阅读说明：本技术 一种焦炉煤气深度脱硫催化剂及其制备方法 (Coke oven gas deep desulfurization catalyst and preparation method thereof ) 是由 何相君 程义安 康颖 于 2020-11-17 设计创作，主要内容包括：本发明属于焦炉煤气脱硫技术领域,具体涉及一种焦炉煤气深度脱硫催化剂及其制备方法。本发明利用天然硅铝酸盐和偏钛酸制备改性TiO_2载体,再用浸渍法负载活性组分Fe后与单分散Mo基分散液反应,制得FeMo/TiO_2催化剂。该催化剂具有较好的热稳定性和机械强度,同时催化活性高、可实现深度脱硫,其制备方法简单易行,适宜于工业化推广应用。(The invention belongs to the technical field of coke oven gas desulfurization, and particularly relates to a coke oven gas deep desulfurization catalyst and a preparation method thereof. The invention uses natural aluminosilicate and metatitanic acid to prepare modified TiO 2 A carrier is loaded with active component Fe by an impregnation method and then reacts with the monodisperse Mo-based dispersion liquid to prepare FeMo/TiO 2 A catalyst. The catalyst has better performanceThe catalyst has high thermal stability and mechanical strength, high catalytic activity, can realize deep desulfurization, has simple and easy preparation method, and is suitable for industrial popularization and application.)

1. A preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

preparation of modified TiO by using natural aluminosilicate and metatitanic acid₂A carrier is loaded with active component Fe by an impregnation method and then reacts with the monodisperse Mo-based dispersion liquid to prepare FeMo/TiO₂A catalyst.

2. The preparation method of the coke oven gas deep desulfurization catalyst according to claim 1, characterized by comprising the following steps:

(1) preparation of the carrier: washing metatitanic acid powder with deionized water, performing filter pressing, drying the prepared metatitanic acid filter cake, and crushing to obtain metatitanic acid powder;

adding natural aluminosilicate and pore-forming agent into metatitanic acid powder, kneading, extruding to obtain clover-shaped strip, drying, roasting in muffle furnace to obtain modified TiO₂A carrier;

(2) loading of active component Fe: mixing Fe (NO)₃)₃Dissolving in water to prepare Fe-based impregnation liquid; adjusting the pH value and aging; mixing the impregnating solution with modified TiO₂Mixing the carriers, dipping, drying and roasting to obtain Fe/TiO₂A catalyst;

(3) loading of an active component Mo: preparation of Na₂MoO₄Adding HCl solution into the solution, and adjusting the pH value to obtain aqueous solution containing Mo anions; adding alkyl quaternary ammonium salt, and continuously adjusting the pH value to obtain white milky suspension; finally, deionized water is added to obtain a dispersion liquid of the monodisperse Mo;

transferring the monodisperse Mo-based dispersion to a Fe/TiO₂Filtering, washing and drying the catalyst in a reaction kettle to obtain an intermediate product, and roasting the intermediate product to obtain the high-activity FeMo/TiO₂A catalyst.

3. The method for preparing the coke oven gas deep desulfurization catalyst according to claim 2,

in the step (1), the mass of the natural aluminosilicate is 10-30% of that of the metatitanic acid powder;

in the step (1), the pore-forming agent is a mixture of silica sol, citric acid and methyl cellulose; wherein the mass ratio of the silica sol to the citric acid to the methyl cellulose is 1-2:1: 1-3; the mass of the pore-forming agent is 2-3.5% of that of the metatitanic acid powder.

4. The method for preparing the coke oven gas deep desulfurization catalyst according to claim 2,

in the step (1), the drying temperature of the metatitanic acid filter cake is 100-200 ℃; the roasting is carried out at the temperature of 450-550 ℃, and the roasting time is 2-4 h.

5. The method for preparing the coke oven gas deep desulfurization catalyst according to claim 2,

in the step (2), the pH value is 5.5-6.5; the dipping time is 8-12 h; the roasting is carried out at the temperature of 330-450 ℃, and the roasting time is 1-2 h.

