阅读说明：本技术 一种异丁烷脱氢用催化剂的再生方法 (Regeneration method of catalyst for isobutane dehydrogenation ) 是由 程杰 张炳亮 赵茁然 万克柔 林涛 张力 高明明 张之翔 于 2019-12-02 设计创作，主要内容包括：本发明公开一种异丁烷脱氢用催化剂的再生方法,包括以下步骤：(1)脱硫：将失活后的催化剂温度控制低于200℃,在空气和氮气的混合氛围下焙烧,使失活催化剂中的硫以氧化态形式去除；(2)除积碳：在空气和氮气的混合氛围下,焙烧；(3)氯化：在再生活化剂氛围下,焙烧；(4)还原：用氮气吹扫,将催化剂降温,同时将系统内氧体积含量降低到1%以下,氯体积含量降低到0.05%以下,通入氢气处理,关闭氢气,在氮气气氛下降至室温。本发明提供的方法,在除积碳后直接进行氯化,能避免烧炭导致的局部活性金属原子被过度烧结,使团聚的金属得到重新分布,提高再生后催化剂的活性,延长了催化剂的使用寿命。(The invention discloses a regeneration method of a catalyst for isobutane dehydrogenation, which comprises the following steps: (1) and (3) desulfurization: controlling the temperature of the deactivated catalyst to be lower than 200 ℃, and roasting the deactivated catalyst in the mixed atmosphere of air and nitrogen to remove sulfur in the deactivated catalyst in an oxidation state; (2) removing carbon deposition: roasting in the mixed atmosphere of air and nitrogen; (3) chlorination: roasting in the atmosphere of a regenerated activating agent; (4) reduction: purging with nitrogen, cooling the catalyst, simultaneously reducing the volume content of oxygen in the system to below 1 percent and the volume content of chlorine to below 0.05 percent, introducing hydrogen for treatment, closing the hydrogen, and reducing the temperature to room temperature in the nitrogen atmosphere. The method provided by the invention can directly chloridize after removing the carbon deposition, can avoid excessive sintering of local active metal atoms caused by carbon burning, redistribute the agglomerated metal, improve the activity of the regenerated catalyst and prolong the service life of the catalyst.)

1. A regeneration method of a catalyst for isobutane dehydrogenation is characterized by comprising the following steps: the method comprises the following steps:

(1) and (3) desulfurization: controlling the temperature of the deactivated catalyst after reaction to be lower than 200 ℃, and then roasting the catalyst in the mixed atmosphere of air and nitrogen to remove sulfur in the deactivated catalyst in an oxidation state;

(2) removing carbon deposition: roasting for 5-10h at the temperature of 450-700 ℃ in the mixed atmosphere of air and nitrogen;

(3) chlorination: roasting for 5-8h at the temperature of 350-500 ℃ in the atmosphere of regenerated activator; the regeneration activating agent consists of air or oxygen, nitrogen or helium and chlorine-containing substances;

(4) reduction: purging with nitrogen, cooling the catalyst to 200 ℃, simultaneously reducing the volume content of oxygen in the system to below 1 percent and the volume content of chlorine to below 0.05 percent, introducing hydrogen, treating at the temperature of 200 plus 400 ℃ for 5-8h, closing the hydrogen, and reducing the temperature to room temperature in the nitrogen atmosphere.

2. A method of regenerating a catalyst for the dehydrogenation of isobutane according to claim 1, characterized in that: in the step (1), the roasting temperature is 300-550 ℃ and the roasting time is 2-4 h.

3. A method of regenerating a catalyst for the dehydrogenation of isobutane according to claim 1 or 2, characterized in that: in the step (1), the volume content of oxygen in the mixed atmosphere of air and nitrogen is controlled to be 0.5-5%, and the space velocity of the mixed atmosphere of air and nitrogen is 500-^-1。

4. A method of regenerating a catalyst for the dehydrogenation of isobutane according to claim 1, characterized in that: in the step (2), the volume content of oxygen in the mixed atmosphere of air and nitrogen is controlled to be 2-8%, and the space velocity of the mixed atmosphere of air and nitrogen is 500-^-1。

5. A method of regenerating a catalyst for the dehydrogenation of isobutane according to claim 1, characterized in that: in the step (3), the chlorine-containing substance is any one or two of chlorine, hydrogen chloride, trichloroethylene, tetrachloroethylene, dichloroacetic acid and monochloroacetic acid.

6. A method of regenerating a catalyst for the dehydrogenation of isobutane according to claim 1 or 5, characterized in that: in the step (3), the volume content of chlorine in the regenerated activator is controlled to be 0.5-5%, the volume content of oxygen is controlled to be 0.5-2%, and the airspeed of the regenerated activator is 500-^-1。

7. A method of regenerating a catalyst for the dehydrogenation of isobutane according to claim 1, characterized in that: in the step (4), the volume content of the hydrogen is controlled to be 0.1-5%, and the space velocity of the hydrogen is 500-^-1。

8. A process for regenerating a catalyst for the dehydrogenation of isobutane according to claim 1 or 2 or 4 or 5 or 7, characterized in that: the catalyst for isobutane dehydrogenation is a catalyst for preparing isobutene by isobutane dehydrogenation.

