CN1724162A

CN1724162A - Multicomponent composite desulfate catalyst

Info

Publication number: CN1724162A
Application number: CN 200510018863
Authority: CN
Inventors: 蒋旭东
Original assignee: Tianbao Chemical Industry Sci & Tech Co Ltd Tianmen City
Current assignee: Tianbao Chemical Industry Sci & Tech Co Ltd Tianmen City
Priority date: 2005-06-07
Filing date: 2005-06-07
Publication date: 2006-01-25
Anticipated expiration: 2025-06-07
Also published as: CN100375651C

Abstract

A multi-element de-sulfurizing catalyst for the raw gas contains proportionally phthalocyanine cobalt derivative, polyphenol compound, Fe salt, the ligand of Fe salt for generating complex and V compound.

Description

Multi-element composite desulfurization catalyst

Technical Field

The invention relates to a wet oxidation desulfurization catalyst, in particular to a multi-element composite system desulfurization catalyst. The desulfurization catalyst is mainly used for the desulfurization and decyanation of semi-water gas and conversion gas in the ammonia synthesis industry, and can also be used in the industries needing to remove inorganic sulfur and organic sulfur, such as city gas, coke oven gas, natural gas, synthesis gas, pyrolysis gas, gasoline, sulfide-containing wastewater and the like.

Background

In the chemical processing process of taking coal, natural gas, petroleum and products thereof as raw materials, sulfur in the raw materials is converted into sulfides (hydrogen sulfide, carbon oxysulfide, carbon disulfide, mercaptan, thioether, metallocenes and the like), organic nitrides are converted into hydrogen cyanide, and the existence of the sulfides and the sulfides seriously affects the chemical processing process, namely poisons the catalyst so that the catalyst cannot be operated, corrodes equipment, affects the product quality and pollutes the environment. Desulfurization is therefore a necessary unit operation for the chemical processing industry that starts from coal, natural gas, petroleum oil and their products.

In the prior art, a plurality of methods for removing sulfide are available, such as activated carbon, ferric oxide and the like in a dry method, and an ADA method, a glue copying method, an MSQ method, a PDS method and the like in a wet method. The above-mentioned various methods and desulfurization catalysts have advantages, but some of them have some defects, some of them have small sulfur capacity, low desulfurization efficiency, some of them can not be stably operated for a long time, some of them have high operation cost, some of them can not be regenerated and can produce secondary pollution in the course of use, and another defect is that the higher and higher sulfur-removing rate contained in the raw material is not high.

As a desulfurization catalyst with excellent performance, cobalt phthalocyanine sulfonate catalysts have been widely used in the desulfurization of various industrial gases since the eighties of the twentieth century, and then improved cobalt phthalocyanine desulfurization catalysts have been continuously proposed to overcome the disadvantages of low desulfurization rate and unstable operation. Among these improved cobalt phthalocyanine desulfurization catalysts, the catalyst with patent number CN96119502 is successful, and it has a desulfurization rate of 99% in the conventional desulfurization process (the sulfur content in the gas is below 1.5 g/cubic meter), but has only a desulfurization rate of about 90% in the increasingly high sulfur (the sulfur content in the gas is above 5 g/cubic meter) system in modern industrial gas, and cannot meet the desulfurization requirement of high sulfur industrial gas.

Disclosure of Invention

The invention aims to provide a multi-element composite desulfurization catalyst which has excellent comprehensive performance, can effectively remove sulfide in high-sulfur-containing feed gas and is a high-efficiency environment-friendly desulfurization catalyst with strong practicability.

In order to achieve the purpose, the invention adopts the technical scheme that: a multi-component composite desulfurization catalyst is characterized by mainly comprising the following components:

(1) cobalt phthalocyanine derivative, (2) polyphenol compound, (3) ferric salt, (4) ligand capable of forming complex with ferric salt, and (5) vanadium compound, wherein the weight percentage of each component is as follows:

20 to 70 percent of cobalt phthalocyanine derivative

10 to 50 percent of polyphenol compounds

10 to 60 percent of iron salt

10% -50% of ligand

1 to 40 percent of vanadium compounds.

