KR20020010006A - A Simultaneous Impregnated Adsorbent for Elimination of Hydrogen Sulfide Gas and a Preparation Method Using the Same - Google Patents

Abstract

PURPOSE: A method for producing an adsorbent that is simultaneously impregnated with sodium hydroxide and diethanolamine for the elimination of hydrogen sulfide gas is provided. CONSTITUTION: The production method of the adsorbent includes: (i) preparation of activated carbon(240mesh size) having a specific surface area 1050m¬2/g and average pore diameter 13-20Å; (ii) dipping the activated carbon in a mixed solution of 0.5-4mol sodium hydroxide and 0.01-0.25mol diethanolamine; (iii) agitating the obtained slurry for 3-5hrs; (iv) washing and filtering the slurry; and (v) drying the washed/filtered slurry in the temperature range 130 to 170deg.C for 18-36hrs.

Description

A Simultaneous Impregnated Adsorbent for Elimination of Hydrogen Sulfide Gas and a Preparation Method Using the Same}

The present invention relates to a co-adsorption adsorbent for removing hydrogen sulfide gas and a method for preparing the same, and more particularly to the rise of two base components in which activated carbon simultaneously co-attached to a mixed solution of sodium hydroxide and diethanolamine is derived from hydroxyl and amine groups. The present invention relates to a co-adhesive adsorbent for removing hydrogen sulfide gas having a hydrogen sulfide adsorption capacity even at a low concentration by the action and a method of manufacturing the same.

The high level of industrial development and subsequent expansion of economic scale led to the generation of a large amount of various harmful substances, which in turn caused serious environmental pollution problems with the limitation of processing capacity. Among them, hydrogen sulfide (H ₂ S) gas generated from waste landfill, petrochemical industry, pulp industry, city gas manufacturing industry, ammonia industry, sewage treatment plant, etc. is a colorless gas that smells like rotting eggs and is absorbed by the human stomach and lungs. As it is classified as a gas with a high risk of suffocation, lung disease, nerve central palsy, etc., finding an effective treatment method has emerged as a challenge.

Accordingly, conventional techniques have been proposed such as deep cooling method, absorption method, membrane separation method and adsorption method, etc. The deep cooling method is economically vulnerable because excessive power costs are required for the liquefaction of separated gas and the absorption method is long-term operation. There is a problem of loss of absorbent liquid, deterioration of performance and corrosion of materials. In the membrane separation method, studies on selectivity, separation speed, and durability of components for separation are not accurately established. In addition, the adsorption method is a method used to selectively separate or purify a certain component from the mixed adsorbate through the physical or chemical combination of the adsorbent surface and the adsorbent (gas to be treated). It has been applied to many commercialization process because there is no burden of power costs, but there was a problem that the temperature range of the adsorbent is narrow and the adsorption performance is low.

The present invention has been made to solve the problems of the prior art as described above, the inventors of the present invention is a co-adhesive activated carbon prepared by simultaneously impregnating activated carbon in an aqueous solution in which sodium hydroxide aqueous solution and diethanolamine aqueous solution is mixed at a constant ratio as an adsorbent. It was successfully used to prepare a coadsorption adsorbent for removing hydrogen sulfide gas with improved adsorption capacity.

In addition, the co-adsorption adsorbent of the present invention comprises the steps of preparing an activated carbon having a particle size of 8 × 30 mesh, a specific surface area of 1050m ² / g, the average pore radius 13 ~ 20Å; Simultaneously attaching activated carbon to a solution in which 0.5 to 4 mol of sodium hydroxide and 0.01 to 0.25 mol of diethanolamine are mixed at a predetermined ratio; Stirring the mixed activated carbon-adhesive slurry in a stirrer for 3-5 hours; Washing and filtering the stirred activated carbon-adhesive slurry; And the washed and filtered activated carbon was dried for 18 to 36 hours at 130 ~ 170 ℃ confirmed that the co-adhesive adsorbent for removing hydrogen sulfide gas was completed the present invention.

After all, it is an object of the present invention to provide a co-adhesive adsorbent for removing hydrogen sulfide gas.

Another object of the present invention is to provide a method for preparing a co-adhesive adsorbent for removing hydrogen sulfide gas.

