阅读说明：本技术 一种炼焦脱硫方法 (Coking desulfurization method ) 是由 仲奇凡 肖劲 王港 犹子涵 叶圣超 于 2020-04-30 设计创作，主要内容包括：本发明涉及一种炼焦脱硫方法,将复合催化剂和水混合,搅获得浓度为0.05-1wt%的浸渍液；提供粒度不超过3mm的高硫炼焦煤,将所述高硫炼焦煤与浸渍液混合,以70-100r/min的速率搅拌1-3h后,于90-110℃条件下干燥10-14h,获得煤样品；对煤样品装入炼焦炉内,升温,待温度达到950-1050℃时,向炼焦炉内通入氢气,使得炼焦炉内氢气的压力不低于1个大气压,保温1.5-2.5h后,冷却,获得焦炭。本发明能获得较好的脱硫效果,且提升焦炭产品的综合性能。(The invention relates to a coking desulfurization method, which comprises the steps of mixing a composite catalyst with water, and stirring to obtain an impregnation liquid with the concentration of 0.05-1 wt%; providing high-sulfur coking coal with the granularity not more than 3mm, mixing the high-sulfur coking coal with an impregnation solution, stirring at the speed of 70-100r/min for 1-3h, and drying at the temperature of 90-110 ℃ for 10-14h to obtain a coal sample; and (2) putting the coal sample into a coke oven, heating, introducing hydrogen into the coke oven when the temperature reaches 950-1050 ℃, so that the pressure of the hydrogen in the coke oven is not lower than 1 atmospheric pressure, preserving the heat for 1.5-2.5h, and cooling to obtain coke. The invention can obtain better desulfurization effect and improve the comprehensive performance of coke products.)

1. A coking desulfurization method is characterized by comprising the following steps:

s1, mixing the composite catalyst and water, and stirring to obtain an impregnation liquid with the concentration of 0.05-1 wt%;

the preparation method of the composite catalyst comprises the following steps:

providing a mixed solution; wherein, in the mixed solution, nickel acetate, molybdenum acetate and H₃BO₃In a molar ratio of 1: (0.3-0.5): (0.05-0.2);

drying the mixed solution to obtain a solid sample;

calcining the solid sample at the temperature of 600-800 ℃ for 2-4h, and grinding to obtain the composite catalyst with the particle size of less than or equal to 0.05 mm;

s2, providing high-sulfur coking coal with the granularity not more than 13mm, mixing the high-sulfur coking coal with the impregnation liquid obtained in the step S1, stirring at the speed of 70-100r/min for 1-3h, and drying at the temperature of 90-150 ℃ for 10-14h to obtain a coal sample;

wherein, the mass ratio of the high-sulfur coking coal to the composite catalyst in the impregnation liquid is (100- & ltSUB & gt 1000-): 1;

s3, loading the coal sample obtained in the step S2 into a coke oven, heating, introducing hydrogen into the coke oven when the temperature reaches 950 ℃ and 1050 ℃, keeping the pressure of the hydrogen in the coke oven not lower than 1 atmospheric pressure, and cooling after 1.5-2.5h of heat preservation to obtain coke.

2. The coking desulfurization method according to claim 1, wherein in S1, the nickel acetate solution and the molybdenum acetate solution are mixed with H₃BO₃The solution is mixed and stirred for 0.5 to 1 hour at the speed of 350-450r/min to obtain a mixed solution.

3. The coking desulfurization method as claimed in claim 1, wherein the drying process in S1 is carried out at 100-150 ℃.

4. The coking desulfurization method according to claim 1, wherein in S1, the mixed solution contains nickel acetate, molybdenum acetate and H₃BO₃In a molar ratio of 1: (0.35-0.45): (0.1-0.15).

5. The coking desulfurization method according to claim 1, wherein in S2, high-sulfur coking coal having a particle size of 3mm or less is provided.

6. The coking desulfurization method according to claim 1, wherein the stirring in S2 is carried out at a rate of 80 to 90r/min for 1 to 3 hours.

7. The coking desulfurization method according to claim 1, wherein the coal sample is obtained by drying at 95 to 105 ℃ for 11 to 13 hours in S2.

8. The coking and desulfurization method as claimed in claim 1, wherein in S2, the mass ratio of the high-sulfur coking coal to the composite catalyst in the impregnation liquid is (150- & 800): 1.

9. the coking desulfurization method according to any one of claims 1 to 8, wherein the hydrogen gas is introduced at a rate of 10 to 20L/h in S3.

Technical Field

The invention relates to a coking desulfurization method, belonging to the technical field of coking.

Background

The coke is an important raw material and fuel for metallurgy, chemical industry and non-ferrous industry, and plays an important role in national economic development. The sulfur content in the coke is one of the main indexes for evaluating the quality, price and the like of the coke, and obviously influences the energy consumption, the production capacity, the molten iron quality and the price of the coke in the international market of blast furnace iron making. China is the first coke producing country and export country in the world, but because of the characteristics of the traditional coking process and the lack of low-sulfur coking coal resources, the production of high-quality low-sulfur coke is restrained, and simultaneously, the environment is also severe. The design and development of the low-cost low-energy-consumption pollution-free desulfurization technology in the coal coking process have important significance for industrial production, economic markets and the like, and are also important components of clean coal utilization technology.

