 49 39 17 2 133 215 44 34 14 3 110 165 23 49 16 4 87 95 24 31 11 5 74 93 23 31 10 6 69 84 22 30 8

Example 1-16

(25) The effect of the reaction time on the yields (mg/g lignin) of the grouped products are shown as follows. The reaction conditions were the same as in Example 1-9, with the exception of the reaction time.

(26) TABLE-US-00008 Reaction time Yield of Yield of Yield of Yield of benzyl Yield of (h) alcohols esters phenols alcohols arenes 0.5 2 5 12 2 1 2 133 215 44 34 14 4 178 189 23 49 43 6 155 134 19 57 39 12 164 128 16 35 39

Example 1-17

(27) The effect of the gas atmosphere on the yields (mg/g lignin) of the products are shown as follows. The reaction conditions were the same as in Example 1-9, with the exception of the gas atmosphere.

(28) TABLE-US-00009 Gas Yield of Yield of Yield of Yield of benzyl Yield of atmosphere alcohols esters phenols alcohols arenes H.sub.2-0 MPa 63 251 40 39 22 N.sub.2-0 MPa 57 262 43 42 23

Example 1-18

(29) The effect of the reaction time on the yields (mg/g lignin) of the grouped products under nitrogen atmosphere are shown as follows. The reaction conditions were the same as in Example 1-9, with the exception of the reaction time.

(30) TABLE-US-00010 Reaction time Yield of Yield of Yield of Yield of benzyl Yield of (h) alcohols esters phenols alcohols arenes 0.5 13 29 3 3 1 2 57 283 43 42 23 4 139 469 50 91 56 6 252 368 57 123 113 12 278 406 78 71 131

Example 1-19

(31) The prepared catalysts were transferred to the batch reactor which was loaded with 1.0 g enzymatic hydrolysis lignin, 0.5 g catalyst and 100 mL ethanol. The initial gas pressure was 0 MPa of nitrogen. After reaction for 6 h at 280° C., the system was cooled to room temperature. After releasing the gas, the reaction mixture was filtrated and analyzed. The liquid product contained alcohols (polyhydric alcohols), phenols (guaiacol, 4-methyl guaiacol, 4-ethyl guaiacol, 4-propyl guaiacol, 4-propenyl guaiacol, 2-ethyl phenol, 4-ethyl phenol, 2,5-diethyl phenol), benzyl alcohols (benzyl alcohol, 2-methyl benzyl alcohol). The hydroxyl number of liquid products were analyzed according to the methods of ISO 14900:2001, Plastics—polyols for use in the production of polyurethane—Determination of hydroxyl number. The weight-average molecular weight (M.sub.w) and Polydispersity index (PDI) of liquid products were measured with a GPC-HPLC instrument, UV detector set at 270 nm, Waters Styragel HR1 column at 40° C.) using tetrahydrofuran as the eluent at a flow rate of 1 ml/min with linear polystyrene standards for the molecular weight calibration curve. Phenols and benzyl alchols were qualitatively analyzed with GC-MS (Agilent GC6890-MS5973). The columns used with the FID and MS detector were both HP-5MS capillary columns (30 m×0.25 mm x 0.25 μm). The yield of liquid products was expressed as mg/g lignin.

(32) The effect of the reaction temperature on the yield (mg/g lignin) of liquid products, hydroxyl number, M.sub.w and PDI of liquid products obtained from the lignin depolymerization are shown as follows. The reaction conditions were the same as in Example 19, with the exception of the reaction temperature.

(33) TABLE-US-00011 Reaction Yield of liquid Hydroxyl number temperature (° C.) products (mg KOH/g) M.sub.w PDI 240 689 236 2480 2.58 260 783 289 2246 2.36 280 936 345 1860 2.12 300 994 289 1099 1.83 320 995 268 1065 2.23

Example 1-20

(34) The effect of reaction time on the yield (mg/g lignin) of liquid products, hydroxyl number, M.sub.w and PDI of the liquid products obtained from the lignin conversion are shown as follows. The reaction conditions were the same as in Example 1-19, with the exception of the reaction time.