The multi-component composite desulfurization catalyst is characterized in that:

(1) the derivative of cobalt phthalocyanine is cobalt phthalocyanine sulfonate or poly cobalt phthalocyanine formate; cobalt phthalocyanine sulfonate or poly cobalt phthalocyanine formate is potassium, sodium and ammonium salt;

(2) one or more of polyphenol compounds, hydroquinone, resorcinol, catechol, phloroglucinol, pyrogallol and tannin;

(3) iron salt, wherein the iron salt is ferric thiocyanate or ferric carbonate;

(4) a ligand capable of forming a complex with an iron salt, wherein the ligand is one or a combination of more than one of citric acid, amino acid, tartaric acid, salicylic acid and sulfosalicylic acid;

(5) a vanadium compound, wherein the vanadium compound is vanadium pentoxide or metavanadate.

The multi-component composite desulfurization catalyst is characterized in that: the catalyst takes an alkaline solution as a buffer solution of the catalyst.

The multi-component composite desulfurization catalyst is characterized in that: the pH value of the desulfurization solution prepared by the catalyst is in the range of 7-11.

The multi-component composite desulfurization catalyst is characterized in that the alkaline solution comprises the following alkaline substances: ammonia, ammonium carbonates, ammonium bicarbonates, alkali metal carbonates, alkali metal bicarbonates.

The use of the multi-component composite desulfurization catalyst is characterized in that: the desulfurizing liquid prepared by it can be used in industries needing to remove inorganic sulfur and organic sulfur, such as semi-water gas, city gas, coke oven gas, natural gas, synthetic gas, pyrolysis gas and gasoline, sulfide-containing waste water, and the like.

The relevant content and changes in the above technical solution are explained as follows:

the process of the wet catalytic desulfurization method can be roughly divided into three steps of absorption, oxidation and regeneration, and the functions of the TM desulfurization catalyst in the three steps are respectively explained as follows:

absorption

The main function of this step is to transfer the sulfides (such as hydrogen sulfide) in the raw gas into the desulfurization solution. When liquid-phase desulfurization liquid is contacted with gas-phase raw material gas in a desulfurization tower, sulfide in the gas phase is absorbed by alkaline desulfurization liquid to achieve the purpose of removing sulfide in the gas phase, the step is a main step of a wet catalytic desulfurization method, the desulfurization rate of the raw material gas and the purification rate are controlled by the step, and the main chemical reactions are as follows:

the content of sodium hydrosulfide in the desulfurizing liquid determines the degree of the reaction under certain temperature and alkalinity. According to the principle of chemical equilibrium, the lower the content of sodium hydrosulfide, the more favorable the forward reaction, i.e. the more favorable the desulfurization solution can absorb the hydrogen sulfide in gas phase, the higher the desulfurization rate, and conversely, the higher the content of sodium hydrosulfide in the desulfurization solution, the lower the desulfurization rate. It can be seen that the content of sodium hydrosulfide in the desulfurization solution is one of the key elements for high desulfurization rate. The content of sodium hydrosulfide in the desulfurization solution is mainly controlled by the next step.

Second, oxidation

In the step, sodium hydrosulfide in the desulfurization solution is quickly oxidized into elemental sulfur in the presence of a catalyst, so that the aims of removing the sodium hydrosulfide from the desulfurization solution and regenerating the desulfurization solution are fulfilled. The main chemical reaction is as follows:

