Catalyst system for ethylene carbonylation reaction

Abstract

The invention belongs to the technical field of synthesis of organic chemical products through olefin carbonylation, and particularly relates to a catalyst system for ethylene carbonylation reaction. The catalyst system includes a palladium salt, one or more phosphine ligands, and one or more phosphorus (P)-containing compounds as stabilizers; the molar ratio of the palladium to the phosphine ligand to the stabilizer is 1: (1-6): (60-1000). According to the method, the phosphorus (P)-containing compound serving as the stabilizer is introduced to replace the sulfonic acid, direct use and supplement of the sulfonic acid are avoided, the catalytic activity and stability of a catalyst system can be improved, the equipment and process requirements can be reduced, and the method has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of olefin carbonylation synthesis of organic chemical products, and relates to a high-efficiency catalyst system for preparing methyl propionate by ethylene carbonylation based on an anti-oxidation strategy, in particular to a catalyst system for ethylene carbonylation reaction. Background Art

[0002] Methyl methacrylate (MMA) is the basic raw material for high-end materials such as aerospace, electronic information, optical fiber, optical lenses, robots, etc. In my country, the demand for MMA is relatively large. The industrial production methods of MMA include acetone cyanohydrin (ACH) method, isobutylene oxidation method, C2 method, etc. The ACH method was developed by the British Imperial Chemical Industries (ICI) and industrialized in 1937. The ACH method is mature in technology and has always been the main route for MMA production in my country. The traditional ACH method accounts for nearly 70% of the market. However, this method uses highly toxic hydrocyanic acid and sulfuric acid as raw materials, which puts great pressure on environmental protection.

[0003] The isobutylene process was developed by Nippon Catalyst Chemical Industry Co., Ltd. and Mitsubishi Rayon Co., Ltd. in 1982. More than 20% of the world's MMA production capacity uses the isobutylene process, mainly for the Japanese market. This route has a long process flow, complex equipment, low overall MMA selectivity, and high investment and production costs.

[0004] C2 MMA synthesis technology, the representative Lucite (Lucite, now acquired by Mitsubishi Chemical) α-MMA technology, was developed by Shell and transferred to Lucite through ICI. The latter further developed and industrialized it, and built the first 120,000 tons / year industrial plant on Jurong Island, Singapore in 2008. The 250,000 tons / year MMA production plant built in Saudi Arabia has also been put into operation. This route has mild process conditions, is safe and environmentally friendly, and can save 40% of investment and production costs compared to traditional routes. At present, this technology is monopolized by Japan's Mitsubishi Chemical and has not been transferred to the Chinese market.

[0005] The two-step process for synthesizing MMA by ethylene route includes ethylene hydroesterification to produce methyl propionate, and methyl propionate and formaldehyde condensation to produce MMA. At present, the catalysts used for ethylene carbonylation to synthesize methyl propionate are mainly transition metal complexes, the central metals are mainly transition metals such as Pd, Rh, Ni, etc., the ligands are mainly phosphine ligands such as alkyl phosphine, cycloalkyl phosphine, bidentate phosphine and multidentate phosphine, and the catalytic reaction performance is improved by adding acid promoters. The bidentate phosphide with substituted aromatic bridge disclosed by Lucite International UK Ltd. in CN105153241A coordinates with palladium metal to catalyze carbonylation reaction, and has good activity and selectivity. The process patent CN104011007A disclosed by Lucite International UK Ltd. uses palladium-bidentate phosphine ligand catalyst, and the sulfonic acid content in the carbonylation reactor reaches 0.2% to 0.3%. Southwest Chemical Research and Design Institute Co., Ltd. disclosed in CN103319337A that triphenylphosphine ligand, palladium metal as main catalyst, nickel, cobalt, ruthenium, etc. as co-catalysts, and sulfonic acid additives are added. The composite catalyst can efficiently catalyze the carbonylation of ethylene to produce methyl propionate, and the yield of methyl propionate is higher than 95%. The Institute of Process Engineering of the Chinese Academy of Sciences disclosed in CN114849786A an imidazole sulfonic acid ion liquid-based palladium phosphine complex catalyst for carbonylation of ethylene to synthesize methyl propionate, which has high conversion rate, selectivity and good stability for carbonylation reaction.