(35) TABLE-US-00012 Reaction time Yield of liquid Hydroxyl number (h) products (mg KOH/g) M.sub.w PDI 2 835 326 1820 2.28 3 994 289 1099 1.83 4 962 332 1230 2.13 5 983 310 1450 2.09 6 992 298 1580 2.15

(36) In the examples mentioned above, Klason lignin, milled wood lignin, organosolv lignin, enzymatic hydrolysis lignin can be used as the feedstock to produce aliphatic hydrocarbons, alcohols, esters, phenols, benzyl alcohols, polyols and arenes. The mass ratio of the lignin and solvent is 1:200-1:10, and a preferred range is 1:100-1:80. The mass ratio of the lignin and catalyst is 1:1-200:1, and a preferred range is 10:1-100:1. The reaction temperature is 250-350° C., and a preferred range is 260-300° C. The stirring rate is 100-1500 r/min.

The Second Group of Examples: Decomposition of Lignin with Molybdenum Nitride Catalyst

Example 2-1

(37) For a typical preparation, alumina was impregnated with the solution of ammonium heptamolybdate and the material was dried at 110° C. for 12 h. The samples were then nitrided with a N.sub.2, H.sub.2 (v: v=1:5) mixture following under a four-stage heating ramp: from RT to 350° C. at 10° C./min, and then to 500° C. at 1° C./min and then to 700° C. at 2° C./min, maintaining at that temperature for 2 h. Then the catalyst with an Mo content of 30% was obtained and marked Mo.sub.2N/γ-Al.sub.2O.sub.3 (S. Korlann, Chemistry of Materials, 2002, 14, 4049-4058).

Example 2-2

(38) The same process of catalyst synthesis was used as in example 2-1. Mo2N/γ-Al2O3 Catalysts with different Mo contents (10%, 20%, 30%, 46 wt. %) were synthesized with changing the concentration of the ammonium heptamolybdate solution s or stepwise impregnation.

Example 2-3

(39) The same process of catalyst synthesis was employed as in example 2-1, except that the catalyst support was changed from alumina to NaY zeolite (NaY), SiO.sub.2 to obtain Mo.sub.2N/NaY and Mo.sub.2N/SiO.sub.2.

Example 2-4

(40) The same process of catalyst synthesis was employed as in example 2-1, except that the final nitration temperatures were changed to 600° C., 650° C., 700° C. and 750° C.

Example 2-5

(41) The Kraft lignin was dried overnight at 373 K for 12 h before being used. The prepared catalyst was transferred to the batch reactor which was loaded with 1.00 g Kraft lignin and 100 ml ethanol with nitrogen as shielding gas. After reaction for 6 h at a set temperature, the system was cooled to room temperature. After releasing the gas, the reaction mixture was filtrated and rotary evaporated. The liquid products were qualitatively analyzed with GC-MS (Agilent GC6890-MS5973), and quantitatively analyzed with GC (Agilent GC6890 with a FID) with internal tagging method. The columns used with the FID and MS detector were both HP-5MS capillary columns (30 m×0.25 mm×0.25 μm). The yield of liquid products was calculated as: (products quality/mg)/(lignin quality/mg). The liquid product contains alcohols (monohydric alcohols such as butanol, butenol, hexyl alcohol, 2-hexenol, 2-ethyl butanol, 2-methyl pentenol), esters (ethyl acetate, butyl acetate, ethyl butyrate, ethyl hexanoate, ethyl 3-hexenoate, ethyl 2-hexenoate, ethyl 3-methylpentanoate, ethyl 4-octanoate, ethyl octanoate), phenols (guaiacol, 4-methyl guaiacol, 4-ethyl guaiacol, 4-propyl guaiacol), benzyl alcohols (benzyl alcohol, 2-methyl benzyl alcohol, 4-ethyl benzyl alcohol, 2,4,5-trimethyl benzyl alcohol) and arenes (toluene, xylene, 3-methyl ethylbenzene, 2,4-dimethyl ethylbenzene, 2,5-dimethyl ethylbenzene)

Example 2-6

(42) Performance comparison of Mo.sub.2N/Al.sub.2O.sub.3, Mo.sub.2N/NaY and Mo.sub.2N/SiO.sub.2 is shown in the following table. The reaction process is the same as in example 2-5. The maximum product yield appeared when Mo.sub.2N/Al.sub.2O.sub.3 was used, which indicates that alumina is the preferable catalyst support.