6. The method for preparing the coke oven gas deep desulfurization catalyst according to claim 2,

in the step (3), the pH value is adjusted to 3.8-5, and the pH value is continuously adjusted to 3.8-5.

7. The preparation method of the coke oven gas deep desulfurization catalyst according to claim 2, characterized in that in the step (3), the alkyl quaternary ammonium salt is a long-chain alkyl quaternary ammonium salt solution, and the long-chain alkyl quaternary ammonium salt solution is a mixed solution of CTAB and DTAB, wherein the molar ratio CTAB: DTAB =1-2: 1.

8. The preparation method of the coke oven gas deep desulfurization catalyst according to claim 2, wherein in the step (3), the molar ratio of the quaternary ammonium salt to Mo is 0.4-0.6: 1.

9. The preparation method of the coke oven gas deep desulfurization catalyst as claimed in claim 2, wherein in the step (3), the calcination temperature is 400-600 ℃, and the calcination time is 1-2 h.

10. The coke oven gas deep desulfurization catalyst prepared by the method for preparing the coke oven gas deep desulfurization catalyst according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of coke oven gas desulfurization, and particularly relates to a coke oven gas deep desulfurization catalyst and a preparation method thereof.

Background

The coke oven gas comprises the following components: h₂ 58.48％、CO 6.20％、CO₂ 2.2％、CH₄ 26.49％、C_mH_n2.0%, inert gas 4% and part of the sulphur-containing compounds. The sulfur-containing compound being predominantly H₂S, COS, thiophene, etc., wherein the organic sulfur content is about 100-600mg/m³The inorganic sulfur content is 2000-8000mg/m³. If the coke oven gas is directly discharged, the environment is seriously polluted, and huge waste of energy is caused. At present, the purification of the impurity sulfur in the coke oven gas in industry is a combined use of wet desulphurization and dry desulphurization, and the wet desulphurization can only purify most inorganic sulfur (mainly H) in the coke oven gas₂S) removing organic sulfur and residual H in the coke-oven gas₂S must be removed by dry desulfurization. At present, the high-efficiency synthesis catalyst used in industry mainly takes Fe, Mo and the like as active components and Al₂O₃As a carrier, although coke oven gas hydrodesulfurization catalysts are generally used, a plurality of problems still exist in practical application: for example, the catalyst has short service life, low catalyst activity, low desulfurization rate and the like, and deep desulfurization of coke oven gas is imperative.

Compared with the conventional carrier Al₂O₃，TiO₂The surface has suitable acidity and the interaction between the active ingredients is weak, thereby increasing the dispersion degree of the active ingredients and the reduction degree of the active phase, and thus is considered as a new generation of active carrier. Currently, few commercial hydrodesulfurization catalysts use TiO₂As a carrier, TiO is currently commercially available for this reason₂The specific surface area is small, and is generally 10m²About/g, and the specific surface area of the supported catalyst carrier needs at least 100m²(ii) in terms of/g. At the same time, TiO₂Poor thermal stability and mechanical strength, which seriously affect the catalyst performance. In addition, during conventional impregnation, a large number of chemical bonds with strong interactions are easily formed between the Mo-based active precursor and the support, which often results in MoO₃The uneven particle size and poor dispersibility cause the generation of a large amount of low-activity active phases in the vulcanized catalyst, the full play of the function is difficult, and the deep desulfurization of the coke oven gas cannot be realized.

Therefore, it is necessary to develop a catalyst which can deeply desulfurize and has a high desulfurization rate, a high catalyst strength and a long catalyst life.

Disclosure of Invention

In order to overcome the technical problems, the invention provides the coke oven gas deep desulfurization catalyst which has better thermal stability and mechanical strength, high catalytic activity and capability of realizing deep desulfurization, and the preparation method is simple and easy to implement and is suitable for industrial popularization and application.

