CN118743904A - A kind of hydrocarbon gas desulfurizing agent and preparation method thereof - Google Patents

Abstract

The present invention discloses a hydrocarbon gas desulfurizer, the desulfurizer composition includes: a desulfurizer A with a mass percentage of 60% to 90% and a desulfurizer B with a mass percentage of 10% to 40%; the desulfurizer A is a modified molecular sieve, which uses transition metal elements including at least one of Fe, Mn, Cu, and Ag to modify the molecular sieve, and the molecular sieve includes one of _NH4Y , 13X, and A-type molecular sieves; the desulfurizer B is a transition metal oxide including at least one of iron oxide, manganese oxide, copper oxide, and zinc oxide. The present invention is a desulfurizer for removing inorganic sulfur such as hydrogen sulfide and organic sulfur compounds such as carbonyl sulfide, mercaptan, sulfide, disulfide, and saturated heterocyclic sulfur compounds from gaseous fuels and hydrocarbons at room temperature.

Description

A kind of hydrocarbon gas desulfurizing agent and preparation method thereof

Technical Field

The invention relates to the technical field of desulfurizing agents, and in particular to a hydrocarbon gas desulfurizing agent and a preparation method thereof.

Background Art

At present, under the existing technology, in order to facilitate people to detect whether the gas fuel is leaking, a small amount of sulfur compounds, including thiophene, hydrogen sulfide, sulfide, etc., are usually added to the gas fuel. This sulfide-containing fuel will produce sulfur oxides when burned, which will pollute the environment. Sulfur-containing exhaust gas will also cause the catalysts that remove other harmful substances at the back end to be poisoned and deactivated, resulting in additional pollution. Many catalysts used in industry to refine and process fuels will also be affected by sulfur poisoning. In fuel cells, the core component is an electrocatalyst with precious metal platinum as the active center, which is highly sensitive to sulfides. Therefore, the sulfur content of the fuel gas that provides power for the fuel cell must be strictly limited, and the sulfide content in the fuel gas is required to be below 0.1ppm.

At present, the method for removing sulfur compounds in hydrocarbon fuel gas is mainly to contact the feed gas with a catalyst adsorbent containing precious metals, zeolite and alumina, and remove it at a relatively high temperature (150-400°C). This method has high energy consumption in the desulfurization process and is only applicable to the removal of carbonyl sulfide and saturated heterocyclic sulfur compounds, such as tetrahydrothiophene, mercaptans and hydrogen sulfide. For sulfides containing complex C-S-C or C-S-S-C bond structures, such as carbonyl sulfide (COS), diethyl sulfide, and diethyl disulfide, they usually need to be removed by adsorption and hydrolysis. Conventional methods cannot remove them, and when sulfide and inorganic sulfur coexist, competitive adsorption will occur, which reduces the removal efficiency of organic sulfur such as sulfide.

Summary of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and to provide a hydrocarbon gas desulfurizer, which is used for removing inorganic sulfur such as hydrogen sulfide and organic sulfur compounds such as carbonyl sulfide, mercaptans, sulfides, disulfides and saturated heterocyclic sulfur compounds (including tetrahydrothiophene) from gaseous fuels and hydrocarbons (such as natural gas) at room temperature.

The present invention is achieved through the following technical solutions:

A hydrocarbon gas desulfurizer, the desulfurizer composition comprising: a desulfurizer A with a mass percentage of 60% to 90% and a desulfurizer B with a mass percentage of 10% to 40%;

The desulfurizer A is a modified molecular sieve, which is modified by using at least one transition metal element including Fe, Mn, Cu, and Ag to modify the molecular sieve, and the molecular sieve includes one of NH ₄ Y, 13X, and A-type molecular sieve;

The desulfurizing agent B is a transition metal oxide including at least one of iron oxide, manganese oxide, copper oxide and zinc oxide.

Furthermore, the transition metal in the modified molecular sieve accounts for 1% to 20% by mass, and the molecular sieve accounts for 80% to 99% by mass.

Furthermore, the transition metal used in the modified molecular sieve is a soluble metal salt, and the soluble metal salt is a nitrate or an acetate.

Furthermore, the particle size of the molecular sieve is in the range of 1-10 μm.

Furthermore, the molecular sieve has a specific surface area ranging from 80 to 150 m ² /g.

