Eco-friendly process for hydrogenation or/and hydrodeoxygenation of organic compound using hydrous ruthenium oxide catalyst

Abstract

The invention discloses a process for hydrogenation (alkenes, carbonyl compounds and aromatics) and hydrodeoxygenation (methoxy phenols) of organic molecules using hydrous ruthenium oxide (HRO) and its supported form as a recyclable heterogeneous catalyst in aqueous medium with good yield of desired products (70-100%) under mild reaction conditions.

Claims

1. A process for hydrogenation or/and hydrodeoxygenation of organic compound, wherein said process comprises: (i) mixing an organic compound in water at a temperature in the range of 24 to 28 C. in a reactor vessel to form a solution wherein the organic compound is used in a concentration in the range of 1 to 20 wt. % with respect to water; (ii) adding a catalyst to the solution obtained in (i) to obtain a mixture, wherein said catalyst is hydrous ruthenium oxide or supported hydrous ruthenium oxide; (iii) regulating pressure and increasing temperature of the reactor vessel in at least one of two modes, wherein the at least one of two modes comprises adding and removing H.sub.2 into the mixture obtained in (ii) at 1-2 bar three times followed by adding H.sub.2 to attain a pressure in the range of 2 to 50 bar in the reactor vessel; and heating the reactor vessel to a temperature ranging between 70 to 200 C. followed by stirring the reaction mixture at 600-1000 rpm after attaining temperature for a time period of 5 min to 6 h; (iv) cooling down the reactor vessel to a temperature in the range 25 to 28 C. and releasing unreacted H.sub.2 and separating the catalyst to obtain a product mixture; and (v) separating product from the product mixture obtained in (iv) via direct solvent evaporation or by extractive separation to obtain an hydrogenated or/and hydrodeoxygenated organic compound.

2. The process as claimed in claim 1 wherein the organic compound is selected from the group consisting of an alkene, a carbonyl compound and an aromatic compound; wherein the alkene is selected from cyclohexene or -angelica lactone; wherein the carbonyl compound is selected from the group consisting of furfural, glucose, mannose, xylose, acetone, cyclohexanone, 2-butanone, 2-hexanone and methyl isobutyl ketone; wherein the aromatic compound is selected from the group consisting of phenol, benzyl alcohol, anisole, aniline, methyl nicotinate, benzoic acid, benzaldehyde, acetophenone, methoxy phenol, guiacol and syringiol.

3. The process as claimed in claim 1, wherein the supported hydrous ruthenium oxide is supported with Na-, H- and TiO.sub.2.

4. The process as claimed in claim 1, wherein the organic compound is used in a concentration in the range of 2 to 12.5 wt. %.

5. The process as claimed in claim 1, wherein conversion and yield of the hydrogenated or/and hydrodeoxygenated compound is in the range of 70 to 100%.

6. The process as claimed in claim 1, wherein the catalyst is reusable.

7. A process for hydrogenation or/and hydrodeoxygenation of organic compound, wherein said process comprises: (i) mixing an organic compound in water at a temperature in the range of 24 to 28 C. in a reactor vessel to form a solution wherein the organic compound is used in a concentration in the range of 1 to 20 wt. % with respect to water; (ii) adding a catalyst to the solution obtained in (i) to obtain a mixture, wherein said catalyst is hydrous ruthenium oxide or supported hydrous ruthenium oxide; (iii) regulating pressure and increasing temperature of the reactor vessel in at least one of two modes wherein the at least one of two modes comprises adding and removing H.sub.2 into the mixture obtained in (ii) at 1-2 bar three times followed by heating the reactor vessel to attain a temperature ranging between 70 to 160 C.; and adding H.sub.2 continuously into the reactor vessel at a flow rate ranging between 10-100 ml/min through a mass flow controller (MFC) while simultaneously stirring the mixture at 600-1000 rpm for 30 min to 10 hrs; (iv) cooling down the reactor vessel to a temperature in the range 25 to 28 C. and releasing unreacted H.sub.2 and separating the catalyst to obtain a product mixture; and (v) separating product from the product mixture obtained in (iv) via direct solvent evaporation or by extractive separation to obtain a hydrogenated or/and hydrodeoxygenated organic compound.