In order to achieve the above purpose, the technical scheme provided by the invention is as follows:

a preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

preparation of modified TiO by using natural aluminosilicate and metatitanic acid₂A carrier is loaded with active component Fe by an impregnation method and then reacts with the monodisperse Mo-based dispersion liquid to prepare FeMo/TiO₂A catalyst.

Preferably, the preparation method of the coke oven gas deep desulfurization catalyst comprises the following steps:

(1) preparation of the carrier: washing metatitanic acid powder with deionized water, performing filter pressing, drying the prepared metatitanic acid filter cake, and crushing to obtain metatitanic acid powder;

adding natural aluminosilicate and pore-forming agent into metatitanic acid powder, kneading, extruding to obtain clover-shaped strip, drying, roasting in muffle furnace to obtain modified TiO₂A carrier;

(2) loading of active component Fe: mixing Fe (NO)₃)₃Dissolving in water to prepare Fe-based impregnation liquid; adjusting the pH value and aging; mixing the impregnating solution with modified TiO₂Mixing the carriers, dipping, drying and roasting to obtain Fe/TiO₂A catalyst;

(3) loading of an active component Mo: preparation of Na₂MoO₄Adding HCl solution into the solution, and adjusting the pH value to obtain aqueous solution containing Mo anions; adding alkyl quaternary ammonium salt, and continuously adjusting the pH value to obtain white milky suspension; finally, deionized water is added to obtain a dispersion liquid of the monodisperse Mo;

transferring the monodisperse Mo-based dispersion to a Fe/TiO₂Filtering, washing and drying the catalyst in a reaction kettle to obtain an intermediate product, and roasting the intermediate product to obtain the high-activity FeMo/TiO₂A catalyst.

Preferably, in the step (1), the drying temperature of the metatitanic acid filter cake is 100-200 ℃; preferably 150-.

Preferably, in step (1), the natural aluminosilicate is one or more of kaolin, rectorite, illite and montmorillonite.

Preferably, the natural aluminosilicate is a mixture of kaolin and illite, wherein the mass ratio of the kaolin to the illite is 1: 1-2.

Preferably, in the step (1), the mass of the natural aluminosilicate is 10-30% of the mass of the metatitanic acid powder; preferably 17%.

Preferably, in the step (1), the pore-forming agent is a mixture of silica sol, citric acid and methyl cellulose. Wherein the mass ratio of the silica sol, the citric acid and the methyl cellulose is 1-2: 1-3.

Preferably, in the step (1), the mass of the pore-forming agent is 2-3.5% of the mass of the metatitanic acid powder.

Preferably, in the step (1), the roasting is carried out at the temperature of 450-550 ℃ for 2-4 h.

Preferably, in the step (2), the reagent for adjusting the pH value is at least one of citric acid, oxalic acid and phosphoric acid.

Preferably, in step (2), the reagent for adjusting pH is phosphoric acid.

Preferably, in step (2), the pH value is 5.5-6.5.

Preferably, in the step (2), the aging time is 2-4 h.

Preferably, in the step (2), the impregnation time is 8-12 h; preferably 8 h.

Preferably, in the step (2), the drying is carried out at the temperature of 100-120 ℃, and the drying time is 1-2 h.

Preferably, in the step (2), the roasting is carried out at the temperature of 330-450 ℃, and the roasting time is 1-2 h.

Preferably, in step (3), the pH is adjusted to 3.8 to 5, preferably to 4.5. The pH value is continuously adjusted to 3.8-5, preferably 4.5.

Preferably, in step (3), the alkyl quaternary ammonium salt is a long-chain alkyl quaternary ammonium salt solution, and the long-chain alkyl quaternary ammonium salt solution is a mixed solution of CTAB (cetyl trimethyl ammonium bromide) and DTAB (dodecyl trimethyl ammonium bromide), wherein the molar ratio CTAB: DTAB is 1-2: 1.

Preferably, in step (3), the molar ratio of the quaternary ammonium salt to Mo is 0.4-0.6:1, preferably 0.53: 1.

Preferably, in the step (3), the roasting temperature is 400-.

