A dealkalization refining agent, its preparation method and application

Abstract

The present invention discloses a de-alkalization refining agent, a preparation method thereof and an application. The de-alkalization refining agent includes a microchannel, and the inner surface of the microchannel includes a silane film and a modified layer from outside to inside; the modified layer contains a sulfonic acid group and a secondary amino group. The preparation method of the de-alkalization refining agent includes: preparing a microchannel coated with a silane film; and then treating the microchannel coated with the silane film with a modifier to obtain the de-alkalization refining agent. The method of the present invention can be used in the process of removing basic impurities from dry gas.

Description

Technical Field

[0001] The present invention relates to the technical field of ethylbenzene production from dry gas, and relates to a de-alkali refining agent and a preparation method thereof, and an application in efficiently removing impurities (especially alkaline impurities) in dry gas. Background Art

[0002] Dry gas refers to the tail gas that cannot be liquefied in a refinery, mainly from the secondary processing of crude oil. The dry gas of refinery enterprises mainly comes from catalytic cracking gas and is generally used as fuel. In order to make full use of this part of dilute ethylene resources in dry gas, improve the utilization rate of petroleum resources, and at the same time solve the current shortage of the ethylbenzene / styrene market, the process of producing ethylbenzene from dry gas has been developed. Generally, in the presence of a catalyst and at a reaction temperature of 200°C to 500°C, ethylene and a small amount of propylene and butene in dry gas react with benzene to form ethylbenzene, propylbenzene, butylbenzene, polyalkylbenzene, etc.

[0003] Ethylbenzene alkylation catalysts generally use acidic molecular sieves. Due to the complex impurities in dry gas, especially the presence of certain alkaline impurities, the operation cycle of the ethylbenzene alkylation catalyst is significantly shortened.

[0004] Patent CN109574780A discloses a method for adsorbing ammonia in dry gas using modified activated carbon. Since the ammonia content in dry gas is unstable and generally fluctuates greatly between 1 and 500 ppm, the adsorbent is extremely easy to be saturated when the ammonia content is high, resulting in frequent loading and unloading of the adsorbent.

[0005] Patent CN111450662A discloses a combined ammonia removal process of a water washing tower - cyclone separator - coalescer - adsorption tower. The washing liquid is selected from industrial water or acidic aqueous solution, and the adsorbent is formed activated carbon, silica, alumina, formed molecular sieve, strongly acidic cation exchange resin, etc. loaded with inorganic acid or organic acid. In this process, due to the limited operation flexibility of the water washing and rectification tower, it is difficult to effectively remove ammonia in dry gas when the ammonia content in the raw material fluctuates greatly. Even if an adsorption tower is set up later, the adsorbent in the adsorption tower is quickly saturated due to the too high ammonia content in dry gas.

[0006] "Research on Absorbing Ammonia in Phosphorus Fertilizer Tail Gas by Rotating Packed Bed" (Chemical Intermediate, No. 7, 2009) discloses a process for absorbing ammonia in phosphorus fertilizer tail gas using phosphoric acid wastewater. Compared with traditional tower equipment, the absorption efficiency of this process has increased to a certain extent, but the deep ammonia removal effect is average.

[0007] In summary, the existing technology in the field of ammonia removal mainly has small operation flexibility and low removal depth, which in turn leads to continuous slow deactivation or rapid deactivation of the alkylation catalyst. Therefore, continuously and efficiently removing alkaline impurities in dry gas is one of the important problems that need to be solved urgently in the ethylbenzene unit under the background of crude oil inferiorization. Summary of the Invention

[0008] The technical problem to be solved by the present invention is the problem that the content of alkaline impurities in dry gas is high in the prior art and it is difficult to continuously and efficiently remove them. A de-alkalization refining agent, a preparation method thereof, and an application in removing alkaline impurities in dry gas are provided. The de-alkalization refining agent of the present invention is particularly suitable for separating alkaline impurities in dry gas that significantly affect the activity of the ethylbenzene alkylation catalyst, effectively eliminating the cumulative effect of alkaline impurities on the catalyst, and can significantly extend the operation cycle of the alkylation catalyst, realizing low-cost and continuous production of ethylbenzene.

[0009] In the first aspect of the present invention, a de-alkalization refining agent is provided, wherein the de-alkalization refining agent includes microchannels, and the inner surface of the microchannels includes a silane film and a modified layer from the outside to the inside; the modified layer contains sulfonic acid groups and secondary amine groups.

[0010] In the above technical solution, in the silane film, the molar ratio of siloxyl groups to silicon-carbon groups is 0.6 to 1.1, and the thickness of the silane film is 10 to 30 microns.

[0011] In the above technical solution, in the modified layer, the content of sulfonic acid groups is 0.2 to 0.6 mol / m 2 , and the content of secondary amine groups is 0.08 to 0.42 mol / m 2 .

[0012] In the above technical solution, preferably, the inner surface of the modified layer further includes a surface treatment layer; in the surface treatment layer, the content of sulfonic acid groups is 6 to 20 mmol / m 2 , the content of secondary amine groups is 10 to 36 mmol / m 2 , and the content of methoxy groups is 20 to 90 mmol / m 2 .

[0013] In the above technical solution, the microchannels are preferably zigzag microchannels, and further preferably zigzag microchannels with a square cross-section (such as a rectangle or a square) and a longitudinal tooth shape or a wavy shape, and the bending angle is 30° to 150°, preferably 60° to 120°. The cross-section of the microchannels is square, the width is 300 to 1000 microns, the aspect ratio of length to width is 1.5 to 6, the height of the modified microchannels is 1 to 3 cm, and the single-segment zigzag span is 0.6 cm to 23 cm. The material of the microchannels is metal, preferably 304, 304L, 316, 316L, or titanium material.

[0014] In the above technical solution, the silanization reagent used for the silane film is selected from at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, etc.

