REGENERABLE HYDROGEN SULFIDE ADSORBENT AND PREPARATION METHOD THEREOF AND APPLICATION THEREOF

Abstract

The present invention relates to a regenerable hydrogen sulfide adsorbent and a preparation method thereof. The preparation method specifically includes: 1) combining meta-aluminate as an active component with activated alumina as a carrier in a manner of impregnation, spray coating or solid phase mixing to obtain a precursor; 2) aging and drying the precursor, and finally performing roasting to obtain the adsorbent; and 3) processing the adsorbent to present a specific size and shape through shaping measures to meet industrial application requirements. Compared with the prior art, the adsorbent obtained according to the present invention can achieve an efficient removal effect on hydrogen sulfide gas at a material inlet, with a concentration adaption range of 0 to 1000 ppm and an effective removal precision of 0.1 ppm or below.

Claims

1. A regenerable hydrogen sulfide adsorbent, consisting of two parts: an active component and a carrier, wherein the active component is meta-aluminate, and the carrier is activated alumina.

2. The regenerable hydrogen sulfide adsorbent according to claim 1, wherein a weight ratio of the meta-aluminate is 0.5 to 40%, and a weight ratio of the activated alumina is 60 to 99.5%.

3. The regenerable hydrogen sulfide adsorbent according to claim 1, wherein the activated alumina is chi-phase alumina, rho-phase alumina, eta-phase alumina, gama-phase alumina or a mixed phase thereof.

4. The regenerable hydrogen sulfide adsorbent according to claim 1, wherein the meta-aluminate is a metal salt compound of a “AlO.sub.2.sup.−” atomic group and a metal element M and/or hydrogen element, and the metal element M is selected from one or a combination of more of alkali metal and/or alkaline earth metal elements.

5. The regenerable hydrogen sulfide adsorbent according to claim 4, wherein the metal element M is one or a mixture of Na and K.

6. The regenerable hydrogen sulfide adsorbent according to claim 4, wherein in the meta-aluminate, a mole ratio of the metal element M to an aluminum element is 1-5.5:1.

7. A preparation method of the regenerable hydrogen sulfide adsorbent according to claim 1, comprising: firstly weighing an active component, combining the active component with a carrier to obtain a precursor, and then performing aging, drying and roasting to obtain a target product.

8. The preparation method of the regenerable hydrogen sulfide adsorbent according to claim 7, wherein the active component is combined with the carrier in a manner of solution impregnation, spray coating or solid mixing.

9. The preparation method of the regenerable hydrogen sulfide adsorbent according to claim 7, wherein an aging temperature is 25 to 150° C., and the aging time is 8 to 48 h; a drying temperature is 60 to 150° C., and the drying time is 0.5 to 24 h; and a roasting temperature is 300 to 600° C., and the rotating time is 1 to 5 h.

10. An application of the regenerable hydrogen sulfide adsorbent according to claim 1, wherein the adsorbent is used for removing water and hydrogen sulfide from a hydrocarbon stream comprising saturated and/or unsaturated hydrocarbons.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIGURE is an XRD diagram of using conventional commercially available gama-phase alumina as a carrier and using the activated alumina specially prepared according to the present invention as a carrier sample.

DESCRIPTION OF THE EMBODIMENTS

[0028] The present invention will be further illustrated in detail in conjunction with drawings and specific embodiments hereafter. The present embodiment is implemented on the premise of the technical solution of the present invention. Detailed implementations and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0029] In each of the following embodiments, commercially available gama phase-alumina, pseudo-boehmite and activated alumina powder were all purchased from Aluminum Corporation of China, and hydrogen sulfide standard gas was purchased from Shanghai Shenkai gas technology Co., Ltd.

[0030] In each of the following embodiments, each of prepared catalyst samples was subjected to desulfurization performance evaluation tests and butadiene side reaction evaluation experiments. The specific data were as follows.

[0031] The evaluation conditions were shown in Table 1.

TABLE-US-00001 TABLE 1 Adsorbent evaluation condition Standard gas 1000 ppm H.sub.2S, 50% V propene, composition and the balance N.sub.2 Test pressure 1.5 MPa Evaluation 25-30° C. temperature Sample loading 40.00 ± 0.1 g volume Flow rate 2000 mL/min Regeneration H.sub.2 medium Regeneration 250° C. constant temperature for 1.5 h condition 0.5 MPa Flow rate 500 mL/min

