Efficient separation method for acetylene in mixed gas
阅读说明：本技术 一种混合气中乙炔的高效分离方法 (Efficient separation method for acetylene in mixed gas ) 是由 陈杨 李立博 王小青 李晋平 于 2020-12-11 设计创作，主要内容包括：本发明涉及了一种混合气中乙炔的高效分离方法,将含有乙炔的混合气体在一定温度及压力下通过装填有吸附剂的容器完成乙炔的吸附,通过在升温条件下惰性气体吹扫或者抽真空完成吸附剂的脱附再生,吸附剂为Zn-2(bpy)(btec),具体的制备方法为：将去离子水中加入锌源、均苯四甲酸二酐和4,4’-联吡啶,搅拌混合均匀后加入氨水,并持续搅拌一段时间,然后将所得沉淀物过滤、洗涤及干燥后制得。本发明提供的乙炔分离方法降低了分离的难度,扩大了分离方法的适用范围,并不受限于混合气体的种类及乙炔浓度,能够得到高纯度的乙烯回收物；采用本发明方法制备的吸附剂过程简单,收率高,适用于工业化生产,对于低浓度乙炔表现出比传统方法更为优异的捕集效果。(The invention relates to a high-efficiency separation method of acetylene in mixed gas, which comprises the steps of adsorbing acetylene in the mixed gas containing acetylene through a container filled with an adsorbent at a certain temperature and under a certain pressure, and performing desorption regeneration of the adsorbent through inert gas purging or vacuumizing under the condition of temperature rise, wherein the adsorbent is Zn 2 (bpy) (btec), the specific preparation method is as follows: adding a zinc source, pyromellitic dianhydride and 4,4' -bipyridyl into deionized water, stirring and mixing uniformly, adding ammonia water, continuously stirring for a period of time, and then filtering, washing and drying the obtained precipitate to obtain the catalyst. The acetylene separation method provided by the invention reduces the separation difficulty, enlarges the application range of the separation method, and is not limited by mixingThe type of the synthetic gas and the concentration of acetylene can obtain high-purity ethylene recovered substances; the adsorbent prepared by the method has simple process and high yield, is suitable for industrial production, and has more excellent trapping effect on low-concentration acetylene than the traditional method.)
1. A method for efficiently separating acetylene from mixed gas is characterized by comprising the following steps:
step 1: the mixed gas containing acetylene passes through a container filled with an adsorbent at a certain temperature and pressure to complete the adsorption of acetylene;
step 2: the desorption regeneration of the adsorbent is completed by inert gas purging under the condition of temperature rise or vacuum negative pressure;
the preparation method of the adsorbent comprises the following steps:
1) adding a zinc source, pyromellitic dianhydride and 4,4' -bipyridyl into deionized water, and stirring;
2) stirring and mixing evenly, then adding ammonia water or ammonium salt, and continuously stirring and reacting for a period of time;
3) after the reaction is finished, filtering, washing and drying the obtained precipitate to obtain the chemical formula [ Zn ]2(bpy)(btec)(H2O)2]·2H2An adsorbent having a metal organic framework of O.
2. The method for efficiently separating acetylene from a mixed gas according to claim 1, wherein the mixed gas comprises acetylene and a separation gas, and the separation gas comprises one or more of organic and/or inorganic gases.
3. The method for efficiently separating acetylene from a mixed gas according to claim 1, wherein the volume fraction of acetylene in the mixed gas is 0-50% and does not contain zero value.
4. The method for efficiently separating acetylene from a mixed gas as claimed in claim 1, wherein the adsorption temperature of acetylene on the adsorbent is 10-30 ℃ and the pressure in the container is 1bar or more.
5. The method for efficiently separating acetylene from mixed gas according to any one of claims 1 to 4, wherein the reaction space velocity is 5 to 100h when acetylene is adsorbed on the adsorbent-1And the purity of acetylene obtained by desorption of the adsorbent under the vacuum-pumping negative pressure condition is more than 92.5 percent.
