A harmless inactivation treatment method for ethylene oligomerization catalyst

Abstract

The present application relates to the technical field of catalyst deactivation, in particular to a harmless deactivation treatment method for ethylene oligomerization catalyst, comprising: (1) injecting ethylene oligomerization waste catalyst mixture and composite inorganic salt deactivator into a reaction kettle, and controlling the temperature and pressure in the reaction kettle; (2) stirring the materials in the reaction kettle, and obtaining a mixed liquid after mixing reaction; (3) separating the filter residue and filtrate from the mixed liquid through a filter, thereby completing the harmless conversion of the waste catalyst. The present application uses low-cost composite inorganic salt as the deactivator to replace the traditional amine and alcohol deactivator for treating waste catalyst, converts the harmful titanium and aluminum compounds into harmless landfill solids, and removes them through a filter; and the alpha-olefin products and other solvents and reagents contained therein can be recovered by distillation. The above treatment method not only achieves the purpose of deactivating the catalyst, but also saves production cost and reduces environmental pollution.

Description

Technical Field

[0001] This invention relates to the field of catalyst inactivation technology, specifically to a method for harmlessly inactivating ethylene oligomerization catalysts. Background Technology

[0002] Catalysts for ethylene oligomerization are deactivated using inactivating agents such as amines and alcohols. For example, French IFP patents CN96108936.9 and CN86103014A use decylamine as a catalyst inhibitor to contact the reactor effluent, thereby deactivating the catalyst. French patent FR2581381 describes a method for treating ethylene dimerization titanium-based catalyst waste by distilling a mixture of decylamine or dodecylamine and crude dimerization products at a temperature above the dimerization temperature to neutralize the catalyst and separate high-purity 1-butene. Patent EP0221206 terminates the catalytic reaction by adding methanol to the reaction mixture. IFP patent CN109942362 discloses a method for treating ethylene dimerization effluent by neutralizing the catalytic system by adding alcohols such as 2-ethylhexanol and 1-dodecanol to the reaction mixture. Patent FR3061175B1 discloses a method for neutralizing an olefin dimerization catalytic system containing at least one halogen derivative by contacting the reaction effluent with acetonitrile to deactivate the catalyst.

[0003] Long-chain amines or alcohols have relatively high boiling points, making them less likely to be released into recycled ethylene and products. However, their higher price increases the production cost of α-olefins. Low-boiling-point short-chain alcohols are relatively cheaper than amines for treating catalyst waste, but they may reduce the purity of recycled ethylene and the product 1-butene, thus affecting the performance and applications of ethylene oligomerization and polymerization products. Currently, long-chain amine deactivators are widely used in industry. The mixture after adding deactivators contains product olefins, hydrocarbon solvents, and derivatives formed by the deactivator and catalyst / co-catalyst. This waste mixture must be sent to a qualified hazardous waste treatment company for incineration. This treatment method not only releases harmful air pollutants into the atmosphere, such as carbon dioxide, alumina, and titanium dioxide nanoparticles, but also increases the production cost of α-olefins. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for the harmless inactivation of ethylene oligomerization catalysts. It uses inexpensive composite inorganic salts as inactivating agents to convert harmful titanium and aluminum compounds into harmless landfillable solids, thereby saving production costs and reducing environmental pollution.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for harmlessly inactivating ethylene oligomerization catalysts, comprising the following steps:

[0006] (1) Inject the mixture of ethylene oligomerization waste catalyst and composite inorganic salt inactivator into the reactor, and control the temperature and pressure inside the reactor;

[0007] (2) Stir the materials in the reactor and after mixing and reaction, obtain a mixed liquid;

[0008] (3) Pass the mixture through a filter to separate the dark gray filter residue and the colorless transparent filtrate, thus completing the harmless conversion of the waste catalyst.

