Method for preparing methyl isoamyl ketone

Abstract

The invention provides a novel method for preparing methyl isoamyl ketone. The method comprises the following steps: catalyzing by-product waste liquid of an isobutane co-oxidation method through a bifunctional catalyst, and reacting acetone with IBO to generate MIAK. Compared with the prior art, on one hand, the assistant is added into the bifunctional catalyst, so that the acid-base property of the catalyst can be effectively regulated, the metal active components are dispersed more uniformly, and the catalytic activity of the catalyst is greatly improved; on the other hand, different from the production process of isobutyraldehyde and acetone adopted by the existing industrial device, the new method for preparing MIAK is adopted, waste is turned into wealth, the production cost is saved, and the comprehensive economic benefit of the device is improved.

Description

Technical Field

[0001] The present invention belongs to the field of organic synthesis, and particularly relates to a method for preparing methyl isopentyl ketone. Background Art

[0002] The industrial co-oxidation method (PO / TBA) plant produces a large amount of waste liquid. The composition of this waste liquid is complex. In addition to containing a large amount of acetone, the main impurities are isobutylene oxide (IBO), methanol, tert-butanol, etc. Since the boiling points of the components are close, and there are multiple azeotropes such as methanol / acetone, acetone / isobutylene oxide, and tert-butanol / water, conventional separation cannot achieve a satisfactory separation effect. Therefore, the utilization of this material is severely restricted. Industrially, it is generally used as organic waste for incineration to recover some heat, and its utilization value is very limited.

[0003] Patents CN201610878107.5 and CN201610875280.X mention the utilization of acetone in the waste liquid by-produced from the co-oxidation method (PO / MTBE) plant. In the patents, acetone is converted into methyl isobutyl ketone through a condensation dehydration hydrogenation reaction, thereby realizing the efficient utilization of the waste liquid. However, the isobutylene oxide in the by-produced waste liquid has not been purified and utilized, and the utilization value of incineration for recovering heat is limited.

[0004] Patent CN202311562290.4 mentions a method for recovering IBO. Through separation means, IBO pure product with a purity ≥ 97% and a water content ≤ 0.1% can be obtained, thereby improving the economic efficiency of the plant. However, the market volume of IBO pure product is limited, and the separation process is complex, and other utilization ways of IBO need to be found.

[0005] Methyl isopentyl ketone (MIAK), as an important fine chemical intermediate, has important applications in the fields of paint coatings, digital printing inks, electronic chemicals, process solvents, synthesis of rubber antioxidant PPDs, etc., and the global market demand is also showing an increasing trend year by year.

[0006] Patents CN202310448388.0 and CN202011635892.4 introduce a method for synthesizing MIAK by a two-step reaction of acetone and isobutyraldehyde. Acetone and isobutyraldehyde first undergo condensation dehydration to form 5-methyl-3-en-2-hexanone, and then hydrogenation to form MIAK. The disadvantage of this method is that the process flow is complex. Patent CN202011199013.8 introduces a one-step method for synthesizing MIAK. After acetone, isobutyraldehyde, and hydrogen are mixed, MIAK is obtained through reaction in a fixed-bed reactor with a Pd / phosphonic acid resin catalyst, but the selectivity of MIAK is relatively low.

[0007] In summary, the cost of preparing MIAK using acetone and isobutyraldehyde as raw materials is relatively high, and there is no literature report on the production of MIAK using industrial by-product waste liquid. Therefore, a new method for preparing methyl isopentyl ketone is needed. On the one hand, it reduces the incineration amount of the device waste liquid and reduces carbon emissions; on the other hand, it turns waste into treasure and improves the economy of the device. Summary of the Invention

[0008] The purpose of the present invention is to provide a method for preparing methyl isopentyl ketone, specifically, the waste liquid containing isobutylene oxide (IBO) and acetone by-produced from the co-oxidation method of isobutane (PO / TBA) is catalytically reacted to generate MIAK under the catalysis of a catalyst.

[0009] To achieve the above invention purpose, the technical solution adopted by the present invention is as follows:

[0010] A method for preparing methyl isopentyl ketone, the method comprising the following steps: the waste liquid by-produced from the co-oxidation method of isobutane is catalytically reacted by a bifunctional catalyst to react acetone and IBO to generate MIAK.