6. The method for efficiently separating acetylene from mixed gas according to claim 5, wherein the purity of acetylene obtained by desorption of the adsorbent under the condition of vacuum negative pressure is more than 98.5%.
7. The method for efficiently separating acetylene from a mixed gas according to claim 1, wherein in the step of preparing the adsorbent, the total molar concentrations of the zinc source, the pyromellitic dianhydride and the 4,4' -bipyridine are as follows: 1.2-1.8 mol/L, the molar weight of pyromellitic dianhydride is equal to that of 4,4' -bipyridine, and the molar weight of zinc source is as follows: the molar weight of 4,4' -bipyridine = 1.3-3.3.
8. The method for efficiently separating acetylene from a mixed gas according to claim 1 or 7, wherein in the step of preparing the adsorbent, the molar weight of ammonia water is as follows: the molar weight of the pyromellitic dianhydride = 0.03-0.15.
9. The method for efficiently separating acetylene from mixed gas according to claim 8, wherein in the step of preparing the adsorbent, the reaction temperature is controlled to be 20-50 ℃, and the reaction time is controlled to be 0.5-2 h.
10. The method for efficiently separating acetylene from mixed gas according to claim 8, wherein the zinc source is zinc acetate or zinc nitrate, the ammonium salt is ammonium nitrate or ammonium bicarbonate, and the volume ratio of the zinc source to the ammonium salt is 1:1 as a precipitation washing solution.
Technical Field
The invention relates to a gas separation technology, in particular to a high-efficiency separation method of acetylene in mixed gas.
Background
Acetylene is an important petrochemical basic raw material, about 1% of acetylene impurities exist in the traditional process of preparing ethylene by naphtha cracking, and in order to obtain polymerization-grade ethylene, the acetylene is converted into the ethylene by a noble metal catalytic reaction hydrogenation mode. However, in order to ensure that the concentration of acetylene in ethylene is reduced to below 10ppm, the selectivity is obviously reduced while high conversion rate is maintained, and a part of ethylene products are excessively hydrogenated to generate ethane, so that not only is the waste of ethylene products caused, but also the task of later ethane/ethylene separation is aggravated. If the method can realize the high-efficiency separation and enrichment of the low-concentration acetylene component in the ethylene or the related low-carbon hydrocarbon component to obtain the high-purity chemical product-grade acetylene, the method has great significance
As can be seen from the ethylene production process, the main gas components in the application scenario involving acetylene separation are acetylene, ethylene, ethane and carbon dioxide. For the adsorption separation process, the main adsorption separation mechanisms are mainly divided into three types, namely thermodynamic separation, kinetic separation and size screening, in order to realize high-selectivity acetylene capture and desorption to obtain a high-purity acetylene product, and meanwhile, the process cannot cause overhigh adsorption heat, so the size screening mechanism is more suitable. The Metal Organic Framework (MOF) material has a highly ordered three-dimensional pore channel structure, finely adjustable pore channel sizes and rich functional pore channel surfaces, shows great application potential in the field of gas adsorption and separation in recent years, can develop an MOF material capable of industrially preparing, separating and adsorbing low-concentration acetylene and has great application prospects. However, in the prior art, due to the restrictions of process conditions and material properties, the separation efficiency of acetylene is not high, and the purity of the obtained acetylene needs to be improved due to poor selectivity.
Disclosure of Invention
The invention provides a high-efficiency separation method of acetylene in mixed gas, which improves the gas separation efficiency and the purity of the obtained acetylene.