1 is a diagram of the adsorption equilibrium experiment apparatus of the present invention

Figure 2 is an electron scanning micrograph of the co-adhesive adsorbent according to the present invention

♣ Explanation of symbols for the main parts of the drawing ♣

1: thermometer 2: pressure gauge

3: stirring motor 4: recorder

5: adsorbent fixing plate 6: water bath

7: nitrogen gas 8: hydrogen sulfide gas

a: Electron scanning micrograph of the co-adhesive adsorbent according to Example 1

b: Electron scanning micrograph of the co-adhesive adsorbent according to Example 8

c: Electron scanning micrograph of the co-adhesive adsorbent according to Example 10

d: Electron scanning micrograph of the co-adhesive adsorbent according to Example 16

Hereinafter, the present invention will be described in more detail.

The coadsorption adsorbent for achieving the object of the present invention is to remove the hydrogen sulfide gas is prepared by simultaneously attaching activated carbon to a solution mixed with 0.5 to 4 mol of sodium hydroxide and 0.01 to 0.25 mol of diethanolamine in a constant ratio Provided is a coadsorption adsorbent for removing hydrogen sulfide gas. Preparing an activated carbon having a particle size of 8 × 30 mesh, a specific surface area of 1050 m ² / g, and an average pore radius of 13 to 20 GPa; Simultaneously attaching activated carbon to a solution in which 0.5 to 4 mol of sodium hydroxide and 0.01 to 0.25 mol of diethanolamine are mixed at a predetermined ratio; Stirring the mixed activated carbon-adhesive slurry in a stirrer for 3-5 hours; Washing and filtering the stirred activated carbon-adhesive slurry; And washing and drying the filtered activated carbon at 130 to 170 ° C. for 18 to 36 hours to provide a method for preparing a co-adhesive adsorbent for removing hydrogen sulfide gas.

Hereinafter, the present invention will be described in more detail with reference to the following examples. These examples are only for illustrating the present invention, and it will be apparent to those skilled in the art that the scope of the present invention is not limited to these examples according to the gist of the present invention.

Table 1 below shows the physical properties of the activated carbon in the unimpregnated state used in the present invention.

[Comparative Example] Activated carbon having a particle size of 8 × 30 mesh, a specific surface area of 1050m ² / g, and an average pore radius of 13 to 20 세척 was washed several times with distilled water, and then dried in an oven at 150 ° C. for 24 hours to be impregnated. Unactivated carbon was prepared and stored in a desiccator.

Example of Co-Adsorption Adsorption Agent for Removing Sulfuric Gas: 10 g of activated carbon prepared in Comparative Example was co-attached to a solution in which sodium hydroxide and diethanolamine were mixed at a constant ratio, and the mixed activated carbon-adhesive slurry was stirred for 4 hours in a stirrer. The stirred and activated carbon-adhesive slurry was washed, filtered and washed, and the filtered activated carbon was dried at 150 ° C. for 24 hours to prepare a coadsorption adsorbent.

In the above comparative examples and examples, the evaluation of the co-adhesive adsorbent for removing hydrogen sulfide gas was carried out to evaluate the adhesion force, specific surface area measurement, SEM measurement, thermobalance analysis, pH analysis, neutralization titration analysis, etc. of the impregnated adsorbent.

(1) adsorption equilibrium experiment apparatus

A diagram of the adsorption equilibrium experiment apparatus of the present invention is shown in FIG. It consists of two cylindrical chambers (7cm inner diameter and 25cm length) with a total internal volume of 1680ml to fill the adsorbent and adsorbate gas.They are connected by two tubes (2.2cm outer diameter) with a ball valve. . In addition, a pressure transducer is installed in the connecting pipe to measure the pressure change in the enclosed space during the adsorption process, and the output of the pressure transducer according to the internal pressure change during the adsorption process is recorded on three pin recorders. It was made. In addition, a T-type thermocouple is installed at the upper end of the space of the adsorbent pedestal filled with a predetermined amount of the adsorbent in order to detect the change in the adsorption temperature in the cylindrical chamber. In the sealed space where the adsorbate gas is injected, an impeller with permanent magnets can be installed and rotated to assist gas mixing. In addition, the entire test facility was placed in a temperature control tank for adsorption equilibrium experiments at isothermal temperature.

(2) Measurement of adhesion amount of co-adhesive adsorbent

In order to evaluate the adhesion force of the co-adhesive adsorbent for removing hydrogen sulfide gas, changes in the adhesion amount (% by weight) of the adsorbents of Examples 2 to 6, 9 to 13, 15 to 19, and 21 to 25 of the present invention were measured. As a result, it can be seen from Table 2 that the amount of deposition increases as the concentration of sodium hydroxide increases for a certain diethanolamine concentration.