(43) TABLE-US-00013 Yield of Yield of Yield of Yield of benzyl Yield of Catalysts alcohols esters phenols alcohols arenes Mo.sub.2N/Al.sub.2O.sub.3 108.7 589.3 21.3 81.4 64.1 Mo.sub.2N/NaY 30.7 337.1 27.4 29.9 34.0 Mo.sub.2N/SiO.sub.2 22.4 255.0 8.4 19.1 61.1

Example 2-7

(44) Performance comparison of catalysts prepared at different temperatures is shown in the following table. The reaction process is the same as in example 2-5. It is evident that all the Mo.sub.2N/Al.sub.2O.sub.3 synthesized at these temperatures performed well resulting in high product yields, while the highest total product yield is attributed to Mo.sub.2N/Al.sub.2O.sub.3 obtained at 700° C.

(45) TABLE-US-00014 Nitration Yield of Yield of Yield of Yield of benzyl Yield of Temperature/° C. alcohols esters phenols alcohols arenes 600 81.2 523.7 24.3 59.6 75.8 650 108.7 589.3 21.3 81.4 64.1 700 149.0 759.2 31.8 154.4 90.5 750 109.3 573.6 27.0 117.4 77.9

Example 2-8

(46) Performance comparison of the catalysts with Mo content of 10%, 20%, 30%, 46 wt. % is shown in the following table. The reaction process is the same as in example 2-5. As the data show that pure alumina has a low catalytic activity in the reaction and the total product yield rises in the first stage and then decreases as the Mo content increases. The total yield is almost the same when the Mo content is 20 wt. % and 30 wt. % and also the most. The yields of esters, phenols, benzyl alcohols and arenes are consistent with the total yield while the alcohol yield goes down as the Mo content increases.

(47) TABLE-US-00015 Mo content Yield of Yield of Yield of Yield of benzyl Yield of wt. % alcohols esters phenols alcohols arenes 0 51.6 141.4 14.5 58.1 26.0 10 497.4 494.8 5.4 11.4 45.3 20 143.1 831.1 27.2 93.7 88.7 30 149.0 759.2 31.8 154.4 90.5 47 59.6 481.2 26.9 72.1 88.0

Example 2-9

(48) The comparison of product yields obtained at different reaction temperature is shown in the following table. The reaction process is the same as in example 2-5, with the exception of the reaction temperature.

(49) TABLE-US-00016 Reaction Yield of Yield of Yield of Yield of benzyl Yield of Temperature/° C. alcohols esters phenols alcohols arenes 270 39.8 395.0 10.1 50.4 73.9 280 149.0 759.2 31.8 154.4 90.5 290 154.8 804.1 49.2 133.0 117.0 300 146.8 770.8 46.2 65.6 110.9

The Third Group of Examples: Decomposition of Lignin with WP and MoP Catalysts

Example 3-1

(50) For a typical preparation, alumina was impregnated with the solution of diammonium hydrogen phosphate and ammonium meta-tungstate, then the mixtures were dried at 120° C. for 12 h and calcined at 500° C. for 4 h. The precursor was finally reduced at flowing hydrogen atmosphere, and the obtained catalyst was WP/Al.sub.2O.sub.3 with the W content was 29 wt. %. The temperature programmed reduction was set by heating from room temperature to 300° C., and then from 300° C. to 650° C. at a rate of 1° C./min and finally held at 650° C. for 120 min. The unsupported WP catalyst was prepared by evaporation of the water in a solution of diammonium hydrogen phosphate and ammonium meta-tungstate, then dried and reduced under flowing hydrogen atmosphere.

Example 3-2

(51) The same catalyst synthesis process was employed as in example 3-1, with the exception of the W content. The content of W in the WP/Al.sub.2O.sub.3 catalyst was set as 1 wt. %, 5 wt. %, 10 wt. %, 15 wt. %, 20 wt. %, 30 wt. % and 50 wt. %.

Example 3-3

(52) The same catalyst synthesis process was employed as in example 3-1, with the exception that the catalyst support was changed from alumina to SiC, SiO.sub.2 and AC. Tungsten phosphide catalysts with different supports were obtained.