The technical scheme adopted by the invention is as follows:
a method for efficiently separating acetylene from mixed gas comprises the following steps:
step 1: the mixed gas containing acetylene passes through a container filled with an adsorbent at a certain temperature and pressure to complete the adsorption of acetylene;
step 2: the desorption regeneration of the adsorbent is completed by inert gas purging under the condition of temperature rise or vacuum negative pressure;
the preparation method of the adsorbent comprises the following steps:
1) adding a zinc source, pyromellitic dianhydride and 4,4' -bipyridyl into deionized water, and stirring;
2) stirring and mixing evenly, then adding ammonia water or ammonium salt, and continuously stirring and reacting for a period of time;
3) after the reaction is finished, filtering, washing and drying the obtained precipitate to obtain the chemical formula [ Zn ]2(bpy)(btec)(H2O)2]·2H2An adsorbent having a metal organic framework of O.
Further, the mixed gas comprises acetylene and a separation gas, and the separation gas comprises one or more of organic and/or inorganic gases.
Further, the volume fraction of the acetylene in the mixed gas is 0-50%, and zero is not contained.
Further, when acetylene is adsorbed on the adsorbent, the adsorption temperature is 10-30 ℃, and the pressure in the container is 1bar or more.
Further, when acetylene is adsorbed on the adsorbent, the reaction space velocity is 5-100 h-1And the purity of acetylene obtained by desorption of the adsorbent under the vacuum-pumping negative pressure condition is more than 92.5 percent. Preferably, the purity of acetylene obtained by desorbing the adsorbent under the vacuum negative pressure condition is more than 98.5%.
Further, in the preparation step of the adsorbent, the total molar concentrations of the zinc source, the pyromellitic dianhydride and the 4,4' -bipyridine are as follows: 1.2-1.8 mol/L, the molar weight of pyromellitic dianhydride is equal to that of 4,4' -bipyridine, and the molar weight of zinc source is as follows: the molar weight of 4,4' -bipyridine = 1.3-3.3.
Further, in the step of preparing the adsorbent, the molar amount of ammonia water: the molar weight of the pyromellitic dianhydride = 0.03-0.15.
Further, in the preparation step of the adsorbent, the reaction temperature is controlled to be 20-50 ℃, and the reaction time is controlled to be 0.5-2 h.
Further, the zinc source is zinc acetate or zinc nitrate, the ammonium salt is ammonium nitrate or ammonium bicarbonate, and the volume ratio of the ammonium salt to the ammonium nitrate is 1:1 as a precipitation washing solution.
Due to the adoption of the technical scheme, the invention has the beneficial effects that:
1) according to the high-efficiency acetylene separation method provided by the invention, the special method is adopted to prepare the adsorbent, so that the separation difficulty is reduced, the application range of the separation method is expanded, the method is not limited by the composition of inorganic and organic gases in mixed gas and the concentration of acetylene in the mixed gas, and high-purity acetylene recovered substances can be obtained;
2) compared with the traditional preparation method, the method adopts the method of adding ammonia water or ammonium salt and stirring and synthesizing at a lower temperature, the whole step is quicker, simpler and more convenient, the ammonium pyromellitic acid salt can be formed by adding the ammonia water, the solubility of the pyromellitic dianhydride is obviously improved, the combination of the pyromellitic dianhydride and Zn ions in an aqueous solution is accelerated, the quick growth of the MOF is promoted, and the yield is finally improved, so that the problems that the hydrothermal synthesis in the prior art needs high temperature and long reaction time and [ Zn ] needs long reaction time2(bpy)(btec)(H2O)2]·2H2The yield of O is low, thus being beneficial to industrial scale preparation;
3) compared with the MOF prepared by the traditional hydrothermal method, the MOF prepared by the invention has smaller granularity, a loose structure and more excellent trapping effect on the efficient trapping of low-concentration acetylene.
Drawings
Fig. 1 is an SEM image of the adsorbents obtained in example 1 and comparative examples 1 and 2.
FIG. 2 shows the adsorbents obtained in example 1 and comparative example 1, [ Zn ]2(bpy)(btec)(H2O)2]·2H2XRD pattern of O theoretical structure crystal form.
FIG. 3 shows adsorbent pair C obtained in example 12H2、C2H4And CO2Adsorption curve of (2).
