A process for the preparation of multibranched alkanes

Abstract

The application relates to the technical field of catalytic material applications, and discloses a method for preparing multi-branched alkanes. The method comprises the following steps: performing a hydrogenation reaction on light components in an olefin hydroformylation product in the presence of a catalyst and hydrogen to obtain multi-branched alkanes; the light components in the olefin hydroformylation product contain olefins and alkanes; the number of branches of the olefins and the alkanes is greater than or equal to 1; and the chemical formula of the catalyst is NiCu a A b O x ; wherein a is 0.1-1.5, b is 0.1-4; x is the number of oxygen atoms satisfying the valence requirements of various metal elements; and A is Al and / or Si. The method provided by the application can hydrogenate the light components in the light component olefin hydroformylation product into alkanes under lower temperature and hydrogen pressure, the olefin hydrogenation conversion rate is high, the selectivity is high, and high-purity alkanes can be obtained after hydrogenation.

Description

Technical Field

[0001] This invention relates to the technical field of catalytic materials applications, and specifically to a method for preparing multi-branched alkanes. Background Technology

[0002] Isononol is primarily used in the reaction with phthalic anhydride to produce diisononyl phthalate (DINP), a plasticizer for PVC. DINP is an excellent, general-purpose, non-toxic plasticizer. Compared to dioctyl phthalate (DOP), DINP has a larger molecular weight and a longer carbon chain, resulting in better aging and migration resistance. Therefore, it is widely used in toy films, wires, and cables. As an environmentally friendly substitute for DOP, the rapidly increasing demand for DINP has led to a rapid rise in the consumption of isononol. Isononol is mainly produced from mixed C4 olefins, a byproduct of petrochemical processes, through a dimerization and hydroformylation reaction.

[0003] CN1370137A discloses a continuous method for hydroformylation of olefins having 6-20 carbon atoms, wherein: a) an aqueous solution of cobalt(II) salt is thoroughly contacted with hydrogen and carbon monoxide to form a hydroformylation active cobalt catalyst; then, an aqueous phase containing the cobalt catalyst is thoroughly contacted with the olefin and optionally an organic solvent, as well as hydrogen and carbon monoxide, in at least one reaction zone, whereby the cobalt catalyst is extracted into the organic phase and the olefin is hydroformylated; b) effluent from the reaction zone is treated with oxygen in the presence of an acidic aqueous solution of cobalt(II) salt, wherein the cobalt catalyst decomposes to form cobalt(II) salt and these substances are back-extracted into the aqueous phase; and subsequently, the phases are separated; c) the aqueous solution of cobalt(II) salt is recycled to step a) in an unchanged form.

[0004] EP2881173A4 discloses a catalyst composition and a method for hydroformylating olefins using the catalyst composition. By simultaneously using specific ligands for a transition metal catalyst and a ligand stabilizer during the hydroformylation of olefins, the catalyst activity can be maintained by improving catalyst stability, reducing the amount of ligand required, and improving selectivity for isoformaldehydes. This indicates that stability is a common problem for hydroformylation catalysts; the activity of hydroformylation catalysts generally decreases significantly with prolonged reaction time.

[0005] DE59704070D1 discloses a method for preparing alcohols having 7-18 carbon atoms, comprising hydroformylating the corresponding olefin with a syngas at a temperature of 50-220°C and a pressure of 100-400 bar in the presence of a cobalt-containing organic phase, followed by hydrogenation of the resulting alcohol. The method involves reacting an aqueous solution of a cobalt salt with the syngas to form a cobalt catalyst in the presence of an organic solvent miscible with or only slightly miscible with water. The cobalt catalyst is then extracted from the aqueous phase using an organic extractant miscible with or only slightly miscible with water to prepare the cobalt-containing organic phase. The formation of the cobalt catalyst, the extraction of the cobalt catalyst from the organic phase, and the hydroformylation of the corresponding olefin are carried out in a one-step process. The carbonyl synthesis alcohol prepared by this method is used to prepare carboxylic acid esters as plasticizers, with reaction times typically exceeding 10 hours.

[0006] In the above-mentioned hydroformylation reaction, a certain amount of light components are generated in the hydroformylation product. The light components are mainly alkanes and alkenes with similar structures to alkanes. The two have similar boiling points and are difficult to separate. However, the presence of alkenes will affect the purity of the alkane product. In order to obtain high-purity alkanes, the alkenes in the alkanes need to be removed, but the above-mentioned existing technologies do not involve the purification of the light component products of hydroformylation. Summary of the Invention

[0007] The purpose of this invention is to overcome the problem in the prior art that the purity of alkanes is low due to the difficulty in separating the light components of olefins and alkanes in olefin hydroformylation products.

