A purifying agent, a preparation method thereof, an olefin disproportionation raw material purifying method, and a propylene polymerization method

Abstract

The present application relates to the field of chemical raw material purification, and discloses a kind of purifying agent and its preparation method, olefin disproportionation raw material purification method and propylene polymerization method.The purifying agent contains Cu-Ce-x-y-O composite oxide, wherein the molar ratio of Cu element, Ce element, x element and y element is 1:A:B:C;X includes Ti element and / or La element;Y includes other metal elements of the same group as Ti and / or group IIB metal elements;A is 0.01-0.5;B is 0.01-0.25;C is 0-1.5.The purifying agent in the present application has good purification effect, for example, trace amounts of carbon monoxide and hydrogen contained in the olefin disproportionation raw material can be removed, which can improve the selectivity of the disproportionation reaction.The raw material after purification is used to prepare polypropylene by disproportionation, without subsequent deoxygenation and dehydration steps.

Description

Technical Field

[0001] This invention relates to the field of chemical raw material purification technology, specifically to a purification agent and its preparation method, a method for purifying olefin disproportionation raw materials, and a method for propylene polymerization. Background Technology

[0002] Olefin disproportionation is a process in which the C=C double bonds in olefins are broken and reformed under the action of a transition metal compound catalyst to obtain new olefin products.

[0003] By utilizing the cross-disproportionation effect of butene and ethylene, the relatively surplus and low-value-added C4 olefin feedstock can be converted into high-value-added propylene products by adding an appropriate amount of ethylene.

[0004] The olefin feedstock used in disproportionation reactions often comes from steam cracking or catalytic cracking units and contains small amounts of water, oxygen-containing compounds, and sulfur-containing compounds, among which the oxygen-containing compounds are mostly alcohols or ethers. These compounds can easily occupy the reactive sites of the disproportionation catalyst, thus causing catalyst poisoning. Therefore, the feedstock must be purified before it enters the bed to contact the disproportionation catalyst. Summary of the Invention

[0005] The purpose of this invention is to overcome the difficulties in removing hydrogen and carbon monoxide from olefin disproportionation feedstocks in olefin disproportionation industrial applications, and the need for secondary purification before polymer-grade propylene production, which involves large investments, long processes, and high operating pressures. This invention provides a feedstock purification method for olefin disproportionation industrial applications, specifically relating to an olefin disproportionation feedstock purifier and its preparation and purification methods.

[0006] As mentioned earlier, currently used purification processes only target the removal of oxygen- and sulfur-containing compounds from olefin feedstocks, which is sufficient for conventional disproportionation reactions. The applicant of this application has discovered that trace amounts of hydrogen in olefin feedstocks can affect the selectivity of olefin disproportionation reactions, reduce the yield of the target product, and cause additional material and energy consumption. Furthermore, if hydrogen, carbon monoxide, and oxygen in the feedstock are not treated, they may also affect the quality of the propylene product, making it unusable as a direct feedstock for polymerization-grade propylene and requiring secondary purification. Secondary purification necessitates the addition of an oxygen-containing compound removal unit, extending the reaction process, increasing investment, and hindering the efficient integration of production facilities.

[0007] To achieve the above objectives, the present invention provides a purifying agent containing a Cu-Ce-xyO composite oxide, wherein the molar ratio of Cu, Ce, x, and y elements is 1:A:B:C; x includes Ti and / or La; y includes other metal elements of the same group as Ti and / or Group IIB metal elements; A is 0.01-0.5; B is 0.01-0.25; and C is 0-1.5.

[0008] The second aspect of the present invention provides a method for preparing a purifying agent, the method comprising: mixing a precursor salt solution of Cu, a precursor salt solution of Ce, a precursor salt solution of x, and optionally a precursor salt solution of y, then adding an alkaline solution for co-precipitation, followed by filtration, washing, drying the filter cake, and calcination.

[0009] A third aspect of the present invention provides the use of the above-mentioned purifying agent in treating raw materials containing CO, hydrogen and optionally oxygen.

[0010] A fourth aspect of the present invention provides the application of the above-mentioned purifying agent in the purification and removal of impurity gases from raw materials containing impurity gases, wherein the impurity gases contain CO, hydrogen and optionally oxygen.

[0011] The fifth aspect of this invention provides a method for purifying olefin disproportionation feedstock, the method comprising:

[0012] (1) The above-mentioned purifying agent is reduced to obtain an activator;

[0013] (2) In the presence of the activator, the olefin disproportionation feedstock containing impurity gas is purified to remove the impurity gas, which contains CO, hydrogen and optionally oxygen.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects:

[0015] (1) The specific proportions of Cu, Ce, x and y elements in the purifier of the present invention work synergistically with each other, so that the purifier of the present invention can, on the one hand, use oxygen impurities in the raw materials to increase the removal efficiency and removal capacity of hydrogen and carbon monoxide; at the same time, consume some oxygen to reduce the removal pressure of subsequent deoxygenation; on the other hand, it can also directly remove hydrogen and carbon monoxide from raw materials without oxygen impurities.