FIG. 4 is a graph showing the adsorption curves of the adsorbent obtained in example 1 for lower hydrocarbons.
FIG. 5 shows the adsorbent obtained in example 1 for CO2、H2、O2And N2Adsorption curve of (2).
FIG. 6 shows that when the mixed gas is C2H2/C2H4(1/99), the breakthrough curve and desorption curve of the adsorbent obtained in example 1.
FIG. 7 shows that when the mixed gas is C2H2/CO2(50/50), the breakthrough curve and desorption curve of the adsorbent obtained in example 1.
FIG. 8 shows that when the mixed gas is CH4/C2H2/C2H4/C2H6/C3H6/C3H8/CO2/H2(30/1/10/25/10/10/1/13), the breakthrough curve and desorption curve of the adsorbent obtained in example 1.
FIG. 9 shows that when the mixed gas is C2H2/C2H4(1/99), breakthrough cycling profile of the adsorbent obtained in example 1.
FIG. 10 shows that when the mixed gas is C2H2/CO2(50/50), breakthrough cycling profile of the adsorbent obtained in example 1.
FIG. 11 is a graph of example 1 and the prior art MOF vs. C2H2/C2H4(1/99) graph comparing performance at different pressures.
FIG. 12 is a graph of example 1 and the prior art MOF vs. C2H2/CO2(50/50) graph comparing performance at different pressures.
FIG. 13 shows the results of example 1 and the prior art MOF report for C2H2/C2H4(1/99) and C2H2/CO2(50/50) comparison of adsorption performance.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention is described in detail below with reference to specific examples and experimental data, and it should be understood that the specific examples described herein are only for explaining the present invention and are not intended to limit the present invention.
A method for efficiently separating acetylene from mixed gas comprises the following steps:
step 1: the mixed gas containing acetylene passes through a container filled with an adsorbent at a certain temperature and pressure to complete the adsorption of acetylene;
step 2: the desorption regeneration of the adsorbent is completed by inert gas purging under the condition of temperature rise or vacuum negative pressure;
the preparation method of the adsorbent comprises the following steps:
1) adding a zinc source, pyromellitic dianhydride and 4,4' -bipyridyl into deionized water, and stirring;
2) stirring and mixing evenly, then adding ammonia water, and continuously stirring and reacting for a period of time;
3) after the reaction is finished, filtering, washing and drying the obtained precipitate to obtain the chemical formula [ Zn ]2(bpy)(btec)(H2O)2]·2H2An adsorbent having a metal organic framework of O.
In the synthesis process, ammonia water is added, which can form pyromellitic acid ammonium salt with pyromellitic dianhydride, and accelerate the combination of pyromellitic acid ammonium salt and Zn ions in the aqueous solution to promote [ Zn ]2(bpy)(btec)(H2O)2]·2H2O grows rapidly and can increase [ Zn ]2(bpy)(btec)(H2O)2]·2H2The yield of O, thereby reducing the reaction temperature, the time required by the reaction and improving the product yield, and being beneficial to the industrialized preparation of the catalyst. The zinc source in this embodiment can be selected from zinc acetate, zinc sulfate, zinc chloride, zinc nitrate and other zinc sources, preferably zinc acetate or zinc nitrate, and will not generate other impurity elements such as S atoms or Cl atoms to interfere with the synthesis of MOF, thereby possibly reducing the yield of MOFOr quality.
The method for efficiently separating the acetylene has simple steps, when the acetylene needs to be recovered into product gas, the acetylene is desorbed on the adsorbent by adopting a vacuumizing method, and when the acetylene does not need to be recovered, the temperature can be raised to 50 ℃ or above, and the inert gas such as nitrogen is used for purging, so that the regeneration of the adsorbent is realized.
In some embodiments, the mixed gas comprises acetylene and a separation gas comprising one or more of an organic and/or inorganic gas. The organic gas can include hydrocarbons generated in the ethylene preparation process, including but not limited to saturated or unsaturated hydrocarbons of C1-C4, and the inorganic gas can include common CO2、N2、O2、H2And the like.