[0015] In the above technical solution, the modifiers used in the modification layer include a pretreatment agent, a catalyst, and a solvent. The catalyst is selected from one of Lewis acids or Lewis bases, and is preferably at least one of anhydrous zinc chloride, anhydrous tin tetrachloride, and anhydrous aluminum chloride. The solvent is selected from at least one of toluene, p-xylene, m-xylene, and o-xylene. The pretreatment agent is obtained by further treating at least one selected from 4,4'-dichlorodiphenylmethanol, p-chlorobenzhydryl chloride, and 4-chlorodiphenylchloromethane (preferably p-chlorobenzhydryl chloride) with fuming sulfuric acid.

[0016] In the above technical solution, the surface treatment agent used in the surface treatment layer includes N-(carbamoylmethyl)-2-aminoethanesulfonic acid, 3,5-dichloro-2-methoxyaniline, a catalyst, and a solvent. The catalyst is selected from one of Lewis acids or Lewis bases, and is preferably at least one of anhydrous zinc chloride, anhydrous tin tetrachloride, and anhydrous aluminum chloride. The solvent is selected from at least one of toluene, p-xylene, m-xylene, and o-xylene.

[0017] In the above technical solution, the contents of sulfonic acid groups, secondary amine groups in the modification layer, and sulfonic acid groups, secondary amine groups, and methoxy groups in the surface treatment layer are all based on the inner surface area of the microchannels per square meter.

[0018] The second aspect of the present invention provides a method for preparing the above-mentioned dealkalization refining agent, including:

[0019] (1) Preparing a microchannel coated with a silane film;

[0020] (2) Treating the microchannel coated with a silane film in step (1) with a modifier to obtain a dealkalization refining agent.

[0021] In the above technical solution, the microchannel in step (1) is preferably a baffle microchannel, and more preferably a baffle microchannel with a square cross-section (such as a rectangle or a square) that is longitudinally serrated or wavy, and the bending angle is 30° to 150°, preferably 60° to 120°. The cross-section of the microchannel is square, the width is 300 to 1000 microns, the aspect ratio of length to width is 1.5 to 6, the height of the modified microchannel is 1 to 3 cm, and the single-segment baffle span is 0.6 cm to 23 cm. The material of the microchannel is metal, preferably 304, 304L, 316, 316L, or titanium.

[0022] In the above technical solution, the microchannel coated with a silane film in step (1) is a microchannel with a silane film with a thickness of 10 to 30 microns coated on the inner surface of the microchannel.

[0023] In the above technical solution, in step (1), the method of coating the inner surface of the microchannel with a silane film can adopt a conventional flow modification method in the art. For example, the inner surface of the microchannel can be polished first with a chemical polishing solution (such as a chemical polishing solution based on nitric acid and hydrofluoric acid. Preferably, based on the mass of the chemical polishing solution, nitric acid is 3% - 5%, hydrogen fluoride is 2% - 4%, hydrogen peroxide is 3% - 6%, and the other components are water. The polishing conditions are as follows: the volume ratio of the chemical polishing solution to the microchannel is 1 - 4, the polishing temperature is 40 - 60 °C, and the polishing time is 30 - 60 seconds). Then, it is successively washed with deionized water (washing temperature is 20 - 40 °C, washing time is 20 - 30 minutes), acetone (washing temperature is 20 - 40 °C, washing time is 20 - 30 minutes), alkali washing (the composition of the alkali solution, by mass content, sodium hydroxide is 5% - 7%, sodium phosphate is 0.5% - 1%, the alkali washing temperature is 60 - 90 °C, and the alkali washing time is 20 - 30 minutes), rinsed with deionized water 4 - 6 times, and blown dry with nitrogen at 20 - 40 °C. Subsequently, a silane reagent solution (the silane reagent is selected from at least one of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, etc.) is used for cyclic silanization, and then dried and cured to obtain a silane film with a thickness of 10 - 30 microns. Generally, the silanization treatment conditions are as follows: the composition of the silanization reagent solution, by volume fraction, is silane reagent: deionized water: absolute ethanol = (2 - 4):(10 - 15):(83 - 97), the pH value is 8 - 9, and the preparation method of the silanization reagent solution is to mix the silanization reagent, deionized water, and absolute ethanol according to the ratio for pre-hydrolysis, and the pre-hydrolysis time is 12 - 18 hours. The conditions for cyclic silanization are as follows: the silanization temperature is 40 - 60 °C, and the silanization time is 10 - 20 minutes. The drying and curing temperature is 100 - 120 °C, and the drying atmosphere is nitrogen.

[0024] In the above technical solution, in the dealkalization refining agent described in step (2), after the microchannel coated with a silane film is treated with a modifier, the amount of sulfonic acid groups introduced into the dealkalization refining agent is 0.2 - 0.6 mol / m 2 , and the content of secondary amino groups is 0.08 - 0.42 mol / m 2 .

[0025] In the above technical solution, the modifier described in step (2) includes a pretreatment agent, a catalyst, and a solvent. The catalyst is selected from one of Lewis acids or Lewis bases, preferably at least one of anhydrous zinc chloride, anhydrous tin tetrachloride, and anhydrous aluminum chloride. The solvent is selected from at least one of toluene, p-xylene, m-xylene, and o-xylene. The preparation method of the pretreatment agent is as follows: The pretreatment raw material (selected from at least one of 4,4'-dichlorodiphenylmethanol, p-chlorodibenzyl chloride, and 4-chlorodiphenylchloromethane, preferably p-chlorodibenzyl chloride) reacts with fuming sulfuric acid to obtain the pretreatment agent. Among them, the reaction conditions are as follows: The pretreatment raw material and fuming sulfuric acid, by mass, the pretreatment raw material: fuming sulfuric acid = (20 - 40):(50 - 80), the reaction temperature is 60°C - 90°C, and the reaction time is 3 - 6 hours. The reaction product obtained can be extracted by ethers (preferably extracted by diethyl ether), and the process conditions of the ether extraction are as follows: By volume, the reaction product: ethers = 1:(10 - 20), the extraction temperature is 20°C - 30°C, the continuous extraction time is 2 - 3 hours, the extraction liquids are combined, and then the ethers are evaporated to dryness at 50°C - 70°C to obtain the pretreatment agent.