[0006] Under the action of strong acid additives, phosphine ligands will undergo alkylation, leading to catalyst deactivation and short catalyst life. Phosphine ligands must be continuously added during use, increasing production costs. Sulfonic acid additives are highly acidic and corrosive, and have a high boiling point. The introduction of sulfonic acid also brings about process problems such as equipment corrosion and sulfonic acid accumulation (the pH value of the reaction liquid continues to decrease). The carbonylation reactor used for this reaction generally uses special materials such as zirconium and Hastelloy, which increases equipment investment. The sulfonic acid that continuously enters the reaction system and continues to accumulate with the added catalyst needs to be specifically treated in the process, increasing investment and operating costs. Summary of the invention

[0007] The purpose of the present invention is to: in view of the problems existing in the prior art, the present invention proposes to introduce a phosphorus (P)-containing compound as a stabilizer to replace sulfonic acid, thereby avoiding the direct use and addition of sulfonic acid. The method of the invention can not only improve the catalytic activity and stability of the catalyst system, but also reduce the equipment and process requirements, and has good application prospects.

[0008] In order to achieve the purpose of the present invention, the specific technical scheme of the present invention is as follows:

[0009] A catalyst system for ethylene carbonylation reaction, the catalyst system comprises palladium salt, one or more phosphine ligands, and one or more phosphorus (P)-containing compounds as stabilizers; the molar ratio of palladium, phosphine ligand and stabilizer is 1:(1-6):(60-1000); specifically, it can be 1:1-6:100, 1:1-6:200, 1:1-6:300, 1:1-6:400, 1:1-6:500, 1:1-6:600, 1:1-6:700, 1:1-6:800, 1:1-6:900, 1:1-6:1000, 1:1:60-100, 1:2:60-100, 1:3:60-100, 1:4:60-100, 1:5:60-100, 1:6:60-100, etc.

[0010] Furthermore, the catalyst system and the solvent together constitute a reaction liquid, and the solvent includes but is not limited to methanol, methyl propionate or a mixture thereof, and the total mass content of palladium salt, phosphine ligand and stabilizer in the reaction liquid is 0.5% to 30% (specifically 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, etc.).

[0011] Preferably, in the catalyst system, the molar ratio of palladium, phosphine ligand and stabilizer is 1:(1-5):(100-1000).

[0012] Furthermore, the stabilizer is a phosphorus (P) compound, including but not limited to R 1 R 2 R 3 P=O、R 1 R 2 R 3 P, where P, O, R 1 , R 2 , R 3 They are phosphorus element, oxygen element and hydrocarbon group respectively.

[0013] Further, the phosphorus (P) compound used as a stabilizer includes but is not limited to tripropyl phosphine oxide, tributyl phosphine oxide, tripentyl phosphine oxide, trihexyl phosphine oxide, triheptyl phosphine oxide, trioctyl phosphine oxide, dipropyl methyl phosphine oxide, dipropyl ethyl phosphine oxide, dibutyl methyl phosphine oxide, dibutyl ethyl phosphine oxide, dibutyl propyl phosphine oxide, dipentyl methyl phosphine oxide, dipentyl ethyl phosphine oxide, dipentyl propyl phosphine oxide, dipentyl butyl phosphine oxide, dihexyl pentyl phosphine oxide, dioctyl hexyl phosphine oxide, tripropyl phosphine, tributyl phosphine, tripentyl phosphine, trihexyl phosphine, triheptyl phosphine, trioctyl phosphine, dipropyl methyl phosphine, dipropyl ethyl phosphine, dibutyl methyl phosphine, dibutyl ethyl phosphine, dibutyl propyl phosphine, dipentyl methyl phosphine, dipentyl ethyl phosphine, dipentyl propyl phosphine, dipentyl butyl phosphine, dihexyl pentyl phosphine, and dioctyl hexyl phosphine.

[0014] Further, the stabilizer is an acid-functionalized phosphorus (P) compound, comprising a combination of one or more cations and one or more anions; the cations include but are not limited to [R 1 R 2 P = O] + , [R 1 R 2 P] + , [R 1 R 2 R 3 P] + and [R 1 R 2 R 3 R 4 P] + , where P, O, R 1 , R 2 , R 3 , R 4 respectively phosphorus element, oxygen element and hydrocarbon group; the anion includes but is not limited to [HCOO] － , [RCOO] － , [RSO 3 ] － and [PO 4 ] 3－ , where P, S, O, and R represent phosphorus, oxygen, and hydrocarbon groups, respectively.