In some specific embodiments, the volume fraction of the acetylene in the mixed gas is 0-50%, and the acetylene does not contain a zero value, so that the acetylene concentration range applicability is wide.
In some embodiments, the adsorption temperature of acetylene on the adsorbent is 10-30 ℃, and the pressure in the container is 1bar or more. The adsorption condition of the invention is mild, and the invention is easy for industrial implementation and large-scale application.
In some embodiments, the reaction space velocity of acetylene adsorbed on the adsorbent is 5-100 h-1And the purity of acetylene obtained by desorption of the adsorbent under the vacuum-pumping negative pressure condition is more than 92.5 percent. Preferably, the purity of acetylene obtained by desorbing the adsorbent under the vacuum negative pressure condition is more than 98.5%. The invention has wide applicable airspeed range under the condition of ensuring the purity of acetylene, and the obtained acetylene has higher concentration and can improve the economic benefit.
In some embodiments, the total molar concentration of the zinc source, pyromellitic dianhydride, and 4,4' -bipyridine during the preparation of the adsorbent is: 1.2-1.8 mol/L, the molar weight of pyromellitic dianhydride is equal to that of 4,4' -bipyridine, and the molar weight of zinc source is as follows: the molar weight of 4,4' -bipyridyl = 1.3-3.3, and [ Zn ] is favorably formed2(bpy)(btec)(H2O)2]·2H2O, increasing the yield of MOF.
In some embodimentsIn the examples, the molar amount of ammonia water in the preparation of the adsorbent: the molar weight of the pyromellitic dianhydride = 0.03-0.15, and the appropriate ammonia water amount is selected so as to form pyromellitic ammonium salt, which is beneficial to the formation of pyromellitic ammonium salt and Zn2+Bind to thereby promote [ Zn ]2(bpy)(btec)(H2O)2]·2H2O grows rapidly, and the invention finds that in the experiment, when the ammonia water content is too high, the solution is alkaline, and the yield of the MOF is reduced.
In some specific embodiments, in the preparation process of the adsorbent, the reaction temperature is controlled to be 20-50 ℃, and the reaction time is controlled to be 0.5-2 h.
In some embodiments, it is preferable to use a volume ratio of 1: the water/ethanol mixed solution of 1 is used as a precipitation washing liquid, the sources of the two washing liquids are easy to obtain, and under the mixing proportion, impurities and residual reactants on the MOF surface can be effectively and quickly washed, so that the purity of the product is improved. The invention is not limited to such washing solutions at this ratio, and other organic, inorganic or mixed solutions capable of effectively washing MOF precipitates are equally suitable for use in the invention.
Specific examples are exemplified below.
Example 1
Adding 0.150 kg of zinc acetate, 0.0764 kg of pyromellitic dianhydride and 0.0547 kg of 4,4' -bipyridine into 1.0L of deionized water, stirring and mixing uniformly, adding 2mL of ammonia water with the mass concentration of 25%, controlling the temperature at 25 ℃, continuously stirring for 2 h, filtering, washing with a water/ethanol (1: 1) mixed solution, and drying the obtained filter cake to obtain the product.
Example 2
Adding 0.150 kg of zinc acetate, 0.0764 kg of pyromellitic dianhydride and 0.0547 kg of 4,4' -bipyridine into 1.0L of deionized water, stirring and mixing uniformly, adding 2mL of ammonia water with the mass concentration of 25%, controlling the temperature at 50 ℃, continuously stirring for 0.5 h, filtering, washing with a water/ethanol (1: 1) mixed solution, and drying the obtained filter cake to obtain the product.
Example 3
Adding 0.150 kg of zinc acetate, 0.0764 kg of pyromellitic dianhydride and 0.0547 kg of 4,4' -bipyridine into 1.0L of deionized water, stirring and mixing uniformly, adding 3mL of ammonia water with the mass concentration of 25%, controlling the temperature at 50 ℃, continuously stirring for 0.5 h, filtering, washing with a water/ethanol (1: 1) mixed solution, and drying the obtained filter cake to obtain the product.
