阅读说明：本技术 甲烷氧化偶联与乙烷裂解耦合的制烯烃工艺 (Olefin preparation process by coupling methane oxidation coupling and ethane cracking ) 是由 盛在行 刘罡 王振维 赵百仁 孙丽丽 李少鹏 聂毅强 丁利伟 于 2019-03-27 设计创作，主要内容包括：本发明属于石油化工领域,富甲烷气体、富氧气体和乙烷在装有甲烷氧化偶联反应催化剂的反应器中混合接触,得到含乙烯的反应气；反应器为固定床反应器,反应器压力为0.1～1.0MPaG,催化剂床层高度为100～500mm,体积空速为2000～10000h<Sup>-1</Sup>,反应气温升范围为100～200℃。通过在氧化偶联反应过程中补入一定的乙烷使其裂解吸收氧化偶联反应放出的热量,既可以控制甲烷氧化偶联反应的温度,同时提高了烯烃的收率。(The invention belongs to the field of petrochemical industry, and is characterized in that methane-rich gas, oxygen-rich gas and ethane are mixed and contacted in a reactor filled with a methane oxidative coupling reaction catalyst to obtain reaction gas containing ethylene; the reactor is a fixed bed reactor, the pressure of the reactor is 0.1-1.0 MPaG, the height of a catalyst bed layer is 100-500 mm, and the volume space velocity is 2000-10000 h ‑1 The temperature rise range of the reaction temperature is 100-200 ℃. By supplementing a certain amount of ethane in the oxidative coupling reaction process to crack and absorb the heat released by the oxidative coupling reaction, the temperature of the methane oxidative coupling reaction can be controlled, and the yield of olefin is improved.)

1. A methane oxidative coupling and ethane cracking coupling olefin preparation process is characterized in that methane-rich gas, oxygen-rich gas and ethane are mixed and contacted in a reactor filled with a methane oxidative coupling reaction catalyst to obtain reaction gas containing ethylene; the reactor is a fixed bed reactor, the pressure of the reactor is 0.1-1.0 MPaG, the height of a catalyst bed layer is more than 100mm and less than or equal to 500mm, and the volume space velocity is 2000-10000 h^-1The temperature rise range of the reaction temperature is 100-200 ℃.

2. The process for preparing olefin coupled with methane oxidation coupling and ethane cracking according to claim 1, wherein the temperature of the mixing contact is 800-900 ℃.

3. The process for preparing the olefin by coupling the methane oxidation coupling and the ethane cracking according to claim 1, wherein a plurality of catalyst beds connected in series are arranged in the reactor, and the number of the bed sections is preferably 2-6.

4. The process of claim 3, wherein the lower part of each catalyst bed is a heat extraction section, and the reaction gas enters the next catalyst bed after heat exchange.

5. The process for the oxidative coupling of methane and the cracking of ethane coupled to olefin as claimed in claim 4, wherein the heat removal section comprises at least one stage of heat removal means; preferably, at least one stage of the heat removal means is coil heat removal.

6. The process for preparing olefin by coupling methane oxidation coupling and ethane cracking according to claim 3, wherein ethane is fed from the middle part of each catalyst bed or is fed from the top of each catalyst bed together with methane-rich gas.

7. The process of claim 1, wherein when the oxidative coupling reaction is a multi-stage reaction, the ethane and all or part of the reaction gas obtained from the oxidative coupling reaction in the previous stage enter the lower part of the reactor bed or the next stage for thermal cracking reaction.

8. The process for preparing olefin by coupling methane oxidation coupling and ethane cracking of claim 1, wherein at least one of unreacted methane, generated CO and ethane in the reaction gas is returned to the reaction system to continuously participate in the oxidation coupling reaction.

9. The process for the oxidative coupling of methane and the cracking of ethane coupled to the production of olefins according to claim 1, wherein the methane-rich gas has a methane content of > 50% by volume, preferably > 90% by volume, and the methane-rich raw gas is preferably natural gas and/or shale gas;

the volume content of oxygen in the oxygen-enriched gas is 12-100%.

10. The process for preparing olefin by oxidative coupling of methane and cracking of ethane as claimed in claim 1, wherein a thermal insulation structure is disposed in the fixed bed reactor for separating a high temperature region from a low temperature region.

Technical Field

The invention belongs to the field of petrochemical industry, and particularly relates to a process for preparing olefin by coupling methane oxidation coupling and ethane cracking.

Background

Ethylene is one of the chemical products with the largest yield in the world, the ethylene industry is the core of the petrochemical industry, and the ethylene product accounts for more than 75 percent of petrochemical products and occupies an important position in national economy. Ethylene production has been used worldwide as one of the important indicators for the development of petrochemical in one country.