(3) Measurement of specific surface area of co-adhesive adsorbent

The specific surface area of the coadsorption adsorbent according to the present invention was measured by the multipoint method using BET (Brunauer, Emmet, Teller) nitrogen adsorption and desorption force, and the analyzer used Autosorb-1 manufactured by Quanta Chromer, USA. The specific surface areas of the coadsorption adsorbents of Examples 1, 8, 10 and 16 were respectively measured as 973.4m ² / g, 958.5m ² / g, 923m ² / g and 846m ² / g, respectively. As the concentration of the mixed solution of the amine increases, the micropore of the coadsorption adsorbent is prevented, so that the specific surface area of the coadsorption adsorbent is inversely proportional to the concentration of the mixed solution, and the results are shown in Table 3.

(4) SEM measurement

The pores of the coadsorption adsorbents of Examples 1, 8, 10 and 16 according to the present invention were measured by magnification 1,000 times with an electron scanning microscope, and the results are shown in FIG. As the concentration of the mixed solution of sodium hydroxide and diethanolamine increased, it was confirmed that a phenomenon in which the micropores inside the coadsorption adsorbent were clogged.

(5) Thermal balance analysis of co-adhesive adsorbent

Thermo balance (Du-pont, 2050) to investigate the thermal change characteristics of the impregnated adsorbents of Examples 3, 5, 7, 10, 12, 14, 16, 18, 20, 22, 24, and 26 according to the present invention Using the temperature increase / desorption experiment was performed. After placing the adsorbent sample on the sample pan, it was heated to 10 ^o C / min under nitrogen gas atmosphere, maintained at 100 ° C for 1 hour, and then heated up to 1000 ° C at 10 ^o C / min while oxygen was present on the carbon surface. The mass reduction properties associated with the decomposition of the group into the carbon monoxide and carbon dioxide were investigated. The results are shown in Table 4, and as the concentration of the mixed solution of sodium hydroxide and diethanolamine increases, the mass decrease caused by the temperature increase and desorption combines oxygen and carbon to form C _X O _Y , a compound of various compositions. Since the compound is rapidly decomposed into a mixture of CO and CO ₂ by heating, the mass loss rate of the coadsorption adsorbent is increased.

(6) pH analysis of coadsorption adsorbent

12 hours after adding 0.5 g of a co-adhesive adsorbent prepared in Examples 3, 5, 7, 10, 12, 14, 16, 18, 20, 22, 24 and 26 according to the present invention to a Pyrex container containing 20 ml of distilled water. While mechanical shaking was performed and the solution was filtered through a 4.5 탆 nylon membrane filter to measure the pH of the supernatant with a pH meter (HM-30V). The results are shown in Table 5, and the coadsorption adsorbent prepared with a mixed solution of sodium hydroxide and diethanolamine had a pH of 0.0125 mol diethanolamine mixed with 1, 2, 3, and 4 mol of sodium hydroxide, respectively. It was found that the pH increased from 11.05 to 11.29 when prepared by mixing from 10.75 to 10.96 and mixing 0.025 moles of diethanolamine with 1, 2, 3, and 4 moles of sodium hydroxide, respectively, and also 0.125 moles of diethanolamine. Was prepared by mixing with 1, 2, 3 and 4 moles of sodium hydroxide, respectively, and the pH was increased from 11.23 to 11.36. The reason for this is that as the concentration of the mixed solution increases, the acidic functional group on the surface of the adsorbent decreases due to the neutralizing function of the adsorbent surface by the alkaline component, and thus the pH value increases.

(7) Chinese titration curve

The amount of acidic surface functional groups present on the surface of the coadsorption adsorbent was measured according to the Boehm method. Each 1 g of the coadsorption adsorbent was added to 100 ml of a basic solution of 0.1 normal concentration of sodium hydrogencarbonate, sodium carbonate and sodium hydroxide having different strengths Each mixture was mechanically shaken for 48 hours, and then the adsorbent was allowed to settle to obtain a clear solution. The amount of the acidic surface functional groups present on the carbon surface of Examples 1, 8, 10 and 16 was measured using a titrator (Metrohm titroprocessor Model 682) equipped with a pH measuring device 10ml of the supernatant. The results are shown in Table 6, and when the concentration of sodium hydroxide mixed with 0.0125 moles of diethanolamine was increased from 0.5 to 3 moles, the strongly acidic carboxyl groups titrated by sodium bicarbonate were 0 to 0.096 meq / g-AC, The lactone group, which is a carboxyl group titrated with sodium carbonate and a weakly acidic carboxyl group, is 0 to 0.269 meq / g-AC. Inversely, the pH was shown to change. This is because the amount of carboxyl, lactone and phenol groups belonging to the acidic functional groups decreases as the concentration increases.