[0008] To achieve the above objectives, a first aspect of the present invention provides a method for preparing multi-branched alkanes, the method comprising:

[0009] In the presence of a catalyst and hydrogen, the light component in the hydroformylation product of an olefin is hydrogenated to obtain a multi-branched alkane.

[0010] The number of branches in both the olefin and the alkane is greater than or equal to 1.

[0011] The chemical formula of the catalyst is NiCu a A b O x ;

[0012] Where a is 0.1-1.5, b is 0.1-4; x is the number of oxygen atoms that meet the valence requirements of each metal element; A is Al and / or Si.

[0013] The method for preparing multi-branched alkanes provided by this invention can hydrogenate olefins in the light component products of olefin hydroformylation to alkanes at relatively low temperatures and hydrogen pressures. The olefin hydrogenation conversion rate is high, and the selectivity is high, yielding high-purity alkanes, especially highly branched, high-octane alkanes. Furthermore, the alcohol content in the light component feedstock of the olefin hydroformylation product does not decrease. Detailed Implementation

[0014] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0015] As previously described, a first aspect of the present invention provides a method for preparing multi-branched alkanes, the method comprising:

[0016] In the presence of a catalyst and hydrogen, the light component in the hydroformylation product of an olefin is hydrogenated to obtain a multi-branched alkane.

[0017] The number of branches in both the olefin and the alkane is greater than or equal to 1.

[0018] The chemical formula of the catalyst is NiCu a A b O x ;

[0019] Where a is 0.1-1.5, b is 0.1-4; x is the number of oxygen atoms that meet the valence requirements of each metal element; A is Al and / or Si.

[0020] Preferably, a is 0.2-1 and b is 0.2-3. The inventors have found that under this preferred condition, the hydrogenation conversion rate and selectivity of the light olefin component in the olefin hydroformylation product are higher, and the purity of the obtained alkane is higher.

[0021] Preferably, in the light component, the olefin content x is 0 < x ≤ 100 wt%, and the alkane content y is 0 ≤ y < 100 wt%. Preferably, the olefin content x is 0 < x ≤ 70 wt%, and the alkane content y is 30 ≤ y < 100 wt%. Preferably, the olefin content x is 0 < x ≤ 40 wt%, and the alkane content y is 60 ≤ y < 100 wt%. More preferably, the olefin content x is 0 < x ≤ 25 wt%, and the alkane content y is 75 ≤ y < 100 wt%. More preferably, the olefin content x is 0 < x ≤ 15 wt%, and the alkane content y is 85 ≤ y < 100 wt%.

[0022] Preferably, the light component may also contain aldehydes or alcohols.

[0023] In a preferred embodiment, the hydrogenation reaction is carried out in a trickle bed reactor. The inventors have discovered that in this preferred embodiment, the light components in the olefin hydroformylation product do not require gasification, thus saving energy and reducing processing costs.

[0024] Preferably, the conditions for the hydrogenation reaction include: a reaction temperature of 40-200℃ and a reaction pressure of 0.1-10.0 MPa.

[0025] Preferably, the conditions for the hydrogenation reaction include: a reaction temperature of 70-200℃ and a reaction pressure of 1.0-7.0 MPa.

[0026] Preferably, the conditions for the hydrogenation reaction include: a reaction temperature of 100-190°C and a reaction pressure of 1.0-3.0 MPa.

[0027] More preferably, the conditions for the hydrogenation reaction include: a reaction temperature of 150-190°C and a reaction pressure of 1.0-3.0 MPa.

[0028] In a preferred embodiment, the mass hourly space velocity (HSV) of the light component feed is 0.1-20 h⁻¹. -1 Preferably 0.5-7h -1 More preferably 0.5-2h -1 .

[0029] In a preferred embodiment, the volume ratio of hydrogen to the light component is (0.1-1000):1; more preferably (0.1-500):1; and even more preferably (0.1-200):1.

[0030] More preferably, the volume ratio of hydrogen to the light component is (1-100):1. In this preferred case, the conversion rate of the light component olefin in the olefin hydroformylation product is higher, and higher purity alkanes can be obtained after hydrogenation.

[0031] According to a preferred embodiment, the method further includes: pre-reducing the catalyst with a reducing gas before carrying out the hydrogenation reaction to obtain a pre-reduced catalyst. The inventors of this invention have discovered that, in this preferred embodiment, hydrogenation of the light component in the olefin hydroformylation product can yield alkanes of higher purity.

