A method for online recovery of rhodium activity in deactivated propylene hydroformylation catalyst

Abstract

The present application provides a process for recovering the activity of deactivated rhodium in the propylene hydroformylation catalyst on-line. The method comprises: introducing an activator into the reaction product after the removal of propylene, so that the catalyst and mixed butyraldehyde, the activator enter the catalyst recovery unit together, and the activation reaction of the deactivated rhodium is carried out in the catalyst recovery unit, and finally the activated catalyst returns to the reactor for continuous reaction, the butyraldehyde product and the activator enter the activator recovery together, the recovered activator is recycled, and the butyraldehyde product enters the downstream for further separation. Through the process, the deactivated rhodium catalyst can be recovered in activity, the on-line time of the catalyst is prolonged, and the operation cost of the device is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic chemical industry, and particularly relates to a method for recovering the activity of deactivated rhodium in propylene hydroformylation catalysts on line. BACKGROUND

[0002] Propylene hydroformylation has developed from high-pressure cobalt catalyst to low-pressure rhodium noble metal catalyst. In the hydroformylation reaction, rhodium catalyst will be internally deactivated, resulting in rhodium chain formation (also known as rhodium agglomeration or rhodium hand holding), which leads to a decrease in catalyst activity. In order to maintain production capacity, industrial devices need to periodically supplement fresh rhodium pascals to maintain the stability of active rhodium content. When the amount of active rhodium accumulates to a certain content, the device needs to be shut down for overall replacement of new rhodium. In recent years, the price of noble metal rhodium is relatively high, and the average price in 2021 was as high as 4700 yuan / g. The overall replacement of new rhodium has a high price, and a new process needs to be developed to find a process for recovering the activity of deactivated rhodium in propylene hydroformylation catalysts on line.

[0003] Patent CN104028311A discloses a method for chemical regeneration of butyl octanol carbonyl synthesis catalyst. The catalyst is purified by removing S and Cl, then activated by adding alcohol amine and organic acid, and the rhodium catalyst is recovered after neutralization and washing with lye. This process needs to be regenerated off line, uses many types of reagents, and has a high loss of rhodium in the recovery process, which is not feasible for industrial implementation.

[0004] Patent CN202011172210 discloses a regeneration method for deactivated rhodium phosphine catalyst. A cycloalkane containing 6-9 carbon atoms or an alkane containing 5-20 carbon atoms is used as an extractant to separate the rhodium cluster compound to be activated by polar solvent extraction, and further combined with the presence of citric acid catalyst, the rhodium phosphine catalyst is regenerated by oxidative activation reaction, which significantly improves the deactivation of rhodium phosphine catalyst caused by the formation of rhodium cluster compound, effectively solves the problems of concentration and separation of rhodium phosphine catalyst and its inhibitor high-boiling-point alcohol aldehyde condensate. However, this process will have a lot of rhodium loss, and the activation is not economical.

[0005] Patent CN105013537A discloses a method for improving the activity of deactivated butyl octanol carbonyl synthesis catalyst, which comprises the following steps: (1) taking out the deactivated rhodium-triphenyl phosphine catalyst mother liquor in the butyl octanol carbonyl synthesis reactor, removing the interfering gas containing propylene by N2purging, and then adding a solvent to adjust the rhodium concentration in the mother liquor; (2) adding a rhodium-bis-phosphinic acid ester complex to the mother liquor treated in step (1), and then stirring to fully mix them to form a rhodium-triphenyl phosphine and rhodium-bis-phosphinic acid ester dual catalyst system. This process will introduce new chemicals into the reaction system, increasing the risk of reaction and product separation.

[0006] In summary, the existing disclosed rhodium activation method is off-line activation of catalyst, and needs to add new processes and equipment such as extraction, pickling, nitrogen blowing, which is not conducive to maximizing the use of existing device equipment to realize low-cost rhodium activation regeneration and flexible change according to activity, and flexible adjustment of the recovery speed of deactivated rhodium online activation process. SUMMARY

[0007] The purpose of the present application is to provide a method for recovering the activity of deactivated rhodium in propylene hydroformylation catalyst. The existing device equipment can be maximized to realize low-cost rhodium activation regeneration and flexible change according to activity, and flexible adjustment of the recovery speed of deactivated rhodium online activation process.