[0015] Furthermore, the phosphine ligand includes monodentate phosphines, bidentate phosphines and polydentate phosphines containing chain and cyclic alkyl and / or aryl groups, wherein the alkyl and / or aryl groups connected to the phosphine may be the same or different.

[0016] Preferably, the phosphine ligand includes any one or more of triphenylphosphine, tri-tert-butylphosphine, 1,2-bis(di-tert-butylphosphinomethyl)benzene, 1,2-bis(dicyclohexylphosphinomethyl)benzene, 1,2-bis(di-tert-butylphosphinomethyl)ferrocene, 1,1-bis(di-tert-butylphosphinomethyl)cyclopentane, and 1,2-bis(dicyclohexylphosphinomethyl)ferrocene.

[0017] The present invention also protects the use of the above catalyst system, which is used to catalyze the carbonylation reaction of ethylene, carbon monoxide and methanol, ethanol, propanol, butanol or other alcohols with more carbon atoms.

[0018] Furthermore, the carbonylation reaction temperature is 60-200° C. and the pressure is 10-30 bar.

[0019] Furthermore, sulfonic acid may be additionally added to the catalyst system, and the sulfonic acid includes p-toluenesulfonic acid and methanesulfonic acid.

[0020] The carbonylation reaction requires intermittent or continuous addition of catalyst to maintain production capacity. The supplementary catalyst includes a palladium salt, one or more phosphine ligands, and one or more phosphorus (P)-containing compounds as stabilizers.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) Sulfonic acid additives are highly acidic and corrosive, and have a high boiling point. The introduction of sulfonic acid also brings about process problems such as equipment corrosion and sulfonic acid accumulation (the pH value of the reaction solution continues to decrease). In addition, the carbonylation reactor used for this reaction generally uses special materials such as zirconium and Hastelloy, which increases equipment investment. The sulfonic acid that continuously enters the reaction system with the added catalyst and continues to accumulate requires targeted processing in the process, which increases investment and operating costs. The present invention proposes to introduce a phosphorus (P) compound as a stabilizer to replace sulfonic acid, avoiding the direct use and addition of sulfonic acid. That is, it avoids the problem that the phosphine ligand will be alkylated under the action of the strong acid additive, resulting in catalyst deactivation, resulting in a short catalyst life, and the phosphine ligand must be continuously added during use, increasing the production cost.

[0023] (2) The method of the invention can not only improve the catalytic activity and stability of the catalyst system, but also reduce the equipment and process requirements, and has good application prospects. DETAILED DESCRIPTION

[0024] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0025] Any feature disclosed in this specification (including claims and abstract), unless otherwise stated, may be replaced by other equivalent or alternative features having similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0026] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0027] Carbonylation experiment: Weigh a certain amount of palladium salt, phosphine ligand, stabilizer and methanol, add them into a 500mL high-pressure reactor, seal the high-pressure reactor, replace and start stirring, then heat the reactor to a temperature of 80-120°C, stir at a rate of 300-1200r / min, introduce raw gas into the reactor, increase the pressure to 10-30bar, start the reaction, continuously add raw gas to maintain a stable reaction pressure, and take the liquid product for chromatographic analysis after a period of reaction.

[0028] Embodiment 1:

[0029] 200 g of degassed methanol was added to a 500 mL reactor, followed by the addition of Pd 2 (dba) 3 7mg, 1,2-bis(di-tert-butylphosphinomethyl)ferrocene 15mg, add 1.5g of tri-n-hexylphosphine, seal the high-pressure reactor, replace and start stirring, introduce ethylene and CO raw gas, heat the reactor to 100℃, start counting when the pressure in the reactor stabilizes at 15bar, end the experiment after 30min, average TOF 31000h －1 The selectivity of methyl propionate is higher than 99%. There is no obvious precipitation in the kettle liquid after the reaction.

[0030] Embodiment 2:

[0031] Add 200 g of methanol to a 500 mL reactor, followed by the addition of Pd 2 (dba) 3 7mg, 1,2-bis(di-tert-butylphosphinomethyl)benzene 12mg, add tri-n-butylphosphine oxide 1.8g, seal the high-pressure reactor, replace and start stirring, introduce ethylene and CO raw gas, heat the reactor to 100℃, start counting when the pressure in the reactor stabilizes at 15bar, end the experiment after 30min, average TOF 35000h －1 The selectivity of methyl propionate is higher than 99%. There is no obvious precipitation in the kettle liquid after the reaction.