[0016] (2) The Cu-Ce-Ti-xO composite oxide contained in this invention is used to purify the olefin disproportionation feedstock. By amount of substance, the carbon monoxide content in the purified feedstock is less than 0.05 ppm and the hydrogen content in the purified olefin disproportionation feedstock is less than 1 ppm.

[0017] (3) The purification agent of the present invention can directly remove impurities from olefin disproportionation feedstock in a single reaction tower;

[0018] (4) The purifier of the present invention can remove trace amounts of carbon monoxide and hydrogen contained in olefin disproportionation raw materials, which can improve the selectivity of disproportionation reaction. After the purified raw materials are disproportionated to obtain propylene-containing raw materials, they can be directly carried out in the adsorption reaction unit of polypropylene to remove oxygen-containing compounds. After removing oxides, they can be directly carried out in the next polymerization step without further deoxygenation, dehydration and other gas treatment steps. This shortens the process of existing disproportionation-polymerization combination process that requires at least two removal of oxygen-containing compounds, and has great industrial value. Attached Figure Description

[0019] Figure 1 The image shows the XRD pattern of the purifying agent in Example 4. Detailed Implementation

[0020] 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.

[0021] The first aspect of this invention provides a purifying agent containing a Cu-Ce-xyO composite oxide, wherein the molar ratio of Cu, Ce, x, and y elements is 1:A:B:C; x includes Ti and / or La; y includes other metal elements of the same group as Ti and / or Group IIB metal elements; A is 0.01-0.5; B is 0.01-0.25; and C is 0-1.5.

[0022] According to the present invention, as long as the purpose of the present invention can be achieved, x can be Ti element or La element alone, or any combination of Ti element and La element, for example, a combination of Ti element and La element in a molar ratio of 1.2, 1:1.25 or 1:1.3.

[0023] According to the present invention, the Cu-Ce-xyO composite oxide of metal oxides with specific proportions and components can effectively remove hydrogen and carbon monoxide impurities. It can remove trace amounts of carbon monoxide and hydrogen contained in raw materials in the presence or absence of oxygen. When used for purifying olefin disproportionation raw materials, it can improve the selectivity of the disproportionation reaction. In particular, in the presence of oxygen, the purifier of the present invention can also consume all or part of the oxygen, reduce the adsorption reaction units for the re-removal of oxygen-containing compounds, and simplify the process flow.

[0024] According to the present invention, in some embodiments, A is 0.01-0.4, for example 0.01, 0.02, 0.03, 0.046, 0.093, 0.1, 0.2 or 0.3, preferably 0.03-0.3, and more preferably 0.03-0.2. By employing the aforementioned embodiments, the activity of copper species can be better increased, thereby enhancing the performance of the purifying agent.

[0025] According to the present invention, in some embodiments, B is 0.01-0.2, for example 0.01, 0.015, 0.02, 0.03, 0.07, 0.098, 0.1, 0.12, 0.15 or 0.2, preferably 0.015-0.15; more preferably 0.015-0.12. By employing the aforementioned embodiments, the purifying agent can effectively remove carbon monoxide and hydrogen impurities from the raw materials under both aerobic and oxygen-free conditions.

[0026] According to the present invention, in some embodiments, C is 0-1.3, for example 0, 0.1, 0.24, 0.35, 0.4, 0.5, 0.6, 0.7, 1, 1.1 or 1.3, preferably 0.1-1.1, and more preferably 0.1-0.7. By employing the aforementioned method, the activity of copper species can be better increased. The Cu, Ce, x, and y species have a synergistic effect, enabling the purifying agent to effectively remove carbon monoxide and hydrogen impurities from the raw materials under both aerobic and anaerobic conditions.

[0027] According to the present invention, in some embodiments, y includes other metal elements of the Ti group, wherein the molar ratio of Cu to other metal elements of the Ti group is 1:(0.05-0.6), preferably 1:(0.06-0.5), for example 1:0.06, 1:0.09, 1:0.1, 1:0.33, 1:0.45, 1:0.4, or 1:0.5. Using the aforementioned embodiments, the purification effect of the purifying agent on carbon monoxide and hydrogen can be significantly improved.

[0028] According to the present invention, in some embodiments, y includes a Group IIB metal element, wherein the molar ratio of Cu to the Group IIB metal element is 1:(0.08-0.9), preferably 1:(0.1-0.8). Examples include 1:0.1, 1:0.14, 1:0.15, 1:0.25, 1:0.3, 1:0.4, 1:0.5, 1:0.65, 1:0.7, or 1:0.8. Using the aforementioned embodiments, the catalytic / oxidative capacity of the purifier can be significantly improved when metal species coexist in the composite oxide.