[0011] In the present invention, the by-produced waste liquid comes from an isobutane co-oxidation device, more specifically a PO / TBA device. Based on the mass of the by-produced waste liquid, its composition includes 10wt%-90wt% acetone, 5wt%-70wt% IBO, 0.5wt%-8wt% water, 0wt%-15wt% methanol, 0wt%-10wt% MTBE, 0wt%-5wt% tert-butanol, 0wt%-15wt% formate, 0wt%-5wt% C3-C5 hydrocarbons, 0wt%-10wt% C6 hydrocarbons, 0wt%-5wt% C7-C8 hydrocarbons. It should be noted that in the method of the present invention, acetone and IBO must be contained as reaction raw materials, and the contents of other components in the waste liquid except acetone and IBO are not limited and required.

[0012] In the present invention, the bifunctional catalyst is a supported catalyst, comprising a support, an active metal, and an assistant. The support is one or more of alumina, zirconia, titania, silica, molecular sieve (such as Hβ molecular sieve, HZSM-5 molecular sieve, etc.), heteropolyacid (such as phosphotungstic heteropolyacid, etc.), acidic kaolin, diatomite, cation exchange resin (such as sulfonic acid resin, phosphoric acid resin, etc.), solid superacid (such as WO4 / Fe2O3, WO4 / TiO2, etc.), preferably alumina, molecular sieve, and sulfonic acid resin. The active metal is one or more of Pt, Pd, Ni, Fe, Co, Ru, Cu, Rh, Ir, preferably Pt, Pd, Ni, Ru, Rh. The assistant is a pyridinedicarboxylic acid compound, specifically selected from one or more of 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, 2,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, 3,4-pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, 4-oxo-1,4-dihydro-2,6-pyridinedicarboxylic acid, preferably 2,6-pyridinedicarboxylic acid and 4-oxo-1,4-dihydro-2,6-pyridinedicarboxylic acid.

[0013] In the present invention, preferably, based on the total mass of the catalyst, the total content of the support in the supported catalyst is 79%-99.8%, preferably 90%-99.5%; the total content of the active metal is 0.1%-20%, preferably 0.5%-10%; the content of the assistant is 0.01%-1%.

[0014] In the present invention, the bifunctional catalyst is prepared by an impregnation method, and the preparation method comprises the following steps:

[0015] (1) Weigh the hydrochloride or nitrate of the active component and prepare a precursor aqueous solution;

[0016] (2) Take the support, add it to the precursor solution, stir and filter to obtain a precipitate, wash it with deionized water and then dry it;

[0017] (3) Then evenly spray a certain amount of ethanol solution containing the assistant on the catalyst obtained in step (2), and then dry it to obtain a catalyst loaded with the corresponding active component.

[0018] In the present invention, in step (1), the concentration of the aqueous solution of the hydrochloride or nitrate of the active metal is 0.01%-50%;

[0019] In the present invention, in step (2), the mass ratio of the support to the precursor solution is 1:2-1:3;

[0020] In the present invention, in step (2), the stirring temperature is 10°C-80°C, and the stirring time is 2h-24h;

[0021] In the present invention, in the step (2), the drying temperature is 80°C - 200°C, and the drying time is 2h - 24h; the drying temperature is preferably 100°C - 150°C;

[0022] In the present invention, in the step (3), the mass concentration of the ethanol solution of the auxiliary agent is 1% - 5%;

[0023] In the present invention, in the step (3), the drying temperature is 50°C - 180°C, the drying time is 2h - 24h, and the preferred drying temperature is 100°C - 150°C.

[0024] In the present invention, the specific surface area of the catalyst loaded with the corresponding active component is 5m 2 / g - 500m 2 / g, and the pore size is 0.1nm - 60nm.

[0025] In the present invention, the reactor for preparing methyl isopentyl ketone adopts a fixed-bed reactor, the reaction temperature is 80°C - 250°C, preferably 90°C - 160°C; the reaction pressure is 0.5MPa - 5MPa gauge pressure, preferably 2MPa - 5MPa; the space velocity of the reaction raw materials (excluding hydrogen) is 0.1h -1 -5h -1 , preferably 0.5h -1 -3h -1 ; the hydrogen-oil ratio (molar ratio of hydrogen to organic components) is 0.5 - 10, preferably 1 - 5.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) By using the above method, MIAK is prepared from the waste liquid of the isobutane co-oxidation device, reducing the waste liquid discharge amount, thereby reducing the carbon emission amount of the device and reducing the three-waste treatment cost of the device.

