CN110961112A

CN110961112A - Catalyst for acetylene hydrochlorination reaction and preparation method and application thereof

Info

Publication number: CN110961112A
Application number: CN201811140845.5A
Authority: CN
Inventors: 李斗星; 齐兰芝; 穆晓蕾; 贾春革
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-04-07

Abstract

The invention discloses a catalyst for acetylene hydrochlorination, which comprises a carrier, an active component and an auxiliary agent, wherein the carrier comprises aluminum oxide, the active component comprises copper, and the auxiliary agent comprises at least one of bismuth, barium, manganese, iron and magnesium. The weight content of the active component is 5-60 wt%, preferably 10-45 wt%, based on the weight of the carrier. The invention also discloses a preparation method of the catalyst. The catalyst of the invention takes copper as a main active component, and can achieve certain activity and good stability when being applied to acetylene hydrochlorination. Especially in the case of higher metal loadings, the activity and stability can be improved.

Description

Catalyst for acetylene hydrochlorination reaction and preparation method and application thereof

Technical Field

The invention relates to a catalyst for acetylene hydrochlorination and a preparation method thereof, in particular to a mercury-free non-noble metal catalyst for acetylene hydrochlorination and a preparation method thereof, and application of the catalyst in acetylene hydrochlorination.

Background

Polyvinyl chloride is one of the most expensive synthetic resins in our country, and vinyl chloride is a monomer required for the synthesis of polyvinyl chloride. The basic national situation of more coal and less oil in China determines that the vinyl chloride produced by the acetylene hydrochlorination method still occupies the leading position in China. At present, the main problem in the synthesis of vinyl chloride by hydrochlorinating acetylene is environmental pollution caused by the use of mercury catalysts. With the effectiveness of water guarantee and the increasingly strict environmental requirements of each layer of the country, the use of mercury catalysts is strictly limited, and the development of mercury-free catalysts and processes thereof is imperative.

In general, acetylene hydrochlorination is realized by completing a gas-solid reaction between acetylene gas and hydrogen chloride gas at 50-300 ℃ through a catalyst bed. At present, mercury-free catalysts for acetylene hydrochlorination can be divided into three different research directions of base metals, precious metals and non-metals.

The base metals are widely concerned by researchers due to low price, wherein the catalytic systems of CN101497046, CN101671293 and CN102151581A respectively taking the base metals such as Cu, Bi, MoP and the like as main active components have certain effects, but the base metal catalysts can not meet the industrial application in general.

Research on noble metal catalysts has also progressed to some extent. In patent CN200810044560.1, 0.24-1.43% of palladium, platinum, gold and rhodium chloride is used as a main active component, one or more of cuprous chloride, cerium chloride and bismuth chloride is added as a cocatalyst, and the space velocity is 250-500 h^-1Under the reaction condition that the reaction temperature is 110-160 ℃, the acetylene conversion rate is 95-98%, and the vinyl chloride selectivity is more than 99%. The patent CN200910196849.X mainly adopts 0.1-10% of gold halide and complex as main materialsAdding 0.1-10% of halides, acetates, phosphates and complexes of potassium, barium, lanthanum and copper as auxiliary agents into the spark component at an airspeed of 50-200 h^-1Under the condition that the reaction temperature is 120-180 ℃, the conversion rate of acetylene is 90-99%, and the selectivity of chloroethylene is 97-99.9%.

Non-metal catalysts have also attracted the interest of some researchers, for example, Li of China's science and technology university, which uses glucose as raw material and prepares nitrogen-doped carbon catalyst through hydrothermal polymerization and high-temperature ammoniation, the catalyst has rich microporous structure and high nitrogen doping amount (10 wt%). The catalyst shows good catalytic acetylene hydrochlorination reaction capability, under given reaction conditions, the acetylene conversion rate can reach 80-90%, the vinyl chloride selectivity is over 95%, but the activity of the catalyst is reduced due to carbon deposition after the catalyst reacts for a period of time.