[0029] According to the present invention, the selection of other metal elements in the Ti group is not limited as long as the purpose of the present invention can be achieved. In some embodiments, the metal elements in the Ti group include one or more of Zr, Hf, and Rf; in some preferred embodiments, Zr is selected as the metal element in the Ti group. By adopting the foregoing embodiments, the dispersibility of other elemental components can be significantly improved, the agglomeration of oxides can be avoided, and highly active nanocatalytic particles can be formed.

[0030] According to the present invention, the selection of the Group IIB metal element is not limited as long as the objective of the present invention can be achieved. In some embodiments, the Group IIB metal element includes one or more of Zn, Cd, and Hg; in some preferred embodiments, Zn is selected as the Group IIB metal element. By employing the aforementioned embodiments, the transfer capacity of hydrogen and oxygen atoms on the surface of the purifier can be enhanced, the reactivity of the purifier can be improved, and the operating temperature of the purifier can be reduced.

[0031] To achieve the objectives of this invention, according to a preferred embodiment of the invention, one or more elements selected from the group of Ti and group IIB metals can be combined with Cu, Ce, Ti and / or La to achieve the objectives. Simultaneously, according to the invention, to increase the overall performance of the purifying agent and reduce its operating temperature, specific proportions of group of Ti metals, group IIB metals, Cu, Ce, Ti and / or La elements can be selected to synergistically interact.

[0032] The second aspect of the present invention provides a method for preparing a purifying agent, the method comprising: mixing a precursor salt solution of Cu, a precursor salt solution of Ce, a precursor salt solution of x, and optionally a precursor salt solution of y, then adding an alkaline solution for co-precipitation, followed by filtration, washing, drying the filter cake, and calcination.

[0033] According to the present invention, as long as the purpose of the present invention can be achieved, there are no restrictions on the selection of the precursor salt solution of Cu, the precursor salt solution of Ce, the precursor salt solution of x, and the precursor salt solution of y, and no further details are provided here.

[0034] According to the present invention, the choice of alkaline solution is not limited, and includes, but is not limited to, alkaline solutions of NaOH and / or Na2CO3.

[0035] According to the present invention, in order to increase efficiency, mixing can be carried out under ultrasonic, stirring or shearing conditions as needed.

[0036] According to the present invention, the drying conditions are not required as long as the purpose of the present invention can be achieved.

[0037] According to the present invention, in some embodiments, the drying temperature is 80-150°C, for example 80°C, 100°C, 130°C or 150°C.

[0038] According to the present invention, in some embodiments, the drying time is 6-24 hours, for example 6 hours, 8 hours, 10 hours, 15 hours, 20 hours or 24 hours.

[0039] According to the present invention, in some embodiments, the calcination temperature is 250-550°C, for example 250°C, 300°C, 350°C, 400°C, 450°C, 480°C or 550°C.

[0040] According to the present invention, in some embodiments, the calcination time is 2-12 hours, for example 2 hours, 3 hours, 5 hours, 8 hours, 10 hours or 12 hours.

[0041] According to the present invention, in some embodiments, the co-precipitation time is 0.5-6 hours.

[0042] A third aspect of the present invention provides the use of the above-mentioned purifying agent in treating raw materials containing CO, hydrogen and optionally oxygen.

[0043] According to the present invention, the purifying agent can be used in any raw material containing CO, hydrogen, and optionally oxygen, wherein "optionally oxygen" means that the raw material may or may not contain oxygen. Existing purifying agents typically purify raw materials under anaerobic conditions, primarily utilizing the properties of the catalyst itself. Compared to the prior art, the composite oxide formed by specific metal species in the present invention can purify raw materials not only under anaerobic conditions but also under aerobic conditions, consuming some or all of the oxygen during purification. The inventors speculate that the purifying agent of the present invention can not only purify raw materials using its own properties but also utilize oxygen to oxidize hydrogen and carbon monoxide, enhancing the removal effect of carbon monoxide and hydrogen, reducing the consumption of the purifying agent itself, extending the service life of the purifying agent, and broadening its application range.

[0044] A fourth aspect of the present invention provides the application of the above-mentioned purifying agent in the purification and removal of impurity gases from raw materials containing impurity gases, wherein the impurity gases contain CO, hydrogen and optionally oxygen.

[0045] According to the present invention, in some embodiments, the raw material contains, by molar amount, 0.01-200.0 ppm CO, 0.01-200.0 ppm hydrogen, and 0-200.0 ppm oxygen; in some preferred embodiments, the raw material contains 0.01-50.0 ppm CO (e.g., 0.01 ppm, 5.0 ppm, 30.0 ppm, or 50.0 ppm), 0.01-75.0 ppm hydrogen (e.g., 0.01 ppm, 5 ppm, 10.0 ppm, 20.0 ppm, 40.0 ppm, 60.0 ppm, or 75.0 ppm) and 0-120.0 ppm oxygen (e.g., 0 ppm, 20.0 ppm, 30.0 ppm, 80.0 ppm, 100.0 ppm, or 120.0 ppm).

