A method for preparing a cucl material adsorbent for chlorine gas removal

Abstract

The application discloses a preparation method of a CuC material adsorbent for chlorine gas removal and relates to the technical field of special gas adsorbent synthesis. The method comprises the following steps: (1) Cu(OH)2 is used as an active agent and is mixed with coal, and a ball mill is used for mechanical mixing for 2h; (2) the mixed coal powder is subjected to programmed temperature rising, is first raised in temperature to 450-500 DEG C and is kept for 2h; then the temperature is continuously raised to 950-1000 DEG C and is kept for 1h, so that activated carbon material is prepared; and (3) the activated carbon material prepared in the step (2) is reduced by using hydrogen or sodium borohydride, so that the coal-based Cu modified activated carbon is prepared. The application can use coal to prepare activated carbon, and uses Cu(OH)2 as an active agent, so that the activated carbon is expanded, and the adsorption active site Cu is introduced, and the adsorption capacity is improved.

Description

Technical Field

[0001] This invention relates to the field of specialty gas adsorbent synthesis technology, specifically to a method for preparing a CuC material adsorbent for chlorine gas removal. Background Technology

[0002] Chlorine is a yellowish-green, toxic gas with a strong, suffocating odor. Prolonged inhalation of high concentrations of chlorine can harm the skin, mucous membranes, respiratory system, and gastrointestinal tract. The mechanism by which chlorine causes harm involves its reaction with water and mucous membranes to form harmful substances, thus exerting its toxic effect. Removing chlorine is essential in air purification processes. How to efficiently remove chlorine is a hot topic in air purification research.

[0003] However, traditional chlorine adsorbents have poor adsorption performance and complex preparation processes, making large-scale industrial application difficult. In their paper "Research on NO Removal using Microwave-Based Coal-Supported Catalysts," Liu Fu, Liu Yang, and others proposed a preparation scheme using coal-based carbon-supported metal catalysts under microwave irradiation. Furthermore, given my country's rich coal reserves, deep processing of coal to produce high-value-added products is beneficial for upgrading my country's coal chemical industry chain. Therefore, we also attempted to use coal-based Cu to adsorb and treat chlorine. We found that the CuC material prepared by this method can improve the adsorption effect to some extent, but its adsorption capacity for chlorine remains relatively low. Summary of the Invention

[0004] The present invention aims to provide a method for preparing CuC material adsorbent for chlorine gas removal, so as to solve the technical problem that the adsorption capacity of CuC material prepared by existing methods for chlorine gas is still relatively low.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a CuC material adsorbent for chlorine gas removal includes the following steps:

[0007] (1) Cu(OH)2 was used as an activator and mixed with coal. The mixture was mechanically mixed for 2 hours using a ball mill.

[0008] (2) The mixed coal powder is heated in a programmed manner, first to 450-500℃ and held for 2 hours; then the temperature is raised to 950-1000℃ and held for 1 hour to obtain activated carbon material.

[0009] (3) The activated carbon material obtained in step (2) is reduced by hydrogen or sodium borohydride to obtain coal-based Cu modified activated carbon.

[0010] Preferably, the coal in step (1) is one or more of anthracite, coking coal, fat coal, lignite, long-flame coal, lean coal, semi-coal, weakly caking coal, and gas coal.

[0011] Preferably, in step (1), the mass ratio of Cu(OH)2 to coal is 1.1:1.

[0012] Preferably, step (2) involves heating at a rate of 10 °C / min.

[0013] Preferably, the hydrogen reduction conditions in step (3) are: the reducing gas composition is 50% H2 and 50% N2; the reduction temperature is 550℃; and the reduction time is 2h.

[0014] Preferably, the sodium borohydride reduction conditions in step (3) are as follows: 1g of activated carbon material is ultrasonically dispersed into 25mL of deionized water, and 0.1mol / L sodium borohydride solution is added dropwise until no bubbles are generated.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention can use coal-derived activated carbon, and specifically uses Cu(OH)2 as an activator, which not only expands the pores of the activated carbon, but also introduces Cu adsorption active sites, thereby improving the adsorption capacity. Attached Figure Description

[0017] Figure 1 This is a line graph showing the adsorption capacity versus pressure variation of the adsorbent obtained in Example 1 at different temperatures;

[0018] Figure 2 A bar chart showing the adsorption performance of adsorbents prepared for different coal precursors at 0℃ and 0.35MPa.

[0019] Figure 3 A bar chart showing the adsorption performance of adsorbents prepared with different active agents and different ratios of active agents to coal at 0℃ and 0.35MPa.

[0020] Figure 4 A bar chart showing the adsorption performance of adsorbents prepared at different activity temperatures under conditions of 0℃ and 0.35MPa.

[0021] Figure 5 Line graph showing the adsorption capacity versus pressure variation of adsorbents prepared by different reduction methods at 0℃;

[0022] Figure 6 The graph shows the adsorption capacity versus pressure change of the adsorbent obtained in Example 1 and the traditional chlorine adsorbent at 0°C. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described below in conjunction with various embodiments and accompanying drawings. The implementation of the present invention includes, but is not limited to, the following embodiments.

[0024] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0025] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0026] The following examples demonstrate the preparation of different catalysts under different reaction conditions and the verification of their catalytic activity.

[0027] Example 1

[0028] In this embodiment, Cu(OH)₂ is selected as the activator, and anthracite is used as the precursor for activated carbon material. Coal-based Cu-modified activated carbon is prepared by the following method:

[0029] (1) Mix Cu(OH)2 with anthracite at a mass ratio of 1.1:1 and mechanically mix using a ball mill for 2 hours;

[0030] (2) The mixed coal powder is heated in a programmed manner at a heating rate of 10℃ / min to 450℃ (the temperature error before and after should not exceed 10℃) for 2 hours, and then the temperature is further increased to 950℃ (the temperature error before and after should not exceed 10℃) for 1 hour to obtain activated carbon material.