[0032] A specific evaluation method was as follows. Firstly, 40.0 g of fresh adsorbent was added into a fixed bed reactor, nitrogen gas was introduced to purge a system, then, a back pressure valve was adjusted so that a system pressure was stabilized at 1.5 MPa, and then, the operation entered an evaluation step. A gas path was switched to introduce the hydrogen sulfide standard gas into the system, a parameter of a mass flowmeter was set to be 2000 mL/min, and the evaluation was started. Tail gas was introduced into gas chromatography. The tail gas was collected once every 3 min. When the outlet concentration of hydrogen sulfide is higher than 0.1 ppm, the condition was regarded as adsorption saturation, and the operation entered a regeneration step. Firstly, the gas path was switched into hydrogen gas to purge the system for 10 min, a pressure was adjusted to 0.5 MPa, and then, temperature rise was started. The bed layer temperature rise speed was 4° C./min. After the bed layer temperature reached 250° C. , the temperature kept constant for 3.5 h, and the regeneration was finished. Then, the system lowers the temperature to a room temperature, the gas path was switched to the hydrogen sulfide standard gas, the flow rate was adjusted, and the second adsorption was started. The adsorption performance was calculated according to the adsorption time. After the adsorption time decreases, the condition showed that the service life of the adsorbent started to attenuate. When the adsorption time was reduced to 75% of the initial adsorption time, it was regarded that the bed layer was inactivated.

[0033] Butadiene side reaction evaluation experiment: A sample to be evaluated was charged into a pressure container. Then, a temperature of the pressure container was raised to 200° C. Next, butadiene was introduced. The pressure was about 0.5 atmospheric pressure. The sample was maintained at this pressure for 7 h. The self-polymerization degree of the butadiene was calculated by recording a pressure drop value. In a blank experiment, after 7 h, the pressure drop was about 5%.

[0034] The rest raw materials or processing techniques, if not specified, are all conventional commercially available raw materials or conventional processing techniques in the art.

Embodiment 1

[0035] In the present embodiment, a desulfurizer was prepared from activated alumina, sodium hydroxide and aluminum hydroxide as raw materials.

[0036] Firstly, 4.1 kg of sodium hydroxide was dissolved in 6.2 kg of deionized water. Then, 3.9 kg of aluminum hydroxide was dissolved into a sodium hydroxide solution to be prepared into a clear and transparent sodium meta-aluminate solution. Next, 8.0 kg of deionized water was slowly supplemented. 21.2 kg of activated alumina (with chi-rho and eta phases in crystal phase structures) and the sodium meta-aluminate solution were sufficiently combined in an equivalent-volume impregnation form. Then, aging was performed for 12 h under the condition of 130° C. Next, the treated raw materials were put into a baking oven of 120° C. at a constant temperature for 3 h to be thoroughly dried. Finally, activation was performed for 2 h in a 450° C. muffle furnace, and an adsorbent sample was obtained. The sample was subjected to tabletting and crushing to obtain irregular particles with the particle size being about 2 mm, and was marked as S1. Through the butadiene side reaction test, the pressure drop was about 13.5%.

Embodiment 2

[0037] In the present embodiment, a desulfurizer was prepared from activated alumina, potassium hydroxide and aluminum hydroxide as raw materials.

[0038] Spherical particles with the particle size being about 2.0 mm were obtained through forming in a rolling granulation manner. Firstly, 2.9 kg of potassium hydroxide was dissolved in 2.0 kg of deionized water. Then, 3.0 kg of aluminum hydroxide was dissolved into a potassium hydroxide solution to be prepared into a clear and transparent potassium meta-aluminate solution. Next, 5.0 kg of deionized water was slowly added to be prepared into a spray coating solution. 20.1 kg of activated alumina powder (with chi-rho and eta phases in crystal phase structures) was weighed. In rolling forming equipment, the potassium meta-aluminate solution was sprayed and coated onto rapid dehydration powder (activated alumina) to obtain spherical particles. The particle size was about 1.6 to 2.5 mm. Then, the obtained particles were subjected to aging for 24 h under the condition of 130° C. Next, the treated raw materials were put into a baking oven of 120° C. at a constant temperature for 3 h to be thoroughly dried. Finally, activation was performed for 2 h in a 350° C. muffle furnace, and an adsorbent sample was obtained, and was marked as S2. Through the butadiene side reaction test, the pressure drop was about 14.1%.

Embodiment 3

[0039] In the present embodiment, a desulfurizer was prepared from activated alumina and sodium meta-aluminate solid as raw materials.