8. The process as claimed in claim 7, wherein the organic compound is selected from the group consisting of an alkene, a carbonyl compound and an aromatic compound; wherein the alkene is selected from cyclohexene or -angelica lactone; the carbonyl compound is selected from furfural, glucose, mannose, xylose, acetone, cyclohexanone, 2-butanone, 2-hexanone and methyl isobutylketone; and the aromatic compound is selected from phenol, benzyl alcohol, anisole, aniline, methyl nicotinate, benzoic acid, benzaldehyde, acetophenone, methoxy phenol, guiacol and syringiol.

9. The process as claimed in claim 7, wherein the supported hydrous ruthenium oxide is supported with Na-, H- and TiO.sub.2.

10. The process as claimed in claim 7, wherein the organic compound is used in a concentration in the range of 2 to 12.5 wt. %.

11. The process as claimed in claim 7, wherein conversion and yield of the hydrogenated or/and hydrodeoxygenated compound is in the range of 70 to 100%.

12. The process as claimed in claim 7, wherein the catalyst is reusable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: GC profile of the product mixture from Example 31

(2) FIG. 2: UHPLC of the product mixture from Example 14

DETAILED DESCRIPTION OF THE INVENTION

(3) The present invention provides an eco-friendly process for hydrogenation of organic molecules using hydrous ruthenium oxide (HRO; RuO.sub.2.xH.sub.2O) or its supported form as a recyclable efficient catalyst. The organic molecule along with water were taken in a reaction vessel and a pre-calculated quantity of catalyst was added into the vessel. The latter was heated for varied period of time. The reaction was carried out in presence of hydrogen both in a fixed pressure mode and in continuous flow mode. After completion of the reaction, the catalyst was separated by using a centrifuge and the clear product mixture was analyzed by GC-MS and UHPLC. The catalyst provides selective hydrogenation of various organic molecules such as: (i) Hydrogenation of alkenes to alkanes; (ii) Hydrogenation of ketones/aldehydes to alcohols; (iii) Hydrogenation of aromatics and (iv) Hydrodeoxygenation of lignin derived methoxy phenols to cyclohexanols.

(4) The present invention discloses a hydrogenation and hydrodeoxygenation of organic molecules using hydrous ruthenium oxide (HRO) and HRO/supports as efficient and recyclable heterogeneous catalysts in aqueous medium with excellent yields (70-100%) of products while operating under mild reaction conditions in shorter time.

(5) The reactor was loaded with reactants, solvent (water), and catalysts at one time. The reaction was conducted at desired temperature and H.sub.2 pressure with either fixed or flow-controlled variable pressure mode for a specified period of time. After completion of the reaction, reactor was cooled to room temperature and unconsumed hydrogen was released. The solid catalyst was separated by centrifugation and used for next cycle without any treatment. The liquid product mixture was quantified using ultra high-performance liquid chromatography (UHPLC), gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS). The catalysts used in the invention are HRO and supported HRO. The HRO catalyst was prepared by using conventional precipitation method using NaOH or through a modified method using CaCO.sub.3. Supported HRO catalysts (supports used are TiO.sub.2 Na- and H- zeolites) were prepared by precipitation followed by impregnation using dilute RuCl.sub.3 solution (0.001 M) and CaCO.sub.3 as precipitating agent.

(6) The present invention provides hydrogenation and hydrodeoxygenation of organic molecules using HRO and its supported form as catalysts in presence of a solvent selected from water alone. The reactions were performed at a temperature in the range of 25-200 C. and with a hydrogen pressure in the range of 2-50 bar, the ruthenium loading in the range of 0.1-0.7 wt. % with respect to reactants, the concentration of reactants is in the range of 1-20 wt. % with respect to solvent. The reaction progress was monitored at different time intervals in the range of 5 min to 10 h.

(7) In particular, using alkene reactants, the reactions were performed at temperature in the range of 70-80 C. and with a hydrogen pressure in the range of 5-10 bar, the ruthenium loading in the range of 0.25-0.35 wt. % with respect to alkenes, the concentration of alkenes is 5 wt. % with respect to solvent and the reactions were monitored in the time interval in the range of 5 min to 1 h. A maximum conversion of alkenes and the yield of hydrogenated products were achieved using HRO and its supported form catalysts in aqueous medium under mild reaction conditions. 100% conversion of cyclohexene with 100% yield of cyclohexane was achieved using HRO catalyst (Table 1, entry 1, example 1). 100% conversion of -angelica lactone (-al) with 100% yield of -valerolactone (Gvl) was achieved using HRO/Na- catalyst (Table 1, entry 2, example 2).

