阅读说明：本技术 一种二甲醚羰基化mor分子筛催化剂模板剂的回收方法 (Recovery method of dimethyl ether carbonylation MOR molecular sieve catalyst template agent ) 是由 刘亚华 叶秋云 刘芃 王科 李扬 于 2019-10-21 设计创作，主要内容包括：本发明公开了一种二甲醚羰基化MOR分子筛催化剂模板剂的回收方法,解决现有技术中模板剂处理不当造成环境污染,影响MOR分子筛催化剂活性的问题。本发明的回收方法包括：采用乙撑基(双十二烷基二甲基溴化铵)为模板剂制备丝光分子筛,将晶化后的分子筛和母液降温后,进行固液分离；将分离所得分子筛干燥后,加入丙酸钾/乙醇溶液,搅拌,而后过滤分离；采用膜分离法对萃取液中的模板剂和丙酸钾/乙醇溶液进行分离,得到回收的模板剂。本发明采用丙酸钾/乙醇溶液萃取分子筛中的模板剂,能使模板剂完全从分子筛中脱离下来,采用回收后的模板剂制备MOR分子筛,不会对MOR分子筛的活性产生不利的影响。(The invention discloses a method for recovering a template agent of a dimethyl ether carbonylation MOR molecular sieve catalyst, which solves the problems that the template agent is improperly treated in the prior art, so that the environmental pollution is caused, and the activity of the MOR molecular sieve catalyst is influenced. The recovery method of the invention comprises the following steps: preparing a mercerized molecular sieve by using ethylene (didodecyldimethylammonium bromide) as a template agent, cooling the crystallized molecular sieve and a mother solution, and performing solid-liquid separation; drying the molecular sieve obtained by separation, adding a potassium propionate/ethanol solution, stirring, and filtering for separation; and separating the template agent and the potassium propionate/ethanol solution in the extract liquor by adopting a membrane separation method to obtain the recovered template agent. The method adopts the potassium propionate/ethanol solution to extract the template agent in the molecular sieve, so that the template agent can be completely separated from the molecular sieve, and the recovered template agent is adopted to prepare the MOR molecular sieve, so that the activity of the MOR molecular sieve is not adversely affected.)

1. A method for recovering a dimethyl ether carbonylation MOR molecular sieve catalyst template agent is characterized by comprising the following steps:

step 1, preparing a mercerized molecular sieve by using ethylene (didodecyldimethylammonium bromide) as a template agent, cooling the crystallized molecular sieve and mother liquor, and performing solid-liquid separation;

step 2, drying the molecular sieve obtained by separation in the step 1, adding a potassium propionate/ethanol solution, stirring for a period of time to separate the template from the molecular sieve, and then filtering and separating to obtain the molecular sieve and an extract liquid;

and 3, separating the template agent and the potassium propionate/ethanol solution in the extract liquor by adopting a membrane separation method to obtain the recovered template agent.

2. The recovery method according to claim 1, wherein in the step 1, the crystallized molecular sieve and the mother liquor are cooled to 0-10 ℃ and kept for 2-24 hours, and then solid-liquid separation is performed.

3. The recovery method according to claim 2, wherein in the step 1, the crystallized molecular sieve and the mother liquor are cooled to 5 ℃ and kept for 5 hours, and then solid-liquid separation is performed.

4. The recovery method according to claim 1 or 2, wherein the concentration of potassium propionate in the potassium propionate/ethanol solution is 0.01-0.2 mol/L, and the mass ratio of the potassium propionate/ethanol solution to the molecular sieve is more than 5: 1.

5. the recovery process of claim 4, wherein the mass ratio of the potassium propionate/ethanol solution to molecular sieve is 10: 1.

6. the recycling method according to claim 1 or 2, wherein in the step 2, the temperature during stirring is 20 to 60 ℃ and the stirring time is 1 to 10 hours.

7. The recycling method according to claim 6, wherein the temperature during the stirring in the step 2 is 30 ℃ and the stirring time is 5 hours.

8. The recycling method according to claim 6, wherein in the step 2, after the molecular sieve is obtained by filtration and separation, the potassium propionate/ethanol solution is added and stirred, and the process is repeated for 1-3 times.

9. The recovery method according to claim 1, wherein the template recovered in the step 3 is returned to the step 1 for preparing the mercerized molecular sieve.

Technical Field

The invention belongs to the technical field of preparation of molecular sieve catalysts, and particularly relates to a recovery method of a dimethyl ether carbonylation MOR molecular sieve catalyst template.

Background

With the increasing energy demand and the increasing tension of petroleum supply, and the increasing global environmental pressure, the fuel ethanol is widely concerned by countries in the world due to its cleanness and environmental protection. Ethanol is used as an important clean energy source and is mixed with gasoline in a proportion of 10 percent to be used as ethanol gasoline. The fuel ethanol gasoline can reduce the emission of carbon monoxide and hydrocarbon in automobile exhaust, and has important significance for solving the problem of atmospheric pollution and realizing sustainable development in China. China is a country rich in coal and less in oil, so that ethanol prepared by coal chemical industry conforms to the basic national conditions of China. In recent years, researchers at home and abroad explore an economic, environment-friendly and green process route of 'synthesis gas → methanol → dimethyl ether → methyl acetate → ethanol'. At present, the total yield of the domestic dimethyl ether device can reach about 1400 million tons, but the operating rate is only 38%, and the problem that the dimethyl ether capacity is seriously excessive is solved by the route.