The series of catalysts prepared by coprecipitation method and using Feitknecht Compound (FC) structure as precursor are receiving wide attention. FC is a class of synthetic or natural layered compounds, sometimes referred to as Hydrotalcite-like compounds, which are aqueous basic double salts having a double-layered structure composed of divalent and trivalent metal ions and OH^-，CO₃ ^2-And (3) an anion layer with the same composition, wherein two layers are periodically arranged and stacked into an FC structure. From the FC structure, the mixed oxide obtained after calcination has good physicochemical properties including large specific surface area, uniform oxide mixing, small crystal grains and high thermal stability. The inventor obtains good effect by preparing the precursor of FC structure and obtaining the non-noble metal catalyst with higher loading capacity, and applying the catalyst to acetylene hydrochlorination.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a catalyst for acetylene hydrochlorination and a preparation method thereof, in particular to a mercury-free non-noble metal catalyst for acetylene hydrochlorination and a preparation method thereof. Especially in the case of higher metal loadings, the activity and stability can be improved. In addition, the inventor finds that the metal catalyst with high loading capacity has the characteristics of uniform dispersion of active components and small metal crystal grains by preparing the precursor containing the copper FC structure, and the catalyst is used for acetylene hydrochlorination and has good activity and stability.

According to one aspect of the present invention, there is provided a catalyst for hydrochlorination of acetylene, comprising a carrier, an active component and an auxiliary agent, wherein the carrier comprises alumina, the active component comprises copper, and the auxiliary agent comprises at least one of bismuth, barium, manganese, calcium, iron and magnesium.

According to some embodiments of the present invention, the active component is present in an amount of 5 to 60 wt%, preferably 10 to 45 wt%, and more preferably 20 to 42 wt%, calculated as the metal element, based on the weight of the support.

According to some embodiments of the invention, the weight content of the adjuvant, calculated as metallic element, is from 1 to 30% by weight, preferably from 5 to 20% by weight, based on the weight of the support.

According to the catalyst for olefin oxychlorination, the main active component and the auxiliary active component are both in the form of metal oxides.

According to another aspect of the present invention, there is provided a method for preparing the above catalyst, comprising the steps of:

(1) preparing a mixed solution containing an active component, an auxiliary agent and a metal salt of aluminum;

(2) adding a precipitant solution into the mixed solution to carry out coprecipitation reaction to obtain a coprecipitate;

(3) and filtering, washing, drying and calcining the coprecipitate to obtain the catalyst.

According to a preferred embodiment of the present invention, the active ingredient, the auxiliary agent and the metal salt of aluminum comprise at least one of nitrate, hydrochloride and phosphate of the active ingredient, the auxiliary agent and aluminum.

According to a preferred embodiment of the present invention, the ratio of the amount of the divalent metal ion to the trivalent metal ion in the mixed solution of step (1) is 1 to 9, preferably 2 to 8, and more preferably 2.5 to 5.5.

According to a specific embodiment of the present invention, the divalent metal ion in the mixed solution of metal salts includes Cu²⁺And optionally Bi²⁺、Ba²⁺、Mn²⁺、Ga²⁺、Mg²⁺(ii) a The trivalent metal ion includes Al³⁺And optionally Fe³⁺。

According to some embodiments of the invention, the method of the co-precipitation reaction is a method well known to those skilled in the art. In the specific embodiment of the invention, the reaction temperature of the coprecipitation reaction is within 10-70 ℃, and the pH value of the reaction end point is 7-10.

According to some embodiments of the invention, the precipitating agent comprises at least one of urea, aqueous ammonia, ammonium carbonate, ammonium bicarbonate, sodium hydroxide, potassium hydroxide, sodium carbonate, and potash.

According to a preferred embodiment of the present invention, the method of filtering and washing is a method well known to those skilled in the art.

According to a preferred embodiment of the present invention, the drying method is a method well known to those skilled in the art, and for example, a general drying method or a vacuum drying method may be used. In the invention, a vacuum drying method is preferably used, and the drying temperature is 80-130 ℃.

According to some embodiments of the invention, the method of calcining is a method well known to those skilled in the art. In some embodiments, the calcination temperature is 300 to 700 ℃, preferably 400 to 550 ℃.

The method can be used for preparing the catalysts with different copper contents, the grain size of copper species in the prepared catalyst is 2-30 nm, the dispersibility is good, and the catalyst shows good activity stability and selectivity in the hydrochlorination reaction of acetylene.

According to another aspect of the present invention there is provided the use of a catalyst as described above in the hydrochlorination of acetylene.

Detailed Description

The present invention will be described in further detail with reference to specific examples below:

the reaction conditions of the catalyst in acetylene hydrochlorination are as follows: the reaction temperature is 180 ℃, the reaction pressure is normal pressure, and the volume space velocity of acetylene is 80h^-1The catalyst loading was 1.0g, and the volume flow ratio of acetylene to hydrogen chloride gas was 1: 1.1.