[0008] The mixed butyraldehyde generated by propylene hydroformylation reaction is a typical reaction of carbonyl synthesis. After years of development, the catalyst has developed from cobalt to rhodium, and the corresponding process conditions have also changed from high temperature and high pressure reaction conditions to mild process conditions at low temperature and low pressure, and the reaction rate has also been significantly improved. The existing mainstream catalyst type is rhodium-triphenyl phosphine homogeneous catalyst. During the use of the catalyst, there is a slow internal deactivation of rhodium. In industrial operation, the rate of internal deactivation of rhodium can only be slowed down by low temperature, low CO partial pressure and high triphenyl phosphine concentration, but these measures will inhibit the reaction rate and reduce the reaction load.

[0009] Monatomic rhodium loses activity by internal deactivation to form polymeric rhodium. How to split the polymeric rhodium into rhodium catalyst monomer form and restore activity to prolong the service life of the catalyst is the problem to be solved by the present application.

[0010] To achieve the above invention purposes, the present application adopts the following technical solutions:

[0011] By introducing an active agent into the reaction product after propylene hydroformylation, the catalyst and mixed butyraldehyde, the active agent enter the catalyst recovery unit together, and the deactivation of rhodium is activated in it, and finally the activated catalyst returns to the reactor for continuous reaction, the butyraldehyde product and the active agent enter the activator recovery unit together, the recovered activator is recycled, and the butyraldehyde product enters the downstream for further separation.

[0012] In the present application, the active agent is a strong oxidizing acid without halogen and cyanide. Preferably, the peroxo acid is C2-C6, such as peroxo acetic acid, peroxo propionic acid, peroxo butyric acid, etc. More preferably, the unsaturation degree of the carbon chain of the peroxo acid is less than 1. Preferably, the active agent in the catalyst recovery unit is 3000-300000 ppm based on the total mass of the recovered catalyst.

[0013] In the present application, the reaction product after the hydroformylation of propylene is first treated by removing propylene and then enters the catalyst recovery unit. The treatment pressure is 0-1 MPaG, and the temperature is controlled at 80-160℃, preferably at a pressure of 0.5-0.7 MPaG, and the temperature is 100-160℃.

[0014] In the present application, the pressure of the catalyst recovery unit is controlled at 0.02-0.1 MPaG, and the temperature is controlled at 100-160℃ to obtain the activated catalyst returning to the reactor. The preferred pressure is 0.05-0.08 MPaG, and the temperature is 120-140℃.

[0015] In the present application, the mixed butyraldehyde product, catalyst, and activator stay in the catalyst recovery unit for 0.1-30S, and the preferred residence time is 2-10S.

[0016] In the present application, the temperature of the stream containing mixed butyraldehyde and activator flowing out of the catalyst recovery unit is 20-120℃, and the preferred temperature is 60-100℃.

[0017] In the present application, the pressure of the catalyst recovery unit is controlled at 0.02-0.1 MPaG, and the temperature is controlled at 20-120℃ to obtain the stream containing mixed butyraldehyde and activator entering the activator recovery unit. The preferred pressure is 0.05-0.07 MPaG, and the temperature is 60-100℃.

[0018] As a preferred scheme, a rectifying column is selected as the activator recovery unit, and the overhead temperature is controlled at 60-150℃, and the overhead pressure is controlled at 10-120KpaG.

[0019] According to the above process, by adding a low-boiling strong oxidizing agent, a peroxo acid type compound, the polymerized rhodium catalyst is broken and the activity is restored.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] 1. Low equipment investment and operating cost. The process can maximize the use of existing catalyst separation and product separation paths. No redundant evaporation, caustic washing, water washing equipment is needed, and no too many chemicals are introduced.

[0022] 2. Flexible operation. By replacing different types and different concentrations of activators, online activation of the catalyst can be completed according to different proportions of deactivated rhodium without stopping operation.