[0009] Preferably, in step (1), the ethylene oligomerization waste catalyst mixture comprises, by mass percentage, 5-10% titanium-based catalyst Ti(OR1)4 and aluminum-based co-catalyst Al(R2). n X 3-n 5-10% of ethylene polymerization products and 80-90% of titanium-based catalyst Ti(OR1)4 and aluminum-based co-catalyst Al(R2) are further preferred. n X 3-n 5-6%, ethylene polymerization products 88-89%.

[0010] Preferably, by mass percentage, the ethylene polymerization product comprises 5-10% 1-butene, 5-10% 1-hexene, and 80-90% higher olefins and polymers. More preferably, it comprises 8-10% 1-butene, 5-8% 1-hexene, and 85-86% higher olefins and polymers.

[0011] Preferably, R1 is a C1-C8 alkyl or aryl group, selected from any one or a mixture of several of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, n-hexyl, 2-ethylhexyl, phenyl, 2-methylphenyl, 4-methylphenyl, and 2,6-dimethylphenyl. More preferably, R1 is n-butyl.

[0012] Preferably, R2 is a C1-C8 alkyl or aryl group, selected from any one or a mixture of several of methyl, ethyl, propyl, butyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, n-hexyl, 2-ethylhexyl, phenoxy, phenyl, 2-methylphenyl, 4-methylphenyl, and 2,6-dimethylphenyl; X is selected from bromine or chlorine atoms; and n is an integer from 1 to 3. More preferably, R2 is ethyl, and n is 3.

[0013] Preferably, in step (1), the flow ratio of the ethylene oligomerization waste catalyst mixture and the composite inorganic salt inactivator is 1:(0.2~1.1).

[0014] Preferably, in step (1), the composite inorganic salt inactivating agent includes any mixture of calcium hydroxide, sodium hydroxide, potassium hydroxide, zinc hydroxide, sodium bicarbonate, hydrated sodium bicarbonate, calcium bicarbonate, potassium bicarbonate, aluminum bicarbonate, magnesium bicarbonate, ammonium bicarbonate, calcium carbonate, sodium carbonate, potassium carbonate, ammonium carbonate, lead carbonate, cobalt carbonate, magnesium carbonate, manganese carbonate, zinc carbonate, aluminum carbonate, strontium carbonate, iron carbonate, barium carbonate, sodium aluminum carbonate, magnesium calcium carbonate, basic copper carbonate, sodium carbonate monohydrate, triclinic barium calcite, copper zinc ore, azurite, bastnaesite, bismuth monoxide, turquoise, zeolite, montmorillonite, kaolinite, bentonite, zirconium oxide, silica, aluminum silicate, nickel sulfate, and hydroxyapatite.

[0015] Preferably, the composite inorganic salt inactivating agent comprises, by mass percentage, 21.8% sodium bicarbonate, 55.4% kaolin, and 22.8% sodium carbonate.

[0016] Preferably, the composite inorganic salt inactivating agent comprises, by mass percentage, 29.7% calcium bicarbonate, 51.9% montmorillonite, and 18.4% calcium carbonate.

[0017] Preferably, the composite inorganic salt inactivating agent comprises, by mass percentage, 15.2% ammonium bicarbonate, 66.5% bentonite, and 18.3% ammonium carbonate.

[0018] Preferably, in steps (1)-(2), the temperature inside the reactor is 90-112℃, the pressure is 8-9 atm, and the mixing reaction time is 4-8h.

[0019] This invention provides a method for the harmless inactivation treatment of ethylene oligomerization catalysts, which has the following advantages compared with the prior art:

[0020] This invention abandons the traditional method of using expensive amines and alcohols as deactivators to treat spent catalysts. Instead, it employs inexpensive composite inorganic salts as deactivators to convert harmful titanium and aluminum compounds into harmless landfill-compatible solids, which are then removed through a filter. Furthermore, the contained α-olefin products and other solvents and reagents can be recovered through distillation. This treatment method achieves catalyst deactivation while saving production costs and reducing environmental pollution; moreover, the conversion rate of spent catalysts can reach over 98%. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a flow chart of the waste catalyst treatment process of the present invention. Detailed Implementation