[0026] In the above technical solution, the composition of the modifier described in step (2) includes, by mass, the pretreatment agent: the catalyst: the solvent = (5 - 10):(4 - 8):(180 - 360).

[0027] In the above technical solution, the process of treating the microchannel coated with a silane film described in step (1) with the modifier in step (2) is as follows: The modifier enters the microchannel from the microchannel inlet and then flows out from the microchannel outlet, and the above process is carried out cyclically. Among them, the linear velocity of the fluid of the modifier on the inner surface of the microchannel is controlled to be 0.1 - 0.3 m / s, the modification temperature is 50°C - 70°C, and the modification time is 4 - 8 hours. After treating the microchannel coated with a silane film described in step (1) with the modifier, a modified microchannel intermediate is obtained.

[0028] In the above technical solution, in step (2), preferably, the modified microchannel intermediate is further surface-treated with a surface treatment agent. After the surface treatment, the amount of sulfonic acid groups introduced as the de-alkalization refining agent is 6 - 20 mmol / m 2 , the content of secondary amino groups is 10 - 36 mmol / m 2 , and the content of methoxy groups is 20 - 90 mmol / m 2 .

[0029] In the above technical solution, in step (2), the surface treatment agent preferably includes N-(carbamoylmethyl)-2-aminoethanesulfonic acid, 3,5-dichloro-2-methoxyaniline, a catalyst and a solvent. The catalyst is selected from one of Lewis acids or Lewis bases, preferably at least one of anhydrous zinc chloride, anhydrous stannic chloride, and anhydrous aluminum chloride. The solvent is selected from at least one of toluene, p-xylene, m-xylene, and o-xylene. By mass parts, N-(carbamoylmethyl)-2-aminoethanesulfonic acid: 3,5-dichloro-2-methoxyaniline: catalyst: solvent = (4 - 8):(7 - 14):(5 - 10):(150 - 350).

[0030] In the above technical solution, in step (2), the treatment conditions for treating and modifying the microchannel intermediate with the surface treatment agent are as follows: Use an inert gas (such as nitrogen) to purge the modifier in the microchannel until no free liquid flows out. Control the fluid linear velocity of the surface treatment agent on the inner surface of the microchannel to be 0.3 - 0.5 m / s, the surface treatment temperature to be 40 - 60 °C, and the modification time to be 1 - 2 hours.

[0031] In the above technical solution, in step (2), after treatment with the modifier or after treatment with the surface treatment agent, preferably post-modification treatment is carried out. The solvent used for the post-modification treatment is at least one of absolute ethanol, absolute methanol, and absolute acetone. Preferably, the solvent used for the post-modification treatment is absolute ethanol.

[0032] In the above technical solution, in step (2), the post-modification treatment conditions are as follows: The solvent enters the interior of the microchannel from the inlet of the microchannel (modified microchannel intermediate or surface treatment modified microchannel intermediate) and flows out from the outlet of the microchannel, and the above process is carried out cyclically. Among them, control the fluid linear velocity of the solvent used for post-modification treatment on the inner surface of the micro through-hole to be 0.2 - 0.4 m / s, the post-modification treatment temperature to be 60 - 80 °C, and the modification time to be 1 - 3 hours. After post-modification treatment, purge with an inert gas (such as nitrogen) at 110 °C - 130 °C for 0.5 - 1.0 hour.

[0033] The third aspect of the present invention provides an application of the dealkalization refining agent provided in the first aspect or the dealkalization refining agent prepared by the method provided in the second aspect in removing alkaline impurities from dry gas.

[0034] In the above technical solution, the application includes: contacting the raw material dry gas with the dealkalization refining agent to obtain purified dry gas with alkaline impurities removed.

[0035] In the above technical solution, preferably, in the application, a microchannel refiner is adopted, in which a microchannel module composed of parallel and / or series-connected modified microchannels is arranged inside. One end of the microchannel refiner is provided with a raw material dry gas inlet and an inlet dry gas distributor, the raw material dry gas inlet is connected to the inlet dry gas distributor, the inlet dry gas distributor is connected to the microchannel module, the other end is provided with a purified dry gas collecting pipe and a purified dry gas outlet, the purified dry gas collecting pipe is connected to the purified dry gas outlet, the microchannel module is connected to the purified dry gas collecting pipe. The upper end of the microchannel refiner is provided with a regenerant solution inlet and an inlet regenerant solution distributor, the regenerant solution inlet is connected to the inlet regenerant solution distributor, the inlet regenerant solution distributor is connected to the microchannel module. A mist separation layer is arranged inside the microchannel pipeline, and a regenerant solution collector is arranged at the lower end of the microchannel refiner, and the regenerant solution outlet communicates with the regenerant solution collector.

[0036] In the above technical solution, in the application, the microchannel refiner is filled with 500 - 1000 modified microchannel modules, each modified microchannel module is provided with 1000 - 2000 modified microchannels, and the interval between two adjacent parallel modified microchannels is 300 - 500 microns. In each modified microchannel, the cross-section is square, with a width of 300 - 1000 microns, the aspect ratio is 1.5 - 6, and the height of the modified microchannel is 1 - 3 cm. The microchannel is preferably a baffle microchannel, more preferably a toothed or wavy baffle microchannel, the bending angle is 30° - 150°, preferably 60° - 120°, and the single-section baffle span is 0.6 - 23 cm. A mist separation layer is arranged inside the microchannel, and the separation accuracy is 3 - 10 microns.