[0046] According to the present invention, the purifying agent can be used to remove CO, hydrogen, and optionally oxygen impurities from chemical raw materials. When no oxygen is present, the purifying agent of the present invention positively promotes the removal of hydrogen and CO through the synergistic effect between metal species in a specific ratio. When oxygen is present, the purifying agent of the present invention not only positively promotes the removal of hydrogen and CO through the synergistic effect between metal species in a specific ratio, but also uses oxygen as an oxidant to increase the removal efficiency and removal capacity of hydrogen and carbon monoxide, while consuming part or all of the oxygen, thus reducing the removal pressure of the subsequent deoxygenation tower.

[0047] The fifth aspect of this invention provides a method for purifying olefin disproportionation feedstock, the method comprising:

[0048] (1) The above-mentioned purifying agent is reduced to obtain an activator;

[0049] (2) In the presence of the activator, the olefin disproportionation feedstock containing impurity gas is purified to remove the impurity gas, which contains CO, hydrogen and optionally oxygen.

[0050] According to the present invention, in some embodiments, the olefin disproportionation feedstock contains, by molar amount, 0.01-100 ppm CO, 0.01-200.0 ppm hydrogen, and 0-200.0 ppm oxygen; in some preferred embodiments, the olefin disproportionation feedstock contains 0.01-50.0 ppm CO (e.g., 0.01 ppm, 5.0 ppm, 30.0 ppm, or 50.0 ppm), 0.01-75.0 ppm hydrogen (e.g., 0.01 ppm, 5 ppm, 10.0 ppm, 20.0 ppm, 40.0 ppm, 60.0 ppm, or 75.0 ppm) and 0-120.0 ppm oxygen (e.g., 0 ppm, 20.0 ppm, 30.0 ppm, 80.0 ppm, 100.0 ppm, or 120.0 ppm).

[0051] According to the present invention, CO, hydrogen and optionally oxygen impurity gases in olefin disproportionation feedstock can be removed as needed. In some embodiments, the main components of the olefin disproportionation feedstock, by molar amount, include 60-99.5% C2-C4 olefins, 0-15% C1-C4 alkanes, and 0-30% inert gases.

[0052] According to the present invention, C2-C4 olefins, which may be exemplified, include, but are not limited to, ethylene, propylene, and butene.

[0053] According to the present invention, the C1-C4 alkanes that may be exemplified include, but are not limited to, methane, ethane, propane, n-butane and isobutane; and the inert gases that may be exemplified include nitrogen, argon and helium.

[0054] According to the present invention, CO and hydrogen impurities can be removed from olefin disproportionation feedstocks of any source, wherein in some embodiments, the olefin disproportionation feedstocks are derived from crude ethylene and / or crude butene.

[0055] According to some preferred embodiments of the present invention, the olefin disproportionation feedstock comprises, by molar amount, 50-60% ethylene, 30-40% butene, 5-8% methane, 0.01-50.0 ppm CO, 0.01-75.0 ppm hydrogen, 0-120.0 ppm oxygen, and the remainder being nitrogen.

[0056] According to the purification method of the present invention, there are no restrictions on the reduction conditions described in step (1) as long as the purpose of the present invention can be achieved.

[0057] According to the purification method of the present invention, in some embodiments, in step (1), the reduction conditions include: the reducing gas is hydrogen or a mixture of hydrogen and nitrogen. Hydrogen and nitrogen can be mixed in any proportion as the reducing gas. In this invention, a hydrogen-nitrogen mixture with a hydrogen volume content of 5% is used as the reducing gas as an example to illustrate the advantages of the present invention, but the present invention is not limited thereto.

[0058] According to the purification method of the present invention, in some embodiments, in step (1), the reduction conditions include: the volume hourly space velocity of the reducing gas is 100-1000 h⁻¹. -1 Preferably 200-800h -1 For example, 200h -1 300h -1 400h -1 550h -1 700h -1 or 800h -1 .

[0059] According to the purification method of the present invention, in some embodiments, the reduction conditions in step (1) include: a temperature of 60-200°C, preferably 80-180°C, such as 80°C, 100°C, 120°C, 140°C, 160°C or 180°C.

[0060] According to the purification method of the present invention, the purification conditions are not limited as long as the purpose of the present invention can be achieved. In some embodiments, the purification conditions in step (2) include: the gas hourly space velocity of the olefin disproportionation feedstock is 1000-20000 h⁻¹. -1 For example, 1000h -1 3000h -1 5000h -1 7000h -1 8000h -1 12000h -1 15000h -1 18000h -1 or 20000h -1 .