Example 3-4

(53) Placing a certain amount of the diammonium hydrogen phosphate, nickel nitrate and ammonium meta-tungstate into water. After having dissolved well, the solution is then used to impregnate the Al.sub.2O.sub.3 support, then dried at 120° C. for 12 h and calcined at 500° C. for 4 h, and finally reduced under the flowing hydrogen atmosphere. The temperature programmed reduction was set by heating from room temperature to 300° C., and then from 300° C. to 650° C. at a rate of 1° C./min and held at 650° C. for 120 min. Finally the Ni-WP/Al.sub.2O.sub.3 catalyst was obtained with the Ni content of 2 wt. % (2 wt. % Ni-20 wt % WP/Al.sub.2O.sub.3). By changing the promoter Ni to other metals like Fe, Co, Cu and Cr, Fe-WP/Al.sub.2O.sub.3, Co-WP/Al.sub.2O.sub.3, Cu-WP/Al.sub.2O.sub.3 and Cr-WP/Al.sub.2O.sub.3 catalysts are also obtained.

Example 3-5

(54) The same catalyst synthesis process was employed as in example 3-4, with the exception that the catalyst support was changed from alumina to SiC, SiO.sub.2 and AC.

Example 3-6

(55) The same catalyst synthesis process was employed as in example 3-4, with the exception that the metal load was changed. The loading W percent in the Ni-WP/Al.sub.2O.sub.3 catalyst was 1 wt. %, 5 wt. %, 15 wt. %, 30 wt. % and 50 wt. %, respectively.

Example 3-7

(56) The same catalyst synthesis process was employed as in example 3-4, with the exception of changing the weight percentage of the promoter. Different catalysts were prepared containing 1 wt. % Ni-WP/Al.sub.2O.sub.3, 5 wt. % Ni-WP/Al.sub.2O.sub.3, 10 wt. % Ni-WP/Al.sub.2O.sub.3, 0.1 wt. % Fe-WP/Al.sub.2O.sub.3, 5 wt. % Fe-WP/Al.sub.2O.sub.3, 15 wt. % Fe-WP/Al.sub.2O.sub.3, 3 wt. % Cu-WP/Al.sub.2O.sub.3, 8 wt. % Cu-WP/Al.sub.2O.sub.3, 12 wt % Cu-WP/Al.sub.2O.sub.3, 3 wt. % Co-WP/Al.sub.2O.sub.3, 8 wt. % Co-WP/Al.sub.2O.sub.3, 10 wt. % Co-WP/Al.sub.2O.sub.3, 2 wt. % Cr-WP/Al.sub.2O.sub.3, 6 wt. % Cr-WP/Al.sub.2O.sub.3, 12 wt. % Cr-WP/Al.sub.2O.sub.3.

Example 3-8

(57) According to the catalyst synthesis process of examples 3-4 through 7, MoP catalysts were synthesized. For a typical preparation, alumina was impregnated with the solution of diammonium hydrogen phosphate, nickel nitrate and ammonium molybdate, then the mixtures were dried at 120° C. for 12 h and calcined at 500° C. for 4 h. The precursor was finally reduced under flowing hydrogen atmosphere, and the temperature program for the reduction was set by heating from room temperature to 300° C., and then from 300° C. to 650° C. at a rate of 1° C./min and finally held at 650° C. for 120 min. The obtained catalyst was 2 wt. % Ni-20 wt. % MoP/Al.sub.2O.sub.3.

Example 3-9

(58) Support was changed to SiC, SiO2 and AC, and the metal content and the promoter content were also changed. The obtained catalysts contain 1 wt. % Ni-MoP/Al.sub.2O.sub.3, 5 wt. % Ni-MoP/Al.sub.2O.sub.3, 10 wt. % Ni-MoP/Al.sub.2O.sub.3, 0.1 wt. % Fe-MoP/Al.sub.2O.sub.3, 5 wt. % Fe-MoP/Al.sub.2O.sub.3, 15 wt. % Fe-MoP/Al.sub.2O.sub.3, 3 wt. % Cu-MoP/Al.sub.2O.sub.3, 8 wt. % Cu-MoP/Al.sub.2O.sub.3, 12 wt. % Cu-MoP/Al.sub.2O.sub.3, 3 wt. % Co-MoP/Al.sub.2O.sub.3, 8 wt. % Co-MoP/Al.sub.2O.sub.3, 10 wt. % Co-MoP/Al.sub.2O.sub.3, 2 wt. % Cr-MoP/Al.sub.2O.sub.3, 6 wt. % Cr-MoP/Al.sub.2O.sub.3, 12 wt. % Cr-MoP/Al.sub.2O.sub.3.