(8) In particular, using carbonyl compounds as reactants, the reactions were performed at temperature in the range of 80-150 C. and with a hydrogen pressure in the range of 5-50 bar, the ruthenium loading in the range of 0.1-0.35 wt. % with respect to carbonyl compounds, the concentration of carbonyl compounds is in the range of 1.25-12.5 wt. % with respect to solvent and monitored in the time interval in the range of 10 min to 3 h.

(9) A maximum conversion of ketones and the yield of corresponding alcohol products were achieved using HRO and its supported form catalysts in aqueous medium under mild reaction conditions. 100% conversion of ketones such as 2-hexanone, cyclohexanone, methyl isobutyl ketone (MIBK), 2-butanone and acetone with 100% yield of corresponding alcohols were achieved (Table 2, entry 1-8, example 3-10).

(10) A maximum conversion of aldehydes and the yield of corresponding alcohol products were achieved using HRO supported catalysts in aqueous medium under mild reaction conditions. 100% conversion of aldehydes such as furfural, glucose, xylose and mannose with 100% yield of corresponding alcohols were achieved (Table 3, entry 1-9, example 11-19).

(11) In particular, using substituted aromatics, the reactions were performed at temperature in the range of 70-120 C. and with a hydrogen pressure in the range of 10-20 bar, the ruthenium loading in the range of 0.17-0.7 wt. % with respect to aromatics, the concentration of aromatics is in the range of 0.62-2.5 wt. % with respect to solvent and the reactions were monitored in the time interval in the range of 15 min to 2 h.

(12) A maximum conversion of substituted aromatics and yield of ring hydrogenated products were achieved without disturbing of substituents using HRO catalysts in aqueous medium under mild reaction conditions. 100% conversion of substituted aromatics such as phenol, anisole, benzoic acid, and aniline with 100% yield of ring hydrogenated products were achieved (Table 4, entry 1-5, example 20-24).

(13) A maximum conversion of substituted aromatics and yield of ring hydrogenated products were achieved with reduction of substituent groups using HRO catalysts in aqueous medium under mild reaction conditions. 100% conversion of substituted aromatics such as benzaldehyde and acetophenone with 100% yield of ring and ring attached substituents hydrogenated products were achieved (Table 4, entry 7-8, example 26-27).

(14) A maximum conversion of methyl-3-picolinate achieved using HRO supported catalysts in aqueous medium under mild reaction conditions. 100% yield of hydrogenation followed by hydrolysis product was achieved (Table 4, entry 6, example 25).

(15) In particular, using lignin derived methoxy phenols, the reactions were performed at temperature in the range of 25-200 C. and with a hydrogen pressure in the range of 10-30 bar with continuous flow of H.sub.2 (10-50 ml/min) through MFC, the ruthenium loading in the range of 0.17-0.35 wt. % with respect to methoxy phenols, the concentration of methoxy phenols is in the range of 2.5-6.25 wt. % with respect to solvent and the reactions were monitored in the time interval in the range of 1 h to 10 h. A maximum conversion of methoxy phenols and the yield of selective hydrodeoxygenated product were achieved using HRO supported catalysts in aqueous medium under mild reaction conditions. 100% conversion of methoxy phenols such as 2-methoxy phenol (guaiacol), 2,6-dimethoxy phenol (syringol), 3-methoxy phenol and 4-methoxy phenol with 70-100% yield of selective deoxygenated cyclohexanol product was achieved (Table 5, entry 1-10, example 28-37).

(16) Continuous flow of H.sub.2 showed better results compared with batch H.sub.2 for hydrogeoxygenation of methoxy phenols rendering selective formation of cyclohexanol. Decreasing the flow rate of H.sub.2 increased the selectivity of cyclohexanol (Table 5, entry 3, example 30 and Table 6, entry 6, example 38).