[0032] Preferably, the reducing gas is hydrogen and / or carbon monoxide.

[0033] In a preferred embodiment, the flow rate of the reducing gas is 25-500 mL / min.

[0034] In a preferred embodiment, the pre-reduction conditions include a temperature of 150-400°C and a pressure of 0.1-2.0 MPa.

[0035] Preferably, the pre-reduction time is 4-30 hours.

[0036] According to another preferred embodiment, the catalyst is prepared by a method comprising the following steps:

[0037] S1: The metal salt solution is reacted with an alkali to produce a precipitation reaction, yielding intermediate I;

[0038] S2: The intermediate I is subjected to aging treatment to obtain intermediate II;

[0039] S3: In the presence of air, the intermediate II is calcined to obtain the catalyst;

[0040] The metal salt solution contains Ni, Cu, and A elements, wherein the A element is Al and / or Si.

[0041] In a preferred embodiment, the metal salt solution is a soluble metal salt solution containing Ni, Cu, and A elements.

[0042] It should be noted that the metal salt solution can be a metal salt solution containing Ni, Cu and A elements simultaneously, or it can be obtained by mixing a soluble salt solution containing Ni, a soluble salt solution containing Cu, and a soluble salt solution containing A.

[0043] In a preferred embodiment, the metal salt solution is a nitrate solution containing Ni, Cu, and A elements.

[0044] Preferably, in step S1, the amount of alkali is controlled so that the pH of the liquid phase material during the precipitation reaction is 4-11.

[0045] Preferably, in step S1, the alkali is selected from at least one of ammonium carbonate, ammonium bicarbonate, ammonia, sodium carbonate, sodium hydroxide, and potassium hydroxide. More preferably, the alkali is selected from at least one of ammonia, sodium carbonate, and ammonium bicarbonate.

[0046] Preferably, the alkali is added in the form of a solution. For example, when the alkali is sodium carbonate, it is added in the form of a sodium carbonate solution.

[0047] Preferably, the alkali is an alkaline solution with a mass fraction of 5-40 wt%. More preferably, the alkali is an alkaline solution with a mass fraction of 10-35 wt%.

[0048] Preferably, in step S2, the aging treatment conditions include: a temperature of 20-100℃ and a time of 1-10h.

[0049] According to a preferred embodiment, the method further includes: after performing the aging treatment in step S2, filtering, washing, and drying are performed sequentially to obtain the intermediate II.

[0050] Preferably, the drying conditions include a temperature of 70-200°C and a time of 2-30 hours.

[0051] The present invention does not impose any particular requirements on the filtration or washing methods, and those skilled in the art can choose according to known means in the art. For example, water is used for washing.

[0052] Preferably, in step S3, the calcination conditions include: a temperature of 300-900℃ and a time of 2-30h.

[0053] The method described in this invention can also be used for the hydrogenation of unsaturated organic compounds, such as the hydrogenation reaction of olefins, which may or may not contain branches.

[0054] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, the raw materials are all commercially available or self-made.

[0055] Nickel salt: Ni(NO3)2·6H2O: chemically pure, purchased from Beijing Chemical Plant.

[0056] Copper salt: Cu(NO3)2·3H2O: chemically pure, purchased from Beijing Chemical Plant.

[0057] Aluminum salt: Al(NO3)3·9H2O: chemically pure, purchased from Beijing Chemical Plant.

[0058] Sodium carbonate: chemically pure, purchased from a chemical plant in Beijing.

[0059] The conversion rate of 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene = (sum of the molar numbers of the two olefins at the reactor inlet - sum of the molar numbers of the two olefins at the reactor outlet) / sum of the molar numbers of the two olefins at the reactor inlet × 100%; in the formula, "two olefins" refers to 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene.

[0060] Selectivity for 2,2,4-trimethyl-pentane = number of moles of 2,2,4-trimethyl-pentane produced / sum of the number of moles of 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene that reacted × 100%.

[0061] In the following example, the light component of the olefin hydroformylation product was obtained by hydroformylation of a commercially available C8 olefin (composition: 75.1 wt% 2,4,4-trimethyl-1-pentene, 21.2 wt% 2,4,4-trimethyl-2-pentene, with the remainder being multi-branched olefins) followed by separation; wherein, the total content of 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene in this light component was 10.6 wt%, and the content of 2,2,4-trimethyl-pentane was 89.3 wt%.