Example 3-10

(59) The prepared catalysts were transferred to the batch reactor which was loaded with 1.00 g Kraft lignin, 50 mL water and 50 mL ethanol. The initial gas pressure was 2 MPa of hydrogen. After reaction for 2 h at a set temperature of 280° C., the system was cooled to room temperature. After releasing the gas, the reaction mixture was filtrated and analyzed. The liquid products were qualitatively analyzed with GC-MS (Agilent GC6890-MS5973), and quantitatively analyzed with GC (Agilent GC6890 with a FID) with internal standard method. The columns used with the FID and MS detector were both HP-5MS capillary columns (30 m×0.25 mm×0.25 μm). The yield of liquid products was expressed as mg/g lignin.

Example 3-11

(60) The reaction process was the same as employed in example 3-10, with the exception of changing the initial gas to 2 MPa N.sub.2. The results were as follows.

(61) TABLE-US-00017 Initial gas Monophenols yield (mg/g lignin) H.sub.2 2 MPa 49.5 N.sub.2 2 MPa 54.5

Example 3-12

(62) The reaction process was the same as employed in example 3-10, with the exception of changing the support of the catalysts. The results were as follows.

(63) TABLE-US-00018 Catalyst Monophenols yield (mg/g lignin) WP/SiC 39.5 WP/SiO.sub.2 36.5 WP/Al.sub.2O.sub.3 49.5 WP/AC 67.6

Example 3-13

(64) The reaction process was the same as employed in example 3-10, with the exception of changing the catalysts to the catalysts with 2 wt % promoter. The results were as follows.

(65) TABLE-US-00019 Catalyst Monophenols yield (mg/g lignin) Fe—WP/Al.sub.2O.sub.3 39.5 Co—WP/Al.sub.2O.sub.3 35.8 Ni—WP/Al.sub.2O.sub.3 34.5 Cu—WP/Al.sub.2O.sub.3 33.7 Cr—WP/Al.sub.2O.sub.3 48.5

Example 3-14

(66) The reaction process was the same as employed in example 3-10, with the exception of changing the catalysts to the MoP catalysts with 2 wt. % promoter. The results were as follows.

(67) TABLE-US-00020 Catalyst Monophenols yield (mg/g lignin) Fe—MoP/Al.sub.2O.sub.3 61.0 Co—MoP/Al.sub.2O.sub.3 58.5 Ni—MoP/Al.sub.2O.sub.3 56.3 Cu—MoP/Al.sub.2O.sub.3 56.0 Cr—MoP/Al.sub.2O.sub.3 63.2

Example 3-15

(68) The reaction process was the same as employed in example 3-10, with the exception of changing the catalysts. The results were as follows.

(69) TABLE-US-00021 Catalyst Monophenols yield (mg/g lignin) Ni—MoP/Al.sub.2O.sub.3 56.3 Ni—MoP/AC 64.5 Ni—MoP/SiO.sub.2 50.5 Ni—WP/Al.sub.2O.sub.3 34.5 Ni—WP/AC 56.5 Ni—WP/SiO.sub.2 35.5

Example 3-16

(70) The reaction process was the same as employed in example 3-10, with the exception of changing the metal content of the catalysts. The results were as follows.

(71) TABLE-US-00022 Catalyst Monophenols yield (mg/g lignin) 10 wt. % WP/Al.sub.2O.sub.3 22.5 15 wt. % WP/Al.sub.2O.sub.3 38.0 20 wt. % WP/Al.sub.2O.sub.3 49.5 30 wt. % WP/Al.sub.2O.sub.3 51.0

Example 3-17

(72) The reaction process was the same as employed in example 3-10, with the exception of changing the promoter content of the catalysts. The results were as follows.

(73) TABLE-US-00023 Catalyst Monophenols yield (mg/g lignin) 1 wt. % Ni—WP/Al.sub.2O.sub.3 38.5 2 wt. % Ni—WP/Al.sub.2O.sub.3 34.5 5 wt. % Ni—WP/Al.sub.2O.sub.3 31.0 1 wt. % Ni—MoP/Al.sub.2O.sub.3 62.5 2 wt. % Ni—MoP/Al.sub.2O.sub.3 56.3 5 wt. % Ni—MoP/Al.sub.2O.sub.3 54.5

Example 3-18

(74) The reaction process was the same as employed in example 3-10, with the exception of changing the reactive solvent. The results were as follows.