Example 4
Adding 0.165 kg of zinc acetate, 0.0764 kg of pyromellitic dianhydride and 0.0547 kg of 4,4' -bipyridine into 1.0L of deionized water, stirring and mixing uniformly, adding 2mL of ammonia water with the mass concentration of 25%, controlling the temperature at 30 ℃, continuously stirring for 0.5 h, filtering, washing with a water/ethanol (1: 1) mixed solution, and drying the obtained filter cake to obtain the product.
Example 5
Adding 0.128 kg of zinc acetate, 0.0764 kg of pyromellitic dianhydride and 0.0547 kg of 4,4' -bipyridine into 1.0L of deionized water, stirring and mixing uniformly, adding 1mL of ammonia water with the mass concentration of 25%, controlling the temperature at 20 ℃, continuously stirring for 0.5 h, filtering, washing with a water/ethanol (1: 1) mixed solution, and drying the obtained filter cake to obtain the product.
Comparative example 1
0.1097 g of zinc acetate, 0.1091 g of pyromellitic dianhydride, 0.0781 g of 4,4' -bipyridine and 10 mL of deionized water are added into a 25mL reaction kettle, heated to 180 ℃ for five days, cooled to room temperature, filtered, washed by a hot water/ethanol (1: 1) mixed solution, and the obtained filter cake is dried to obtain the product.
Comparative example 2
Adding 0.128 kg of zinc acetate, 0.0764 kg of pyromellitic dianhydride and 0.0547 kg of 4,4' -bipyridyl into 1.0L of deionized water, controlling the temperature to be 20-50 ℃, stirring uniformly, mixing for 2 hours, filtering, washing with a water/ethanol (1: 1) mixed solution, and drying the obtained filter cake to obtain the product.
The yields of the products in the examples and comparative examples were calculated based on 4,4' -bipyridine, and the results are shown in Table 1.
TABLE 1 yield results for the products of the examples and comparative examples
As can be seen from Table 1, when hydrothermal synthesis is not adopted, the reaction temperature is directly reduced and the reaction time is shortened, the yield of the product is only 24.3%, while the method for preparing the product of the invention can improve the yield of the product and control the yield to 87.5%, the method is favorable for industrial preparation due to the adoption of low temperature and low pressure, and when hydrothermal synthesis is adopted, the yield of the product is 45.7%, but the product needs high temperature of 180 ℃ and needs 5 days of synthesis, which is not favorable for industrial production, and even if the product is industrially generated, the high temperature and high pressure state is not as efficient and safe as the method for preparing the product in a low temperature and short time.
To characterize Zn2The microscopic morphology of the (bpy) (btec) material is characterized by SEM of products obtained in example 1, comparative example 1 and comparative example 2, and the result is shown in FIG. 1, wherein b in FIG. 1 is an SEM image of example 1, a in FIG. 1 is an SEM image of comparative example 1, and c in FIG. 1 is an SEM image of comparative example 2, and as can be seen from the images, the sample of example 1 has smaller granularity and a loose structure, and is more beneficial to mass transfer and diffusion of gas compared with comparative example 1; comparative example 2 shows a nano-scale aggregate, the reaction time and reaction temperature were low without addition of ammonia, and the solubility of pyromellitic dianhydride in water was poor, resulting in [ Zn ]2(bpy)(btec)(H2O)2]·2H2The growth process of O is slow, and the granularity of the product is very low.
In order to confirm the crystal structure of the synthesized product, XRD characterization was performed on example 1 and comparative example 1, and the results were compared with [ Zn ]2(bpy)(btec)(H2O)2]·2H2The comparison results are shown in figure 2, and it can be seen from the figure that the theoretical crystal structure is obtained by adopting the invention and hydrothermal synthesisZn of (2)2(bpy) (btec) material.