The invention also aims to provide the coke oven gas deep desulfurization catalyst prepared by the preparation method of the coke oven gas deep desulfurization catalyst.

Compared with the prior art, the invention has the technical advantages that:

(1) FeMo/TiO prepared by the invention₂The catalyst is beneficial to controlling the dispersion degree and the stacking thickness of the active metal Mo, so that the catalyst is not easy to agglomerate and has good desulfurization activity.

(2) The invention uses natural aluminosilicate and metatitanic acid to prepare modified TiO₂The carrier increases the thermal stability of the carrier and is beneficial to controlling the interaction force between the active metal and the carrier.

(3) The impurity Fe and Ti in the natural aluminosilicate used in the invention play the role of a cocatalyst, which is beneficial to improving the catalytic activity.

(4) The natural aluminosilicate adopted by the invention is beneficial to the forming of the carrier, and the strength of the carrier is increased.

Detailed Description

The present invention will be described below with reference to specific examples to make the technical aspects of the present invention easier to understand and grasp, but the present invention is not limited thereto. The experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.

Example 1

A preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

(1) preparation of the carrier: washing metatitanic acid powder with deionized water, performing filter pressing, drying the prepared metatitanic acid filter cake at 150 ℃, and crushing to obtain metatitanic acid powder;

adding a mixture of kaolin and illite with the mass ratio of 1:1 (the total mass is 17% of the mass of the metatitanic acid powder; and) and a mixture of silica sol, citric acid and methyl cellulose with the mass ratio of 2:1 (the total mass is 3% of the mass of the metatitanic acid powder) into the metatitanic acid powder; kneading, extruding to obtain clover-shaped strip, drying, calcining at 450 deg.C in muffle furnace for 2 hr, crushing, and sieving to obtain short strip of modified TiO₂A carrier;

(2) loading of active component Fe: mixing Fe (NO)₃)₃Dissolving in water to prepare Fe-based impregnation liquid; adjusting the pH value to 6.0 by using phosphoric acid, and aging for 2 h; mixing the impregnating solution with modified TiO₂Mixing the carriers, soaking for 8h, drying at 120 deg.C for 1h, and calcining at 450 deg.C for 1h to obtain Fe/TiO₂A catalyst;

(3) loading of an active component Mo: preparation of Na₂MoO₄Adding HCl solution, and adjusting the pH value to 5 to obtain aqueous solution containing Mo anions; adding a mixed solution of CTAB and DTAB with a molar ratio of CTAB to DTAB being 1: 1; making the total molar quantity of CTAB and DTAB be Na₂MoO₄0.53 times of; continuously adjusting the pH value to 5 to obtain white milky suspension; finally, deionized water is added to obtain a dispersion liquid of the monodisperse Mo;

transferring the monodisperse Mo-based dispersion to a Fe/TiO₂Filtering, washing and drying the catalyst in a reaction kettle to obtain an intermediate product, and roasting the intermediate product at 450 ℃ for 1h to obtain FeMo/TiO₂A catalyst.

Example 2

A preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

(1) preparation of the carrier: washing metatitanic acid powder with deionized water, performing filter pressing, drying the prepared metatitanic acid filter cake at 100 ℃, and crushing to obtain metatitanic acid powder;

adding a mixture of kaolin and illite with the mass ratio of 1: 2 (the total mass is 10% of the mass of the metatitanic acid powder; and) and a mixture of silica sol, citric acid and methyl cellulose with the mass ratio of 1: 3 (the total mass is 2% of the mass of the metatitanic acid powder) into the metatitanic acid powder; kneading, extruding to obtain clover-shaped strip, drying, calcining at 450 deg.C in muffle furnace for 4 hr, crushing, and sieving to obtain short strip of modified TiO₂A carrier;

(2) loading of active component Fe: mixing Fe (NO)₃)₃Dissolving in water to prepare Fe-based impregnation liquid; adjusting the pH value to 5.5 by using phosphoric acid, and aging for 4 hours; mixing the impregnating solution with modified TiO₂Mixing the carriers, soaking for 12h, drying at 100 deg.C for 1h, and calcining at 450 deg.C for 1h to obtain Fe/TiO₂A catalyst;