[0062] Catalyst Preparation Example 1

[0063] Dissolve 33.6 g of Ni(NO3)2·6H2O, 5.5 g of Cu(NO3)2·3H2O and 38.9 g of Al(NO3)3·9H2O in 90 mL of deionized water to obtain metal salt solution Y1;

[0064] The catalyst in this embodiment was prepared according to the following steps:

[0065] S1: Metal salt solution Y1 and sodium carbonate solution with a mass fraction of 15 wt% are added dropwise in a co-current manner to carry out a precipitation reaction to obtain intermediate I;

[0066] The amount of sodium carbonate solution used is controlled so that the pH of the liquid phase material during the precipitation reaction is 6.0 ± 0.5.

[0067] S2: The intermediate I is aged at 40°C for 1 hour, and then the aged material is filtered, washed and dried (120°C, 4 hours) to obtain intermediate II.

[0068] S3: In the presence of air, intermediate II is calcined (450°C, 4h) to obtain the catalyst, whose chemical formula is NiCu. 0.2 Al 0.9 O 2.55 It was named Catalyst A.

[0069] Catalyst Preparation Example 2

[0070] 20.3 g of Ni(NO3)2·6H2O, 16.8 g of Cu(NO3)2·3H2O and 52.0 g of Al(NO3)3·9H2O were dissolved in 90 mL of deionized water to obtain metal salt solution Y2.

[0071] The catalyst was prepared using a method similar to that used in Preparation Example 1, except that in step S1, metal salt solution Y1 was replaced with metal salt solution Y2.

[0072] The catalyst was prepared with the chemical formula NiCuAl2O5 and named Catalyst B; all parts not listed are the same as in Catalyst Preparation Example 1.

[0073] Example 1

[0074] Take 14g of catalyst A with an average diameter of 26-40 mesh (Chinese standard sieve), put it into a stainless steel tubular reactor with an inner diameter of 10mm, and pass a reducing gas (H2) at a flow rate of 70mL / min under the conditions of 400℃ and 0.1MPa to pre-reduce the catalyst A for 5h to obtain the pre-reduced catalyst A.

[0075] In the presence of pre-reduced catalyst A and hydrogen, the light component of the olefin hydroformylation product is hydrogenated in a trickle bed reactor to obtain multi-branched alkanes.

[0076] The hydrogenation reaction was carried out at a temperature of 160°C, a pressure of 3.0 MPa, a hydrogen to light component volume ratio of 100:1, and a light component feed liquid hourly space velocity of 1.2 h⁻¹. -1 ;

[0077] Chromatographic analysis of the product showed that the conversion rate of 2,4,4-trimethyl-1-pentene to 2,4,4-trimethyl-2-pentene was 100%, and the selectivity of 2,2,4-trimethyl-pentane was 97%.

[0078] After 500 hours of reaction, under the above reaction conditions, the conversion rates of 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene, as well as the selectivity of 2,2,4-trimethyl-pentane, remained essentially unchanged.

[0079] Example 2

[0080] Take 12g of catalyst A with an average diameter of 26-40 mesh (Chinese standard sieve), put it into a stainless steel tubular reactor with an inner diameter of 10mm, and pass a reducing gas (H2) at a flow rate of 70mL / min under the conditions of 400℃ and 0.1MPa to pre-reduce the catalyst A for 5h to obtain the pre-reduced catalyst A.

[0081] In the presence of pre-reduced catalyst A and hydrogen, the light component in the olefin hydroformylation product is hydrogenated to obtain multi-branched alkanes.

[0082] The hydrogenation reaction was carried out at a temperature of 181°C, a pressure of 1.5 MPa, a hydrogen to light component volume ratio of 160:1, and a light component feed liquid hourly space velocity of 0.6 h⁻¹. -1 ;

[0083] Chromatographic analysis of the product showed that the conversion rate of 2,4,4-trimethyl-1-pentene to 2,4,4-trimethyl-2-pentene was 100%, and the selectivity of 2,2,4-trimethyl-pentane was 96.7%.

[0084] Example 3

[0085] Take 12g of catalyst B with an average diameter of 26-40 mesh (Chinese standard sieve), put it into a stainless steel tubular reactor with an inner diameter of 10mm, and pass a reducing gas (H2) at a flow rate of 70mL / min under the conditions of 400℃ and 0.1MPa to pre-reduce the catalyst A for 5h to obtain the pre-reduced catalyst B.

[0086] In the presence of pre-reduced catalyst B and hydrogen, the light component of the olefin hydroformylation product is hydrogenated to obtain a multi-branched alkane light component.