(17) The catalytic activity of HRO/H- was compared with other conventionally used catalysts such as 5% Ru/C, 5% Pt/C, 5% Pd/C and 65% Ni@SiO.sub.2Al.sub.2O.sub.3 for selective hydrogeoxygenation of guaiacol to cyclohexanol. A set of the reactions were carried out at 160 C., 30 bar H.sub.2, and using 10 wt. % of catalyst (with respect to guaiacol) for 2 h. The HRO/H- catalyst showed better catalytic activity (100% conversion of guaiacol, 79% yield of cyclohexanol) than conventional catalysts5% Ru/C (100% guaaiacol conversion, 65% yield of cyclohexanol), 5% Pt/C (90% guaaiacol conversion, 38% yield of cyclohexanol) 5% Pd/C (100% guaaiacol conversion, 6% yield of cyclohexanol and observed 2-methoxy cyclohexanol as major product (94%)) and 65% Ni@SiO.sub.2Al.sub.2O.sub.3 (59% guaaiacol conversion, 49% yield of cyclohexanol) (Table 6, entry 1-6, example 38).

(18) The active catalyst (HRO and its supported forms) was recycled and reused up to five reaction cycles without drop in its catalysts activity in the case of guaiacol to cyclohexanol and xylose to xylitol. The catalyst was recovered from the product mixture by simple centrifugation; the obtained solid was washed with water and dried at room temperature and used for the next cycle and the same procedure was repeated for five cycles and observed 100% yield of products in all cases (example 42 and 43)).

(19) The hydrodeoxygenation of methoxyphenol to cyclohexanol reaction was scaled up for 2.5 g using 6.2 wt. % guaiacol in water that showed 95% yield of cycloexanol demonstrates the scalability of the process. The catalyst was removed from the product mixture by simple centrifugation, the obtained aqueous product mixture was extracted with dichloromethane (DCM).

(20) The hydrogenation of xylose to xylitol reaction was scaled up for 5 g using 12.5 wt. % xylose in water that showed 100% yield of xylitol demonstrates the scalability of the process. The catalyst was removed from the product mixture by simple centrifugation, the obtained aqueous product mixture is evaporated by using at 100 C. for 12 h and recovered a white solid xylitol.

(21) TABLE-US-00001 TABLE 1 Hydrogenation of alkenes Conv. Yield Ex- S.No Reactant Product (%) (%) ample 1 100 100 1 2 100 100 2 Reactions conditions: S.No 1: 2 g of cyclohexene in 40 ml of H.sub.2O, 10 mg of HRO, 80 C., 10 bar H.sub.2, 5 min S.No 2: 2 g of -angelica lactone in 40 ml of H.sub.2O, 200 mg of HRO/Na-, 70 C., 10 bar H.sub.2, 1 h

(22) TABLE-US-00002 TABLE 2 Hydrogenation of ketones S.No Reactant Product Conv. (%) Yield (%) Example 1 100 100 3 2 100 100 4 3 0 100 100 5 4 100 100 6 5 100 100 7 6 100 100 8 7 100 70 9 8 0 100 100 10 Reactions conditions: S.No 1-4: 1 g of ketones in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 100 C., 15 bar H.sub.2, 30 min S.No 5: 5 g of acetone in 40 ml of H.sub.2O, 250 mg of HRO/Na-, 100 C., 30 bar H.sub.2, 1 h S.No 6: 1 g of 2-butanone in 40 ml of H.sub.2O, 100 mg of HRO/Na-, 100 C., 15 bar H.sub.2, 30 min S.No 7: 1 g of 2-butanone in 40 ml of H.sub.2O, 30 mg of HRO/Na-, 100 C., 15 bar H.sub.2, 30 min S.No 8: 1 g of 2-butanone in 40 ml of H.sub.2O, 5 mg of HRO, 100 C., 15 bar H.sub.2, 30 min

