阅读说明：本技术 一种炼厂干气除杂催化剂 (Dry gas impurity removal catalyst for refinery plant ) 是由 陈静 于 2020-04-21 设计创作，主要内容包括：本发明公开了一种炼厂干气除杂催化剂,其按照重量百分比计包括以Ni<Sub>2</Sub>O<Sub>3</Sub>计的镍氧化物0.5-5％；以CoO计的钴氧化物0.1-1％；以Cr<Sub>2</Sub>O<Sub>3</Sub>计的铬氧化物0.01-0.3％；余量的氧化铝载体。本发明的催化剂能够同时去除炼厂干气或者裂解气中包含的硫、砷、汞、氧气、氮氧化合物、炔烃等杂质,具有广阔的应用前景。(The invention discloses a refinery dry gas impurity removal catalystAn agent comprising, in weight percent, Ni 2 O 3 0.5-5% calculated as nickel oxide; 0.1-1% cobalt oxide calculated as CoO; with Cr 2 O 3 0.01-0.3% of calculated chromium oxide; the balance of alumina carrier. The catalyst can simultaneously remove sulfur, arsenic, mercury, oxygen, oxynitride, alkyne and other impurities contained in refinery dry gas or pyrolysis gas, and has wide application prospect.)

1. A refinery dry gas impurity removal catalyst is characterized by comprising the following components in percentage by weight:

a) with Ni₂O₃Calculated nickel oxide: 0.5 to 5 percent;

b) cobalt oxide as CoO: 0.1 to 1 percent;

c) with Cr₂O₃Calculated chromium oxide: 0.01 to 0.3 percent;

d) with Al₂O₃The alumina carrier is as follows: and (4) the balance.

2. The refinery dry gas impurity removal catalyst of claim 1, wherein the nickel oxide is Ni₂O₃The content is 0.5-4%.

3. The catalyst for the removal of impurities from refinery dry gas according to claim 1, wherein the cobalt oxide is contained in an amount of 0.12-0.8% in terms of CoO.

4. The refinery dry gas impurity removal catalyst of claim 1, wherein the chromium oxide is Cr₂O₃The content is 0.02-0.25%.

5. The refinery dry gas impurity removal catalyst of claim 1, wherein the alumina support material is selected from calcined α -alumina, high purity alumina, activated alumina.

6. The refinery dry gas impurity removal catalyst of claim 1, wherein the nickel oxide is Ni₂O₃1.0-2.0% of cobalt oxide, 0.15-0.20% of cobalt oxide, and Cr oxide, wherein the Cr oxide is Cr₂O₃The content is 0.05-0.10%.

7. A method for preparing the refinery dry gas impurity removal catalyst according to any one of claims 1-6, comprising the steps of:

1) weighing raw materials of each component according to a ratio, preparing a metal salt solution by using deionized water, and uniformly mixing;

2) dipping the alumina carrier particles in a metal salt solution for 0.5-5 hours;

3) washing the impregnated particles with deionized water, separating, and drying;

4) drying the particles obtained in the step 3) at the temperature of 100-150 ℃ for 1-5 hours, drying at the temperature of 200-250 ℃ for 0.5-3 hours, and roasting at the temperature of 500-1000 ℃ for 2-8 hours to obtain the catalyst.

8. The method of claim 7, wherein the nickel oxide feedstock is nickel nitrate, the cobalt oxide feedstock is cobalt nitrate, and the chromium oxide feedstock is chromium nitrate.

9. The method as claimed in claim 7, wherein at least one pore-forming agent selected from graphite, polystyrene microspheres, and carboxymethyl cellulose is further added in step 2), and the amount of the pore-forming agent is 1-10% by weight of the catalyst.

10. Use of the refinery dry gas impurity removal catalyst according to any one of claims 1-6 in the impurity removal of refinery dry gas or pyrolysis gas.

Technical Field

The invention belongs to the fields of petrochemical industry and catalysis, relates to a refinery dry gas impurity removal catalyst, and particularly relates to a nickel-based catalyst for refinery dry gas impurity removal and a preparation method thereof.

Background

Refinery dry gas refers to non-condensed gas generated and recovered in oil refining process of oil refinery, also called distillation gas, mainly derived from secondary processing of crude oil, such as catalytic cracking (FCC), hydrocrackingDelayed coking, etc., wherein the amount of dry gas produced by catalytic cracking is maximized and the yield is maximized. The main component of refinery dry gas is H₂、CO、CO₂、O₂、CH₄、C₂H₄、C₂H₆、C₃H₈、C₃H₆And a small amount of C +4 compounds (heavy components), and further contains trace amounts of inorganic impurities such as sulfur, arsenic, mercury, oxygen, nitrogen oxides, and the like. The content of ethylene and ethane in the refinery dry gas is about 10-30%, and the content of hydrogen is about 20%. If these impurities can be removed by the catalyst, the recovery value of the olefin in the refinery dry gas can be remarkably improved.