Sulfur in coal is divided into two major classes of organic sulfur and inorganic sulfur, and heterocyclic compounds such as thiophene, dibenzothiophene and the like are difficult to remove sulfur in molecules in a desulfurization project. In order to meet the requirements of coal coking desulfurization under the current strict standard, the desulfurization catalyst with higher activity is developed and prepared only by changing the current existing process flow and reaction conditions. For changing the process flow, only the existing reaction device is modified to a certain extent, which can meet the requirement of deep desulfurization of coke to a certain extent, but the equipment investment is increased. If the reaction conditions are changed, such as the conditions of increasing the temperature and pressure of the reaction, side reactions in the process can also be accelerated, so that the yield and the quality of the target product are reduced; the increased pressure also increases the investment and operating costs of the reaction apparatus. Therefore, the best method and the most cost-effective means to solve this problem is to continuously develop a desulfurization catalyst with higher activity to replace the original catalyst material.

The hydrodesulfurization method is characterized in that a catalyst and hydrogen bias are used together, so that a sulfur-containing compound and hydrogen interact in the coal coking process to react and desulfurize to generate a hydrocarbon compound and hydrogen sulfide, the desulfurization reaction is relatively easy to occur for non-heterocyclic sulfur-containing compounds, and the reaction network is very simple. Firstly, the C-S or S-S bond breaking reaction is carried out, then the carbon molecular bone chain is hydrogenated, and finally hydrocarbon and hydrogen sulfide are generated.

Chinese patent specification CN107384503A discloses a method for desulfurizing petroleum coke, which comprisesThe catalyst used is Al₂O₃The nickel-molybdenum catalyst is a carrier, the catalyst is columnar with the diameter of 1mm and the length of 10-15mm, and can obtain a good desulfurization effect, but the addition amount of the catalyst is large in a single treatment process, so that the amount of petroleum coke actually treated in the single treatment process is undoubtedly reduced; in addition, after the desulfurization is completed, the catalyst is screened out by particle size screening, which undoubtedly increases the treatment flow and workload, resulting in increased desulfurization cost.

Disclosure of Invention

In view of the disadvantages of the prior art, the present invention aims to provide a coking and desulfurizing method for efficiently obtaining a coke product having a low sulfur content and a high strength at a low cost.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a coking desulfurization method comprises the following steps:

s1, mixing the composite catalyst and water, and stirring to obtain an impregnation liquid with the concentration of 0.05-1 wt%;

the preparation method of the composite catalyst comprises the following steps:

providing a mixed solution; wherein, in the mixed solution, nickel acetate, molybdenum acetate and H₃BO₃In a molar ratio of 1: (0.3-0.5): (0.05-0.2);

drying the mixed solution to obtain a solid sample;

calcining the solid sample at the temperature of 600-800 ℃ for 2-4h, and grinding to obtain the composite catalyst with the particle size of less than or equal to 0.05 mm;

s2, providing high-sulfur coking coal with the particle size not more than 13mm, mixing the high-sulfur coking coal with the impregnation liquid obtained in the step S1, stirring at the speed of 70-100r/min for 1-3h, and drying at the temperature of 90-110 ℃ for 10-14h to obtain a coal sample;

wherein, the mass ratio of the high-sulfur coking coal to the composite catalyst in the impregnation liquid is (100- & ltSUB & gt 1000-): 1;

s3, loading the coal sample obtained in the step S2 into a coke oven, heating, introducing hydrogen into the coke oven when the temperature reaches 950 ℃ and 1050 ℃, keeping the pressure of the hydrogen in the coke oven not lower than 1 atmospheric pressure, and cooling after 1.5-2.5h of heat preservation to obtain coke.

Further, in S1, a nickel acetate solution, a molybdenum acetate solution and H₃BO₃The solution is mixed and stirred for 0.5 to 1 hour at the speed of 350-450r/min to obtain a mixed solution. Preferably, the stirring rate is 400 r/min.

Further, in S1, the drying process is performed at 100-150 ℃.

Further, in S1, nickel acetate, molybdenum acetate and H are added to the mixed solution₃BO₃In a molar ratio of 1: (0.35-0.45): (0.1-0.15).

Further, in S2, high-sulfur coking coal having a particle size of 3mm or less is provided. Optionally, the high-sulfur coking coal is obtained by crushing and screening high-sulfur coking coal with larger particle size.

Further, in S2, stirring is carried out for 1-3h at a speed of 80-90 r/min.

Further, in S2, the coal sample is obtained after drying for 11-13h at 95-105 ℃.

Further, in S2, the mass ratio of the high-sulfur coking coal to the composite catalyst in the impregnation liquid during mixing is (150-: 1, preferably (200- & ltSUB & gt 800-): 1.

further, in S3, the introduction rate of hydrogen is 10-20L/h.