[0032] Embodiment 3:

[0033] Add 200 g of methanol to a 500 mL reactor, followed by the addition of Pd 2 (dba) 3 7mg, 1,2-bis(di-tert-butylphosphinomethyl)benzene 12mg, add 2.5g of acid-functionalized phosphorus (P) compound, the cation is tetrapropylphosphine, the anion is formate, seal the high-pressure reactor, replace and start stirring, introduce ethylene and CO raw gas, heat the reactor to 100℃, start counting when the pressure in the reactor stabilizes at 15bar, end the experiment after 30min, average TOF 34000h －1 The selectivity of methyl propionate is higher than 99%. There is no obvious precipitation in the kettle liquid after the reaction.

[0034] Embodiment 4:

[0035] Add 200 g of methanol to a 500 mL reactor, followed by the addition of Pd 2 (dba) 37mg, 1,2-bis(di-tert-butylphosphinomethyl)ferrocene 15mg, add 2.5g of acid-functionalized phosphorus (P) compound, the cation is tributyl(methyl)phosphine, the anion is sulfonate, seal the high-pressure reactor, replace and start stirring, introduce ethylene and CO raw gas, heat the reactor to 100℃, start counting when the pressure in the reactor stabilizes at 15bar, end the experiment after 30min, average TOF 33000h －1 The selectivity of methyl propionate is higher than 99%. There is no obvious precipitation in the kettle liquid after the reaction.

[0036] Embodiment 5:

[0037] Add 200 g of methanol to a 500 mL reactor, followed by the addition of Pd 2 (dba) 3 7mg, 1,2-bis(di-tert-butylphosphinomethyl)benzene 12mg, add 80mg of tri-n-butylphosphine oxide, seal the high-pressure reactor, replace and start stirring, introduce ethylene and CO raw gas, heat the reactor to 100℃, start counting when the pressure in the reactor stabilizes at 15bar, end the experiment after 30min, average TOF 12000h －1 , the selectivity of methyl propionate is higher than 99%.

[0038] Embodiment 6:

[0039] 200 g of degassed methanol was added to a 500 mL reactor, followed by the addition of Pd 2 (dba) 3 7mg, 1,2-bis(di-tert-butylphosphinomethyl)benzene 12mg, seal the high-pressure reactor, replace and start stirring, introduce ethylene and CO raw gas, heat the reactor to 100℃, start counting when the pressure in the reactor stabilizes at 15bar, end the experiment after 30min, average TOF 4500h －1 , the selectivity of methyl propionate was higher than 99%. After the reaction, obvious precipitation was found in the kettle liquid.

[0040] Embodiment 7:

[0041] Add 200 g of methanol to a 500 mL reactor, followed by the addition of Pd 2 (dba) 3 7mg, 1,2-bis(di-tert-butylphosphinomethyl)benzene 12mg, 150mg of methanesulfonic acid were added, the high-pressure reactor was sealed, replaced and stirred, ethylene and CO raw gas were introduced, the reactor was heated to 100°C, and when the pressure in the reactor stabilized at 15bar, counting was started. The experiment was terminated after 30min, and the average TOF was 32000h －1 , the selectivity of methyl propionate is higher than 99%.

[0042] Based on the above results, a phosphorus (P)-containing compound is introduced as a stabilizer to replace sulfonic acid, thereby avoiding the direct use and addition of sulfonic acid. The inventive method can effectively improve the catalytic activity and stability of the catalyst system and has good application prospects.

[0043] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

[0044] This background section is provided to generally present the context of the invention, and the work of the presently named inventors, the work to the extent described in this background section, and aspects of this section that did not constitute prior art at the time of application are neither explicitly nor implicitly admitted to be prior art to the present invention.

Claims

1. A catalyst system for ethylene carbonylation reaction, characterized in that: The catalyst system comprises palladium salt, one or more phosphine ligands, and one or more phosphorus (P)-containing compounds as stabilizers; the molar ratio of palladium, phosphine ligand and stabilizer is 1:1-6:60-1000.