[0037] In the above technical solution, preferably, in the application, a microchannel refiner is adopted, in which a microchannel module composed of desalting refining agents in parallel and / or in series is arranged. When the microchannel refiner is put into use, the raw material dry gas enters the microchannel module through the inlet dry gas distributor. At the same time, the regenerant solution enters the microchannel module through the inlet regenerant solution distributor. Under the action of power, the regenerant solution and the dry gas are dispersed in the microchannel and pass through the microchannel, realizing adsorption and regeneration simultaneously. The microchannel is provided with a mist separation layer to capture and coalesce the regenerant solution after the operation, so as to obtain purified dry gas and the regenerant solution after the operation. The specific process is as follows: The raw material dry gas sequentially passes through the raw material dry gas feed port and the dry gas distributor and enters the modified microchannel and flows forward at a high speed with a folded flow in the modified microchannel. The alkaline impurities in the dry gas are selectively adsorbed onto the modified layer in the modified microchannel. At the same time, the regenerant solution enters the microchannel refiner from the regenerant solution feed port through the inlet regenerant solution distributor and collides and disperses with the raw material dry gas coming in through the inlet dry gas distributor. On the one hand, part of the regenerant solution flows into the microchannel under the action of the dry gas flow to regenerate the saturated active sites in the microchannel. On the other hand, part of the regenerant solution directly reacts with the alkaline impurities in the dry gas. Then the regenerant solution is captured and coalesced by the mist separation layer arranged in the microchannel, and then is collected through the regenerant solution collector channel connected to the mist separation layer to the regenerant solution collector, discharged from the microchannel through the regenerant solution outlet, and then enters the regenerant solution storage tank. The obtained purified dry gas is collected by the microchannel purified dry gas header pipe and discharged through the purified dry gas outlet.

[0038] In the above technical solution, in the application, the regenerant is selected from at least one of citric acid, tartaric acid, acetic acid-based succinic acid, methanesulfonic acid, sulfuric acid, and phosphoric acid. Preferably, in terms of the mass composition percentage of the regenerant solution, tartaric acid is 10% - 30%, acetic acid-based succinic acid is 2% - 4%, methanesulfonic acid is 1% - 3%, and the rest is desalted water.

[0039] In the above technical solution, in the application, the microchannel is distributed in the microchannel module as an independent pipeline unit to form a basic contact unit for removing alkaline impurities. Under the action of power, it promotes the liquid to flow with a folded flow, be pulverized, and have high-speed turbulence. It is a multiphase contact unit integrating adsorption and regeneration, adopting on-line in-situ real-time continuous adsorption and regeneration, that is, adsorbing and in-situ regenerating simultaneously in the microchannel. The high-speed turbulent regenerant realizes the regeneration of the adsorption center through mass transfer by contacting the saturated adsorption center. The power is gas driving force and liquid high-pressure injection, preferably gas driving force. The gas driving force comes from the gas conveying equipment of the process system and / or a gas compressor.

[0040] In the above technical solution, in the application, the volumetric space velocity of the raw material dry gas feed is 600 - 3000h -1, the adsorption temperature is 20 - 50 °C, the adsorption pressure (gauge pressure) is 500 - 1200 kPa, and the feed ratio of the raw dry gas to the regenerant solution is 400 - 600 by volume.

[0041] In the above technical solution, in the application, the purified dry gas from which basic impurities are removed is preferably subjected to cyclone liquid separation to remove the trace mist entrained in the dry gas. Among them, the cyclone can adopt a conventional cyclone separator in the art, and the separation accuracy is 200 - 500 microns.

[0042] In the above technical solution, the raw dry gas is derived from refinery catalytic cracking, thermal cracking, delayed coking, and hydrocracking. The raw dry gas includes, but is not limited to, ethylene, methane, ethane, propane, propylene, isobutane, n-butane, trans-butene, n-butene, isobutene, cis-butene, oxygen, nitrogen, hydrogen, carbon monoxide, carbon dioxide, acetylene, 1,3-butadiene, alkanes or alkenes with more than five carbons, and basic impurities. The basic impurities include at least one of chain-like or cyclic nitrogen-containing impurities, which are derived from nitrogen-containing impurities and their degradation components in crude oil, and amine-based desulfurization agents and their degradation components. In the raw dry gas, the volume content of ethylene is 5% - 40%, preferably 10% - 20%. In the raw dry gas, the volume content based on total nitrogen element is not less than 5 ppm, preferably not less than 50 ppm, more preferably not less than 500 ppm, and the volume content based on total nitrogen element is not more than 2000 ppm, preferably not more than 1000 ppm.

[0043] In the above technical solution, the basic impurities include, but are not limited to, at least one of the following substances: ammonia, methylamine, N-methylmethylamine, cyclopropanemethylamine, N-dimethylmethylamine, monoethanolamine, diethanolamine, aminocyclobutane, diisopropanolamine, N-methyldiethanolamine, etc.

[0044] In the above technical solution, the raw dry gas also contains sulfur-containing compounds (such as hydrogen sulfide, etc.). According to the requirement of the sulfur-containing compound content in the product dry gas, the raw dry gas can be contacted with a desulfurization agent to remove the sulfur-containing compounds before contacting with the dealkalization refining agent to obtain desulfurized purified dry gas. The desulfurization agent is a conventional desulfurization agent in the art, preferably amine alcohols, such as at least one of diethanolamine and N-methyldiethanolamine. The conditions for the raw dry gas to contact with the desulfurization agent are as follows: the temperature is 20 - 50 °C, the pressure is 600 - 1300 kPa by gauge pressure, the number of theoretical plates of the desulfurization contact tower is 6 - 11. The dosage ratio of the raw dry gas to the desulfurization agent is 60 - 110 by volume, and the mass concentration of the used desulfurization agent solution is 25% - 40%.

[0045] In the above technical solution, preferably, after the obtained desulfurized and purified dry gas is washed with water, it is then subjected to removal of basic impurities. The washing medium for the water washing is demineralized water. The conditions for the obtained desulfurized and purified dry gas to contact with the demineralized water are as follows: the temperature is 20 to 50 °C, the pressure is, in terms of gauge pressure, 600 to 1300 kPa, and the gas-liquid ratio is, in terms of volume, 10 to 30.