[0023] The following embodiments are provided to illustrate the implementation of this application in detail, so that the process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0024] Example 1

[0025] A method for harmlessly inactivating ethylene oligomerization catalysts includes the following steps:

[0026] (1) The mixture of ethylene oligomerization waste catalyst and composite inorganic salt inactivator is injected into the reactor, and the temperature inside the reactor is controlled at 110.1℃ and the pressure at 9.0 atm. The composite inorganic salt inactivator includes 21.8% sodium bicarbonate, 55.4% kaolin and 22.8% sodium carbonate by mass percentage.

[0027] (2) Stir the materials in the reactor and after mixing and reacting for 6 hours, a mixed liquid is obtained;

[0028] (3) Pass the mixture through a filter to separate the dark gray filter residue and the colorless transparent filtrate, thus completing the harmless conversion of the waste catalyst.

[0029] In this embodiment, the contents of the ethylene oligomerization waste catalyst mixture and the composite inorganic salts are shown in the table below.

[0030] Table 1 Content of reaction raw materials

[0031]

[0032]

[0033] In this embodiment, the yields of components in the filter residue and filtrate are shown in the table below.

[0034] Table 2 Output

[0035] Filter residue components Filtrate components Flow rate, kg / h Titanium oxide production / 2.2 Aluminum hydroxide production / 2.6 Salt production / 30.0 Polymer yield / 68.3 / 1-Butene production 11.3 / 1-Hexene production 7.2 / <![CDATA[C 6+ Olefin and polymer yields 40.1

[0036] Example 2

[0037] A method for harmlessly inactivating ethylene oligomerization catalysts includes the following steps:

[0038] (1) The mixture of ethylene oligomerization waste catalyst and composite inorganic salt inactivator was injected into the reactor, and the temperature inside the reactor was controlled at 100.5℃ and the pressure at 9.0 atm. The composite inorganic salt inactivator included 29.7% calcium bicarbonate, 51.9% montmorillonite and 18.4% calcium carbonate by mass percentage.

[0039] (2) Stir the materials in the reactor and after mixing and reacting for 4 hours, a mixed liquid is obtained;

[0040] (3) Pass the mixture through a filter to separate the dark gray filter residue and the colorless transparent filtrate, thus completing the harmless conversion of the waste catalyst.

[0041] In this embodiment, the contents of the ethylene oligomerization waste catalyst mixture and the composite inorganic salts are shown in the table below.

[0042] Table 3 Content of Reaction Raw Materials

[0043]

[0044]

[0045] In this embodiment, the yields of components in the filter residue and filtrate are shown in the table below.

[0046] Table 4 Output

[0047] Filter residue components Filtrate components Flow rate, kg / h Titanium oxide production / 2.3 Aluminum hydroxide production / 2.7 Salt production / 23.2 Polymer yield / 68.7 / 1-Butene production 11.0 / 1-Hexene production 7.5 / <![CDATA[C 6+ Olefin and polymer yields 40.4

[0048] Example 3

[0049] A method for harmlessly inactivating ethylene oligomerization catalysts includes the following steps:

[0050] (1) The mixture of ethylene oligomerization waste catalyst and composite inorganic salt inactivator is injected into the reactor, and the temperature inside the reactor is controlled at 90.1℃ and the pressure at 9.0 atm. The composite inorganic salt inactivator includes 15.2% ammonium bicarbonate, 66.5% bentonite and 18.3% ammonium carbonate by mass percentage.

[0051] (2) Stir the materials in the reactor and after mixing and reacting for 4 hours, a mixed liquid is obtained;

[0052] (3) Pass the mixture through a filter to separate the dark gray filter residue and the colorless transparent filtrate, thus completing the harmless conversion of the waste catalyst.

[0053] In this embodiment, the contents of the ethylene oligomerization waste catalyst mixture and the composite inorganic salts are shown in the table below.