To characterize Zn2(bpy) (btec) adsorption capacity of the material for different gases the adsorption curve of the product of example 1 for each gas was determined at 298K using a Micromeritics ASAP 2020 instrument, using the product of example 1, and FIG. 3 is C2H2, C2H4And CO2FIG. 4 is an adsorption curve of a lower hydrocarbon, and FIG. 5 is a adsorption curve of CO2, H2, O2And N2The adsorption curves of (1) are shown in FIGS. 3-5, and Zn is observed in the gas mixture of acetylene with organic gas, inorganic gas or organic-inorganic co-mixed gas2The (bpy) (btec) material has excellent adsorption performance on acetylene and weak adsorption on other gases.
To test Zn2Actual separation effect of (bpy) (btec) material on different mixed gases, taking the product obtained in example 1 as an example, the penetration experiment and desorption experiment are carried out on the product obtained in example 1, and the specific process is as follows: accurately controlling the mixed gas to pass through an adsorption column (with the size of phi 4 multiplied by 275 mm) filled with an adsorbent (with the sample amount of 3.0575 g and about 3 ml) at the pressure (1.01 bar) and the flow rate (1.25 ml/min) through a pressure reducing valve and a gas mass flowmeter, controlling the temperature of the adsorbent to be 298K, starting timing at the same time, monitoring the concentration of tail gas in real time through a chromatograph (GC-2014C, TCD detector) at the tail end of the adsorption column, and recording data; and after the adsorption is saturated, switching to vacuum, starting timing, monitoring the tail gas concentration in real time through a chromatograph (GC-2014C, TCD detector) at the tail end of the adsorption column, recording data until the tail end cannot monitor the components of the feed gas, and considering that the desorption of the adsorption column is finished.
When the mixed gas is C2H2/C2H4(volume fraction ratio 1/99), the breakthrough and desorption curves of the adsorbent are shown in the left and right panels, respectively, of FIG. 6, from which it can be seen that the material is effective in separating C2H2/C2H4(1/99) the mixture was separated to obtain 98.5% pure acetylene.
When the mixed gas is C2H2/CO2(volume fraction ratio 50/50), the breakthrough and desorption curves of the adsorbent are shown in the left and right panels, respectively, of FIG. 7, from which it can be seen that the material is effective in separating C2H2/CO2(50/50) the mixture was separated to obtain 92.5% pure acetylene.
When the mixed gas is CH4/C2H2/C2H4/C2H6/C3H6/C3H8/CO2/H2(30/1/10/25/10/10/1/13 volume fraction); the curves of the adsorbent and the desorption curve are respectively shown in the left graph and the right graph of fig. 8, and as can be seen from the graphs, the material can be used for efficiently separating the mixture and separating acetylene with the purity of more than 98.0 percent. Under the condition that the condition of the mixed gas is not changed, the separation conditions are changed, the adsorbents in the embodiments 2-5 are respectively reacted, and the obtained results are shown in the following table.
To test Zn2(bpy) (btec) stability of the material, exemplified by the product of example 1, the material was tested for penetration cycling curves when the gas mixture was C2H2/C2H4(1/99), the breakthrough cycle curves are shown in FIG. 9, where C2H4Is represented by a square, C2H2Represented by circles; when the mixed gas is C2H2/CO2(50/50), the breakthrough cycle curves are shown in FIG. 10, where CO2Represented by triangles, C2H2Indicated by circles, it can be seen from FIGS. 9 and 10 that Zn is present after 5 consecutive cycles2The performance of the (bpy) (btec) material is fully maintained.
FIGS. 11-13 show the mixed gas C of example 1 and the MOF reported in the prior art under the condition of 1bar and 298K2H2/C2H4(1/99) and C2H2/CO2(50/50) comparison of theoretical Selectivity (IAST) of ideal adsorption solution, from whichThe present adsorbents are known to exhibit excellent adsorption selectivity, far superior to the reported MOF materials.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
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