[0028] (2) The present invention adopts a new method to prepare MIAK, which is different from the production process of isobutyraldehyde and acetone used in existing industrial devices, turning waste into treasure, saving production costs, and improving the comprehensive economic benefits of the device.

[0029] (3) In the present invention, a special auxiliary agent is added to the catalyst. On the one hand, adding pyridine dicarboxylic acid compounds can effectively increase the acid amount and acidity of the carrier, promoting the polymerization of IBO and acetone and promoting the dehydration of intermediate products at the same time, improving the reaction conversion rate; on the other hand, the special structure of pyridine dicarboxylic acid compounds can form a metal chelate structure with the active metal components in the catalyst, enabling the metal to be better dispersed on the surface of the carrier, improving the catalytic performance of the catalyst, and at the same time making the metal active components more stable and not easy to agglomerate, improving the service life of the catalyst. Specific embodiments

[0030] To facilitate the understanding of the present invention, the present invention will be further described below in conjunction with embodiments. It should be understood that the following embodiments are only for better understanding of the present invention and do not mean that the present invention is limited only to the following embodiments.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The term "and / or" as used herein may include any and all combinations of one or more of the related listed items.

[0032] The information of the main raw materials is as follows:

[0033] Raw material name Specification Manufacturer Raw material By-product of PO / TBA unit Molecular sieve Hβ Nankai Catalyst Factory Sulfonic acid resin Dandong Mingzhu Aluminum oxide 2 - 4mm Zhengzhou Jinbang Environmental Protection Technology Co., Ltd. 2,6 - Pyridinedicarboxylic acid AR Shanghai Macklin Biochemical Co., Ltd. 2,3 - Pyridinedicarboxylic acid AR Shanghai Macklin Biochemical Co., Ltd. 3,4 - Pyridinedicarboxylic acid AR Shanghai Macklin Biochemical Co., Ltd. 4 - Oxo - 1,4 - dihydro - 2,6 - pyridinedicarboxylic acid AR Shanghai Macklin Biochemical Co., Ltd.

[0034] The information of the equipment is as follows:

[0035]

[0036]

[0037] The gas chromatography analysis conditions are as follows:

[0038] Analysis instrument: Shimadzu HP-PONA (specification: 50m×0.2mm×0.5μm);

[0039] Gas analysis method: corrected normalization method;

[0040] Gas analysis conditions: The vaporization chamber temperature is 230°C, the detector temperature is 300°C, and the column temperature is programmed heating: 40°C for 8 min; rising to 240°C at a rate of 10°C / min.

[0041] The catalyst compositions in each example are shown in Table 1, and the specific preparation method can be seen in Example 1.

[0042] Table 1 Catalyst compositions in each example

[0043]

[0044] The raw material compositions used in each comparative example and example are shown in Table 2:

[0045] Table 2 Raw material compositions

[0046]

[0047]

[0048] Example 1

[0049] Weigh 394.0 g of Ni(NO3)2 and dissolve it in 1000 g of water to prepare an aqueous solution, which is made into precursor solution 1; weigh 500 g of alumina powder, add it to precursor solution 1, stir at 10 °C for 24 h, wash the filtered precipitate with deionized water and then dry it at 200 °C for 2 h; then weigh 632.9 g of an ethanol solution containing 1% 2,6-pyridinedicarboxylic acid and spray it evenly on the catalyst, and then dry it at 150 °C for 12 h to obtain catalyst 1 loaded with Ni. The specific surface area of catalyst 1 is 125 m 2 / g, and the pore size is 17 nm.