With the large fluctuation of the international crude oil price and the technical progress, in order to change the condition that the raw materials for producing ethylene depend on petroleum resources excessively, the raw materials for producing ethylene are changed, and the technology for producing ethylene by taking methanol as the raw material is developed and becomes a technology with wide industrial application in the novel coal chemical industry technology.

The technology for preparing ethylene by oxidative coupling of methane is an important technology for producing ethylene, takes natural gas as a raw material, can prepare ethylene by only one-step reaction process, and has high theoretical value and economic value. After more than 30 years of research, the research on ethylene preparation by a methane one-step method has made a breakthrough, and the industrial demonstration device for preparing ethylene by methane coupling is successfully put into production, which is moving towards the beginning of industrialization. The method has great significance for breaking the bottleneck of raw material sources in the ethylene industry, reducing the production cost and enhancing the competitiveness of the ethylene industry and downstream industries.

Research and development at home and abroad are most typical of Siluria technology company in the United states, and the Siluria develops an industrially feasible methane direct ethylene catalyst by precisely synthesizing a nanowire catalyst by using a biological template. The catalyst can efficiently catalyze the conversion of methane into ethylene under the condition of 200-300 ℃ lower than the operation temperature of the traditional steam cracking method and under the pressure of 5-10 atmospheric pressures. The technology prolongs the service life of the catalyst, greatly reduces the operation temperature, but has no substantial breakthrough on the conversion rate of methane and the yield of ethylene.

Disclosure of Invention

The invention aims to provide a process for preparing olefin by coupling methane oxidation coupling and ethane cracking. Thereby absorbing the heat released by the methane oxidative coupling reaction by utilizing the ethane cracking reaction and simultaneously increasing the olefin yield.

The Oxidative Coupling of Methane (OCM) is a strongly exothermic reaction, and in order to make use of the exothermic heat as much as possible, the OCM can be coupled with ethane cracking, which makes use of the exothermic heat of the OCM, the product being also ethylene. In the conventional coupling reaction, an OCM reaction and an ethane cracking reaction are sequentially carried out in different reaction sections in one reactor or the same reactor.

Specifically, the invention provides a process for preparing olefin by coupling methane oxidation coupling and ethane cracking, wherein a methane-rich gas, an oxygen-rich gas and ethane are mixed and contacted in a reactor filled with a methane oxidation coupling reaction catalyst to obtain a reaction gas containing ethylene; the reactor is a fixed bed reactor, the pressure of the reactor is 0.1-1.0 MPaG, the height of a catalyst bed layer is more than 100mm and less than or equal to 500mm, the preferable range is 150-500 mm, and the volume space velocity is 2000-10000 h^-1The temperature rise range of the reaction temperature is 100-200 ℃.

According to the invention, the temperature of the mixing contact is preferably 800-900 ℃.

According to the invention, preferably, a plurality of catalyst beds connected in series are arranged in the reactor, and the number of the bed layers is preferably 2-6.

Furthermore, the lower part of each section of catalyst bed layer is a heat taking section, and reaction gas enters the next section of catalyst bed layer after heat exchange. Wherein the heat extraction section comprises at least one stage of heat extraction measures; preferably, at least one stage of the heat removal means is coil heat removal.

According to the present invention, ethane may be fed from the middle of each catalyst bed or may be fed together with the methane-rich gas from the top of each catalyst bed.

Further, when the oxidative coupling reaction is a multi-stage reaction, ethane and all or part of reaction gas obtained by the oxidative coupling reaction in the previous stage enter the lower part of the bed layer of the reactor or enter the next stage for thermal cracking reaction.

According to the present invention, at least one of unreacted methane, generated CO and ethane in the reaction gas is preferably returned to the reaction system to continuously participate in the oxidative coupling reaction.

According to the present invention, preferably the methane-rich gas has a methane content of > 50% by volume, preferably > 90% by volume, further preferably the methane-rich gas is natural gas and/or shale gas. The oxygen content of the oxygen-enriched gas is preferably 12-100% by volume.

According to the present invention, preferably, a heat insulation structure is provided inside the fixed bed reactor; the thermal insulation structure is used for separating a high-temperature area from a low-temperature area. The heat insulation structure can use refractory materials as main construction materials, the refractory materials can be selected from corundum refractory bricks and the like, and a high-temperature area in the reactor is separated from a low-temperature area such as an outer wall, a heat extraction structure and a pipeline. For example, the inner walls of the reactor are provided with a refractory lining.

The invention has the beneficial effects that: by supplementing a certain amount of ethane in the oxidative coupling reaction process to crack and absorb the heat released by the oxidative coupling reaction, the temperature of the methane oxidative coupling reaction can be controlled, and the yield of olefin is improved.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings.

FIG. 1 shows a schematic flow diagram of an olefin production process with oxidative coupling of methane and cracking of ethane coupled in accordance with the present invention.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.