[0061] According to the purification method of the present invention, in some embodiments, the purification conditions in step (2) include: a temperature of 20-150°C, preferably 40-120°C, such as 40°C, 60°C, 80°C, 100°C or 120°C.

[0062] According to the purification method of the present invention, in some embodiments, the purification conditions in step (2) include: a pressure of 0.1-6 MPa, for example 0.1 MPa, 1.5 MPa, 2.5 MPa, 3.0 MPa, 3.5 MPa, 4.5 MPa, 5.0 MPa or 6.5 MPa.

[0063] In this invention, the purification agent described in this invention, in conjunction with the purification method of this invention, can more effectively remove CO, hydrogen, and optionally oxygen impurities from olefin disproportionation feedstock.

[0064] A sixth aspect of the present invention provides a method for propylene polymerization, the method comprising,

[0065] (S1) The purified olefin disproportionation feedstock is obtained by purifying according to the method described above;

[0066] (S2) Dehydrate and remove carbon dioxide from the purified olefin disproportionation feedstock;

[0067] (S3) Disproportionate the olefin disproportionated feedstock after dehydration and carbon dioxide treatment to obtain a propylene-containing feedstock;

[0068] (S4) Separate the propylene-containing raw material to obtain polymer-grade propylene;

[0069] (S5) The polymer-grade propylene is polymerized to obtain polypropylene;

[0070] According to the present invention, when there is too much oxygen impurity in the olefin disproportionation feedstock, in some preferred embodiments, after step (S2) and before step (S3), oxides in the purified feedstock are removed as needed.

[0071] According to the present invention, more preferably, after step (S4) is completed, there is no need to remove carbon monoxide and oxygen-containing compounds, and step (S5) is carried out directly. That is, the present invention does not require further gas treatment before polymerization, and does not require gas treatment steps such as deoxygenation and dehydration.

[0072] According to the present invention, after removing CO, hydrogen, and some or all oxygen impurities from olefin disproportionation feedstock in a one-step process, the propylene-containing feedstock after removing oxygen-containing compounds can be directly used to prepare polypropylene, depending on the oxygen content of the purified feedstock. If the feedstock is oxygen-free, the propylene-containing feedstock after removing oxygen and oxygen-containing compounds can be used to prepare polypropylene. In contrast, existing processes require first removing oxides from the olefin disproportionation feedstock before disproportionation to obtain the propylene-containing feedstock, then performing at least two steps to remove hydrogen, carbon monoxide, and oxygen from the propylene-containing feedstock, and finally requiring a second removal of oxides from the propylene feedstock after removing hydrogen and CO. Compared to existing processes, the purifying agent in this invention not only removes CO and hydrogen from the olefin disproportionation feedstock in one step but also reduces the removal pressure of the subsequent deoxygenation tower.

[0073] The present invention will be described in detail below through embodiments.

[0074] Example 1

[0075] Preparation of the purifying agent: A mixed salt solution containing 30.37 g Cu(NO3)2·3H2O, 2.52 g Ce(NO3)3·6H2O, 2.37 g TiCl4 and 500 g H2O was added under ultrasonic conditions; 550 mL of alkaline solution containing 13.64 g NaOH was added for co-precipitation for 2 h, followed by filtration, washing, drying the filter cake at 130 °C for 10 h, and calcining at 350 °C for 4 h to obtain the purifying agent;

[0076] Purification of olefin disproportionation feedstock (containing 60% ethylene, 30% butene, 8% methane, 75.0 ppm hydrogen, 30.0 ppm CO, 35.0 ppm oxygen, and the remainder nitrogen by molar weight):

[0077] (1) The prepared purifying agent is reduced to obtain an activator;

[0078] (2) In the presence of an activator, the olefin disproportionation feedstock containing impurity gases is purified to remove impurity gases;

[0079] The reduction conditions include: the reducing gas is a 5% (v / v) hydrogen / nitrogen mixture; and the volume hourly space velocity (VHSV) of the reducing gas is 200 h⁻¹. -1 The temperature is 140℃.

[0080] The purification conditions include: a gas hourly space velocity (GHSV) of 8000 h⁻¹ for the olefin disproportionation feedstock. -1 Temperature: 100℃; Pressure: 3.0MPa.

[0081] The amounts of CO, oxygen, and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0082] Example 2

[0083] The method according to Example 1 differs in that:

[0084] Preparation of the purifying agent: A mixed salt solution containing 30.37 g Cu(NO3)2·3H2O, 2.52 g Ce(NO3)3·6H2O, 2.37 g TiCl4, 5.48 g Zn(NO3)2·6H2O, 5.23 g Zr(NO3)4·5H2O and 500 g H2O was added under ultrasonic conditions; 550 mL of alkaline solution containing 17.23 g NaOH was added for co-precipitation for 2 h, followed by filtration, washing, drying the filter cake at 130 °C for 10 h, and calcining at 350 °C for 4 h to obtain the purifying agent;

[0085] Purification method for olefin disproportionation feedstock (containing 60% ethylene, 30% butene, 8% methane, 75.0 ppm hydrogen, 30.0 ppm CO, 35.0 ppm oxygen, and the remainder nitrogen by molar amount).