(75) TABLE-US-00024 Catalyst Solvent Monophenols yield (mg/g lignin) WP/Al.sub.2O.sub.3 EtOH 30.5 WP/Al.sub.2O.sub.3 EtOH/H.sub.2O (v:v = 4:1) 33.2 WP/Al.sub.2O.sub.3 EtOH/H.sub.2O (v:v = 1) 49.5

Example 3-19

(76) The reaction process was the same as employed in example 3-10, with the exception of changing the reaction time. The results were as follows.

(77) TABLE-US-00025 Catalyst Reaction time (h) Monophenols yield (mg/g lignin) WP/Al.sub.2O.sub.3 2 49.5 WP/Al.sub.2O.sub.3 3 44.3 WP/Al.sub.2O.sub.3 6 37.0

Example 3-20

(78) The reaction process was the same as employed in example 3-10, with the exception of changing the initial hydrogen pressure. The results were as follows.

(79) TABLE-US-00026 Catalyst Initial pressure (MPa) Monophenols yield (mg/g lignin) WP/Al.sub.2O.sub.3 1 51.4 WP/Al.sub.2O.sub.3 2 49.5 WP/Al.sub.2O.sub.3 3 46.4 WP/Al.sub.2O.sub.3 4 39.7

The Fourth Group of Examples: Decomposition of Lignin with Amorphous Alloy Catalysts

Example 4-1

(80) 3.5 g ammonia paramolybdate was dissolved in 20 mL of aqueous ammonia. Then 4 g activated carbon was added into the solution and impregnated for 10 min. Then the solution was evaporated so as to dry slowly at 70° C. The solid was dried for 12 h at 120° C. and then dried for 2 h at 200° C. The prepared material was the catalyst precursor. 1.5 g NaBH.sub.4 was dissolved in 20 mL water. The precursor was reduced by adding 2 mL/min NaBH.sub.4 solution under stirring in an ice-water bath. When the reaction was completed, the catalyst was filtrated and washed to pH=7 and then washed with ethanol. Finally, the catalyst was kept in ethanol. The as prepared catalyst was denoted by Mo-B/AC.

Example 4-2

(81) 3.5 g ammonia paramolybdate was dissolved in 20 mL of aqueous ammonia. Then 4 g activated carbon was added into the solution and impregnated for 10 min. Then the solution was evaporated so as to dry slowly at 70° C. The solid was dried for 12 h at 120° C. and then dried for 2 h at 200° C. The prepared material was the catalyst precursor. 1.5 g NaPO.sub.2 was dissolved in 20 mL water. The precursor was reduced by adding 2 mL/min NaPO.sub.2 solution under stirring in ice-water bath. When the reaction was completed, the catalyst was filtrated and washed to pH=7 and then washed with ethanol. Finally, the catalyst was kept in ethanol. The as prepared catalyst was denoted by Mo-P/AC.

Example 4-3

(82) The preparation method used is similar to that used in example 4-1. However, the concentrations of ammonia paramolybdate and NaBH.sub.4 change proportionally. The Mo loading was 1 wt. %, 5 wt. %, 10 wt. %, 15 wt. %, 20 wt. %, 30 wt. % for Mo-B/AC respectively. These catalysts were denoted by 1 wt. %, 5 wt. %, 10 wt. %, 15 wt. %, 20 wt. %, 30 wt. % Mo-B/AC, respectively.

Example 4-4

(83) The preparation method used is similar to that used in example 4-1. However, the support is AC, Al.sub.2O.sub.3, SiO.sub.2, SiC, TiO.sub.2, MgO, respectively. These catalysts were denoted by Mo—B/AC, Mo—B/Al2O.sub.3, Mo—B/SiO.sub.2, Mo—B/SiC, Mo—B/TiO.sub.2, Mo—B/MgO.