Furthermore, the transition metal oxide has a particle size ranging from 0.5 to 10 μm.

A method for preparing a hydrocarbon gas desulfurizer, the specific steps of which are as follows:

1) Modification: The transition metal element is fixed on the surface of the molecular sieve by an equal volume impregnation method or an ion exchange method, so that the micro-surface performance of the molecular sieve is improved, and then the transition metal element is further fixed on the surface of the molecular sieve by drying and roasting to obtain a desulfurizer A;

2) Ball milling: Add the obtained desulfurizer A to a ball mill, add desulfurizer B, water and a binder, and prepare a uniformly mixed desulfurizer slurry C by ball milling;

3) Shaping: The obtained desulfurizer slurry C can be used to prepare granular desulfurizer, coated honeycomb desulfurizer and extruded honeycomb desulfurizer.

Furthermore, the isovolumetric impregnation method comprises the following steps: loading the transition metal soluble salt solution onto the molecular sieve material by isovolumetric impregnation method according to the mass ratio of each component, and obtaining the modified molecular sieve after drying and calcining.

Furthermore, the ion exchange method includes the following steps: dispersing the molecular sieve material in the transition metal soluble salt solution according to the mass ratio of each component, mechanically stirring for 2 to 5 hours, filtering, drying and calcining to obtain the modified molecular sieve.

Furthermore, the adhesive includes one of aluminum sol, silica sol and zirconium sol.

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

1. The present invention uses transition metal elements that have a strong complexing effect with sulfur to modify the molecular sieve with a strong acidic surface, thereby enhancing the adsorption capacity of the molecular sieve for sulfides, thereby improving the selectivity and removal rate of the desulfurizer for organic sulfur;

2. The present invention adopts a method of combining a transition metal oxide that is easy to react with inorganic sulfur with a modified molecular sieve, and effectively adsorbs inorganic sulfur through the transition metal oxide, thereby preventing the modified molecular sieve from adsorbing inorganic sulfur, thereby extending the adsorption time of the modified molecular sieve on organic sulfides and extending the service life of the desulfurizer;

3. The present invention adopts modified molecular sieves and transition metal oxides to reduce the use temperature of the desulfurizer, and can remove the sulfur content in the fuel gas to below 50 ppb at below 100°C;

4. The present invention is easy to operate, low in cost, and easy to realize industrial-scale production.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

FIG. 1 is an adsorption curve of sulfide in natural gas by the desulfurizer obtained in Example 5 of the present invention and Comparative Example 1.

DETAILED DESCRIPTION

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary implementation modes of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

Example 1

This embodiment provides a coated honeycomb desulfurizer combining Ag-modified 13X molecular sieve and manganese oxide, wherein the modified molecular sieve components are: Cu accounts for 10% by weight, 13X molecular sieve accounts for 90% by weight. The modified molecular sieve accounts for 80% by weight in the desulfurizer, and the manganese oxide accounts for 20% by weight. The molecular sieve has a specific surface area of ^100m2 /g and a particle size of 4μm.

The preparation method of this embodiment is as follows: _AgNO3 solution is loaded on 13X molecular sieve by equal volume impregnation method, and Ag-modified Ag/13X molecular sieve powder is obtained after drying and calcining; Ag/13X molecular sieve and manganese oxide powder are added into a ball mill according to proportion, and then water and aluminum sol are added, and the slurry is evenly ground into a slurry, which is coated on a honeycomb ceramic substrate, and then dried and calcined to obtain a coated honeycomb desulfurizer.

Example 2

This embodiment provides a granular desulfurizer combining Fe-modified NH4Y molecular sieve and iron oxide powder, wherein the modified molecular sieve composition is: Fe accounts for 1% by weight, NH4Y molecular sieve accounts for 99% by weight. The modified molecular sieve accounts for 90% by weight in the desulfurizer, and manganese oxide accounts for 10% by weight. The molecular sieve has a specific surface area of ^150m2 /g and a particle size of 1μm.

The preparation method of this embodiment is as follows: Fe(NO ₃ ) ₃ solution is loaded on NH4Y molecular sieve by equal volume impregnation method, and after drying and calcining, Fe-modified Ag/13X molecular sieve powder is obtained; Fe/13X molecular sieve and iron oxide powder are added to a granulator in proportion, and then water and zirconium sol are added, and the mixture is kneaded, granulated, and finally dried and calcined to obtain a granular desulfurizer.

