CN1621498A

CN1621498A - Method for preparing active semicoking H2S desulphurizer

Info

Publication number: CN1621498A
Application number: CN 200410079366
Authority: CN
Inventors: 李春虎
Original assignee: Ocean University of China
Current assignee: Ocean University of China
Priority date: 2004-10-16
Filing date: 2004-10-16
Publication date: 2005-06-01
Anticipated expiration: 2024-10-16
Also published as: CN100443161C

Abstract

The present invention discloses the preparation process of active semi-coke H2S desulfurizer. The active semi-coke H2S desulfurizer is prepared with lignite semi-coke, anthracite or soft coal semi-coke and other carbon containing material and through first pressurized hydrothermal chemical modification, subsequent soaking with cuprammonia, CuSO4 solution or K2CO3 solution, drying and high temperature calcining. The present invention has the features of wide material source, low cost, repeated use of the adsorbent product, final use in waste water treatment and as fuel and no secondary pollution. The present invention may be used widely in purifying gas in various plants and environment protecting industry.

Description

Active semicoke H2Preparation method of S desulfurizer

Technical Field

The invention relates to a method for preparing a gas purification desulfurizer in production plants such as petroleum, coal and natural gas production plants and environmental protection industries by using petroleum, coal and natural gas as raw materials, in particular to a method for preparing an active semicoke H₂A preparation method of an S desulfurizer.

Background

The most of the plants for synthesizing ammonia, urea and bi-alcohol in China, which take three carbon-containing resources of petroleum, coal and natural gas as raw materials, wherein coal is about 70 percent of the raw materials. At present, due to the price rise of petroleum, some production plants such as coke-oven plants, gas plants and the like also consider synthesizing methanol and ammonia by taking coke-oven gas as a raw material; also, some large-scale fertilizer plants change the original high-cost production process of ' oil head ' and ' gas head ' gas-making fertilizer into ' coalHead ". Meanwhile, in order to save energy consumption, a low-pressure method is generally adopted to synthesize ammonia, methanol and the like at present, and the selected catalysts are all high-efficiency noble metal catalysts. Can be the sulfide (mainly H) contained in the synthesis gas prepared by using coal as raw material₂S、COS、CS₂Etc.) are easy to cause a series of serious consequences such as poisoning of the noble metal catalyst, great reduction of the service life of the catalyst and the like, so that the plant is frequently started and stopped, and the economic benefit is sharply reduced. Therefore, manufacturers are eagerly hoped to add a normal-temperature desulfurization process to reduce the total sulfur to below 0.5ppm so as to ensure that the service life of the synthetic ammonia and the bi-alcohol catalyst reaches more than one year.

Currently, the desulfurizing agents used at home and abroad are classified into iron-based desulfurizing agents, activated carbon desulfurizing agents, aluminum-based organic sulfur-based catalysts, zinc-based desulfurizing agents and molecular sieve-based desulfurizing agents according to systems. Wherein, the active carbon desulfurizer can be used for removing organic sulfur and inorganic sulfur; can be used for coarse desulfurization of high-concentration sulfur and fine desulfurization of low-concentration sulfur.

Activated carbon was used for industrial desulfurization in the last 30 th century, but it was recognized as an oxidative desulfurization agent in the 70 th century. Compared with other industrial desulfurizing agents, it has the advantages of convenient operation, large sulfur capacity and high desulfurizing efficiency, thus being widely applied, in particular to processing the desulfurizing agent containing low-concentration H₂S gas.

Removal of H from activated carbon₂Principle of S (M represents a divalent metal atom):

(1)

(2)

H₂s and trace oxygen in the raw material gas generate S under the catalytic action of the fine activated carbon desulfurizer, and the S is deposited in gaps of the desulfurizer, or sulfate is generated according to the formula (2).

The activated carbon method can be classified into an adsorption method, an oxidation method, and a catalytic method according to a desulfurization mechanism.

The adsorption method is most effective in removing thiophene by utilizing the characteristic of selective adsorption of activated carbon, but the use is limited because the sulfur capacity is too small.

The catalytic method is to impregnate heavy metals such as copper and iron in the active carbon, so that organic sulfur is catalytically converted into hydrogen sulfide, and the hydrogen sulfide is absorbed by the active carbon.

Oxidation activated carbon desulfurization is one of the most commonly used processes, with the aid of ammonia catalysis, H₂S and COS are oxidized by oxygen in the gas.