[0031] (3) The above activated carbon material is reduced with sodium borohydride: 1g of activated carbon material is ultrasonically dispersed into 25mL of deionized water, and 0.1mol / L sodium borohydride solution is added dropwise until no bubbles are generated, so as to obtain coal-based Cu modified activated carbon.

[0032] The obtained coal-based Cu-modified activated carbon was tested using a dedicated PCT (Pressure-Composition-Temperature) chlorine adsorption device (Beijing Jin'epu Technology Co., Ltd. H-Sorb2600). The adsorption capacity of the coal-based Cu-modified activated carbon was tested at 0℃, 30℃, and 50℃, and the results are summarized below. Figure 1As shown in the figure, coal-based Cu-modified activated carbon exhibits good adsorption performance for chlorine. At 0℃ and 0.35MPa, the adsorption performance (chlorine adsorption capacity g / activated carbon weight g) of coal-based Cu-modified activated carbon reaches 55%.

[0033] Example 2

[0034] This embodiment, based on Example 1, replaces anthracite with coking coal, fat coal, lignite, long-flame coal, lean coal, semi-lean coal, weakly caking coal, and gas coal, respectively, while keeping other conditions unchanged. The resulting adsorbents are compared under the conditions of 0℃ and 0.35MPa as follows. Figure 2 As shown in the figure, activated carbon using anthracite as a precursor has higher adsorption performance.

[0035] Example 3

[0036] This embodiment, based on Example 1, replaces Cu(OH)2 and anthracite in a mass ratio of 0.9, 1, 1.2, or replaces them with CuCl2 and Cu(NO3)2 in a mass ratio of 0.9, 1, 1.1, 1.2 with anthracite, respectively. The resulting adsorbent is compared under the conditions of 0℃ and 0.35MPa as follows. Figure 3 As shown in the figure, at 0℃ and 0.35MPa, the activated carbon prepared using Cu(OH)₂ exhibits significantly better adsorption performance for chlorine. Furthermore, the activated carbon shows optimal adsorption performance when the ratio of activator to coal is 1.1.

[0037] Example 4

[0038] This embodiment, based on Embodiment 1, modifies the two temperature steps in step (2), setting up 8 control experiments. For 4 groups, the second temperature step is fixed at 950℃, and the first temperature steps are set to 350℃, 400℃, 450℃, and 500℃ respectively; for 4 groups, the first temperature step is fixed at 450℃, and the first temperature steps are set to 850℃, 900℃, 950℃, and 1000℃ respectively. The prepared adsorbents under 0℃ and 0.35MPa conditions are compared as follows: Figure 4 As shown, both temperature steps must reach a certain level to obtain an adsorbent with better chlorine adsorption effect.

[0039] Example 5

[0040] This embodiment differs from Embodiment 1 by modifying step (3) and utilizing hydrogen reduction: the reducing gas composition is 50% H2 and 50% nitrogen; the reduction temperature is 550℃; and the reduction time is 2 hours. The adsorption capacity versus pressure curve of the adsorbent obtained in this embodiment at 0℃ is plotted and compared with the adsorption capacity versus pressure curve of the adsorbent obtained in Embodiment 1 at 0℃. Figure 5 As shown in the figure, using a low-concentration sodium borohydride solution for reduction results in coal-based Cu-modified activated carbon with better reduction and adsorption performance. Using a low-concentration sodium borohydride can reduce Cu particles to smaller sizes, which is beneficial for chlorine adsorption.

[0041] Example 6

[0042] like Figure 6 As shown in the figure, this embodiment compares the adsorption capacity of the adsorbent obtained in Example 1 at 0℃ with that of conventional common chlorine adsorbents. The figure shows that the coal-based Cu-modified activated carbon of this invention has a stronger adsorption capacity. Furthermore, this invention uses Cu(OH)₂ as the activator, which not only expands the pores of the activated carbon but also introduces Cu adsorption active sites. The preparation method is simple and inexpensive.

[0043] The above embodiments are merely one of the preferred embodiments of the present invention and should not be used to limit the scope of protection of the present invention. Any modifications or refinements made to the main design concept and spirit of the present invention that are not of substantial significance, but solve the same technical problem as the present invention, should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a CuC material adsorbent for chlorine gas removal, characterized in that, Includes the following steps: (1) Cu(OH)2 was used as an activator and mixed with coal. The mixture was mechanically mixed for 2 hours using a ball mill. (2) The mixed coal powder is heated in a programmed manner, first to 450-500℃ and held for 2 hours; then the temperature is raised to 950-1000℃ and held for 1 hour to obtain activated carbon material. (3) The activated carbon material obtained in step (2) is reduced by hydrogen or sodium borohydride to obtain coal-based Cu modified activated carbon.

2. The preparation method according to claim 1, characterized in that, The coal mentioned in step (1) is one or more of the following: anthracite, coking coal, fat coal, lignite, long-flame coal, lean coal, semi-coal, weakly caking coal, and gas coal.

3. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of Cu(OH)2 to coal is 1.1:

1.

4. The preparation method according to claim 1, characterized in that, Step (2) involves heating at a rate of 10 °C / min.

5. The preparation method according to claim 1, characterized in that, The hydrogen reduction conditions described in step (3) are: the reducing gas composition is 50% H2 and 50% N2; the reduction temperature is 550℃; and the reduction time is 2h.

6. The preparation method according to claim 1, characterized in that, The sodium borohydride reduction conditions in step (3) are as follows: 1g of activated carbon material is ultrasonically dispersed into 25mL of deionized water, and 0.1mol / L sodium borohydride solution is added dropwise until no bubbles are generated.

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