(23) TABLE-US-00003 TABLE 3 Hydrogenation of aldehydes Conv. Yield S.No Reactant Product (%) (%) Example 1 100 100 11 2 100 100 12 3 100 100 13 4 100 100 14 5 0 0 15 6 100 100 16 7 60 60 17 8 100 100 18 9 100 100 19 Reactions conditions: S.No 1 and 2: 0.5 g of carbohydrates in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 120 C., 20 bar H.sub.2, 1 h S.No 3: 0.5 g of xylose in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 120 C., 20 bar H.sub.2, 10 min S.No 4: 0.5 g of xylose in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 80 C., 20 bar H.sub.2, 30 min S.No 5: 0.5 g of xylose in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 80 C., 2 bar H.sub.2, 30 min S.No 6: 5 g of xylose in 40 ml of H.sub.2O, 250 mg of HRO/Na-, 120 C., 50 bar H.sub.2, 30 min S.No 7: 8 g of xylose in 40 ml of H.sub.2O, 400 mg of HRO/Na-, 120 C., 50 bar H.sub.2, 1 h S.No 8: 0.4 g of xylose in 40 ml of H.sub.2O, 20 mg of HRO/Na-, 120 C., 20 bar H.sub.2, 30 min S.No 9: 1 g of furfural in 40 ml of H.sub.2O, 100 mg of HRO/TiO.sub.2, 150 C., 20 bar H.sub.2, 3 h

(24) TABLE-US-00004 TABLE 4 Hydrogenation of substituted aromatics Conv. Yield S.No Reactant Product Time (%) (%) Example Hydrogenation of aromatics-I 1 0 15 min 100 100 20 2 1 h 100 100 21 3 15 min 100 100 22 4 2 h 100 100 23 5 1.5 h 100 100 24 Hydrogenation of aromatics-II 6 0 1 h 100 100 25 Hydrogenation of aromatics-III 7 20 min 100 100 26 8 1 h 100 100 27 Reactions conditions: S.No 1: 1 g of phenol in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 70 C., 10 bar H.sub.2 S.No 2-5: 1 g of aromatics in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 100 C., 20 bar H.sub.2 0.25 g of methyl nicotinate in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 120 C., 15 bar H.sub.2 S.No 7: 1 g of acetophenone in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 100 C., 20 bar H.sub.2 S.No 8: 1 g of benzaldehyde in 40 ml of H.sub.2O, 50 mg of HRO/Na-, 100 C., 20 bar H.sub.2

(25) TABLE-US-00005 TABLE 5 Hydrodeoxygenation of methoxy phenols Conv. Yield Ex- S.No Reactant Product (%) (%) ample 1 100 86 28 2 80 75 29 3 0 100 95 30 4 100 98-99 31 5 100 99 32 6 79 76 33 7 100 95 34 8 0 100 80 35 9 100 85 36 10 100 70 37 Reactions conditions: S.No 1: 1 g of guaiacol in 40 ml of H.sub.2O, 100 mg of HRO/H-, 160 C., slow addition of H.sub.2 through mass flow controller (MFC)-50 ml/min for 1 h S.No 2: 1 g of guaiacol in 40 ml of H.sub.2O, 100 mg of HRO/H-, 160 C., slow addition of H.sub.2 through mass flow controller (MFC)-20 ml/min for 2 h S.No 3: 1 g of guaiacol in 40 ml of H.sub.2O, 100 mg of HRO/H-, 160 C., slow addition of H.sub.2 through mass flow controller (MFC)-20 ml/min for 3 h S.No 4: 1 g of guaiacol in 40 ml of H.sub.2O, 100 mg of HRO/H-, 160 C., slow addition of H.sub.2 through mass flow controller (MFC)-10 ml/min for 6 h S.No 5: 1 g of guaiacol in 40 ml of H.sub.2O, 100 mg of HRO/H-, 160 C., slow addition of H.sub.2 through mass flow controller (MFC)-10 ml/min for 10 h S.No 6: 1 g of guaiacol in 40 ml of H.sub.2O, 50 mg of HRO/H-, 160 C., slow addition of H.sub.2 through mass flow controller (MFC)-10 ml/min for 6 h S.No 7: 2.5 g of guaiacol in 40 ml of H.sub.2O, 250 mg of HRO/H-, 160 C., slow addition of H.sub.2 through mass flow controller (MFC)-20 ml/min for 6 h S.No 8-10: 1 g of methoxy phenols in 40 ml of H.sub.2O, 100 mg of HRO/H-, 160 C., slow addition of H.sub.2 through mass flow controller (MFC)-10 ml/min for 6 h