[0050] Weigh 4.3 g of PtCl4 and dissolve it in 1000 g of water to prepare an aqueous solution, which is made into precursor solution 2; weigh 500 g of sulfonic acid resin, add it to precursor solution 2, stir at 50 °C for 8 h, wash the filtered precipitate with deionized water and then dry it at 100 °C for 12 h; then weigh 20.1 g of an ethanol solution containing 5% 2,3-pyridinedicarboxylic acid and spray it evenly on the catalyst, and then dry it at 100 °C for 10 h to obtain catalyst 2 loaded with Pt. The specific surface area of catalyst 2 is 14 m 2 / g, and the pore size is 58 nm.

[0051] Weigh 128.3 g of Cu(NO3)2 and dissolve it in 1000 g of water to prepare an aqueous solution, which is made into precursor solution 3; weigh 500 g of Hβ zeolite, add it to precursor solution 3, stir at 60 °C for 12 h, wash the filtered precipitate with deionized water and then dry it at 80 °C for 24 h; then weigh 5.4 g of an ethanol solution containing 1% 3,4-pyridinedicarboxylic acid and spray it evenly on the catalyst, and then dry it at 200 °C for 2 h to obtain catalyst 3 loaded with Cu. The specific surface area of catalyst 3 is 485 m 2 / g, and the pore size is 0.58 nm.

[0052] Weigh 1.0 g of RuCl3 and dissolve it in 1000 g of water to prepare an aqueous solution, which is made into precursor solution 4; weigh 500 g of alumina powder, add it to precursor solution 4, stir at 80 °C for 2 h, wash the filtered precipitate with deionized water and then dry it at 150 °C for 8 h; then weigh 16.7 g of an ethanol solution containing 3% 4-oxo-1,4-dihydro-2,6-pyridinedicarboxylic acid and spray it evenly on the catalyst, and then dry it at 50 °C for 24 h to obtain catalyst 4 loaded with Ru. The specific surface area of catalyst 4 is 146 m 2 / g, and the pore size is 13 nm.

[0053] Weigh 389.1 g of Ni(NO3)2 and dissolve it in 1000 g of water to prepare an aqueous solution, forming precursor solution 5; weigh 500 g of alumina powder, add it to precursor solution 1, stir at 10 °C for 24 h, wash the filtered precipitate with deionized water and dry it at 200 °C for 2 h; then dry it at 150 °C for 12 h to obtain catalyst 5 loaded with Ni. The specific surface area of catalyst 5 is 125 m 2 / g, and the pore size is 17 nm. Compared with catalyst 1, 2,6-pyridine dicarboxylic acid additive is not added to catalyst 5.

[0054] Weigh 394.0 g of Ni(NO3)2 and dissolve it in 1000 g of water to prepare an aqueous solution, forming precursor solution 1; weigh 500 g of alumina powder, add it to precursor solution 1, stir at 10 °C for 24 h, wash the filtered precipitate with deionized water and dry it at 200 °C for 2 h; then weigh 632.9 g of ethanol solution dissolved with 1% p-toluenesulfonic acid and spray it evenly on the catalyst, and then dry it at 150 °C for 12 h to obtain catalyst 6 loaded with Ni. The specific surface area of catalyst 6 is 125 m 2 / g, and the pore size is 17 nm. Compared with catalyst 1, the additive added to catalyst 6 is p-toluenesulfonic acid.

[0055] Example 2

[0056] Load 100 mL of catalyst 1 into the reactor, use raw material 1 as the reaction raw material, and the reaction conditions are as follows: temperature 250 °C, reaction pressure 0.5 MPa, feed space velocity of the raw material 5 h -1 , and the hydrogen-oil ratio (molar ratio of hydrogen to organic components) is 0.5. The composition of the reaction liquid is as follows: 0.27% acetone, 57.44% IBO, 18.85% MIAK, 3.00% water, 1.77% methanol, 0.5% MTBE, 0.94% tert-butanol, 4.4% formate, 5% C3-C5 hydrocarbons, 1% C6 hydrocarbons, 5% C7-C8 hydrocarbons, and 1.83% other impurities. The content of IBO in the raw material is in excess, and the acetone conversion rate is 97.30%, and the selectivity of MIAK is 98.48%.