The mordenite molecular sieve (MOR) crystal has two channel structures, one is a 12-membered ring (0.67X 0.70nm) channel parallel to the c-axis direction, and the other is an 8-membered ring (0.26X 0.57nm) channel parallel to the b-axis direction.

In 2007, the Iglesia group researches the reaction activity of dimethyl ether (DME) carbonylation of various molecular sieves to prepare Methyl Acetate (MA), and finds that the catalytic activity of the H-MOR molecular sieve is the highest among the molecular sieves. Many literature reports and patents describe that a high-activity dimethyl ether carbonylation MOR molecular sieve catalyst can be prepared by adding a template agent, but the cost of the template agent is higher, and improper treatment of the template agent after crystallization can not only cause serious environmental pollution, but also influence the activity of the MOR molecular sieve catalyst.

Therefore, the recovery method of the MOR molecular sieve catalyst template agent for dimethyl ether carbonylation is provided, the operation is simple and convenient, the activity of the catalyst is not influenced, the production cost of the catalyst can be reduced, and the environmental pollution is avoided, so that the method becomes a problem to be solved by the technical personnel in the field.

Disclosure of Invention

The technical problem solved by the invention is as follows: provides a method for recovering a dimethyl ether carbonylation MOR molecular sieve catalyst template agent, and solves the problems that the template agent treatment in the prior art causes environmental pollution and influences the activity of the MOR molecular sieve catalyst.

The technical scheme adopted by the invention is as follows:

the invention relates to a recovery method of a dimethyl ether carbonylation MOR molecular sieve catalyst template agent, which comprises the following steps:

step 1, preparing a mercerized molecular sieve by using ethylene (didodecyldimethylammonium bromide) as a template agent, cooling the crystallized molecular sieve and mother liquor, and performing solid-liquid separation;

step 2, drying the molecular sieve obtained by separation in the step 1, adding a potassium propionate/ethanol solution, stirring for a period of time to separate the template from the molecular sieve, and then filtering and separating to obtain the molecular sieve and an extract liquid;

and 3, separating the template agent and the potassium propionate/ethanol solution in the extract liquor by adopting a membrane separation method to obtain the recovered template agent.

Further, in the step 1, the crystallized molecular sieve and the mother liquor are cooled to 0-10 ℃, kept for 2-24 hours, and then subjected to solid-liquid separation.

The crystallized molecular sieve and the mother solution are kept stand at a low temperature, so that the molecular sieve and the template agent can be settled.

As an embodiment of the present invention, in step 1, the crystallized molecular sieve and the mother liquor are cooled to 5 ℃ and kept for 5 hours, and then solid-liquid separation is performed.

In the technical scheme of the invention, the concentration of potassium propionate in the potassium propionate/ethanol solution is 0.01-0.2 mol/L, and the mass ratio of the potassium propionate/ethanol solution to the molecular sieve is more than 5: 1.

the template agent in the molecular sieve is extracted by adding a potassium propionate/ethanol solution.

As an embodiment of the invention, the mass ratio of the potassium propionate/ethanol solution to the molecular sieve is 10: 1.

in the technical scheme of the invention, in the step 2, the temperature during stirring is 20-60 ℃, and the stirring time is 1-10 h.

Under the heating state, the template agent is favorably dissolved in the potassium propionate/ethanol solution, but the temperature is too high, and the solvent is easy to volatilize; therefore, the stirring temperature is set to 20 to 60 ℃. The longer the extraction (stirring) time, the more the amount of template dissolved in the potassium propionate/ethanol solution, but after the dissolution reaches equilibrium, the longer the stirring time, the longer the dissolution of template can not be increased, so the stirring time is set to 1-10 h.

In step 2, the temperature during stirring is 30 ℃ and the stirring time is 5 hours.

In the step 2 of the technical scheme, after the molecular sieve is obtained through filtration and separation, the potassium propionate/ethanol solution is added and stirred, and the stirring is repeated for 1-3 times.

The invention adds potassium propionate/ethanol into the molecular sieve repeatedly for extraction, so that the template agent is completely eluted from the molecular sieve.

As an embodiment of the invention, the template agent recovered in the step 3 is returned to the step 1 for preparing the mercerized molecular sieve.

According to the invention, the recycled template agent is used for preparing the mercerized molecular sieve, so that the production cost is effectively reduced, and the environmental pollution is reduced.

Compared with the prior art, the invention has the following beneficial effects:

the invention has scientific design, simple method and simple and convenient operation, and adopts the potassium propionate/ethanol solution to extract the template agent in the molecular sieve, so that the template agent can be completely separated from the molecular sieve, thereby effectively ensuring the activity of the molecular sieve.

The MOR molecular sieve is prepared by using the ethylene-based (didodecyldimethylammonium bromide) (EDAB for short) template agent recovered by the method, the activity of the MOR molecular sieve is not adversely affected, the production cost can be reduced, the environmental pollution is reduced, the operation is simple, and the large-scale industrialization can be realized.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.