the reaction speed in this step directly influences the equilibrium concentration of sodium hydrosulfide in the desulfurizing liquid. The main difference between different desulfurization catalyst systems is in the performance of the catalysts for the oxidation reactions. The product with high catalytic activity can quickly complete the oxidation reaction, so that the content of sodium hydrosulfide in the desulfurization solution is very low, which is favorable for the balance of absorption reaction, the residual amount of hydrogen sulfide in the purified gas phase is reduced, the desulfurization rate is increased, otherwise, the activity of the catalyst is low, and the desulfurization rate is reduced. The cobalt phthalocyanine derivative has excellent catalytic performance and is applied to industrial gas desulfurization for a long time, but the cobalt phthalocyanine derivative has a macromolecular compound structure and is easy to polymerize, the mass transfer speed of the cobalt phthalocyanine derivative is limited, and the exertion of the catalytic performance of the cobalt phthalocyanine derivative is influenced, so that the desulfurization rate of a pure cobalt phthalocyanine derivative desulfurization system is not high, and the requirement of high sulfur removal rate of modern industrial gas cannot be met.

Aiming at the characteristic of cobalt phthalocyanine derivatives, the desulfurization catalyst of the invention introduces micromolecular catalytic components and a component for preventing the cobalt phthalocyanine derivatives from polymerizing, namely iron salt, into the catalyst, so that on one hand, the mass transfer speed of the catalyst is increased, and on the other hand, the effective concentration of the cobalt phthalocyanine derivatives is fully utilized, so that the concentration of balanced sodium hydrosulfide in the desulfurization solution is very low, and the absorption reaction is more complete andmore thorough. The desulfurization rate of the gas to be purified can be greatly improved.

Third, regenerative flotation

The first function is to make the catalyst return from reduction state to oxidation state by adding air in the regeneration tank, and the other function is to convert the sulfur into multi-sulfur by adding air, and float from the desulfurizing liquid to separate the sulfur from the desulfurizing liquid. The component vanadium compound which can promote the generation of the concatenate sulfur is added into the desulfurization catalyst, so that the generated elemental sulfur can generate easily separated concatenate sulfur more easily.

Detailed Description

The first embodiment is a multi-component composite desulfurization catalyst, which comprises the following components in percentage by weight:

50 percent of cobalt phthalocyanine sulfonate

15 percent of hydroquinone

Sodium hexacyanoferrate 15%

10 percent of sodium gluconate

10% of sodium metavanadate.

The desulfurization catalyst and sodium carbonate are prepared into alkaline solution, wherein the amount of the phthalocyanine cobalt sodium sulfonate is 5-6 g per cubic meter, the pH value of the solution is 8-10, and when the content of hydrogen sulfide in gas is below 10 g per standard cubic meter, the desulfurization efficiency can reach 98-99%.

The second embodiment is a multi-component composite desulfurization catalyst, which comprises the following components in percentage by weight:

50 percent of cobalt sodium phthalocyanine

Tannin extract 15%

15 percent of iron carbonate

Sodium citrate 10%

Vanadium pentoxide 10%

The usage is the same as the first embodiment.

Claims

1. A multi-component composite desulfurization catalyst is characterized by mainly comprising the following components:

20 to 70 percent of cobalt phthalocyanine derivative

10 to 50 percent of polyphenol compounds

10 to 60 percent of iron salt

10% -50% of ligand

1 to 40 percent of vanadium compounds.

2. The multi-component desulfurization catalyst according to claim 1, characterized in that:

(3) iron salt, wherein the iron salt is ferric thiocyanate or ferric carbonate;

3. The multi-component desulfurization catalyst according to claim 1, characterized in that: the catalyst takes an alkaline solution as a buffer solution of the catalyst.

4. The multi-component desulfurization catalyst according to claim 3, characterized in that: the pH value of the desulfurization solution prepared by the catalyst is in the range of 7-11.

5. The multi-component composite desulfurization catalyst according to claim 3, characterized in that the alkaline substance of the alkaline solution is: ammonia, ammonium carbonates, ammonium bicarbonates, alkali metal carbonates, alkali metal bicarbonates.

6. Use of the multicomponent composite desulfurization catalyst according to claim 1, characterized in that: the desulfurizing liquid prepared by it can be used in industries needing to remove inorganic sulfur and organic sulfur, such as semi-water gas, city gas, coke oven gas, natural gas, synthetic gas, pyrolysis gas and gasoline, sulfide-containing waste water, and the like.