[0023] 3. Less by-products of activation reaction. The existing device separation conditions can easily remove the activator and the by-products of the activation reaction from the reaction system. The residual acidic substances in the catalyst will not cause the by-products of butyraldehyde polymerization. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Scheme for the activation route of deactivated rhodium catalysts. DETAILED DESCRIPTION

[0025] The application will be further described by the following examples, but is not limited to the examples.

[0026] The analysis method of n- / iso-butyraldehyde, triphenylphosphine, peroxyacetic acid, and peroxypropionic acid in the catalyst composition uses Agilent chromatographic analysis, and the specific determination method is as follows: injection amount: 0.2 μL; column temperature: 50 ℃ for 4 min, 3 ℃ / min to 60 ℃, 10 ℃ / min to 150 ℃, 20 ℃ / min to 230 ℃, and 8 min; injection port temperature: 250 ℃; spacer purge gas flow rate: 3.0 mL / min; column flow rate (N2): 1 mL / min; split injection, split ratio 30:1; detector: 280 ℃; hydrogen flow rate: 30 mL / min; air flow rate: 400 mL / min; tail gas flow rate: 25 mL / min.

[0027] Reaction rate test: 100 ml of catalyst (before and after activation) is added to a 300 ml autoclave, 30 g of propylene is added, and then the temperature is raised to 85 ℃; nitrogen is pressurized to 1.8 MPaG. After the temperature and pressure are stable for 10 min, synthesis gas is introduced, and after 10 min of reaction, the heating is turned off, the temperature is reduced to room temperature, the residual gas in the reactor is discharged, the reactor is opened, and the amount of butyraldehyde produced is measured. According to the amount of butyraldehyde produced and the reaction time, the reaction rate is calculated.

[0028]

[0029] According to the above test method, the fresh catalyst activity rate r1 and the device deactivated catalyst r2 under the same rhodium and ligand are tested respectively, and the percentage of active rhodium in the device catalyst Y is calculated. 活化前 is:

[0030]

[0031] According to the above test method, the fresh catalyst activity rate r1 and the device activated catalyst r3 under the same rhodium and ligand are tested respectively, and the percentage of active rhodium in the device catalyst Y is calculated. 活化后 is:

[0032]

[0033] Source of raw materials:

[0034] Deactivated rhodium catalyst, provided by the polyol device of Wanhua Chemical Group Co., Ltd., and the catalyst samples were selected from the device running for 5, 6, and 7 years.

[0035] The materials used to evaluate the activity of the new catalyst include: triphenylphosphine, peroxyacetic acid, peroxypropionic acid, acetylacetone triphenylphosphine rhodium carbonyl. The above-mentioned are all provided by the Aladdin reagent, and the purity is greater than 98%;

[0036] Steel bottle gas (CO, H2), purity 99.9%, Yantai Mingtu gas.

[0037] Example 1

[0038] Deactivated rhodium content test: take the rhodium-phosphine homogeneous catalyst used in the polyol device for seven years, calculate the catalyst activity as 55% according to the reaction rate test method described in the above specific implementation (i.e. 45% of rhodium has no catalytic activity).

[0039] Catalyst activation: 120ml of the above-mentioned catalyst containing deactivated rhodium is added to the reactor, propylene and hydrogen, carbon monoxide are continuously introduced from the bottom of the reactor, the reaction temperature is 88℃, the pressure is 1.8MPaG. The propylene feed rate is 0.2g / min, the hydrogen feed rate is 107ml / min under standard conditions, the CO partial pressure is controlled at 0.05MPa in the first stage of the reaction, the reaction is carried out under simulated device operating conditions, the reactor is controlled by liquid level, the mixed reaction product A of the reactor outlet is heated to 100℃ and then enters the propylene removal device (pressure: 0.2MPaG), the vaporized propylene B material is separated from the propylene reactor, the liquid phase C at the bottom is controlled at 120℃, and the flow rate is 2g / min through the production pump and enters the catalyst recovery unit, and then mixed with 0.6g / min of peroxyacetic acid F and introduced into the catalyst recovery unit. The temperature of the catalyst recovery unit after the catalyst recovery unit is controlled at 130℃, the pressure is 0.05MPaG, the production is adjusted, and the residence time is controlled at 2S. The recovered catalyst E is returned to the reactor, the activated agent and mixed butyraldehyde G at the top are controlled at 60℃ and enter the downstream activated agent recovery unit, the pressure of the activated agent recovery unit is controlled at 80KPaG, the tower top temperature is 60℃, and the condensed activated agent H is returned to the front road and mixed with the activated agent F, and the mixed butyraldehyde material I is separated to the lower road.