[0086] The amounts of CO, oxygen, and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0087] Example 3

[0088] The method according to Example 1 differs in that:

[0089] Preparation of the purifying agent: A mixed salt solution containing 30.37 g Cu(NO3)2·3H2O, 5.05 g Ce(NO3)3·6H2O, 0.95 g TiCl4, 5.48 g Zn(NO3)2·6H2O, 5.23 g Zr(NO3)4·5H2O and 500 g H2O was added under ultrasonic conditions; 550 mL of alkaline solution containing 16.95 g NaOH was added for co-precipitation for 3 h, followed by filtration, washing, drying the filter cake at 130 °C for 10 h, and calcining at 350 °C for 4 h to obtain the purifying agent;

[0090] Olefin disproportionation feedstock (by molar amount, it contains 60% ethylene, 30% butene, 8% methane, 75.0 ppm hydrogen, 30.0 ppm CO, 120 ppm oxygen, and the remainder is nitrogen).

[0091] The amounts of CO, oxygen, and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0092] Example 4

[0093] The method of Example 1 differs in that:

[0094] Preparation of the purifying agent: A mixed salt solution containing 30.37 g Cu(NO3)2·3H2O, 2.52 g Ce(NO3)3·6H2O, 2.66 g La(NO3)3·6H2O, 5.48 g Zn(NO3)2·6H2O, 5.23 g Zr(NO3)4·5H2O and 500 g H2O was added under ultrasonic conditions; 550 mL of an alkaline solution containing 15.90 g NaOH was added for co-precipitation for 4 h, followed by filtration, washing, drying the filter cake at 130 °C for 10 h, and calcining at 350 °C for 4 h to obtain the purifying agent;

[0095] The XRD pattern of the purifier is shown below. Figure 1 As shown.

[0096] Olefin disproportionation feedstock (by molar amount, it contains 60% ethylene, 30% butene, 8% methane, 75 ppm hydrogen, 30 ppm CO, 120 ppm oxygen, and the remainder is nitrogen).

[0097] The amounts of CO, oxygen, and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0098] Example 5

[0099] Preparation of the purifying agent: A mixed salt solution containing 30.37 g Cu(NO3)2·3H2O, 1.16 g Ce(NO3)3·6H2O, 0.26 g TiCl4, 0.29 g La(NO3)3·6H2O, 10.96 g Zn(NO3)2·6H2O, 3.48 g Zr(NO3)4·5H2O and 500 g H2O was added under ultrasonic conditions; 550 mL of an alkaline solution containing 15.78 g NaOH was added, and the mixture was co-precipitated for 5 h. After filtration, washing, and drying of the filter cake at 150 °C for 6 h, the purifying agent was obtained by calcination at 300 °C for 2 h.

[0100] A purification method for olefin disproportionation feedstock (containing, by molar amount, 50% ethylene, 40% butene, 8% methane, 10.0 ppm hydrogen, 5.0 ppm CO, 5.0 ppm oxygen, with the remainder being nitrogen), the method comprising:

[0101] (1) The prepared purifying agent is reduced to obtain an activator;

[0102] (2) In the presence of an activator, the olefin disproportionation feedstock containing impurity gases is purified to remove impurity gases;

[0103] The reduction conditions include: the reducing gas is a 5% (v / v) hydrogen mixture; the volume hourly space velocity (VHSV) of the reducing gas is 100 h⁻¹. -1 The temperature is 80℃.

[0104] The purification conditions include: a gas hourly space velocity (GHSV) of 20,000 h⁻¹ for the olefin disproportionation feedstock. -1 The temperature is 120℃ and the pressure is 1MPa.

[0105] The amounts of CO, oxygen, and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0106] Example 6

[0107] The method according to Example 2 differs in that:

[0108] Olefin disproportionation feedstock (by molar amount, containing 50% ethylene, 40% butene, 8% methane, 80.0 ppm hydrogen, 180.0 ppm CO, 180.0 ppm oxygen, with the remainder being nitrogen);

[0109] The purification conditions include: a gas hourly space velocity (GHSV) of 1000 h⁻¹ for the olefin disproportionation feedstock. -1 The temperature is 40℃ and the pressure is 6.0MPa.

[0110] The amounts of CO, oxygen, and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0111] Example 7

[0112] The method according to Example 2 differs in that:

[0113] Olefin disproportionation feedstock (by molar amount, containing 60% ethylene, 30% butene, 8% methane, 75.0 ppm hydrogen, 30.0 ppm CO, and the remainder nitrogen).