(26) TABLE-US-00006 TABLE 6 HRO catalyst comparison for hydrodeoxygenation of methoxy phenols Conv. Yield (%) S.No Catalyst (%) Cyclohexanol Others Example 1 Blank 0 38 2 5% Ru/C 100 65 35 38 3 5% Pt/C 90 38 52 38 4 5% Pd/C 100 6 94 38 5 65% 59 49 10 38 Ni@SiO.sub.2Al.sub.2O.sub.3 6 HRO/H- 100 75 25 38 7.sup.b HRO/H- 100 79 21 39 8.sup.c HRO/H- 0 40 9.sup.d HRO/H- 100 87 13 41 Reaction conditions: 1 g of guaiacol in 40 ml of H.sub.2O, 100 mg of catalyst, 160 C., 30 bar H.sub.2, 2 h, .sup.b200 C., .sup.c25 C., .sup.d10 bar H.sub.2

(27) The following examples are given by way of illustrations and should not construed the scope of the invention.

EXAMPLES

Example: 1

(28) To 2 g of cyclohexene in 40 ml of H.sub.2O, HRO catalyst (10 mg) was added in a reactor vessel. The reactor vessel was then heated at 80 C. for 5 min under H.sub.2 pressure (10 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of cyclohexene with 100% yield of cyclohexane.

Example: 2

(29) To 2 g of -angelica lactone in 40 ml of H.sub.2O, HRO/Na- catalyst (200 mg) was added in a reactor vessel. The reactor vessel was then heated at 70 C. for 1 h under H.sub.2 pressure (10 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of -angelica lactone with 100% yield of -valerolactone.

Example: 3

(30) To 1 g of 2-hexanone in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 30 min under H.sub.2 pressure (15 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of 2-hexanone with 100% yield of 2-hexanol.

Example: 4

(31) To 1 g of cyclohexanone in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 30 min under H.sub.2 pressure (15 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of cyclohexanone with 100% yield of cyclohexanol.

Example: 5

(32) To 1 g of MIBK in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 30 min under H.sub.2 pressure (15 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of MIBK with 100% yield of 4-methylpentan-2-ol.

Example: 6

(33) To 1 g of 2-butanone in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 30-min under H.sub.2 pressure (15 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of 2-butanone with 100% yield of 2-butanol.

Example: 7

(34) To 1 g of acetone in 40 ml of H.sub.2O, HRO/Na- catalyst (250 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 1 h under H.sub.2 pressure (30 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of acetone with 100% yield of isopropyl alcohol.

Example: 8

(35) To 1 g of 2-butanone in 40 ml of H.sub.2O, HRO/Na- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 30 min under H.sub.2 pressure (15 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of 2-butanone with 100% yield of 2-butanol.

Example: 9

(36) To 1 g of 2-butanone in 40 ml of H.sub.2O, HRO/Na- catalyst (30 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 30 min under H.sub.2 pressure (15 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 70% conversion of 2-butanone with 70% yield of 2-butanol.

Example: 10

(37) To 1 g of 2-butanone in 40 ml of H.sub.2O, HRO catalyst (5 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 30 min under H.sub.2 pressure (15 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of 2-butanone with 100% yield of 2-butanol.

Example: 11

(38) To 0.5 g of glucose in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 120 C. for 1 h under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by UHPLC. The reaction gave 100% conversion of glucose with 100% yield of sorbitol.

Example: 12

(39) To 0.5 g of mannose in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel-was then heated at 120 C. for 1 h under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using, centrifuge and the clear product mixture was analyzed by UHPLC. The reaction gave 100% conversion of mannose with 100% yield of mannitol.

Example: 13

(40) To 0.5 g of xylose in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 120 C. for 10 min under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by UHPLC. The reaction gave 100% conversion of xylose with 100% yield of xylitol.

Example: 14

(41) To 0.5 g of xylose in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 80 C. for 30 min under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by UHPLC. The reaction gave 100% conversion of xylose with 100% yield of xylitol.

Example: 15

(42) To 0.5 g of xylose in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 80 C. for 30 min under H.sub.2 pressure (2 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by UHPLC. The reaction gave no conversion, of xylose is observed.

Example: 16

(43) To 5 g of xylose in 40 ml of H.sub.2O, HRO/Na- catalyst (250 mg) was added in a reactor vessel. The reactor vessel was then heated at 120 C. for 30 min under H.sub.2 pressure (50 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by UHPLC. The reaction gave 100% conversion of xylose with 100% yield of xylitol.