Currently, the activated carbon desulfurizer developed and applied in China mainly comprises RS-1, RS-2, EAC-4, T101 (original EAC-1), T102 (original EAC-2) and T103 (original EAC-3) type desulfurizers. They are made up by using coal-base active carbon as carrier, impregnating soluble salt of active metal, activating agent and accelerating agent, drying, roasting and activating. In recent years, the use of these desulfurization agents has been limited due to the rapid rise in the price of coal-based activated carbon; on the other hand, the treatment of the waste activated carbon desulfurization agent is also an important problem.

Disclosure of Invention

Aiming at the defects of the activated carbon desulfurizer, the invention aims to provide the activated semicoke H which is high in efficiency and low in cost₂A preparation method of an S desulfurizer.

Active semicoke H₂The S desulfurizing agent is prepared with brown coal semi-coke, anthracite, bituminous coal semi-coke and other carbon containing material as material and through pressurized water thermochemical modification, soaking in active solution in the same volume, drying and high temperature calcination.

Wherein the active solution is copper ammonia complex solution and CuSO₄Solutions or K₂CO₃And (3) solution.

Wherein the carbon-containing materials such as lignite semicoke or anthracite, bituminous coal semicoke and the like are characterized by the bulk density of 0.5-0.7g/ml and the specific surface area of 10-200m²The carbon content is 70-85%,the hydrogen content is 0.5-2.5%, the oxygen content is 10-30%, the nitrogen content is 0.3-1.2%, the moisture content is 2-9%, the ash content is 3-15%, and the volatile content is 6-18%.

The preparation process is as follows: screening the semicoke meeting the physicochemical conditions to obtain 4-10 mesh particles, mixing the semicoke particles and water according to the volume ratio of 1: 0.6-1.2, adding the mixture into a high-pressure reaction kettle, reacting for 1-8h at the temperature of 150 plus materials at 270 ℃ and under the pressure of 6-43atm, naturally cooling, taking out, drying the semicoke for 2h at the temperature of 100 plus materials at 120 ℃, and then using copper ammonia complex liquid and CuSO at the temperature of normal temperature-60 ℃ to obtain the semicoke with the particle size of 4-10 mesh₄Solution, K₂CO₃Soaking the solution in the same volume,the content of the metal oxide accounts for 0.5 to 10 percent of the total weight of the semicoke, the semicoke is placed for 24 hours, and then the semicoke is heated at the temperature of 400 ℃ and 700 ℃ at the space velocity of 50 to 5000 hours^-1Lower N₂Roasting in the atmosphere for 1-8h and activating.

The activity and sulfur capacity test of the desulfurizer are carried out in a fixed bed glass reactor, the inner diameter of the reactor is 20 mm, the desulfurizer is 4-8 meshes, the filling volume of the desulfurizer is 25ml, the bed height of the reactor is 100mm, and H is removed₂The temperature of S is normal temperature to 60 ℃, and the space velocity is 800-1500h^-1The grain/pipe diameter ratio is 0.1-0.13, and the sulfur-containing gas consists of H₂S1000ppm、H₂O₅% and the balance of N₂And (4) balancing. Sulfur capacity is outlet H₂The S concentration of 0.01ppm is the cumulative sulfur capacity calculated by penetration.

The invention is characterized in that the carbon-based materials such as active semicoke and the like have wide sources and low price, and the prepared adsorbent can be repeatedly regenerated and recycled, and can be finally used for wastewater treatment or boiler fuel without secondary pollution. Can be widely used for gas purification in production plants such as synthetic ammonia, urea, methanol, coking plants, gas plants and the like which take petroleum, coal and natural gas as raw materials and in the environmental protection industry. As is well known, the last century is a silicon material century, and the century is probably a carbon material century, so that the invention has wide application prospect.

Detailed Description

The present invention is described in detail below with reference to specific examples.

Examples 1 to 5:

mixing 4-10 mesh particles obtained by screening bituminous coal semicoke with water according to the volume ratio of 1: 0.83, adding the mixture into a high-pressure reaction kettle, reacting for 4 hours at the temperature of 150 ℃ and the pressure of 270 ℃ under the pressure of 8atm, 10atm, 12atm, 14atm and 43atm respectively, taking out after natural cooling, measuring the specific surface area and the pore volume of the mixture, filling 30ml of the mixture into a fixed bed reactor, measuring the desulfurization activity of the mixture, wherein the inner diameter of the reactor is 20 mm, and the bed height of the reactor is 100 mm. The results are shown in Table 1.