[0046] In the above technical solution, according to the requirement for the propylene content in the product dry gas, the purified dry gas after removing basic impurities can be contacted with a propylene removal agent to obtain purified dry gas with propylene removed. Among them, the propylene removal agent is a conventional propylene removal agent in the art, preferably at least one of benzene and diethylbenzene. The conditions for the dry gas to contact with the propylene removal agent are as follows: the temperature is 10 to 20 °C, the pressure is, in terms of gauge pressure, 900 to 1500 kPa, the number of theoretical plates in the propylene removal contact tower is 9 to 16. The volume ratio of the dry gas to the propylene removal agent is 90 to 120.

[0047] In the above technical solution, preferably, in the obtained purified dry gas, the total nitrogen volume content is not higher than 5 ppm, preferably not higher than 3 ppm, and more preferably not higher than 1 ppm.

[0048] In the above technical solution, preferably, the obtained purified dry gas can meet the requirements for the long-term operation of the ethylbenzene alkylation catalyst.

[0049] The fourth aspect of the present invention provides a separation system for removing impurities from dry gas, including:

[0050] 1) A desulfurization contact tower for removing hydrogen sulfide from the dry gas raw material;

[0051] 2) A dealkalization refiner for removing basic impurities from the desulfurized and purified dry gas;

[0052] 3) A propylene removal contact tower for removing propylene from the deammoniated and purified dry gas.

[0053] In the above technical solution, a dry gas scrubber is provided in front of the dealkalization refiner for scrubbing the gum dust entrained in the desulfurized and purified dry gas.

[0054] In the above technical solution, the dealkalization refiner is a microchannel refiner, which is filled with the dealkalization refining agent for removing basic impurities from the desulfurized and purified dry gas.

[0055] In the above technical solution, a demister (such as a cyclone) is provided at the outlet of the dealkalization refiner for removing the trace mist entrained in the dry gas after deammoniation refining.

[0056] In the above technical solution, a regenerant solution storage tank is provided for caching the regenerant solution. The regenerant solution storage tank is provided with an inlet for fresh regenerant solution or lean regenerant solution and an outlet for rich regenerant solution.

[0057] In the above technical solution, a high-pressure pump is provided for pressurized delivery of the regeneration agent solution.

[0058] In the above technical solution, a liquid collector is provided to collect the liquid retained by the mist separation layer inside the modified microchannel.

[0059] In the above technical solution, a demisting layer is arranged downstream of the microchannel to remove free mist entrained in the dry gas in the microchannel.

[0060] In the above technical solution, the dealkalization refiner is provided with a regeneration agent solution inlet and a regeneration agent solution outlet for introducing and leading the regeneration agent solution into and out of the dealkalization refiner.

[0061] Compared with the prior art, the present invention has the following advantages:

[0062] 1. The inventor of the present invention has found through research that there are alkaline impurities in the dry gas raw material that have a significant impact on the ethylbenzene alkylation catalyst, and these impurities will continue to accumulate in the catalyst, resulting in a decrease in the activity of the ethylbenzene catalyst and a shortened operating cycle. Due to the volatility of crude oil raw materials and the volatility of the desulfurization process, the alkaline impurities in the dry gas raw material continue to fluctuate significantly. If only conventional adsorbents (such as ion exchange resins, activated carbon, etc.) are used for fixed bed adsorption, the adsorbent is easily saturated, conventional regeneration operations are frequent, and the amount of wastewater discharged is large. The inventor has found through further research that the use of dealkalizing refining agents, the use of highly active groups on modified microchannels to efficiently adsorb the alkaline impurities in the raw dry gas, and the use of a preferred regenerant solution with low corrosiveness but desorption function to quickly flow through the adsorption micro-interface of the dealkalizing refining agent under the action of dry gas, contact and transfer mass with the adsorption active center, and achieve the regeneration of the saturated adsorption center, which not only solves the problem that the adsorbent is difficult to continuously regenerate in situ online, but also achieves the good effect of continuous adsorption and regeneration at the same time. At the same time, since the regeneration agent solution is driven by the dry gas co-flow or the regeneration agent is injected or stripped off by power, continuous random high-speed turbulence is used to achieve regeneration of the active centers. Even if the content of alkaline impurities in the dry gas raw material fluctuates greatly, there are sufficient active centers for continuous adsorption, which solves the problem of low elasticity of conventional distillation dealkalization operation.

[0063] 2. During the modification process of the microchannels in the present invention, a silanized layer is first formed on the inner surface of the microchannels. This can give full play to the original role of the microchannels, protect the microchannels from corrosion, and extend their service life. Then, a modifier is used for modification, which can form a modified layer with adsorption active centers having appropriate adsorption strength on the surface of the silanized layer. During continuous adsorption and regeneration operations, good adsorption and regeneration effects can be achieved. Preferably, further treatment with a surface treatment agent can reduce the gas film resistance when the dry gas contacts the modified layer formed by the modifier treatment, improve the mass transfer rate, and the modified layer formed by the surface treatment has a certain absorption effect on each component in the dry gas, forming a dry gas concentration zone with a certain thickness. This concentration zone is in dynamic equilibrium with the main body zone of the dry gas, and the basic impurity components are continuously exchanged to the modified layer formed by the modifier treatment, thereby achieving deep removal of the basic impurities in the dry gas. At the same time, preferably, the regenerant of the present invention has good permeability, especially can effectively desorb the basic impurities adsorbed in the modified layer formed by the modifier treatment to restore the active centers of the modified de-alkalization refining agent, so as to achieve a good balance of continuous adsorption and regeneration.