Example: 17

(44) To 8 g of xylose in 40 ml of H.sub.2O, HRO/Na- catalyst (400 mg) was added in a reactor vessel. The reactor vessel was then heated at 120 C. for 1 h under H.sub.2 pressure (50 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by UHPLC. The reaction gave 60% conversion of xylose with 60% yield of xylitol.

Example: 18

(45) To 0.4 g of xylose in 40 ml of H.sub.2O, HRO/Na- catalyst (20 mg) was added in a reactor vessel. The reactor vessel was then heated at 120 C. for 30 min under H.sub.2 pressure (20 bar).

(46) After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by UHPLC. The reaction gave 100% conversion of xylose with 100% yield of xylitol.

Example: 19

(47) To 1 g of furfural in 40 ml of H.sub.2O, HRO/TiO.sub.2 catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 150 C. for 3 h under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of furfural with 100% yield of furfuryl alcohol.

Example: 20

(48) To 1 g phenol in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 70 C. for 15 min under H.sub.2 pressure (10 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of phenol with 100% yield of cyclohexanol.

Example: 21

(49) To 1 g benzyl alcohol in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 1 h under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of benzyl alcohol with 100% yield of cyclohexylmethanol.

Example: 22

(50) To 1 g anisole in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 15 min under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of anisole with 100% yield of methoxycyclohexane.

Example: 23

(51) To 1 g benzoic acid in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 2 h under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using, centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of benzoic acid with 100% yield of cyclohexanecarboxylic acid.

Example: 24

(52) To 1 g aniline in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 1.5 h under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of aniline with 100% yield of cyclohexanamine.

Example: 25

(53) To 0.25 g methyl nicotinate in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 120 C. for 1 h under H.sub.2 pressure (15 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of aniline with 100% yield of piperidine-3-carboxylic acid.

Example: 26

(54) To 1 g acetophenone in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 20 min under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of acetophenone with 100% yield of 1-cyclohexylethanol.

Example: 27

(55) To 1 g benzaldehyde in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 1 h under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of benzaldehyde with 100% yield of cyclohexylmethanol.

Example: 28

(56) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H-Beta catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 50 ml/min though a mass flow controller (MFC) for 1 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 86% yield of cyclohexanol.

Example: 29

(57) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 20 ml/min though a mass flow controller (MFC) for 2 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 80% conversion of guaiacol with 75% yield of cyclohexanol.

Example: 30

(58) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel.

(59) The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 20 ml/min though a mass flow controller (MFC) for 3 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 95% yield of cyclohexanol.

Example: 31

(60) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 10 ml/min though a mass flow controller (MFC) for 6 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 97-99% yield of cyclohexanol.

Example: 32

(61) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. and H.sub.2 was added, at a flow rate of 10 ml/min though a mass flow controller (MFC) for 10 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 99% yield of cyclohexanol.

Example: 33

(62) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (50 mg) was added in a reactor vessel. The The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 10 ml/min though a mass flow controller (MFC) for 6 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 79% conversion of guaiacol with 76% yield of cyclohexanol.

Example: 34

(63) To 2.5 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (250 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 20 ml/min though a mass flow controller (MFC) for 6 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 95% yield of cyclohexanol.

Example: 35

(64) To 1 g syringol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 10 ml/min though a mass flow controller (MFC) for 6 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 80% yield of cyclohexanol.

Example: 36

(65) To 1 g 3-methoxy phenol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 10 ml/min though a mass flow controller (MFC) for 6 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 85% yield of cyclohexanol.

Example: 37

(66) To 1 g 4-methoxy phenol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. and H.sub.2 was added at a flow rate of 10 ml/min though a mass flow controller (MFC) for 6 h under stirring. After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 70% yield of cyclohexanol.