(3) loading of an active component Mo: preparation of Na₂MoO₄Adding HCl solution, and adjusting the pH value to 3.8 to obtain aqueous solution containing Mo anions; adding a mixed solution of CTAB and DTAB with a molar ratio of CTAB to DTAB of 2: 1; making the total molar quantity of CTAB and DTAB be Na₂MoO₄0.4 times of; continuously adjusting the pH value to 3.8 to obtain white milky suspension; finally, deionized water is added to obtain a dispersion liquid of the monodisperse Mo;

transferring the monodisperse Mo-based dispersion to a Fe/TiO₂Filtering, washing and drying the catalyst in a reaction kettle to obtain an intermediate product, and roasting the intermediate product at 400 ℃ for 2 hours to obtain FeMo/TiO₂A catalyst.

Example 3

A preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

(1) preparation of the carrier: washing metatitanic acid powder with deionized water, performing filter pressing, drying the prepared metatitanic acid filter cake at 200 ℃, and crushing to obtain metatitanic acid powder;

titanium biasAdding a mixture of kaolin and illite (the total mass is 30 percent of the mass of the metatitanic acid powder) and a mixture of silica sol, citric acid and methyl cellulose (the total mass is 3.5 percent of the mass of the metatitanic acid powder) into the acid powder, wherein the mass ratio of the mixture of kaolin and illite is 1: 1; kneading, extruding to obtain clover-shaped strip, drying, calcining at 550 deg.C in muffle furnace for 2 hr, crushing, and sieving to obtain short strip-shaped modified TiO₂A carrier;

(2) loading of active component Fe: mixing Fe (NO)₃)₃Dissolving in water to prepare Fe-based impregnation liquid; adjusting the pH value to 6.5 by using phosphoric acid, and aging for 2 h; mixing the impregnating solution with modified TiO₂Mixing the carriers, soaking for 8h, drying at 100 deg.C for 1h, and calcining at 330 deg.C for 2h to obtain Fe/TiO₂A catalyst;

(3) loading of an active component Mo: preparation of Na₂MoO₄Adding HCl solution, and adjusting the pH value to 4.3 to obtain aqueous solution containing Mo anions; adding a mixed solution of CTAB and DTAB with a molar ratio of CTAB to DTAB being 1-2: 1; making the total molar quantity of CTAB and DTAB be Na₂MoO₄0.6 times of; continuously adjusting the pH value to 4.3 to obtain white milky suspension; finally, deionized water is added to obtain a dispersion liquid of the monodisperse Mo;

transferring the monodisperse Mo-based dispersion to a Fe/TiO₂Filtering, washing and drying the catalyst in a reaction kettle to obtain an intermediate product, and roasting the intermediate product at 600 ℃ for 1h to obtain FeMo/TiO₂A catalyst.

Comparative example 1

The pore former was different from that of example 1.

A preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

(1) preparation of the carrier: washing metatitanic acid powder with deionized water, performing filter pressing, drying the prepared metatitanic acid filter cake at 150 ℃, and crushing to obtain metatitanic acid powder;

adding a mixture of kaolin and illite (the total mass is 17% of the mass of the metatitanic acid powder; the mass ratio is 1: 1) and silica sol, nitric acid and A in a mass ratio of 2:1 into the metatitanic acid powderA mixture of base cellulose (total mass is 3% of the mass of the metatitanic acid powder); kneading, extruding to obtain clover-shaped strip, drying, calcining at 450 deg.C in muffle furnace for 2 hr, crushing, and sieving to obtain short strip of modified TiO₂A carrier;

(2) - (3) step(s) the same as in example 1, to obtain FeMo/TiO₂A catalyst.

Comparative example 2

The quaternary alkyl ammonium salt is different from that of example 1.

A preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

(1) - (2) preparation of Fe/TiO in the same manner as in example 1₂A catalyst;

(3) loading of an active component Mo: preparation of Na₂MoO₄Adding HCl solution, and adjusting the pH value to 5 to obtain aqueous solution containing Mo anions; adding CTAB in a molar ratio; making the total molar quantity of CTAB be Na₂MoO₄0.53 times of; continuously adjusting the pH value to 5 to obtain white milky suspension; finally, deionized water is added to obtain a dispersion liquid of the monodisperse Mo;

transferring the monodisperse Mo-based dispersion to a Fe/TiO₂Filtering, washing and drying the catalyst in a reaction kettle to obtain an intermediate product, and roasting the intermediate product at 450 ℃ for 1h to obtain FeMo/TiO₂A catalyst.

Comparative example 3

Compared with the example 1, the natural silicon-aluminum mineral is not contained.

A preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

(1) preparation of the carrier: washing metatitanic acid powder with deionized water, performing filter pressing, drying the prepared metatitanic acid filter cake at 150 ℃, and crushing to obtain metatitanic acid powder;

adding a mixture of silica sol, citric acid and methyl cellulose (the total mass is 3 percent of the mass of the metatitanic acid powder) with the mass ratio of 2:1 into the metatitanic acid powder; kneading, extruding to obtain clover-shaped strip, drying, roasting at 450 deg.C in muffle furnace for 2 hr, crushing, and sievingTiO in short strip form₂A carrier;

(2) - (3) step(s) the same as in example 1 to obtain FeMo/TiO₂A catalyst.

Comparative example 4

The preparation method is different compared to example 1.

A preparation method of a coke oven gas deep desulfurization catalyst comprises the following steps:

(1) - (2) step As in example 1, Fe/TiO₂A catalyst;

(3) loading of an active component Mo: preparation of Na₂MoO₄Adding HCl solution, and adjusting the pH value to 5 to obtain aqueous solution containing Mo anions; adding a mixed solution of CTAB and DTAB with a molar ratio of CTAB to DTAB being 1: 1; making the total molar quantity of CTAB and DTAB be Na₂MoO₄0.53 times of; continuously adjusting the pH value to 5 to obtain white milky suspension; finally, deionized water is added to obtain a dispersion liquid of the monodisperse Mo;

transferring the monodisperse Mo-based dispersion to a Fe/TiO₂Filtering, washing and drying the catalyst in a reaction kettle to obtain an intermediate product, and roasting the intermediate product at 450 ℃ for 1h to obtain FeMo/TiO₂A catalyst.

Effect test

Simulating coke oven gas: total organic sulfur content 245mg/m³The content of thiophene is 18.8mg/m³。

A reaction device: adopting a miniature fixed bed reactor, pre-vulcanizing the catalyst before reaction, wherein the pre-vulcanizing agent contains 3% of CS₂The pre-vulcanization temperature of the cyclohexane mixed solution is 400 ℃, and the pre-vulcanization time is 3 hours.

The evaluation conditions of the catalyst were: normal pressure; the temperature is 370 ℃; airspeed of 2000h^-1After the reaction was stabilized for 4 hours, sampling analysis was started.

And (3) characterization and analysis: the organic sulfur content in the gas before and after the reaction is determined by a trace sulfur analyzer, the specific surface area and the pore volume of the catalyst are determined by a full-automatic specific surface area and porosity analyzer, and the compressive strength is determined by a catalyst compressive strength determinator. The test results are shown in Table 1.

TABLE 1 Performance index of Coke oven gas desulfurization catalyst

Therefore, the desulfurization catalyst prepared by the method has a good desulfurization effect, can realize deep desulfurization, and has large influence on the performance index of the catalyst due to the selection of each reagent and the parameter range in the preparation process.

The above detailed description is specific to one possible embodiment of the present invention, and the embodiment is not intended to limit the scope of the present invention, and all equivalent implementations or modifications without departing from the scope of the present invention should be included in the technical scope of the present invention.