Example 4-5

(84) 3.5 g ammonia paramolybdate was dissolved in 20 mL of aqueous ammonia. 1.5 g NaBH.sub.4 was dissolved in 20 mL water. Then the ammonia paramolybdate solution was added into aqueous NaBH.sub.4 at a 2 mL/min rate under stirring. When the reaction was completed, the solution was filtrated and the filter cake was washed with water. The as prepared catalyst was denoted by Mo—B amorphous alloy.

Example 4-6

(85) 3.5 g ammonia paramolybdate and 0.3 g Y (Y=Ni(NO.sub.3).sub.2, Co(NO.sub.3).sub.2, Fe(NO.sub.3).sub.3, NaWO.sub.4, K.sub.2Cr.sub.2O.sub.4, K.sub.2RuCl.sub.5) was dissolved in 20 mL of aqueous ammonia. 1.5 g NaBH.sub.4 was dissolved in 20 mL water. Then the solution of ammonia paramolybdate and Y was added into aqueous NaBH.sub.4 at a 2 mL/min rate under stirring. When the reaction was completed, the solution was filtrated and the filter cake was washed with water. The as prepared catalyst was denoted by Mo—B—X (X represents the metal element in Y) amorphous alloy.

Example 4-7

(86) 3.5 g ammonia paramolybdate and 0.3 g Y (Y=Ni(NO.sub.3).sub.2, Co(NO.sub.3).sub.2, Fe(NO.sub.3).sub.3, NaWO.sub.4, K.sub.2Cr.sub.2O.sub.4, K.sub.2RuCl.sub.5) was dissolved in 20 mL of aqueous ammonia. Then 4 g activated carbon was added into the solution and impregnated for 10 min. Then the solution was evaporated so as to dry slowly at 70° C. The solid was dried for 12 h at 120° C. and then dried for 2 h at 200° C. The prepared material was the catalyst precursor. 1.5 g NaBH.sub.4 was dissolved in 20 mL water. The precursor was reduced by adding 2 mL/min NaBH.sub.4 solution under stirring in an ice-water bath. When the reaction was completed, the catalyst was filtrated and washed to pH=7 and then washed with ethanol. Finally, the catalyst was kept in ethanol. The as prepared catalyst was denoted by Mo—B—X/AC amorphous alloy.

Example 4-8

(87) The prepared catalysts were transferred to the batch reactor which was loaded with 1.00 g Kraft lignin, 50 mL water and 50 mL ethanol. The initial gas pressure was 2 MPa of hydrogen. After reaction for 2 h at a temperature of 280° C., the system was cooled to room temperature. After releasing the gas, the reaction mixture was filtrated and analyzed. The liquid products were qualitatively analyzed with GC-MS (Agilent GC6890-MS5973), and quantitatively analyzed with GC (Agilent GC6890 with a FID) with an internal standard method. The columns used with the FID and MS detector were both HP-5MS capillary columns (30 m×0.25 mm×0.25 μm). The yield of liquid products was expressed as mg/g lignin.

Example 4-9

(88) The products of lignin conversion reactions with doped Mo-B/AC catalyst are as follows. The reaction conditions are the same as those employed in example 4-8. As shown in the table, Mo—B—X/AC is active for lignin conversion. Mo-B/AC shows the highest activity.

(89) TABLE-US-00027 Yield Yield of Yield of Yield of of Benzyl Yield of Catalyst alcohols esters Phenols alcohols Arenes Mo—B/AC 55 720 19 6 220 Mo—B—Ni/AC 36 549 17 9 204 Mo—B—Co/AC 30 470 13 14 196 Mo—B—Fe/AC 21 334 19 8 226 Mo—B—W/AC 12 255 21 11 143 No catalyst 5 27 18 — — Mo—P/AC 48 663 22 18 179

Example 4-10

(90) The products of lignin conversion reactions with Mo-B/AC, Mo-B/Al.sub.2O.sub.3, Mo-B/SiO.sub.2, Mo-B/SiC, Mo—B as the catalysts are given as follows. The reaction conditions are the same as those employed in example 4-8. As shown in the table, supported Mo—B is more active than unsupported Mo—B. Catalyst with AC support shows the highest yield.