[0064] 3. The present invention solves the problems of high content of trace basic impurities in the existing dry gas raw materials that affect the ethylbenzene alkylation catalyst and short operation cycle of the alkylation catalyst. By efficiently and continuously adsorbing the basic impurities in the dry gas raw materials, the operation cycle of the alkylation catalyst is greatly improved, and the production cost of ethylbenzene is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a schematic diagram of a separation system for removing impurities from dry gas according to the present invention;

[0066] Among them, the descriptions of the reference numerals are as follows:

[0067] 0101 is a desulfurization contact tower, 0102 is a depropylene contact tower, 2101 is a dry gas scrubber, 2102 is a microchannel refiner, 2103 is a liquid collector, 2104 is a regenerant solution storage tank, 2105 is a regenerant solution circulation pump, 2106 is a cyclone separator, 0201 is a desulfurizer inlet, 0202 is a raw material dry gas inlet, 0203 is a desulfurizer rich liquid outlet, 0204 is a depropylene agent inlet, 0205 is a depropylene purified dry gas outlet, 0206 is a depropylene agent rich liquid outlet, 2201 is a washing water inlet, 2202 is a washing water rich liquid outlet, 2203 is a microchannel reactor inlet, 2204 is a regenerant solution inlet, 2205 is a regenerant solution discharge outlet, 2206 is a fresh regenerant solution or regenerant lean liquid inlet, 2207 is a regenerant solution rich liquid outlet, 2208 is a cyclone separator condensate outlet;

[0068] Figure 2 It is a schematic diagram of the gas-liquid flow in a local microchannel according to the present invention;

[0069] Among them, the description of the attached drawing reference numerals is as follows:

[0070] 2109 is the inlet of the regenerant solution, 2110 is the inlet of the raw material dry gas, 2111 is the modified microchannel, 2112 is the mist separation layer in the modified microchannel, 2113 is the height, and 2114 is the span. Specific implementation manners

[0071] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0072] In the present invention, the inner surface of the microchannel includes a silane film and a modified layer from the outside to the inside, which means that the silane film is on the inner surface of the microchannel and the modified layer is on the inner surface of the silane film.

[0073] In the present invention, the inner surface of the microchannel includes a silane film, a modified layer and a surface treatment layer from the outside to the inside, which means that the silane film is on the inner surface of the microchannel, the modified layer is on the inner surface of the silane film, and the surface treatment layer is on the inner surface of the modified layer.

[0074] In the present invention, the analysis of low-carbon hydrocarbon components is carried out by using a gas chromatograph Agilent 7890A GC (Agilent, USA), equipped with an HP-PLOT Al2O3 KCl (50m×0.53mm×15μm) capillary chromatographic column. The column temperature is maintained at 100°C for 10 minutes, and then raised to 120°C at a rate of 30°C per minute and maintained for 3 minutes. The flow rate of the carrier gas He is 3 mL / min, the injection volume is 0.1 mL (quantitative loop), the split ratio is 5:1, the injection port temperature is 250°C, and the detector (FID) temperature is 250°C.

[0075] In the present invention, the nitrogen element content in the dry gas material is tested by using a Mitsubishi sulfur and nitrogen analyzer NSX-2100V analyzer. The analysis method is that the argon flow rate is 200 ml / min, the oxygen flow rate is 400 ml / min, and the combustion temperature is 1000 - 1050°C.

[0076] A separation system for efficiently removing impurities in dry gas according to the present invention (such as Figure 1As shown in the figure, it includes: 0101 is a desulfurization contact tower, 0102 is a depropylene contact tower, 2101 is a dry gas scrubber, 2102 is a microchannel refiner, 2103 is a liquid collector, 2104 is a regenerant solution storage tank, 2105 is a regenerant solution circulation pump, and 2106 is a cyclone separator. The separation process is as follows: The dry gas raw material (such as from refinery fluid catalytic cracking, thermal cracking, delayed coking, and hydrocracking) enters the desulfurization contact tower 0101 from the raw dry gas inlet 0202 and contacts the amine desulfurizer entering from the desulfurizer inlet 0201 in a countercurrent manner to remove sulfur-containing compounds such as hydrogen sulfide in the dry gas. The bottom product of the desulfurization contact tower 0101 is drawn out from the desulfurizer rich liquid outlet 0203 to the desulfurizer regeneration unit. The top gas phase of the desulfurization contact tower 0101 then enters the dry gas scrubber 2101 and contacts the demineralized water entering from the wash water inlet 2201 to wash and remove the colloidal dust entrained in the desulfurized dry gas. The wash rich liquid of the dry gas scrubber 2101 is discharged from the wash water rich liquid outlet 2202 to the sewage treatment unit. The top product gas of the dry gas scrubber 2101 then enters the microchannel refiner 2102 after being distributed through the microchannel refiner inlet 2203. The alkaline impurities in the dry gas are adsorbed by the active groups on the modified microchannel. At the same time, the regenerant solution in the regenerant solution storage tank 2104 is transported by the regenerant solution circulation pump 2105 from the regenerant solution inlet 2204 to the microchannel liquid inlet of the microchannel refiner 2102. Under the action of the dry gas driving force, the adsorption surface is regenerated with high-frequency pulses. The regenerant solution after work is discharged from the regenerant solution outlet 2205 out of the microchannel refiner 2102. When the regenerant utilization rate reaches the process value (such as ≥95%), the liquid level in the regenerant storage tank 2104 is discharged to 1% - 5% through the regenerant rich liquid outlet 2207, and then fresh regenerant or regenerant lean liquid regenerated by the regenerant regeneration unit is added through the fresh regenerant or regenerant lean liquid inlet 2206. The dry gas at the outlet of the microchannel refiner 2102 is passed through the cyclone separator 2106 to remove the free mist entrained in the dry gas at the outlet of the microchannel refiner. The condensate of the cyclone separator 2106 is discharged from the cyclone separator condensate outlet 2208 to the sewage treatment unit or the regenerant solution storage tank 2104. The top product gas of the cyclone separator 2106 often enters the depropylene contact tower 0102 through a conventional pressurization device or directly and contacts the depropylene agent entering from the depropylene agent inlet 0204 in a countercurrent manner to remove propylene in the dry gas. The bottom product of the depropylene contact tower 0102 is drawn out from the depropylene agent rich liquid outlet 0206 to the depropylene agent regeneration unit. The depropylene-purified dry gas is discharged through the depropylene-purified dry gas outlet 0205 at the top of the depropylene contact tower 0102 to the alkylation reaction system.