Further, in S3, the core temperature of the coal sample was monitored by a thermocouple.

Further, the sulfur content in the high-sulfur coking coal is more than 2 wt%. Optionally, the high-sulfur coking coal is high-sulfur cleaned coal.

According to the invention, the composite catalyst is mixed with the high-sulfur coking coal in the form of impregnation liquid, compared with conventional solid-solid mixing, the composite catalyst and the high-sulfur coking coal are more easily and uniformly mixed, and the composite catalyst dissolved in water can permeate into the high-sulfur coking coal particles and fully contact with the high-sulfur coking coal, so that the efficient utilization of the composite catalyst is realized.

The composite catalyst containing Ni, Mo and B elements can raise coking efficiencyThe desulfurization efficiency of the process hydrodesulfurization and the reduction of CO of the coke during the coking process₂The reactivity is improved, and the strength of the coke after reaction is improved, so that the performance of the coke is further improved on the basis of obtaining the low-sulfur coke. The common characteristics of Ni and Mo are that d electron orbitals are not filled, and the unit cell structures of the Ni and the Mo are either body-centered cubic lattices or hexagonal lattices, so that the Ni and the Mo can be used as catalyst materials in terms of electronic characteristics or geometric characteristics, and the catalytic effect can be improved due to the existence of the Ni and the Mo elements. The reason for improving the coke strength is the introduction of the B in the catalyst, so that the porosity of the coke obtained in the coking process is low, the shrinkage of the system is reduced, the reactivity of the coke is reduced, and the strength after the reaction is improved. During secondary heating of coke, coke CO is inhibited due to the existence of boron₂The reaction greatly reduces the solubility loss reactivity of the coke and improves the strength of the coke after the reaction.

The desulfurization mechanism of the present invention can be explained as follows: firstly, the characteristic that H atoms have good affinity to S atoms is utilized, so that the H atoms can be adsorbed on the S atoms and cause the ring opening of thiophene compounds in the reaction process, but because of the steric hindrance effect of thiophene, H is simply introduced₂And do not sufficiently contact with the S atom on the thiophene, thereby reducing desulfurization efficiency. And by adding the composite catalyst containing Ni and Mo, because the d electron orbits of Ni and Mo atoms are not full, Ni and Mo elements can adsorb nearby S atoms and induce the electron density of the adsorbed S atoms to be enhanced, and further S-C bonds are stretched, so that the conjugated structure of thiophene is damaged, the steric effect of thiophene is weakened, and H atoms can be more fully contacted with the S atoms and carry out ring-opening reaction.

During hydrodesulfurization, sulfur is adsorbed on the catalyst surface. Since the H atoms cannot migrate directly to the thiophene molecules, the sulfur adsorbed by the catalyst acts as a "step" for further hydrogenation reactions. It first accepts H to form S-H and then delivers H to C. Eventually the sulfur on the thiophene will adsorb and remain on the catalyst surface. When the degree of sulfidation of the catalyst is not very high, the migration kinetics of H may not be affectedBut when the catalyst surface is entirely covered with sulfur, the catalyst is deactivated at this time. Therefore, in the desulfurization process, it is necessary to ensure a certain H₂Partial pressure is such that sulfur adsorbed on the surface of the catalyst forms H₂S gas to restore catalytic activity. Therefore, the invention repeatedly researches while considering the blending degree of the catalyst and the high-sulfur coking coal to obtain the proper H₂Pressure and flow rate conditions to ensure that the catalyst surface is not fully sulfided and that high catalytic activity is maintained.

Compared with the prior art, the invention has the following advantages:

(1) the invention realizes the purpose of coke desulfurization in the coking process, reduces the cost and reduces the environmental pollution.

(2) The composite catalyst used in the invention has the advantages of simple preparation, small addition amount and economy.

(3) The composite catalyst used in the invention can improve the strength of coke and the quality of the coke.

(4) According to the invention, through reasonable design of the composite catalyst, the composite catalyst can be prepared into the impregnation liquid and then mixed with the high-sulfur coking coal, so that the effect of uniform mixing can be achieved, and compared with the method of directly adding the solid catalyst into a coal sample, the method improves the mixing effect of the coal and the catalyst; in addition, the introduction of a catalyst carrier is avoided, correspondingly, the amount of coal which can be processed by a single furnace is increased, the subsequent catalyst screening process is not required to be added, the process is simplified, the cost is reduced, the problem of CN107384503A is effectively solved, and the method has a better application prospect.

(5) The invention uses hydrogen to carry out desulfurization treatment on the high-sulfur coking coal, can realize good coke desulfurization in the coal pyrolysis process, and reduces the cost of the subsequent desulfurization treatment of the coke.

Detailed Description

The invention is further illustrated by the following examples, but is not limited thereto.

The high-sulfur cleaned coal used in the examples and comparative examples of the present invention gave a coke sulfur content of 1.65wt% without hydrogenation and catalyst.