[0040] Spherical particles with the particle size being about 2.0 mm were obtained through forming in a rolling granulation manner. The specific steps were as follows: The activated alumina powder (with chi-rho and eta phases in crystal phase structures) and the sodium meta-aluminate solid powder were mixed according to a mass ratio of 19:1. 19.0 kg of activated alumina and 1.0 kg of sodium meta-aluminate were weighed and sufficiently mixed. Then, by using a rolling forming method, bonding was performed through glue water, and a solid content of the glue water was 1.0% wt. Spherical particles with the particle size being about 1.6 to 2.4 mm were obtained, and aging was performed at a temperature of 100° C. for 24 h. Next, the particles were dried for 3 h in a baking oven of 120° C., and were then roasted for 2 h under the condition of 400° C. to obtain a sample, and the sample was marked as S3. Through the butadiene side reaction test, the pressure drop was about 13.3%.

Embodiment 4

[0041] In the present embodiment, a desulfurizer was prepared from activated alumina and sodium meta-aluminate solid as raw materials.

[0042] Spherical particles with the particle size being about 2.0 mm were obtained through forming in a rolling granulation manner. The specific steps were as follows: 30 kg of activated alumina powder (with chi-rho and eta phases in crystal phase structures) and 10 kg of sodium meta-aluminate solid were weighed according to a mass ratio of 3:1. After the activated alumina and the sodium meta-aluminate were sufficiently mixed, spherical particles with the particle size being about 1.6 to 2.4 mm were obtained in a rolling granulation manner. A sample was subjected to aging for 24 h at a temperature of 100° C., was dried at 120° C., and was then roasted for 2 h under the condition of 400° C. to obtain a sample, and the sample was marked as S4. Through the butadiene side reaction test, the pressure drop was about 14.3%.

Embodiment 5

[0043] In the present embodiment, pseudo-boehmite and sodium meta-aluminate solid were used as raw materials.

[0044] Extrusion forming was adopted to obtain strip-shaped particles with the strip diameter being about 2.0 mm. The specific steps were as follows: After the pseudo-boehmite and the sodium meta-aluminate solid powder were sufficiently mixed, 30 kg of pseudo-boehmite and 10 kg of sodium meta-aluminate solid were weighed according to a mass ratio of 3:1, and then, a strip-shaped sample with the strip diameter being 2.0 mm was obtained in a basic forming manner. The sample was subjected to aging for 24 h at a temperature of 100° C., was dried for 3 h at 120° C., and was then roasted for 2 h under the condition of 450° C. to obtain a gama-alumina loaded sodium meta-aluminate sample, and the sample was marked as S5. Through the butadiene side reaction test, the pressure drop was about 14.3%.

Comparative Example 1

[0045] Commercially available gama-alumina with the particle size being 2.0 mm was used as a sample, and was marked as D1. Through the butadiene side reaction test, the pressure drop was about 40.2%.

Comparative Example 2

[0046] Sodium meta-aluminate was used as a sample to be subjected to extrusion forming and crushing to obtain irregular particles in the particle size range about 2.0 mm as a sample, and the sample was marked as D2. Through the butadiene side reaction test, the pressure drop was about 13.8%.

Comparative Example 3

[0047] Comparative example 3 was similar to Embodiment 4. The differences were that aging treatment was not performed, drying and roasting were directly performed, and a sample was marked as D3. Through the butadiene side reaction test, the pressure drop was about 43.5%.

Comparative Example 4

[0048] Comparative example 4 was similar to Embodiment 4. The differences were that the aging conditions were changed into 50° C. and 48 h, and a sample was marked as D4. Through the butadiene side reaction test, the pressure drop was about 14.7%.

Comparative Example 5

[0049] In the present embodiment, commercially available gama-alumina particles and a sodium meta-aluminate solution were used as raw materials for preparation.

[0050] 2.0 kg of gama-alumina particles in a particle size range of 1.6 to 2.0 mm were weighed. Before use, the particles were activated at 250° C. for 2 h, and were cooled to a room temperature. Then, 2.5 kg of sodium meta-aluminate (Na:Al=1.3:1) solution was impregnated onto the alumina particles, a concentration of the prepared sodium meta-aluminate was 15% wt, and a sample with a theoretical loading capacity of 15.8% wt was finally obtained. The sample was dried for 3 h at 120° C., was then activated for 3 h under the condition of 300° C., and was marked as D5. Through the butadiene side reaction test, the pressure drop was about 14.6%.

[0051] The physical parameter indexes of samples of each embodiment and comparative example were shown in Table 2 below.