[0040] Deactivated rhodium content test of the activated catalyst in the reactor: the activated catalyst is tested for activity. The catalyst activity is calculated as 82%, which is higher than the catalyst activity of 55% before activation.

[0041] Example 2

[0042] Deactivated rhodium content test: take the rhodium-phosphine homogeneous catalyst used in the polyol device for six years, calculate the catalyst activity as 60% according to the reaction rate test method described in the above specific implementation (i.e. 40% of rhodium has no catalytic activity).

[0043] Catalyst activation: 120 ml of the above described rhodium deactivated catalyst was charged into the reactor, propylene and hydrogen, carbon monoxide were continuously fed from the bottom of the reactor, the reaction temperature was 88 °C, the pressure was 1.8 MPaG. The propylene feed rate was 0.2 g / min, the hydrogen feed rate was 107 ml / min at standard conditions, the CO partial pressure was controlled at 0.05 MPa in the first stage of the reaction, the reaction was carried out under simulated device operating conditions, the reactor was controlled by liquid level, the mixed reaction product A from the reactor was heated to 120 °C and then entered the propylene removal device (pressure: 0.4 MPaG), the vaporized propylene B was separated from the propylene reactor, the liquid phase C at the bottom was controlled at 110 °C, and was fed into the catalyst recovery unit at a flow rate of 10 g / min, mixed with 0.03 g / min of peroxoacetic acid F in the pipeline, and then fed into the catalyst recovery unit, the temperature of the material after the catalyst recovery unit was controlled at 150 °C, the pressure was 0.06 MPaG, the withdrawal was adjusted, and the residence time was controlled at 2 S. The recovered catalyst E was returned to the reactor, the mixed butyraldehyde G after the reaction was controlled at 60 °C and entered the downstream activator recovery unit, the pressure of the activator recovery unit was controlled at 80 KPaG, the overhead temperature was 80 °C, the condensed activator H was returned to the front line and mixed with the activator F, and the mixed butyraldehyde material I was separated in the downstream line.

[0044] Test of the deactivated rhodium content in the activated catalyst in the reactor: the activated catalyst was tested for activity. The catalyst activity was calculated to be 96%, higher than the activity of the catalyst before activation, which was 60%.

[0045] Example 3

[0046] Test of the deactivated rhodium content: the rhodium-phosphine homogeneous catalyst used in the polyol device for five years was tested according to the above described reaction rate test method, and the catalyst activity was calculated to be 63% (i.e. 37% of the rhodium had no catalytic activity).

[0047] Catalyst activation: 120 ml of the above-mentioned device catalyst containing deactivated rhodium was added to the reactor, propylene and hydrogen, carbon monoxide were continuously fed from the bottom of the reactor, the reaction temperature was 88℃, the pressure was 1.8 MPaG. The propylene feed rate was 0.2 g / min, the hydrogen feed rate was 107 ml / min under standard conditions, the CO partial pressure was controlled at 0.05 MPa in the first stage of the reaction, the reaction was carried out under simulated device operating conditions, the reactor was controlled by liquid level, the mixed reaction product A from the reactor was heated to 160℃ and then entered the propylene removal device, the vaporized propylene B material was separated from the propylene reactor, the pressure was 0.6 MPaG, the temperature of the liquid phase C at the bottom was controlled at 140℃, and the material was fed into the catalyst recovery unit at a flow rate of 10 g / min by the production pump, mixed with 0.3 g / min of peroxypropionic acid in the pipeline, and then fed into the catalyst recovery unit, the temperature of the material after the catalyst recovery unit was controlled at 150℃, the pressure was 0.07 MPaG, the production was adjusted, and the residence time was controlled at 5S. The recovered catalyst E was returned to the reactor, the activated catalyst and mixed butyraldehyde G at the top were controlled at 100℃ and entered the downstream activated catalyst recovery unit, the pressure of the activated catalyst recovery unit was controlled at 10 KPaG, the overhead temperature was 80℃, and the condensed activated catalyst H was returned and mixed with the activated catalyst F in the front line, and the mixed butyraldehyde material I was separated in the downstream line.