[0077] The gas-liquid flow in the modified microchannel is as Figure 2As shown in the figure, the microchannel is a zigzag baffle microchannel longitudinally. The height of the modified microchannel is 2113, and the single-section baffle span is 2114. The regenerant solution entering from the regenerant solution inlet 2109 collides and mixes with the feed dry gas entering from the feed dry gas inlet 2110, and then flows forward in the modified microchannel 2111. The alkaline impurities in the dry gas are adsorbed by the active groups on the inner surface of the modified microchannel. After the adsorbed and purified dry gas coalesces and separates the liquid through the mist separation layer 2112 in the modified microchannel, it enters the subsequent modified microchannel for further adsorption. Under the driving force of the dry gas, the regenerant solution turbulates randomly at a high frequency on the inner surface of the modified microchannel to regenerate the adsorbed active sites. Subsequently, after being intercepted by the mist separation layer 2112 in the microchannel, it enters the liquid collector 2103 and returns to the regenerant solution storage tank 2104.

[0078]

Example 1

[0079] In this example, the dry gas raw material comes from a refinery fluid catalytic cracking unit. The composition of the dry gas by volume fraction includes: methane 17.8769%, ethane 8.1116%, aminocyclobutane 0.0038%, ethylene 15.9982%, N-methylmethylamine 0.0024%, propane 0.1859%, propylene 0.8415%, isobutane 0.0811%, n-butane 0.0157%, cyclopropanemethylamine 0.0034%, N,N-dimethylmethylamine 0.0019%, trans-butene 0.0067%, isobutene 0.0381%, cis-butene 0.0002%, N-methyldiethanolamine 0.0019%, oxygen 0.1370%, aminomethane 0.0034%, nitrogen 13.5422%, hydrogen 29.4523%, ammonia 0.0312%, carbon monoxide 1.4971%, carbon dioxide 3.3268%, acetylene 0.0053%, 1,3-butadiene 0.0001%, hydrogen sulfide 6.6733%, alkanes or alkenes with more than five carbons 1.1937%, and other components 0.9499%. The volume content of alkaline impurities calculated by total nitrogen element is 350 ppm.

[0080] The separation process of this example is as Figure 1 shown, and the gas-liquid micro-flow in the local microchannel is as Figure 2 shown.

[0081] The microchannel refiner is a dynamic adsorption bed provided with a modified microchannel, i.e., a de-alkalization refiner, in which the regenerant solution flows in parallel with the dry gas in the microchannel to continuously regenerate the adsorption active centers.

[0082] The preparation method of the modified microchannel includes: first, the microchannel is silanized to obtain a microchannel coated with a silane film, and then the microchannel coated with the silane film is treated with a modifier. After being treated with a surface treatment agent, it is further treated by post-modification to obtain the modified microchannel.

[0083] The microchannel refiner is filled with 760 microchannel modules, and each microchannel module is provided with 1,600 modified microchannels. The interval between two adjacent parallel modified microchannels is 400 microns. The modified microchannel is a tooth-shaped baffle microchannel, and the bending angle is 90°. Each tooth-shaped baffle span is 4 cm. In each modified microchannel, the width of the channel cross-section is 650 microns, the length of the channel is 3,300 microns, and the height of the modified microchannel is 2 cm. The modified microchannel is made of metal 316L. The silanization treatment adopts a flow modification method. First, the inner surface of the modified microchannel is polished with a chemical polishing solution, and then it is successively washed with deionized water, acetone, alkali solution, rinsed with deionized water, and dried with nitrogen. Subsequently, it is subjected to cyclic silanization with a silane reagent (γ-aminopropyltriethoxysilane) solution, and then dried and cured to obtain a silane film with a molar ratio of siloxy group to silicon carbide group of 0.8 and a thickness of 20 microns. Among them, the silanization treatment conditions are as follows: for the chemical polishing solution, by mass content, nitric acid is 4%, hydrogen fluoride is 3%, hydrogen peroxide is 4.5%, the volume ratio of the chemical polishing solution to the microchannel is 2.5, the polishing temperature is 50 °C, and the polishing time is 45 seconds; the conditions for deionized water washing are: the washing temperature is 30 °C, and the washing time is 25 minutes; the conditions for acetone washing are: the washing temperature is 30 °C, and the washing time is 25 minutes; the composition of the alkali solution, by mass content, sodium hydroxide is 6%, sodium phosphate is 0.7%, the alkali washing temperature is 75 °C, and the alkali washing time is 25 minutes; the microchannel after alkali washing is rinsed with flowing deionized water 5 times and dried with nitrogen at 30 °C; the composition of the silanization reagent solution, by volume fraction, silane reagent: deionized water: absolute ethanol = 3:12:90, the pH value is 8.5, the pre-hydrolysis time is 15 hours; the cyclic silanization temperature is 50 °C, and the silanization time is 15 minutes; the drying and curing temperature is 110 °C, and the drying atmosphere is nitrogen.

[0084] The modifier is a pretreatment agent, toluene, and zinc chloride. The preparation method of the pretreatment agent is as follows: p-chlorodiphenylmethyl chloride reacts with fuming sulfuric acid to obtain a reaction product, and the reaction product is extracted with ether. The reaction conditions of p-chlorodiphenylmethyl chloride and fuming sulfuric acid are as follows: p-chlorodiphenylmethyl chloride and fuming sulfuric acid, by mass fraction, p-chlorodiphenylmethyl chloride: fuming sulfuric acid = 30:65, the reaction temperature is 75 °C, and the treatment time is 4.5 hours. The process conditions for ether extraction are as follows: the reaction product and ether, by volume, reaction product: ether = 1:15, the extraction temperature is 25 °C, continuously extracted for 2.5 hours, the extraction liquids are combined, and then the ether is evaporated to dryness at 60 °C to obtain the pretreatment agent.