[0057] Example 3

[0058] Load 100 mL of catalyst 2 into the reactor, use raw material 2 as the reaction raw material, and the reaction conditions are as follows: temperature 80 °C, reaction pressure 5 MPa, feed space velocity of the raw material 0.1 h -1, the hydrogen-oil ratio (molar ratio of hydrogen to organic components) is 10. The reaction liquid composition is as follows: 14.87% acetone, 2.06% IBO, 26.52% MIAK, 5.72% water, 14.3% methanol, 9.9% MTBE, 1.84% tert-butanol, 14.1% formate, 1% C3-C5 hydrocarbons, 4% C6 hydrocarbons, 1% C7-C8 hydrocarbons, and 4.70% other impurities. The acetone content in the raw material is in excess, the IBO conversion rate is 89.72%, and the selectivity of MIAK is 93.32%.

[0059] Example 4

[0060] Charge 100 mL of catalyst 3 into the reactor, use raw material 3 as the reaction raw material, and the reaction conditions are as follows: temperature 120 °C, reaction pressure 2 MPa, feed space velocity of the raw material 3 h -1 , the hydrogen-oil ratio (molar ratio of hydrogen to organic components) is 5. The reaction liquid composition is as follows: 38.1% acetone, 0.3% IBO, 29.89% MIAK, 12.19% water, 0.48% methanol, 0.5% MTBE, 4.27% tert-butanol, 0.43% formate, 0.2% C3-C5 hydrocarbons, 10% C6 hydrocarbons, 0.3% C7-C8 hydrocarbons, and 3.35% other impurities. The acetone content in the raw material is in excess, the IBO conversion rate is 98.52%, and the selectivity of MIAK is 95.78%.

[0061] Example 5

[0062] Charge 100 mL of catalyst 4 into the reactor, use raw material 4 as the reaction raw material, and the reaction conditions are as follows: temperature 160 °C, reaction pressure 1 MPa, feed space velocity of the raw material 2 h -1 , the hydrogen-oil ratio (molar ratio of hydrogen to organic components) is 2. The reaction liquid composition is as follows: 85.96% acetone, 0.16% IBO, 7.48% MIAK, 6.05% water, and 0.35% other impurities. The acetone content in the raw material is in excess, the IBO conversion rate is 96.88%, and the selectivity of MIAK is 97.52%.

[0063] Comparative Example 1

[0064] Compared with Example 2, in Comparative Example 1, the catalyst used was Catalyst 5, and the other conditions were the same as those in Example 2. The composition of the reaction solution was as follows: 2.42% acetone, 67.93% IBO, 2.52% MIAK, 0.71% water, 1.48% methanol, 0.43% MTBE, 0.98% tert-butanol, 4.71% formate, 5% C3-C5 hydrocarbons, 1% C6 hydrocarbons, 5% C7-C8 hydrocarbons, and 7.82% other impurities. The IBO content in the raw material was in excess, and the acetone conversion rate was 75.80%, and the selectivity of MIAK was 16.90%.

[0065] Comparative Example 2

[0066] Compared with Example 2, in Comparative Example 2, the catalyst used was Catalyst 6, and the other conditions were the same as those in Example 2. The composition of the reaction solution was as follows: 1.12% acetone, 61.79% IBO, 8.82% MIAK, 1.60% water, 0.93% methanol, 0.43% MTBE, 0.38% tert-butanol, 4.51% formate, 5% C3-C5 hydrocarbons, 1% C6 hydrocarbons, 5% C7-C8 hydrocarbons, and 9.42% other impurities. The IBO content in the raw material was in excess, and the acetone conversion rate was 88.80%, and the selectivity of MIAK was 50.49%.

[0067] It is easy to understand that the above examples are only for clear illustration and do not mean that the present invention is limited thereto. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for preparing methyl isopentyl ketone, the method comprising the following steps: subjecting the waste liquid by-produced in the co-oxidation of isobutane to catalytic reaction with a bifunctional catalyst to react acetone and IBO to form methyl isopentyl ketone.

2. The method according to claim 1, wherein The waste liquid by-produced in the co-oxidation of isobutane comes from the isobutane co-oxidation unit, more specifically the PO / TBA unit. Based on the mass of the by-produced waste liquid, its composition includes 10 wt% - 90 wt% of acetone, 5 wt% - 70 wt% of IBO, 0.5 wt% - 8 wt% of water, 0 wt% - 15 wt% of methanol, 0 wt% - 10 wt% of MTBE, 0 wt% - 5 wt% of tert-butanol, 0 wt% - 15 wt% of formate, 0 wt% - 5 wt% of C3-C5 hydrocarbons, 0 wt% - 10 wt% of C6 hydrocarbons, 0 wt% - 5 wt% of C7-C8 hydrocarbons.