9. A method of regenerating a catalyst for the dehydrogenation of isobutane according to claim 8, characterized in that: the catalyst for isobutane dehydrogenation is a catalyst which takes an alumina or silicon-aluminum molecular sieve as a carrier and is loaded with Pt, Na, Ce and C.

Technical Field

The invention belongs to the technical field of catalyst regeneration, and particularly relates to a regeneration method of a catalyst for isobutane dehydrogenation.

Background

Isobutene is an important organic chemical raw material and is mainly used for preparing methyl tert-butyl ether (MTBE), butyl rubber, isoprene rubber and polyisobutylene. In addition, it can be used for the synthesis of various organic raw materials and fine chemicals such as Methyl Methacrylate (MMA), isoprene, 1, 4-butanediol, tert-butylamine, tert-butylphenol, ABS resin, etc.

In the conventional process, the main sources of isobutene are a by-product C4 fraction from an ethylene production plant by steam cracking of naphtha, a by-product C4 fraction from a refinery Fluid Catalytic Cracking (FCC) plant, and a by-product t-butyl alcohol (TAB) in the synthesis of propylene oxide by the Halcon process. With the development and utilization of downstream products of isobutene, the contradiction of global isobutene resource shortage is increasingly prominent. Isobutene from conventional sources has not been able to meet the demand. Therefore, expanding the source of isobutene and increasing the yield of isobutene are urgent matters for the development of petrochemical industry all over the world.

The process for producing isobutene by dehydrogenating isobutane is carried out in a high-temperature environment of 500-650 ℃, and the used catalyst gradually loses activity due to surface and pore carbon deposition and easy agglomeration of active components, so the catalyst needs to be frequently regenerated, the regeneration aims at removing the surface and the pore carbon deposition of the deactivated catalyst, and the active metal components are redistributed by a regeneration technology. The development of a simple and efficient regeneration process has important significance in that the deactivated catalyst achieves the same high conversion rate and high selectivity as a fresh catalyst.

The invention aims to provide a regeneration method of a catalyst in the process aiming at the fact that carbon deposit and active metal components are aggregated, gradually deactivated and frequently regenerated in industrial production of the catalyst for preparing isobutene by isobutane dehydrogenation.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a regeneration method of a catalyst for isobutane dehydrogenation, which can improve the activity of the regenerated catalyst and prolong the service life of the catalyst.

A regeneration method of a catalyst for isobutane dehydrogenation comprises the following steps:

(1) and (3) desulfurization: controlling the temperature of the deactivated catalyst to be lower than 200 ℃, and then roasting the deactivated catalyst in the mixed atmosphere of air and nitrogen to remove sulfur in the deactivated catalyst in an oxidation state;

(2) removing carbon deposition: roasting for 5-10h at the temperature of 450-700 ℃ in the mixed atmosphere of air and nitrogen;

(3) chlorination: roasting for 5-8h at the temperature of 350-500 ℃ in the atmosphere of regenerated activator; the regeneration activating agent consists of air or oxygen, nitrogen or helium and chlorine-containing substances;

(4) reduction: purging with nitrogen, cooling the catalyst to 200 ℃, simultaneously reducing the volume content of oxygen in the system to below 1 percent and the volume content of chlorine to below 0.05 percent, introducing hydrogen, treating at the temperature of 200 plus 400 ℃ for 5-8h, closing the hydrogen, and reducing the temperature to room temperature in the nitrogen atmosphere.

Preferably, in the step (1), the roasting temperature is 300-550 ℃ and the roasting time is 2-4 h.

Preferably, in the step (1), the oxygen volume content in the mixed atmosphere of air and nitrogen is controlled to be 0.5-5%, and the space velocity of the mixed atmosphere of air and nitrogen is 500-^-1。

Preferably, in the step (2), the volume content of oxygen in the mixed atmosphere of air and nitrogen is controlled to be 2-8%, and the space velocity of the mixed atmosphere of air and nitrogen is 500-^-1。

Preferably, in the step (3), the chlorine-containing substance is any one or two of chlorine, hydrogen chloride, trichloroethylene, tetrachloroethylene, dichloroacetic acid and monochloroacetic acid.

Preferably, in the step (3), the volume content of chlorine in the regenerated activator is controlled to be 0.5-5%, the volume content of oxygen is controlled to be 0.5-2%, and the space velocity of the regenerated activator is 500-^-1。

Preferably, in the step (4), the volume content of the hydrogen is controlled to be 0.1-5%, and the space velocity of the hydrogen is 500-^-1。

Preferably, the catalyst for isobutane dehydrogenation is a catalyst for preparing isobutene by isobutane dehydrogenation.

Preferably, the catalyst for isobutane dehydrogenation is a catalyst which takes an alumina or silicon-aluminum molecular sieve as a carrier and is loaded with Pt, Na, Ce and C.

The space velocity refers to the volume space velocity.

The invention has the advantages that:

1. according to the method provided by the invention, the chlorination is directly carried out after the carbon deposition is removed, so that the excessive sintering of local active metal atoms caused by carbon burning can be avoided, agglomerated metal can be redistributed through the chlorination, the activity of the regenerated catalyst is improved, and the service life of the catalyst is prolonged;

2. during reduction, nitrogen dilutes hydrogen, and compared with pure hydrogen, the safety is higher; and the nitrogen flow is large, so that the water can be taken away in time, and the problem of catalyst activity reduction caused by untimely water transfer is avoided.

Detailed Description