The following important meanings are provided for recovering light hydrocarbon from refinery dry gas: A) the recovered light hydrocarbon can be sent to an ethylene separation system to recover ethylene, propylene and liquefied gas, and the recovered alkane can return to a cracking furnace, so that additional economic value is brought to a downstream ethylene or olefin device; B) the recovered ethylene can be reacted with benzene to produce ethylbenzene, which is used as a feedstock for the production of styrene. C) The recovered hydrogen can be sent to a refinery hydrogen network. D) The polypropylene comonomer ethylene can be provided to a fuel-type refinery polypropylene plant.

The process for recovering light hydrocarbon from refinery dry gas needs to jointly use a plurality of catalysts to respectively remove various impurities, for example, different catalysts are used to respectively remove oxygen, acetylene, methylacetylene, propadiene, arsenic, sulfur and the like, and the process gas components are relatively mixed, the content of various components is often not fixed, so that the surface carbon deposition of the conventional catalyst is easily increased, and the stability and the activity of the catalyst are reduced, which is the biggest problem for developing the catalyst.

Disclosure of Invention

In order to overcome the problems in the existing process for recovering light hydrocarbon from refinery dry gas, the inventor carries out deep research on a catalyst system in the process, focuses on improving the carbon deposition resistance, the carbon removal capability and the catalyst stability of the catalyst, and gives consideration to the removal of all impurities, thereby developing a nickel-based catalyst for the impurity removal of the refinery dry gas.

Specifically, the present invention includes the following technical solutions.

A refinery dry gas impurity removal catalyst is characterized by comprising the following components in percentage by weight:

a) with Ni₂O₃Calculated nickel oxide: 0.5 to 5 percent;

b) cobalt oxide as CoO: 0.1 to 1 percent;

c) with Cr₂O₃Calculated chromium oxide: 0.01 to 0.3 percent;

d) with Al₂O₃The alumina carrier is as follows: and (4) the balance.

The above nickel oxide is Ni₂O₃The content may be 0.5 to 4%, preferably 0.8 to 3.5%, more preferably 1.0 to 3%, more preferably 1 to 2%.

The content of the above cobalt oxide in terms of CoO may be 0.12 to 0.8%, preferably 0.13 to 0.7%, more preferably 0.14 to 0.6%, still more preferably 0.15 to 0.5%.

The chromium oxide is Cr₂O₃The content may be 0.02 to 0.25%, preferably 0.03 to 0.23%, more preferably 0.04 to 0.2%, more preferably 0.05 to 0.15%.

The alumina carrier material may be selected from calcined α -alumina, gamma-alumina, high purity alumina, and activated alumina.

The invention also provides a method for preparing the refinery dry gas impurity removal catalyst, wherein the catalyst is prepared by adopting an impregnation method and specifically comprises the following steps:

1) weighing raw materials of each component according to a ratio, preparing a metal salt solution by using deionized water, and uniformly mixing;

2) immersing alumina carrier particles in the above metal salt solution for 0.5 to 5 hours, for example, 1 to 2 hours;

3) washing the impregnated particles with deionized water, separating, and drying;

4) the particles obtained in step 3) are dried at 100-150 ℃, e.g. 120-130 ℃, for 1-5 hours, e.g. 2-3 hours, at 200-250 ℃, e.g. 220-240 ℃, for 0.5-3 hours, e.g. 1-2 hours, and at 500-1000 ℃, e.g. 700-800 ℃, for 2-8 hours, e.g. 4-6 hours, to obtain the catalyst.

In the method, the nickel oxide raw material can be nickel nitrate, the cobalt oxide raw material can be cobalt nitrate, and the chromium oxide raw material can be chromium nitrate.

Preferably, at least one pore-forming agent can be further added in the step 2), and the dosage of the pore-forming agent is 1-10% of the weight of the catalyst. The pore-forming agent can be selected from graphite, polystyrene microspheres and carboxymethyl cellulose.

The diameter of the sphere in the above step 3) is preferably 6 to 8 mm.

The invention also provides the application of the refinery dry gas impurity removal catalyst in the refinery dry gas impurity removal or pyrolysis gas.

The nickel-based catalyst has a comprehensive impurity removal function, can simultaneously remove impurities such as sulfur, arsenic, mercury, oxygen, oxynitride, alkyne and the like in refinery dry gas or pyrolysis gas, reduces the loss of olefin, and controls the loss of olefin within 1 percent, thereby having wide application prospect.