[0114] The amounts of CO and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0115] Example 8

[0116] This embodiment provides a method for disproportionation-propylene polymerization, the method comprising:

[0117] S1 uses the olefin disproportionation feedstock purified in Example 7;

[0118] S2 dehydrates and removes carbon dioxide from the purified raw materials;

[0119] The olefin disproportionation feedstock after S3 dehydration and carbon dioxide disproportionation is disproportionated to obtain a propylene-containing feedstock.

[0120] S4 separates propylene-containing raw materials to obtain polymer-grade propylene, which contains no more than 1 ppm of hydrogen, no more than 0.05 ppm of CO, and no more than 1 ppm of oxygen.

[0121] S5 takes the separated polymer-grade propylene and uses a conventional gas-phase process, employing a conventional main catalyst, support, activator, third component, and other components as catalysts, to directly polymerize polypropylene.

[0122] Comparative Example 1

[0123] The method of Example 1 differs in that:

[0124] Preparation of the purifying agent: A mixed salt solution containing 30.37 g Cu(NO3)2·3H2O, 5.05 g Ce(NO3)3·6H2O and 500 g H2O was added under ultrasonic conditions; 550 mL of an alkaline solution containing 12.51 g NaOH was added and the mixture was co-precipitated for 2 h. After filtration and washing, the filter cake was dried at 130 °C for 10 h and then calcined at 350 °C for 4 h to obtain the purifying agent.

[0125] The amounts of CO, oxygen, and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0126] Comparative Example 2

[0127] The method of Example 1 differs in that:

[0128] Preparation of the purifying agent: A mixed salt solution of 30.37 g Cu(NO3)2·3H2O, 4.75 g TiCl4 and 500 g H2O was added under ultrasonic conditions; 550 mL of alkaline solution containing 14.77 g NaOH was added and co-precipitated for 2 h. After filtration, washing, drying the filter cake at 130 °C for 10 h, and calcining at 350 °C for 4 h, the purifying agent was obtained.

[0129] The amounts of CO, oxygen, and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0130] Comparative Example 3

[0131] The method according to Example 7 differs in that:

[0132] Preparation of the purifying agent: Under ultrasonic conditions, 30.37 g of Cu(NO3)2·3H2O and 500 g of H2O salt solution were added, and 550 mL of alkaline solution containing 10.56 g of NaOH was added. After co-precipitation for 2 h, the solution was filtered, washed, and the filter cake was dried at 130 °C for 10 h and then calcined at 350 °C for 4 h to obtain the purifying agent.

[0133] The amounts of CO and hydrogen in the olefin disproportionation feedstock before and after purification are shown in Table 1.

[0134] Comparative Example 4

[0135] This comparative example provides an existing method for disproportionation-propylene polymerization, which includes:

[0136] (S1) Purify the olefin disproportionation feedstock according to the method in Comparative Example 3.

[0137] (S2) Dehydrate and remove carbon dioxide from the purified raw materials;

[0138] (S3) The raw material after dehydration and carbon dioxide treatment is disproportionated to obtain a propylene-containing raw material;

[0139] (S4) Separate the propylene-containing raw material to obtain propylene raw material, wherein the propylene raw material contains more than 5.0 ppm of hydrogen and 1.0 ppm of CO, and cannot be directly fed into the polypropylene unit for polymerization.

[0140] (S5) The propylene feedstock is purified according to the method of Example 7;

[0141] (S6) The purified propylene raw material from step (S5) is dehydrated and carbon dioxide is removed to obtain polymer grade propylene;

[0142] (S7) Polypropylene is obtained by directly polymerizing the polymer-grade propylene using a gas-phase process with a main catalyst, a support, an activator, and a third component as catalysts.

[0143] Table 1. Impurity content in olefin disproportionation feedstock before and after purification

[0144]

[0145] As can be seen from the results in Table 1, the purifiers of Examples 1-7 of the present invention, which use Cu-Ce-xyO composite oxide, where x includes Ti and / or La elements and y includes metal elements of the same group as Ti and / or metal elements of Group IIB, can effectively remove CO and hydrogen from the raw materials in the presence or absence of oxygen.

[0146] As demonstrated in Example 8 and Comparative Example 4, the purifying agent of the present invention can efficiently remove carbon monoxide and hydrogen, avoiding the need for multiple raw material purification processes and thus reducing the associated removal of oxygen-containing compounds (water and carbon dioxide). Example 8, using the carbon monoxide and hydrogen purifying agent of the present invention, completed the raw material purification with only one purification-oxygen-containing compound removal process, which, combined with olefin disproportionation-separation, met the production requirements for polymer-grade propylene. In contrast, Comparative Example 4, using a conventional carbon monoxide and hydrogen purifying agent, required two purification-oxygen-containing compound removal processes to complete the raw material purification, necessitating two sets of purification equipment and significantly increasing energy and material consumption.