Example: 38

(67) To 1 g guaiacol in 40 ml of H.sub.2O, several catalysts comprising 5% Ru/C, 5% Pd/C, 5% Pt/C, 65% Ni@SiO.sub.2A1.sub.2O.sub.3, and HRO/H- catalysts (100 mg) was added in a reactor vessel besides carrying out the reaction without adding any catalyst. The reactor vessel was then heated at 160 C. for 2 h under H.sub.2 pressure (30 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. In the absence of any catalyst, no conversion of guaiacol was observed while the catalysts gave following conversion and yields: 5% Ru/C (100% conversion with 65% yield of cyclohexanol), 5% Pd/C (100% conversion with 6% yield of cyclohexanol and 94% yield of 2-methoxy cyclohexanol), 5% Pt/C (90% conversion with 38% yield of cyclohexanol), 65% Ni@SiO.sub.2Al.sub.2O.sub.3 (59% conversion with 49% yield of cyclohexanol), HRO/H- (100% conversion with 75% yield of cyclohexanol).

Example: 39

(68) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 200 C. for 2 h under H.sub.2 pressure (30 bar). After completion of the reaction, the catalyst was separated by using-centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 79% yield of cyclohexanol.

Example: 40

(69) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 25 C. for 2 h under H.sub.2 pressure (30 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave no conversion of guaiacol.

Example: 41

(70) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. for 2 h under H.sub.2 pressure (10 bar). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by GC-MS. The reaction gave 100% conversion of guaiacol with 87% yield of cyclohexanol.

Example: 42

(71) To 1 g guaiacol in 40 ml of H.sub.2O, HRO/H- catalyst (100 mg) was added in a reactor vessel. The reactor vessel was then heated at 160 C. for 3 h under slow addition of required amount of H.sub.2 pressure (20 ml/min) though mass flow controller (MFC). After completion of the reaction, the catalyst was separated by using centrifuge and it was used as such for next cycle without any pre-treatment and this procedure was followed for five subsequent cycles. The catalyst activity did not change and all cycles gave 90-95% yield of cyclohexanol.

Example: 43

(72) To 0.5 g of xylose in 40 ml of H.sub.2O, HRO/Na- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 120 C. for 10 min under H.sub.2 pressure (20 bar). After completion of the reaction, the catalyst was separated by using centrifuge and it was used as such for next cycle without any pre-treatment and this procedure was followed for five subsequent cycles. The catalyst activity did not change and all cycles gave 97-100% yield of xylitol.

Example: 44

(73) To 0.5 g xylose in 40 ml of H.sub.2O, HRO/H- catalyst (50 mg) was added in a reactor vessel. The reactor vessel was then heated at 100 C. for 30 min under slow addition of required amount of H.sub.2 pressure (100 ml/min) though mass flow controller (MFC). After completion of the reaction, the catalyst was separated by using centrifuge and the obtained clear product mixture was analyzed by UHPLC. The reaction gave 10% conversion of xylose with 10% yield of xylitol.

(74) The present invention discloses the utility of hydrous ruthenium oxide (HRO) as energy efficient reusable heterogeneous catalyst for hydrogenation of various organic molecules of industrial importance in aqueous medium under mild reaction conditions in shorter time and achieved maximum selectivity and yield of hydrogenated products. The present invention reports for the first time the use of HRO as heterogeneous catalyst for hydrogenation and hydrodeoxygenation of various organic molecules. The prior art cited above did not teach nor disclose the use of HRO as catalyst for hydrogenation of organic molecules under mild reaction conditions. In the present invention, the problem of separation of final product from the catalyst is made easier and less time consumed by the use of heterogeneous catalyst. The use of HRO reduces the reaction time making the process economical. Moreover the use of expensive metals like palladium, platinum and rhodium (Pd, Pt and Rh) along with Ru and use of hazardous solvent have been dispensed and the process is made benign. In the present invention the inventive step is the reduction of catalyst in situ and thus obviates the need of hydrogen for external reduction and thereby makes the process more energy efficient. Furthermore, this invention introduced addition of hydrogen by flow-controlled variable pressure mode which gives better selectivity of the desired product, in particular for cyclohexanol from methoxy phenols and renders safety.

ADVANTAGES OF THE INVENTION

(75) Diverse reaction scope Reactions under mild conditions Nearly 100% conversion of organic molecules comprising alkenes, carbonyl compounds, and aromatics Nearly 70-100% selectivity of the desired products Better selectivity control of the desired product via flow-controlled variable pressure mode addition of H2 besides rendering process safety Lesser reaction time Lesser weight % of Ru Higher wt. % of reactants Does not require any catalyst prior reduction Efficient recovery and reuse of the heterogeneous catalyst, in particular supported catalysts without any pretreatment