(91) TABLE-US-00028 Yield of Yield of Yield of Yield of Benzyl Yield of Catalyst alcohols esters Phenols alcohols Arenes Mo—B/AC 5.5 72.0 1.9 0.6 22.0 Mo—B/Al.sub.2O.sub.3 4.0 75.6 1.2 0.2 19.3 Mo—B/SiO.sub.2 4.6 64.3 0.6 0.5 9.3 Mo—B/SiC 3.2 50.9 2.2 1.1 7.8 Mo—B 4.3 69.0 1.5 0.4 23.0

Example 4-11

(92) The products of lignin conversion reactions with 30 wt. % Mo-B/AC, 20 wt. % Mo-B/AC, 10 wt. % Mo-B/AC as catalysts are listed as follows. The reaction conditions are the same as those employed in example 4-8. As shown in the table, Mo-B/AC with different Mo loading shows good activity. 20 wt. % Mo-B/AC shows the highest yield.

(93) TABLE-US-00029 Yield Yield of Yield of Yield of of Benzyl Yield of Catalyst alcohols esters Phenols alcohols Arenes 30 wt. % 52 693 15 7 235 Mo—B/AC 20 wt. % 55 720 19 6 220 Mo—B/AC 10 wt. % 32 484 16 6 194 Mo—B/AC 5 wt. % 30 306 14 5 181 Mo—B/AC

Example 4-12

(94) The products of lignin conversion reactions with Mo-B/AC as the catalyst in different solvents are given as follows. The reaction conditions are the same as those employed in example 4-8, with the exception of the solvent used. As shown in the table, water has the best selectivity for phenols, while ethanol gives the highest yield.

(95) TABLE-US-00030 Yield of Yield of Yield of Yield of Benzyl Yield of Solvent alcohols esters Phenols alcohols Arenes Water — 2 24 — — Water/Ethanol 12 135 17 1 — (v:v = 1:1) Ethanol 55 720 19 6 220

Example 4-13

(96) The products of lignin conversion reactions with Mo-B/AC as the catalyst under different hydrogen pressures. Reaction conditions are the same as those employed in example 4-8, with the exception of the hydrogen pressure.

(97) TABLE-US-00031 Initial hydrogen Yield of Yield of Yield of Yield of Benzyl Yield of pressure (MPa) alcohols esters Phenols alcohols Arenes 0 54 743 23 5 203 1 86 562 25 6 126 2 97 553 18 4 119 3 82 509 9 13 125 4 61 268 9 4 101

Example 4-14

(98) The products of lignin conversion reactions with Mo-B/AC catalysts with different reaction times. The reaction conditions are the same as those employed in example 4-8, with the exception of the reaction time.

(99) TABLE-US-00032 Reaction time Yield of Yield of Yield of Yield of Benzyl Yield of (h) alcohols esters Phenols alcohols Arenes 0.5 3 59 9 1 12 2 38 796 43 3 136 4 47 748 27 6 275 6 43 690 15 4 230

Example 4-15

(100) The products of lignin conversion reactions with Mo-B/AC as the catalyst under different atmospheres. The reaction conditions are the same as those employed in example 4-8, with the exception of the atmosphere.

(101) TABLE-US-00033 Gas Yield of Yield of Yield of Yield of Benzyl Yield of atmosphere alcohols esters Phenols alcohols Arenes H.sub.2-0 MPa 48 659 14 4 168 N.sub.2-0 MPa 55 720 19 6 220

Example 4-16

(102) The products of lignin conversion reactions with Mo-B/AC catalysts under 0 MPa N.sub.2 with different reaction times. The reaction conditions are the same as those employed in example 4-8, with the exception of the reaction time and N.sub.2 atmosphere.

(103) TABLE-US-00034 Reaction time Yield of Yield of Yield of Yield of Benzyl Yield of (h) alcohols esters Phenols alcohols Arenes 0.5 12 129 1 1 42 2 27 357 7 4 121 4 35 479 26 12 193 6 55 720 19 6 220

(104) In the examples mentioned above, Klason lignin, milled wood lignin, enzymatic hydrolysis lignin, organosolv lignin can be used as feedstock to produce alcohols, esters, phenols, benzyl alcohols and arenes. The mass ratio of the lignin and solvent is 1:200-1:10, and a preferred range is 1:100-1:80. The mass ratio of the lignin and catalyst is 1:1-200:1, and a preferred range is 10:1-100:1. The reaction temperature is 250-350° C., and a preferred range is 260-300° C. The stirring rate is 100-1500 r/min.