TABLE 1 active semicoke H after thermochemical modification of water at different pressures₂Specific surface area and pore volume of S desulfurizer

And influence on the sulfur capacity

Sample raw material semicoke 8atm, 10atm, 12atm, 14atm and 43atm

Specific surface area m²/g 49.19 1115.84 610.35 414.74 510.63 482.64

Pore volume ml/g 0.03510.45930.34120.13100.24700.3214

Sulfur capacity gH₂S/100gC 3.11 3.63 6.54 8.14 9.17 12.45

And (3) testing conditions are as follows: temperature: 40 ℃; space velocity: 1200h^-1；H₂The concentration of S: 1000 ppm; h₂O(g)：5％。

Thus, the sulfur capacity of the semicoke is obviously improved after the pressurized water thermochemical modification.

Examples 6 to 10:

the modified semicoke obtained by the preparation method of the embodiment 1-5 is soaked in copper-ammonia complex liquid with the same volume at normal temperature, so that the CuO accounts for 8.0 percent of the total weight of the semicoke, the semicoke is placed for 24 hours, and then the temperature is 700 ℃ and the space velocity is 1000 hours^-1Lower N₂And (5) roasting in the atmosphere for 6h for activation. The desulfurization activity was then measured (method 1). The results are shown in Table 2.

TABLE 2 thermochemical modification of semicoke by pressurized water, isovolumetric immersion modification of copper ammonia complex solution and N at 700 deg.C₂

Change in sulfur capacity after activation

Sample raw material semicoke 8atm, 10atm, 12atm, 14atm and 43atm

Penetration time h 1.511.5141515.515.9

Sulfur capacity gSO₂/100gC 3.11 8.20 9.4612.78 14.50 16.84

Visible semicoke subjected to pressurized water thermochemical modification is subjected to isovolumetric impregnation modification by copper-ammonia complex solution and subjected to 700 ℃ N₂After activation, the sulfur capacity can be increased by about 3 times.

Examples 11 to 13:

active semicoke H obtained by the preparation method described in example 7₂S desulfurization agent (the agent was prepared at 40 atm.) desulfurization/regeneration experiments were performed using two columns in series, and the results are shown in Table 3.

TABLE 3 active semicoke H₂Relationship between S desulfurizer regeneration frequency and sulfur capacity

Sample twice three times

Sulfur capacity (gS/100Gc) 12.3011.8212.23

Regeneration conditions are as follows: at normal temperature at an airspeed of 50h^-1Air was passed through the tube for 40 hours.

It can be seen that after 3 times of desulfurization regeneration, the desulfurization activity is not significantly reduced. Illustrating the active semicoke H₂The S desulfurizer has great desulfurization potential.

Claims

1. Active semicoke H₂A process for preparing S-desulfurizing agent features that the raw materials of semi-coke of lignite, anthracite or bituminous coal are thermochemically modified by pressurized waterAnd then soaking the active solution in the same volume, drying and calcining at high temperature to obtain the catalyst.

2. The method according to claim 1, wherein the active solution is a copper ammine complex solution or CuSO₄Solutions or K₂CO₃And (3) solution.

3. The desulfurizing agent preparation method according to claim 1, wherein the lignite semicoke or anthracite, bituminous coal semicoke has a bulk density of 0.5-0.7g/ml and a specific surface area of 10-200m²The carbon content is 70-85%, the hydrogen content is 0.5-2.5%, the oxygen content is 10-30%, the nitrogen content is 0.3-1.2%, the moisture content is 2-9%, the ash content is 3-15%, and the volatile content is 6-18%.

4. The method for preparing desulfurizing agent according to claim 1, wherein the pressurized water thermochemical modification is carried out by mixing semicoke and water, adding into a high-pressure reactor, and reacting at 150-270 ℃ and 6-43atm for 1-8 h.

5. The method for preparing desulfurizer as claimed in claim 1, wherein the semicoke is sieved to obtain 4-10 mesh particles, the semicoke particles and water are mixed according to the volume ratio of 1: 0.6-1.2, and then added into a high-pressure reaction kettle to react for 1-8h at 150-₄Solution, K₂CO₃Soaking in equal volume of solution to make CuO and K₂The amount of O accounts for 0.5-10% of the total weight of the semicoke, the semicoke is placed for 24 hours, and then the space velocity is 50-5000 hours at the temperature of 500-^-1N₂Roasting in the atmosphere for 1-8h for activation.