Example 3

This embodiment provides an extruded honeycomb desulfurizer in which a Mn-modified A-type molecular sieve is combined with copper oxide powder, wherein the modified molecular sieve composition is: Mn accounts for 20% by weight, and A-type molecular sieve accounts for 80% by weight. The modified molecular sieve accounts for 70% by weight in the desulfurizer, and the copper oxide accounts for 30% by weight. The molecular sieve has a specific surface area of ^80m2 /g and a particle size of 10μm.

The preparation method of this embodiment is as follows: Mn(NO ₃ ) ₂ solution is loaded on type A molecular sieve by an equal volume impregnation method, and after drying and calcining, Mn-modified Mn/type A molecular sieve powder is obtained; Mn/type A molecular sieve and copper oxide powder are added to an extruder in proportion, and then water and aluminum sol are added, and the mixture is kneaded, kneaded, extruded, and finally dried and calcined to obtain an extruded honeycomb desulfurizer.

Example 4

This embodiment provides a coated honeycomb desulfurizer combining Cu-modified 13X molecular sieve and manganese oxide powder, wherein the modified molecular sieve composition is: Cu accounts for 10% by weight, 13X molecular sieve accounts for 90% by weight. The modified molecular sieve accounts for 80% by weight in the desulfurizer, and the manganese oxide accounts for 20% by weight. The molecular sieve has a specific surface area of ^100m2 /g and a particle size of 4μm.

The preparation method of this embodiment is as follows: Cu(NO ₃ ) ₂ solution is loaded on 13X molecular sieve by ion exchange method, and Cu-modified Cu/13X molecular sieve powder is obtained after drying and calcining; Cu/13X molecular sieve and manganese oxide powder are added into a ball mill according to proportion, and then water and silica sol are added, and the slurry is ground into a slurry, which is coated on a honeycomb ceramic substrate, and the coated honeycomb desulfurizer is obtained after drying and calcining.

Example 5

This embodiment provides a coated honeycomb desulfurizer combining Cu-modified 13X molecular sieve and manganese oxide powder, wherein the modified molecular sieve composition is: Cu accounts for 10% by weight, 13X molecular sieve accounts for 90% by weight. The modified molecular sieve accounts for 80% by weight in the desulfurizer, and the manganese oxide accounts for 20% by weight. The molecular sieve has a specific surface area of ^100m2 /g and a particle size of 4μm.

The preparation method of this embodiment is as follows: Cu(NO ₃ ) ₂ solution is loaded on type A molecular sieve by an equal volume impregnation method, and after drying and calcining, Cu-modified Cu/13X molecular sieve powder is obtained; Cu/13X molecular sieve and manganese oxide powder are added to a ball mill in proportion, and then water and aluminum sol are added, and the slurry is ground evenly to form a slurry, which is coated on a honeycomb ceramic substrate, and after drying and calcining, a coated honeycomb desulfurizer is obtained.

Comparative Example 1

This comparative example provides a coated honeycomb desulfurizer composed of 13X molecular sieve and manganese oxide powder, wherein the mass proportion of 13X molecular sieve in the desulfurizer is 80%, the mass proportion of manganese oxide is 20%, the specific surface area of the molecular sieve is ^100m2 /g, and the particle size is 4μm.

The preparation method of this comparative example is as follows: 13X molecular sieve and manganese oxide powder are added into a ball mill according to a proportion, and then water and aluminum sol are added, and the slurry is evenly ground, and the slurry is coated on a honeycomb ceramic substrate, and the coated honeycomb desulfurizer is obtained after drying and calcining.

Comparative Example 2

This comparative example provides a coated honeycomb desulfurizer of Cu-modified 13X molecular sieve, wherein the modified molecular sieve components are: Cu accounts for 10% by mass, and 13X molecular sieve accounts for 90% by mass. The molecular sieve has a specific surface area of 100 m ² /g and a particle size of 4 μm.

The preparation method of this comparative example is as follows: Cu(NO ₃ ) ₂ solution is loaded on 13X molecular sieve by equal volume impregnation method, and after drying and calcining, Cu-modified Cu/13X molecular sieve powder is obtained; Cu/13X molecular sieve is added to a ball mill, and then water and aluminum sol are added, and the slurry is evenly ground into a slurry, which is coated on a honeycomb ceramic substrate, and after drying and calcining, a coated honeycomb desulfurizer is obtained.