Example 1:

preparing Cu (NO) according to the molar ratio of Cu to Bi to Al of 1 to 1 at room temperature₃)₂，Bi(NO₃)₂，Al(NO₃)₃The total concentration of metal cations in the mixed solution is 0.6mol/L, and then 1mol/L of Na is added under the condition of strong stirring₂CO₃Until the pH of the mixture was 9. And filtering the mixture, repeatedly washing, drying at 110 ℃ for 10 hours, and calcining at 500 ℃ for 5 hours to obtain a finished catalyst. The loading of Cu in the catalyst was 41 wt%. The results of the reaction are tabulated in table 1.

Example 2

Preparing Cu (NO) according to the molar ratio of Cu to Bi to Ba to Al of 1 to 0.5 to 1 at room temperature₃)₂，Bi(NO₃)₂，Ba(NO₃)₂，Al(NO₃)₃The total concentration of metal cations in the mixed solution is 0.6mol/L, and then 1mol/L of Na is added under the condition of strong stirring₂CO₃Until the pH of the mixture was 9. And filtering the mixture, repeatedly washing, drying at 110 ℃ for 10 hours, and calcining at 500 ℃ for 5 hours to obtain a finished catalyst. The loading of Cu in the catalyst was 29 wt%. The results of the reaction are tabulated in table 1.

Example 3:

the procedure and method were the same as in example 2, except that the ratio of metal ions was changed to 0.6:1:0.4:1 (molar ratio) of Cu to Bi to Mn to Al. The loading of Cu in the catalyst was 25 wt%. The results of the reaction are tabulated in table 1.

Example 4:

the procedure and method were the same as in example 2, using Cu (NO)₃)₂，Bi(NO₃)₂，Ca(NO₃)₂，Al(NO₃)₃The metal ion ratio of the mixed solution of (1) was changed to 0.5:0.5:1:1 (molar ratio) of Cu: Bi: Ca: Al. The loading of Cu in the catalyst was 20 wt%. The results of the reaction are tabulated in table 1.

Example 5:

the procedure and method were the same as in example 2, except that the ratio of metal ions was changed to 0.5:1:1:1 (molar ratio) of Cu to Bi to Mg to Al. The loading of Cu in the catalyst was 20 wt%. The results of the reaction are tabulated in table 1.

Example 6:

the procedure and method were the same as in example 2, except that the ratio of metal ions was changed to 1.5:1:0.5:1 (molar ratio) of Cu to Bi to Fe to Al. The loading of Cu in the catalyst was 46 wt%. The results of the reaction are tabulated in table 1.

Example 7:

the operation steps and the method are the same as the example 2, the precipitator selects the mixed solution of sodium hydroxide and potassium hydroxide, the concentration is 1mol/L, and the finished product of the catalyst is obtained. The loading of Cu in the catalyst was 29 wt%. The results of the reaction are tabulated in table 1.

Example 8

The procedure and method were the same as in example 2, except that the ratio of metal ions was changed to 1: Bi: Ba: Al: 1:1.5:0.5:1 (molar ratio). The loading of Cu in the catalyst was 26 wt%. The results of the reaction are tabulated in table 1.

Example 9

The procedure and method were the same as in example 2, except that the ratio of metal ions was changed to 2: Bi: Ba: Al: 2:1.5:0.5:1 (molar ratio). The Cu loading in the catalyst was 39 wt%. The results of the reaction are tabulated in table 1.

Example 10

The procedure and method were the same as in example 2, except that the ratio of metal ions was changed to 2:2:1.5:1 (molar ratio) of Cu: Bi: Ba: Al. The loading of Cu in the catalyst was 38 wt%. The results of the reaction are tabulated in table 1.

Example 11

The procedure and method were the same as in example 2, except that the ratio of metal ions was changed to 3:2:3:1 (molar ratio) of Cu: Bi: Ba: Al. The loading of Cu in the catalyst was 24 wt%. The results of the reaction are tabulated in table 1.

Example 12

Cu (NO) is prepared at room temperature according to the molar ratio of Cu to Bi to Ba to Mn to Al of 1 to 0.5 to 1₃)₂，Bi(NO₃)₂，Ba(NO₃)₂，Mn(NO₃)₂，Al(NO₃)₃The total concentration of metal cations in the mixed solution is 0.6mol/L, and then 1mol/L of Na is added under the condition of strong stirring₂CO₃Until the pH of the mixture was 9. And filtering the mixture, repeatedly washing, drying at 110 ℃ for 10 hours, and calcining at 500 ℃ for 5 hours to obtain a finished catalyst. The loading of Cu in the catalyst was 25 wt%. The results of the reaction are tabulated in table 1.