2. A catalyst system for ethylene carbonylation reaction as claimed in claim 1, characterized in that: The catalyst system and the solvent together constitute a reaction liquid, and the solvent includes but is not limited to methanol, methyl propionate or a mixture thereof; in the reaction liquid, the total mass content of the palladium salt, the phosphine ligand and the stabilizer is 0.5% to 30%.

3. A catalyst system for ethylene carbonylation reaction as claimed in claim 1, characterized in that: In the catalyst system, the molar ratio of palladium, phosphine ligand and stabilizer is preferably 1:1-5:100-1000.

4. A catalyst system for ethylene carbonylation reaction as claimed in claim 1, characterized in that: The stabilizer is a phosphorus (P)-containing compound, including but not limited to R1R2R3P=O, R1R2R3P, wherein P, O, R1, R2, and R3 are phosphorus element, oxygen element, and hydrocarbon group, respectively.

5. A catalyst system for ethylene carbonylation as claimed in any one of claims 1 to 4, characterized in that: The phosphorus (P)-containing compound used as a stabilizer includes, but is not limited to, tripropyl phosphine oxide, tributyl phosphine oxide, tripentyl phosphine oxide, trihexyl phosphine oxide, triheptyl phosphine oxide, trioctyl phosphine oxide, dipropyl methyl phosphine oxide, dipropyl ethyl phosphine oxide, dibutyl methyl phosphine oxide, dibutyl ethyl phosphine oxide, dibutyl propyl phosphine oxide, dipentyl methyl phosphine oxide, dipentyl ethyl phosphine oxide, dipentyl propyl phosphine oxide, dipentyl butyl phosphine oxide, dihexyl pentyl phosphine oxide, dioctyl hexyl phosphine oxide, tripropyl phosphine, tributyl phosphine, tripentyl phosphine, trihexyl phosphine, triheptyl phosphine, trioctyl phosphine, dipropyl methyl phosphine, dipropyl ethyl phosphine, dibutyl methyl phosphine, dibutyl ethyl phosphine, dibutyl propyl phosphine, dipentyl methyl phosphine, dipentyl ethyl phosphine, dipentyl propyl phosphine, dipentyl butyl phosphine, dihexyl pentyl phosphine, and dioctyl hexyl phosphine.

6. A catalyst system for ethylene carbonylation reaction as claimed in claim 5, characterized in that: The stabilizer is an acid-functionalized phosphorus (P) compound, comprising a combination of one or more cations and one or more anions; the cations include but are not limited to [R1R2P=O] + , [R1R2P] + 、[R1R2R3P] + and [R1R2R3R4P] + , wherein P, O, R1, R2, R3, and R4 are phosphorus, oxygen, and hydrocarbon groups, respectively; the anion is not limited to [HCOO] - , [RCOO] - , [RSO3] - and [PO4] 3- , where P, S, O, and R represent phosphorus, oxygen, and hydrocarbon groups, respectively.

7. A catalyst system for ethylene carbonylation reaction as claimed in claim 6, characterized in that: The phosphine ligands include monodentate phosphines, bidentate phosphines and polydentate phosphines containing chain and cyclic alkyl and / or aryl groups, wherein the alkyl and / or aryl groups connected to the phosphine may be the same or different.

8. A catalyst system for ethylene carbonylation reaction as claimed in claim 7, characterized in that: The phosphine ligand is one or more of triphenylphosphine, tri-tert-butylphosphine, 1,2-bis(di-tert-butylphosphinomethyl)benzene, 1,2-bis(dicyclohexylphosphinomethyl)benzene, 1,2-bis(di-tert-butylphosphinomethyl)ferrocene, 1,1-bis(di-tert-butylphosphinomethyl)cyclopentane, and 1,2-bis(dicyclohexylphosphinomethyl)ferrocene.

9. Use of a catalyst system for ethylene carbonylation reaction as claimed in any one of claims 1 to 4 and 6 to 8 in catalyzing the carbonylation reaction of ethylene, carbon monoxide and alcohols having carbon atoms; characterized in that: The carbonylation reaction temperature is 60-200° C. and the pressure is 10-30 bar.

10. The use according to claim 9, characterized in that: Sulfonic acid may be additionally added to the catalyst system; the sulfonic acid includes p-toluenesulfonic acid and methanesulfonic acid.