[0087] The hydrogenation reaction was carried out at a temperature of 140°C, a pressure of 1.5 MPa, a hydrogen to light component volume ratio of 100:1, and a light component feed liquid hourly space velocity of 1.2 h⁻¹. -1 ;

[0088] Chromatographic analysis of the product showed that the conversion rate of 2,4,4-trimethyl-1-pentene to 2,4,4-trimethyl-2-pentene was 70.5%, and the selectivity of 2,2,4-trimethyl-pentane was 94.5%.

[0089] Example 4

[0090] Take 14g of catalyst B with an average diameter of 26-40 mesh (Chinese standard sieve), put it into a stainless steel tubular reactor with an inner diameter of 10mm, and pass a reducing gas (H2) at a flow rate of 70mL / min under the conditions of 400℃ and 0.1MPa to pre-reduce the catalyst A for 5h to obtain the pre-reduced catalyst B.

[0091] In the presence of pre-reduced catalyst B and hydrogen, the light component of the olefin hydroformylation product is hydrogenated to obtain a multi-branched alkane light component.

[0092] The hydrogenation reaction was carried out at a temperature of 160°C, a pressure of 1.5 MPa, a hydrogen to light component volume ratio of 100:1, and a light component feed liquid hourly space velocity of 1.2 h⁻¹. -1 ;

[0093] Chromatographic analysis of the product showed that the conversion rate of 2,4,4-trimethyl-1-pentene to 2,4,4-trimethyl-2-pentene was 97.5%, and the selectivity of 2,2,4-trimethyl-pentane was 97.3%.

[0094] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing multi-branched alkanes, characterized in that, The method includes: In the presence of a catalyst and hydrogen, the light component in the hydroformylation product of an olefin is hydrogenated to obtain a multi-branched alkane. The number of branches in both the olefin and the alkane is greater than or equal to 1. The chemical formula of the catalyst is NiCu a A b O x ; Where a is 0.1-1.5, b is 0.1-4; x is the number of oxygen atoms that meet the valence requirements of each metal element; A is Al and / or Si.

2. The method according to claim 1, characterized in that, a is 0.2-1, b is 0.2-3.

3. The method according to claim 1 or 2, characterized in that, The hydrogenation reaction is carried out in a trickle bed reactor.

4. The method according to any one of claims 1-3, characterized in that, The conditions for the hydrogenation reaction include: a reaction temperature of 40-200℃ and a reaction pressure of 0.1-10.0 MPa; Preferably, the conditions for the hydrogenation reaction include: a reaction temperature of 70-200℃ and a reaction pressure of 1.0-7.0 MPa; Preferably, the conditions for the hydrogenation reaction include: a reaction temperature of 100-190°C and a reaction pressure of 1.0-3.0 MPa.

5. The method according to any one of claims 1-4, characterized in that, The mass hourly space velocity (HSV) of the light component feed is 0.1-20 h⁻¹. -1 ; Preferably, the mass hourly space velocity (HSV) of the light component feed is 0.5-7 h⁻¹. -1 ; Preferably, the mass hourly space velocity (HSV) of the light component feed is 0.5-2 h⁻¹. -1 .

6. The method according to any one of claims 1-5, characterized in that, The volume ratio of hydrogen to the light component is (0.1-1000):1; Preferably, the volume ratio of hydrogen to the light component is (0.1-500):1; Preferably, the volume ratio of hydrogen to the light component is (0.1-200):1; Preferably, the volume ratio of hydrogen to the light component is (1-100):

1.

7. The method according to any one of claims 1-6, characterized in that, The method further includes: pre-reducing the catalyst with a reducing gas before carrying out the hydrogenation reaction to obtain a pre-reduced catalyst.

8. The method according to claim 7, characterized in that, The reducing gas is hydrogen and / or carbon monoxide.

9. The method according to claim 7 or 8, characterized in that, The pre-reduction conditions include: a temperature of 150-400℃ and a pressure of 0.1-2.0MPa.

10. The method according to any one of claims 1-9, characterized in that, The catalyst is prepared by a method comprising the following steps: S1: The metal salt solution is reacted with an alkali to produce a precipitation reaction, yielding intermediate I; S2: The intermediate I is subjected to aging treatment to obtain intermediate II; S3: In the presence of air, the intermediate II is calcined to obtain the catalyst; The metal salt solution contains Ni, Cu, and A elements, wherein the A element is Al and / or Si.

11. The method according to claim 10, characterized in that, In step S3, the calcination conditions include: a temperature of 300-900℃ and a time of 2-30h.