3. The method according to claim 1 or 2, characterized in that The bifunctional catalyst is a supported catalyst, comprising a support, active metals and promoters; preferably, the support is one or more of alumina, zirconia, titania, silica, molecular sieve (such as Hβ molecular sieve, HZSM-5 molecular sieve, etc.), heteropolyacid (such as phosphotungstic heteropolyacid, etc.), acidic kaolin, diatomite, cation resin (such as sulfonic acid resin, phosphoric acid resin, etc.), solid superacid (such as WO4 / Fe2O3, WO4 / TiO2, etc.), preferably alumina, molecular sieve and sulfonic acid resin; and / or, the active metals are one or more of Pt, Pd, Ni, Fe, Co, Ru, Cu, Rh, Ir, preferably Pt, Pd, Ni, Ru, Rh; and / or, the promoters are pyridine dicarboxylic acid compounds, specifically selected from one or more of 2,3-pyridine dicarboxylic acid, 2,4-pyridine dicarboxylic acid, 2,5-pyridine dicarboxylic acid, 2,6-pyridine dicarboxylic acid, 3,4-pyridine dicarboxylic acid, 3,5-pyridine dicarboxylic acid, 4-oxo-1,4-dihydro-2,6-pyridine dicarboxylic acid, preferably 2,6-pyridine dicarboxylic acid and 4-oxo-1,4-dihydro-2,6-pyridine dicarboxylic acid.

4. The method according to any one of claims 1 to 3, characterized in that, Based on the total mass of the catalyst, the total content of the support in the supported catalyst is 79% - 99.8%, preferably 90% - 99.5%; the total content of the active metals is 0.1% - 20%, preferably 0.5% - 10%; the content of the promoter is 0.01% - 1%.

5. The method according to any one of claims 1-4, characterized in that, The bifunctional catalyst is prepared by an impregnation method, and the preparation method comprises the following steps: (1) Weigh the hydrochloride or nitrate of the active component and prepare it into a precursor aqueous solution; (2) Take the support, add it to the precursor solution, stir and filter to obtain a precipitate, wash it with deionized water and then dry it; (3) Then evenly spray a certain amount of ethanol solution containing the promoter on the catalyst obtained in step (2), and then dry it to obtain a catalyst loaded with the corresponding active components.

6. The method according to claim 5, characterized in that, In step (1), the concentration of the aqueous solution of the hydrochloride or nitrate of the active metal is 0.01% - 50%.

7. The method according to claim 5 or 6, characterized in that In the step (2), the mass ratio of the carrier to the precursor solution is 1:2 - 1:3; and / or, in the step (2), the stirring temperature is 10°C - 80°C, and the stirring time is 2 h - 24 h; and / or, in the step (2), the drying temperature is 80°C - 200°C, and the drying time is 2 h - 24 h.

8. The method according to any one of claims 5 to 7, characterized in that, In the step (3), the mass concentration of the ethanol solution of the auxiliary agent is 1% - 5%; and / or, in the step (3), the drying temperature is 50°C - 180°C, and the drying time is 2 h - 24 h.

9. The method according to any one of claims 5-8, characterized in that, The specific surface area of the catalyst loaded with the corresponding active component is 5 m 2 / g to 500 m 2 / g, and the pore size is 0.1 nm - 60 nm.

10. The method according to any one of claims 1-9, characterized in that, The reactor for preparing methyl isopentyl ketone is a fixed-bed reactor, the reaction temperature is 80°C - 250°C, preferably 90°C - 160°C; and / or, the reaction pressure is a gauge pressure of 0.5 MPa - 5 MPa, preferably 2 MPa - 5 MPa; and / or, the space velocity of the reaction raw materials (excluding hydrogen) is 0.1 h -1 -5 h -1 , preferably 0.5 h -1 -3 h -1 ; and / or, the hydrogen-oil ratio (molar ratio of hydrogen to organic components) is 0.5 - 10, preferably 1 - 5.

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