TABLE-US-00002 TABLE 2 Sample physical parameter index Whether aging treatment Sample Stacking Crushing is received number density strength Abrasion or not S1 — — — Yes S2 0.75 g/mL  33N/particle 0.28 wt % Yes S3 0.74 g/mL  51N/particle 0.15 wt % Yes S4 0.78 g/mL  53N/particle 0.23 wt % Yes S5 0.71 g/mL  40N/particle 0.13 wt % Yes D1 0.71 g/mL 118N/particle 0.25 wt % No D2 0.58 g/mL — — No D3 0.74 g/mL  9N/particle 0.65 wt % No D4 0.74 g/mL  23N/particle 0.47 wt % Low aging temperature D5 0.63 g/ml  68N/particle 0.33 wt % No

[0052] The performance indexes of samples of each embodiment and comparative example were shown in Table 3 below.

TABLE-US-00003 TABLE 3 Performance comparison of samples Attenuation M.sub.2O Specific Pore condition of Serial content M:Al** surface volume Adsorption adsorption time Preparation number *wt % mol % area m.sup.2/g cm.sup.3/g time min after 15 cycles method S1 10.82 2.05:1   116.5 0.301 104 No attenuation Impregnation S2 8.93 1.34:1   133.2 0.280 106 No attenuation Rolling granulation S3 2.55 1:1 175.8 0.362 84 No attenuation Rolling granulation S4 9.33 1:1 144.7 0.387 106 No attenuation Rolling granulation S5 10.67 1:1 127.7 0.375 92 No attenuation Strip extrusion D1 0.65 — 307.5 0.392 46 Attenuation was — started after 6 times of experiments, and bed layer inactivation occurred in the eighth time of experiments. D2 36.71 1:1 12.75 0.04 38 No attenuation — D3 9.42 1:1 138.5 0.375 62 No attenuation Rolling granulation D4 8.95 1:1 141.3 0.346 70 No attenuation Rolling granulation D5 10.55 1.3:1   98.5 0.296 65 No attenuation Impregnation * XRF test results **Theoretical feeding value

[0053] According to Embodiments 1-4, a desulfurizer prepared by combining activated alumina (with chi-rho and eta phases in crystal phase structures) and meta-aluminate had good hydrogen sulfide adsorption capability. Additionally, there was no attenuation after several cycles. According to Embodiment 5, a dechlorinating agent containing gamma-phase activated alumina and prepared by combining pseudo-boehmite and meta-aluminate had the performance a little weaker than that of Embodiment 1 under the condition of the similar active component content. D1-D5 were used as comparative examples to compare the H.sub.2S adsorption performance and the physical performance, such as the stacking density and the crushing strength, of the pure gamma-phase alumina and the pure sodium meta-aluminate, and the influence of different aging conditions on the performance of the desulfurizer were compared at the same time. From the above embodiments and comparative examples, it could be seen that by using the activated alumina (with chi-rho and eta phases in crystal phase structures) and meta-aluminate and performing aging treatment under a certain condition, the sample showed the optimum hydrogen sulfide adsorption performance and regeneration performance, and at the same time, the side reactions were minimum.

[0054] FIGURE is an XRD diagram of an adsorbent sample prepared from gama-phase alumina as a carrier and the activated alumina as a carrier. From the FIGURE, it could be seen that the desulfurizer prepared from the activated alumina (with chi-rho and eta phases in crystal phase structures) according to the present invention showed a mixed phase at its characteristic peak. Additionally, a characteristic peak of the meta-aluminate was not found through XRD, and it showed that the meta-aluminate was in a highly scattered state on alumina.

Embodiment 7

[0055] The present embodiment was most identical to Embodiment 1, except for the adjustment on the mass of the activated alumina to enable a mass ratio of the activated alumina in the obtained adsorbent sample to be about 75%.

Embodiment 8

[0056] The present embodiment was most identical to Embodiment 1, except for the adjustment on the mass of the activated alumina to enable a mass ratio of the activated alumina in the obtained adsorbent sample to be about 95%.

Embodiment 9

[0057] The present embodiment was most identical to Embodiment 1, except for the adjustment on the mass of the activated alumina to enable a mass ratio of the activated alumina in the obtained adsorbent sample to be about 60%.

Embodiment 10

[0058] The present embodiment was most identical to Embodiment 1, except for the aging temperature being 800° C., the aging time being 24 h, [0059] the drying temperature being 80° C., the drying time being 0.5 h, [0060] the roasting temperature being 450° C., and the rotating time being 1 h.

Embodiment 11

[0061] The present embodiment was most identical to Embodiment 1, except for the aging temperature being 130° C., the aging time being 12 h, [0062] the drying temperature being 120° C., the drying time being 0.5 h, [0063] the roasting temperature being 350° C., and the rotating time being 5 h.

[0064] The embodiments described above are intended to facilitate understanding and use of the invention by those of ordinary skill in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present disclosure without departing from the scope of the present invention shall all fall within the protection scope of the present invention.