[0048] Test of the content of deactivated rhodium in the activated catalyst in the reactor: the activated catalyst was tested for activity. The catalyst activity was calculated to be 98%, higher than the catalyst activity of 63% before activation.

[0049] Based on the method of the present application, the skilled person can flexibly realize the online activation of the deactivated rhodium catalyst without stopping and adding new equipment.

[0050] The above-mentioned is only a few embodiments of the present application, which is described in more detail, but cannot be understood as limiting the present application to the disclosed content. It should be clear that without departing from the core idea of the present application, a number of corresponding modifications and improvements can be made, any simple acid form, simple change of the type and amount of oxidizing agent, and simple process flow change modification all belong to the protection scope of the present application.

Claims

1. A method for on-line recovery of rhodium activity in a deactivated propene hydroformylation catalyst, characterized in that, The application relates to a process for the production of butyl alcohols by hydroformylation of propylene, comprising: The activated agent is introduced into the reaction product after the hydroformylation of propylene, so that the catalyst and mixed butyl alcohols and the activated agent enter the catalyst recovery unit together, and the deactivation rhodium is activated in the catalyst recovery unit, and finally the activated catalyst returns to the reactor, the butyl alcohol product and the activated agent enter the activated agent recovery unit together, the activated agent is recycled after recovery, and the butyl alcohol product enters the downstream for further separation; the activated agent is a C2-C6 peroxy acid without halogen and cyanide, and the carbon chain of the activated agent peroxy acid is less than 1 in unsaturation degree.

2. The method of claim 1, wherein, The amount of activated agent entering the catalyst recovery unit is 3000-300000 ppm based on the mass of the catalyst recovery unit feed without the activated agent.

3. The method according to claim 1 or 2, characterized in that, The reaction product after the hydroformylation of propylene is first treated by removing propylene and then enters the catalyst recovery unit, the treatment pressure is 0-1 MPaG, and the temperature is controlled to be 80-160 DEG C.

4. The method of claim 3, wherein, The reaction product after the hydroformylation of propylene is first treated by removing propylene and then enters the catalyst recovery unit, the treatment pressure is 0.5-0.7 MPaG, and the temperature is 100-160 DEG C.

5. The method of claim 3, wherein, The pressure of the catalyst recovery unit is controlled to be 0.02-0.1 MPaG, and the temperature is controlled to be 100-160 DEG C to obtain the activated catalyst returning to the reactor.

6. The method of claim 5, wherein, The pressure of the catalyst recovery unit is controlled to be 0.05-0.08 MPaG, and the temperature is controlled to be 120-140 DEG C to obtain the activated catalyst returning to the reactor.

7. The method of claim 3, wherein, The mixed butyl alcohol product, the catalyst and the activated agent stay in the catalyst recovery unit for 0.1-30 s.

8. The method of claim 7, wherein, The mixed butyl alcohol product, the catalyst and the activated agent stay in the catalyst recovery unit for 2-10 s.

9. The method of claim 3, wherein, The pressure of the catalyst recovery unit is controlled to be 0.02-0.1 MPaG, and the temperature is controlled to be 20-120 DEG C to obtain the mixed butyl alcohol and the activated agent flow entering the activated agent recovery unit.

10. The method of claim 9, wherein, The pressure of the catalyst recovery unit is controlled to be 0.05-0.07 MPaG, and the temperature is controlled to be 60-100 DEG C to obtain the mixed butyl alcohol and the activated agent flow entering the activated agent recovery unit.

11. The method of claim 9 or 10, wherein, The activated agent recovery unit is a rectifying tower, the top temperature of which is controlled to be 60-150 DEG C, and the top pressure is controlled to be 10-120 KPaG.

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