Detailed Description

For convenience of description, the "refinery dry gas removal catalyst" of the present invention is sometimes referred to herein simply as "refinery dry gas catalyst", "nickel-based catalyst" or "catalyst".

The nickel-based catalyst is used for simultaneously removing inorganic impurities such as sulfur, arsenic, mercury, oxygen, oxynitride and the like and organic impurities such as alkyne and the like in refinery dry gas. When refinery dry gas is treated by the nickel-based catalyst, inorganic impurities such as sulfur, arsenic, mercury, oxygen and nitrogen oxides can react as follows:

H₂s participates in the sulfuration of the catalyst, so that the catalyst is changed into a nickel sulfide state;

heavy metals of mercury and arsenic are adsorbed by the catalyst;

NO_X+H₂→NH₃+H₂o, wherein NO_XRepresents one or more nitrogen oxides;

O₂+H₂→H₂O。

organic impurities alkynes undergo the following reactions:

the acetylene is mostly converted to ethylene: CH ≡ CH + H₂→CH₂＝CH₂；

The hydrogenation of methylacetylene and propadiene to produce propylene. CH (CH)₃CH≡CH+H₂→CH₃CH＝CH₂；

CH₂＝C＝CH₂+H₂→CH₃CH＝CH₂。

The ethylene and the propylene are needed by users and can be used for synthesizing different products in the downstream.

In preparing the nickel-based catalyst, the nickel oxide raw material may be selected from nickel salts such as nickel nitrate, nickel carbonate, nickel hydrochloride, nickel sulfate, nickel oxide, nickel protoxide, nickel tetraoxide, or a mixture of two or more thereof, preferably nickel nitrate. Nickel oxide with Ni₂O₃The content is 0.5-5%, preferably about 1.0-2.0%.

It should be understood that when numerical features are expressed herein, the terms "about" or "approximately" mean that the number indicated may have a margin of error or variance of 10%, ± 9%, ± 8%, ± 7%, ± 6% or ± 5%.

When the content of nickel oxide is lower than 0.5%, the catalytic activity of the catalyst is remarkably reduced, and impurities in the refinery dry gas are difficult to be catalyzed to fully react so as to remove the impurities; when the content of nickel oxide is more than 5%, the balance effect of remarkably improving the catalytic activity cannot be obtained, and the production cost of the catalyst is increased, and the loss rate of olefin is increased, resulting in a serious decrease in economical efficiency.

The catalytic activity or catalytic active body of the catalyst can be represented by indexes such as ethylene loss rate, acetylene conversion rate, methyl acetylene conversion rate, propadiene conversion rate, oxygen conversion rate and the like of refinery dry gas.

The cobalt oxide starting material may be selected from cobalt salts such as cobalt nitrate, cobalt carbonate, cobalt hydrochloride, cobalt sulfate, CoO, Co₃O₄、CoO₂Or a mixture of two or more thereof, preferably cobalt nitrate. The cobalt oxide content, calculated as CoO, is 0.1-1%, preferably about 0.15-0.20%.

When the cobalt oxide content is less than 0.1%, the ethylene loss rate is high, resulting in a reduction in product economy; when the cobalt oxide content is more than 1%, a balance effect of remarkably improving the catalytic activity cannot be obtained, and the production cost of the catalyst is increased.

The chromium oxide raw material may be selected from chromium salts such as chromium nitrate, chromium carbonate, chromium hydrochloride, chromium sulfate, chromia (CrO), chromium oxide (Cr)₂O₃) Chromium trioxide (CrO)₃) Chromium dioxide (CrO)₂) Or a mixture of two or more thereof, preferably chromium nitrate. Chromium oxide with Cr₂O₃The content is 0.01-0.3%, preferably about 0.05-0.10%.

When the chromium oxide content is less than 0.01%, the ethylene loss rate is high, resulting in a decrease in product economy; when the content of chromium oxide is more than 0.3%, the balance effect of remarkably improving the catalytic activity cannot be obtained and the production cost of the catalyst is increased.

In order to realize the maximum distribution uniformity of the nickel oxide, the cobalt oxide and the chromium oxide in the catalyst, the raw materials of the components can be mixed by a wet method, that is, the water-soluble raw materials of the nickel oxide, the cobalt oxide and the chromium oxide are firstly dissolved in water (such as deionized water) to prepare a metal salt solution, and then the alumina serving as a catalyst carrier is soaked in the metal salt solution, so that the raw materials of the components are mixed, namely the step 1 is completed.

Nickel nitrate, cobalt nitrate and chromium nitrate are all water-soluble metal salts that can be conveniently used for the above-mentioned wet mixing.

In order that the invention may be more readily understood, preferred embodiments will now be described in detail. It will be understood by those skilled in the art that the following examples are illustrative of the present invention only and are not intended to limit the present invention.