(8) Effect of temperature on the equilibrium adsorption amount of the coadsorption adsorbent

Table 7 shows the change of equilibrium adsorption amount of hydrogen sulfide gas of non-adsorption adsorbent with temperature change. When the adsorption temperature of hydrogen sulfide gas was increased from 4.96mg / L to 25 ° C to 45 ° C, the hydrogen sulfide adsorption amount decreased by 85% from 13.24mg / gAC to 2.01mg / gAC. The equilibrium adsorption amount of hydrogen sulfide is inversely proportional to the adsorption temperature because the non-adsorption adsorbent increases the volatility of the adsorbate gas as the temperature increases, thereby preventing physical bonding.

Table 8 shows the change in the equilibrium adsorption amount according to the adsorption temperature of the coadsorption adsorbents of Examples 1, 3, and 8, and the equilibrium adsorption amount increases when the adsorption temperature is increased from 25 ° C to 45 ° C. Comparing results are shown. This is because in the case of the impregnated binder, the equilibrium adsorption amount increases as the temperature increases mainly by chemical adsorption, and thus, it can be seen that the high temperature condition can be effectively applied to the hydrogen sulfide gas adsorption treatment of the coadsorbent.

(9) Change in equilibrium adsorption according to the concentration of coadsorption adsorbent

Table 9 shows the adsorption characteristics of hydrogen sulfide gas according to the concentration change of sodium hydroxide and diethanolamine mixed solution of Examples 3, 4, 6, 10, 11, 13, 16, 17, 19, 22, 23 and 25 of the present invention. It is shown. Overall, the adsorption amount was found to correspond to 30.7 mg / g-AC at 13.4 mg / g-AC, and the coadsorption adsorbent prepared in Example 10 showed the maximum adsorption amount. The maximum amount of hydrogen sulfide adsorption of the coadsorption adsorbent was found to have a value increased by more than 2 times compared with the comparative example.

Table 10 shows the change in the adsorption amount of the coadsorption adsorbents prepared in Examples 3, 4, 6, 10, 11, 13, 16, 17, 19, 22, 23, and 25. Under the concentration, the concentration of diethanolamine decreased with increasing concentration, and the coadsorption adsorbent prepared in Example 10 showed the highest adsorption amount. As the concentration of sodium hydroxide or diethylamine increases, the adsorption amount of base reagent increases on the surface of the adsorbent pores as the concentration of sodium hydroxide or diethylamine increases. Because it is reduced.

In the above performance evaluation, as can be seen in the hydrogen sulfide gas adsorption amount change experiment of the coadsorption adsorbent, the product of the present invention was found to have excellent adsorption power of hydrogen sulfide gas even at a low concentration of the mixed solution of sodium hydroxide and diethanolamine.

As described above, according to the present invention, considering the fact that a high adsorption capacity of hydrogen sulfide gas can be obtained at a low concentration of a mixed solution of sodium hydroxide and diethanolamine, it is possible to remove harmful gases such as hydrogen sulfide, odors and volatile organic substances. It is effective as an adhesive adsorbent for.

Claims (4)

A co-adsorption adsorbent for removing hydrogen sulfide gas, characterized in that it is produced by co-attaching activated carbon to a solution in which sodium hydroxide and diethanolamine are mixed at a constant ratio. The method of claim 1, The sodium hydroxide gas co-adhesive adsorbent for removing hydrogen sulfide gas, characterized in that 0.5 to 4 mol, diethanolamine is 0.01 to 0.25 mol. The method of claim 1, The particle size of the activated carbon is 8 × 30 mesh, the specific surface area of 1050m ² / g, the average pore radius is 13 to 20 kPa, hydrogen sulfide gas removal co-adhesive adsorbent. Preparing activated carbon having a particle size of 8 x 30 mesh, a specific surface area of 1050 m ² / g, and an average pore radius of 13 to 20 microns; Simultaneously attaching activated carbon to a solution in which 0.5 to 4 mol of sodium hydroxide and 0.01 to 0.25 mol of diethanolamine are mixed at a predetermined ratio; Stirring the mixed activated carbon-adhesive slurry in a stirrer for 3-5 hours; Washing and filtering the stirred activated carbon-adhesive slurry; And washing and drying the filtered activated carbon at 130 to 170 ° C. for 18 to 36 hours.