The desulfurization performance test was carried out on the desulfurization agents obtained in the above examples. Specifically, the test conditions were as follows: the test atmosphere was 2% ethane, 0.3% propane, 1% CO ₂ , 0.5% N ₂ , 5ppm tetrahydrothiophene, 10ppm H ₂ S, 2ppm CS ₂ , CH ₄ as the balance gas, the air velocity was 2000h- ¹ , the pressure was 2bar, the desulfurizer was placed in a fixed bed reactor, the test was carried out continuously at 38°C, and the total sulfur content in the desulfurized tail gas was recorded, as shown in Figure 1. When the total sulfur content in the tail gas reaches 50ppb, it means that the sulfide has penetrated, and the time taken for the penetration is the penetration time, and the penetration time of the desulfurizer for the sulfide is obtained as shown in Table 1. The test equipment uses a gas chromatograph and a trace sulfur analyzer for analysis. The gas chromatograph uses a 60m×320μm capillary column for sulfide separation, and the trace sulfur analyzer uses a high-performance FPD detector for sulfur detection. The operating detection limit of the system is 10ppb.

Table 1 Penetration time of desulfurizers obtained in Examples and Comparative Examples for sulfides in natural gas

The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims (10)

1. A hydrocarbon gas desulfurizing agent, wherein the desulfurizing agent composition comprises: 60-90% of desulfurizing agent A and 10-40% of desulfurizing agent B;

The desulfurizing agent A is a modified molecular sieve, at least one of transition metal elements Fe, mn, cu, ag is adopted to modify the molecular sieve, and the molecular sieve comprises one of NH ₄ Y and 13X, A type molecular sieve;

The desulfurizing agent B is at least one of transition metal oxide including ferric oxide, manganese oxide, copper oxide and zinc oxide.

2. The hydrocarbon gas desulfurizing agent according to claim 1, wherein the transition metal in the modified molecular sieve is 1-20% by mass and the molecular sieve is 80-99% by mass.

3. The hydrocarbon gas desulfurizing agent according to claim 1, wherein the transition metal used in the modified molecular sieve is a soluble metal salt, and the soluble metal salt is nitrate or acetate.

4. A hydrocarbon gas desulfurizing agent according to claim 1, wherein said molecular sieve has a particle size in the range of 1 to 10 μm.

5. A hydrocarbon gas desulfurizing agent according to claim 1, wherein said molecular sieve has a specific surface area in the range of 80-150m ²/g.

6. A hydrocarbon gas desulfurizing agent according to claim 1, wherein said transition metal oxide has a particle size in the range of 0.5 to 10 μm.

7. The method for preparing a hydrocarbon gas desulfurizing agent according to any one of claims 1 to 6, which comprises the steps of:

1) Modification: fixing transition metal elements on the surface of the molecular sieve by adopting an isovolumetric impregnation method or an ion exchange method, so that the micro-surface performance of the molecular sieve is improved, and then further fixing the transition metal elements on the surface of the molecular sieve by drying and roasting to obtain a desulfurizing agent A;

2) Ball milling and mixing: adding the obtained desulfurizing agent A into a ball milling tank, adding the desulfurizing agent B, water and an adhesive, and ball milling to obtain uniformly mixed desulfurizing agent slurry C;

3) Shaping: the obtained desulfurizing agent slurry C can be used for preparing a granular desulfurizing agent, a coated honeycomb desulfurizing agent and an extruded honeycomb desulfurizing agent.

8. The method for producing a hydrocarbon gas desulfurizing agent according to claim 7, wherein said isovolumetric impregnation method comprises the steps of: and respectively loading the transition metal soluble salt water solution on the molecular sieve material according to the mass ratio of each component by an isovolumetric impregnation method, and drying and roasting to obtain the modified molecular sieve.

9. The method for producing a hydrocarbon gas desulfurizing agent according to claim 7, wherein said ion exchange method comprises the steps of: and (3) respectively dispersing the molecular sieve material in the transition metal soluble salt water solution according to the mass ratio of each component, mechanically stirring for 2-5 h, filtering, drying and roasting to obtain the modified molecular sieve.

10. The method for preparing a hydrocarbon gas desulfurizing agent according to claim 7, wherein said binder is one of aluminum sol, zirconium sol and silica sol.