Comparative example 1:

a commercially available alumina carrier was purchased and an isometric impregnation method was used to prepare the Cu-based catalyst. 130ml of Bi (NO) of 6mol/L are used first₃)₂The catalyst obtained by impregnating 80g of alumina was dried at 110 ℃ for 10 hours, calcined at 500 ℃ for 5 hours, and then used at 6mol/LBa (NO)₃)₂The obtained catalyst was dried at 110 ℃ for 10 hours and calcined at 500 ℃ for 5 hours after impregnation of a total of 130ml of the solution. Finally, 6mol/L Cu (NO) is used twice₃)₂An equal volume of impregnation was carried out each time 130ml to finally obtain a Cu loading 29 wt% acetylene hydrochlorination catalyst. The results of the reaction are tabulated in table 1.

Comparative example 2:

the procedure and method were the same as in example 1, except that the ratio of metal ions was changed to 1: Bi: Ba: Al: 0.5:0.5:10 (molar ratio). The Cu loading in the catalyst was 9.4 wt%. X-ray diffraction detection shows that no FC structural precursor is formed in the catalyst preparation process. The results of the reaction are tabulated in table 1.

Comparative example 3:

the procedure and method were the same as in example 1, except that the ratio of metal ions was changed to 3.5:2.5:5:1 (molar ratio). The loading of Cu in the catalyst was 19 wt%. X-ray diffraction detection shows that no FC structural precursor is formed in the catalyst preparation process. The results of the reaction are tabulated in table 1.

TABLE 1 catalyst Properties and reaction results

Numbering	Copper content (wt%)	Highest conversion rate of acetylene%	Vinyl chloride Selectivity%	Time h taken for activity to decrease by 10%
					Example 1	41	80	98～99	210
Example 2	29	76	98～99	175
					Example 3	25	72	98～99	190
Example 4	20	70	98～99	153
					Example 5	20	70	98～99	101
Example 6	46	73	98～99	180
					Example 7	29	72	98～99	142
Example 8	26	75	98～99	185
					Example 9	39	82	98～99	235
Example 10	38	80	98～99	224
					Example 11	24	76	98～99	186
Example 12	25	78	98～99	196
					Comparative example 1	29	42	98～99	12
Comparative example 2	9.4	29	98～99	3
					Comparative example 3	19	40	98～99	15

As can be seen from the examples and comparative examples, in the process of preparing the catalyst, the ratio of the amount of the divalent metal ion to the trivalent metal ion in the mixed solution is limited to a certain range, and the content of the active component copper in the catalyst is limited to a certain range, so that the active component in the catalyst can be well dispersed, and good activity, selectivity and stability can be exhibited in the acetylene hydrochlorination reaction.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.

Claims

1. A catalyst for acetylene hydrochlorination comprises a carrier, an active component and an auxiliary agent, wherein the carrier comprises aluminum oxide, the active component comprises copper, and the auxiliary agent comprises at least one of bismuth, barium, manganese, calcium, iron and magnesium.

2. The catalyst according to claim 1, wherein the active component is present in an amount of 5 to 60 wt.%, preferably 10 to 45 wt.%, more preferably 20 to 42 wt.%, based on the weight of the support.

3. The method for preparing a catalyst according to claim 1 or 2, comprising the steps of:

4. The method of claim 3, wherein the active ingredient, the auxiliary agent and the metal salt of aluminum comprise at least one of nitrate, hydrochloride and phosphate of the active ingredient, the auxiliary agent and aluminum.

5. The method according to claim 3 or 4, wherein the ratio of the amount of the divalent metal ion to the trivalent metal ion in the mixed solution of the step (1) is 1 to 9, preferably 2 to 8, and more preferably 2.5 to 5.5.

6. The method according to any one of claims 3 to 5, wherein the precipitant comprises at least one of urea, aqueous ammonia, ammonium carbonate, ammonium bicarbonate, sodium hydroxide, potassium hydroxide, sodium carbonate, and potash.

7. The preparation method according to any one of claims 3 to 6, wherein the reaction temperature of the coprecipitation reaction is within 10 to 70 ℃, and the pH value at the end of the reaction is 7 to 10.

8. The method according to any one of claims 3 to 7, wherein the drying temperature in step 3 is 80 to 130 ℃; the calcination temperature is 300-700 ℃, preferably 400-550 ℃.

9. Use of a catalyst according to claim 1 or 2 or prepared by a process according to any one of claims 3 to 8 in the hydrochlorination of acetylene.

10. A method of preparing vinyl chloride, comprising: reacting acetylene and hydrogen chloride in the presence of a catalyst according to claim 1 or 2 or a catalyst prepared by a process according to any one of claims 3 to 8 under conditions for the hydrochlorination of acetylene.