[0054] Table 5 Contents of Reaction Raw Materials

[0055]

[0056] In this embodiment, the yields of components in the filter residue and filtrate are shown in the table below.

[0057] Table 6 Output

[0058] Filter residue components Filtrate components Flow rate, kg / h Titanium oxide production / 2.1 Aluminum hydroxide production / 2.5 Salt production / 35.4 Polymer yield / 68.0 / 1-Butene production 11.5 / 1-Hexene production 7.1 / <![CDATA[C 6+ Olefin and polymer yields 39.9

[0059] Waste catalyst conversion rate

[0060] The elemental contents of titanium and aluminum in the filter residue were detected by X-ray fluorescence (XRF) analysis, and the conversion rates of Ti and Al compounds were calculated using the following formula:

[0061]

[0062] In the formula, wt%Al is the Al element content measured by XRF, wt%Ti is the Ti element content measured by XRF, m1 is the mass of filter residue, m2 is the amount of triethylaluminum fed, m3 is the amount of tetrabutyl titanate fed, 114 is the molecular weight of triethylaluminum, 27 is the relative atomic mass of aluminum, 340 is the molecular weight of tetrabutyl titanate, and 48 is the relative atomic mass of titanium.

[0063] The conversion rates of the corresponding spent catalysts in Examples 1-3 were calculated and tested according to the above method. The specific results are shown in the table below.

[0064] Table 7. Conversion rate of spent catalyst

[0065]

[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for harmlessly inactivating ethylene oligomerization catalysts, characterized in that, Includes the following steps, (1) Inject the mixture of ethylene oligomerization waste catalyst and composite inorganic salt inactivator into the reactor, and control the temperature and pressure inside the reactor; By mass percentage, the compound inorganic salt inactivating agent comprises 21.8% sodium bicarbonate, 55.4% kaolin, and 22.8% sodium carbonate; or 29.7% calcium bicarbonate, 51.9% montmorillonite, and 18.4% calcium carbonate; or 15.2% ammonium bicarbonate, 66.5% bentonite, and 18.3% ammonium carbonate. (2) Stir the materials in the reactor and after mixing and reaction, obtain a mixed liquid; In steps (1) to (2), the temperature inside the reactor is 90 to 112°C, the pressure is 8 to 9 atm, and the mixing reaction time is 4 to 8 hours. (3) Pass the mixture through a filter to separate the filter residue and filtrate, thus completing the harmless conversion of the waste catalyst.

2. The method for harmlessly inactivating ethylene oligomerization catalyst according to claim 1, characterized in that, In step (1), the percentage by mass is: The ethylene oligomerization waste catalyst mixture includes 5-10% titanium-based catalyst Ti(OR1)4 and aluminum-based co-catalyst Al(R2). n X 3-n 5-10%, ethylene polymerization products 80-90%; The ethylene polymerization products include 5-10% 1-butene, 5-10% 1-hexene, and 80-90% higher carbon olefins and polymers.

3. The method for harmlessly inactivating ethylene oligomerization catalyst according to claim 2, characterized in that, R1 is a C1-C8 alkyl or aryl group, selected from any one or a mixture of several of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, n-hexyl, 2-ethylhexyl, phenyl, 2-methylphenyl, 4-methylphenyl, and 2,6-dimethylphenyl.

4. The method for harmlessly inactivating ethylene oligomerization catalyst according to claim 2, characterized in that, R2 is a C1-C8 alkyl or aryl group, selected from any one or a mixture of several of methyl, ethyl, propyl, butyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, n-hexyl, 2-ethylhexyl, phenoxy, phenyl, 2-methylphenyl, 4-methylphenyl, and 2,6-dimethylphenyl; X is selected from bromine or chlorine atoms; n is an integer from 1 to 3.

5. The method for harmlessly inactivating ethylene oligomerization catalyst according to claim 1, characterized in that, In step (1), the flow ratio of the ethylene oligomerization waste catalyst mixture and the composite inorganic salt inactivator is 1:(0.2~1.1).

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