[0147] 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 purifying olefin disproportionation feedstock, characterized in that, The method includes: (1) The purifying agent is reduced to obtain the activator; (2) In the presence of the activator, the olefin disproportionation feedstock containing impurity gas is purified to remove the impurity gas, wherein the impurity gas contains CO, hydrogen and optionally oxygen; This purifying agent contains Cu-Ce-xyO composite oxide, wherein, The molar ratio of Cu, Ce, x, and y elements is 1:A:B:C; x includes Ti elements and / or La elements; y is a Group IIB metallic element; A is 0.01-0.5; B is 0.01-0.25; C is 0.1-1.

3.

2. The purification method according to claim 1, wherein, A is 0.01-0.4; and / or B is 0.01-0.

2.

3. The purification method according to claim 2, wherein, A is 0.03-0.3; and / or B is 0.015-0.15; and / or C is 0.1-1.

1.

4. The purification method according to claim 3, wherein, A is 0.03-0.2; and / or B is 0.015-0.12; and / or C is 0.1-0.

7.

5. The purification method according to claim 1 or 2, wherein, y is a Group IIB metallic element, and the molar ratio of Cu to the Group IIB metallic element is 1:(0.08-0.9); and / or The Group IIB metal elements include one or more of Zn, Cd, and Hg.

6. The purification method according to claim 5, wherein, y is a Group IIB metallic element, and the molar ratio of Cu to the Group IIB metallic element is 1:(0.1-0.8); and / or The Group IIB metal element is Zn.

7. The purification method according to claim 1 or 2, wherein, The preparation method of this purifying agent includes: The precursor salt solutions of Cu, Ce, x, and y elements were mixed, and then an alkaline solution was added for co-precipitation. After filtration, washing, drying, and calcination of the filter cake, the mixture was then subjected to further processing.

8. The purification method according to claim 7, wherein, The drying temperature is 80-150℃; and / or The drying time is 6-24 hours; and / or The roasting temperature is 250-550℃; and / or The roasting time is 2-12 hours; and / or The co-precipitation time is 0.5-6 hours.

9. The purification method according to claim 1, wherein, The olefin disproportionation feedstock contains 0.01-200.0 ppm CO, 0.01-200.0 ppm hydrogen and 0-200.0 ppm oxygen by molar amount.

10. The purification method according to claim 1, wherein, The olefin disproportionation feedstock contains, by molar amount, 0.01-50.0 ppm CO, 0.01-75.0 ppm hydrogen and 0-120.0 ppm oxygen.

11. The purification method according to claim 1, wherein, By molar amount, the main components of the olefin disproportionation feedstock include 60-99.5% C2-C4 olefins, 0-15% C1-C4 alkanes, and 0-30% inert gases; and / or The olefin disproportionation feedstock is derived from crude ethylene and / or crude butene.

12. The purification method according to claim 1, wherein, In terms of molar amount, the olefin disproportionation feedstock comprises 50-60% ethylene, 30-40% butene, 5-8% methane, 0.01-50.0 ppm CO, 0.01-75.0 ppm hydrogen, 0-120.0 ppm oxygen, and the remainder being nitrogen.

13. The purification method according to claim 1, wherein, In step (1), the restoration conditions include: The reducing gas is hydrogen or a mixture of hydrogen and nitrogen; and / or The volume hourly space velocity of the reducing gas is 100-1000 h⁻¹ -1 ; and / or Temperatures of 60-200℃; and / or In step (2), the purification conditions include: The gas hourly space velocity (GHSV) of the olefin disproportionation feedstock is 1000-20000 h⁻¹. -1 ; and / or Temperatures range from 20 to 150°C; and / or The pressure ranges from 0.1 to 6.0 MPa.

14. The purification method according to claim 13, wherein, In step (1), the restoration conditions include: The volume hourly space velocity (VHSV) of the reducing gas is 200-800 h⁻¹ -1 ; and / or Temperature is 80-180℃; and / or In step (2), the purification conditions include: The temperature is 40-120℃.

15. A method for disproportionation-propylene polymerization, characterized in that, The method includes, (S1) The purified olefin disproportionation feedstock is obtained by purification according to the method described in claims 1-14; (S2) Dehydrate and remove carbon dioxide from the purified olefin disproportionation feedstock; (S3) Disproportionate the olefin disproportionation feedstock after dehydration and carbon dioxide treatment to obtain a propylene-containing feedstock; (S4) Separate the propylene-containing raw material to obtain polymer-grade propylene; (S5) Polymerize the polymer grade propylene directly to obtain polypropylene.

16. The method according to claim 15, wherein, The method includes: Before step (S3), remove oxygen-containing compounds from the purified raw materials as needed; and / or After step (S4) is completed, proceed directly to step (S5).

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