[0085] The composition of the modifier is, by mass parts, pretreatment agent: zinc chloride: toluene = 7.5: 6: 270. The zinc chloride used is anhydrous zinc chloride. After passing through a buffer tank, the modifier is transported to the inlet of the microchannel by a material pump. After flowing through the interior of the channel and exiting from the outlet of the microchannel, it returns to the modifier buffer tank at the inlet of the material pump. The fluid linear velocity on the inner surface of the channel is 0.2 m / s, the circulating modification temperature is 60 °C, and the modification time is 6 hours. After treating the microchannel with the modifier, a modified microchannel intermediate is obtained. After the microchannel coated with a silane film is treated with the modifier, the content of sulfonic acid groups introduced into the modified microchannel is 0.4 mol / m 2 , and the content of secondary amino groups is 0.25 mol / m 2 .

[0086] The modified microchannel intermediate is further surface-treated with a surface treatment agent. The surface treatment agent includes N-(carbamoylmethyl)-2-aminoethanesulfonic acid, 3,5-dichloro-2-methoxyaniline, zinc chloride, and toluene. By mass parts, N-(carbamoylmethyl)-2-aminoethanesulfonic acid: 3,5-dichloro-2-methoxyaniline: zinc chloride: toluene = 6: 10: 7: 250. The surface treatment conditions are as follows: Nitrogen is used to purge the modifier in the microchannel until no free liquid flows out. The fluid linear velocity of the surface treatment agent on the inner surface of the microchannel is controlled to be 0.40 m / s, the surface treatment temperature is 50 °C, and the modification time is 1.5 hours. After being treated with the surface treatment agent, the content of sulfonic acid groups introduced into the modified microchannel by the surface treatment agent is 13 mmol / m 2 , the content of secondary amino groups is 23 mmol / m 2 , and the content of methoxy groups is 55 mmol / m 2 .

[0087] The modified microchannel intermediate is subjected to post-modification treatment to obtain a modified microchannel. The solvent used for the post-modification treatment is anhydrous ethanol. The post-modification treatment conditions are as follows: After passing through a buffer tank, anhydrous ethanol is transported to the inlet of the microchannel by a material pump. After flowing through the interior of the channel and exiting from the outlet of the microchannel, it returns to the anhydrous ethanol buffer tank at the inlet of the material pump. The fluid linear velocity on the inner surface of the channel is 0.3 m / s, the circulating post-modification treatment temperature is 70 °C, and the modification time is 2 hours. After ethanol treatment, it is purged with nitrogen at 120 °C for 0.7 hours.

[0088] In the microchannel refiner, the dry gas feed volume space velocity of the microchannel refiner pretreatment is 1900 h -1 , the adsorption temperature is 35 °C, and the adsorption pressure (gauge pressure) is 850 kPa. The regenerant solution is tartaric acid, acetic acid-based succinic acid, methanesulfonic acid, and demineralized water. Among them, by mass composition percentage, tartaric acid is 20%, acetic acid-based succinic acid is 3%, methanesulfonic acid is 2%, and the rest is demineralized water. Among them, the feed volume ratio of the raw material dry gas to the regenerant solution is 500 by volume.

[0089] In the desulfurization contact tower, the desulfurizer is N-methyldiethanolamine. The conditions for the raw dry gas to contact the desulfurizer are as follows: the temperature is 35°C, the pressure is, in gauge pressure, 950 kPa, and the number of theoretical plates in the desulfurization contact tower is 8. The volume ratio of the raw dry gas to the desulfurizer is, by volume, 85, and the mass concentration of the desulfurizer is 32%. In the dry gas scrubber, the scrubbing medium is demineralized water. The conditions for the desulfurized purified dry gas to contact the demineralized water are as follows: the temperature is 35°C, the pressure is, in gauge pressure, 950 kPa, and the gas-liquid ratio is, by volume, 20.

[0090] A mist separation layer is provided in the microchannel, and the separation accuracy is 6 microns. The cyclone separator is a cyclone, and the separation accuracy is 350 microns.

[0091] In the depropylene contact tower, the depropylene agent is benzene. The conditions for the raw dry gas to contact the depropylene agent are as follows: the temperature is 15°C, the pressure is, in gauge pressure, 1200 kPa, and the number of theoretical plates in the depropylene contact tower is 12. The volume ratio of the raw dry gas to the depropylene agent is, by volume, 105.

[0092] The total nitrogen volume content in the depropylene-purified dry gas obtained in this example is 3.2 ppm.

[0093]

Example 2

[0094] The dry gas raw material described in this example is the same as that in Example 1, and the separation process is as Figure 1 shown, and the local microchannel gas-liquid microscopic flow is as Figure 2 shown.

[0095] The microchannel refiner is a dynamic adsorption bed with a modified microchannel having an adsorption function, i.e., a de-alkali refiner, and the regenerant solution flows in parallel with the dry gas in the microchannel to continuously regenerate the adsorption active centers.

[0096] The preparation method of the modified microchannel includes: first subjecting the microchannel to a silanization treatment to obtain a microchannel coated with a silane film, then treating the microchannel coated with the silane film with a modifier, after surface treatment, and then after modified post-treatment, to obtain the modified microchannel.

[0097] The microchannel refiner is filled with 900 microchannel modules, and each microchannel module is provided with 1800 modified microchannels. The interval between two adjacent parallel modified microchannels is 350 microns. The modified microchannel is a toothed baffle microchannel, and the bending angle is 60°. The span of each toothed baffle is 1.8 cm. In each modified microchannel, the width of the channel cross-section is 360 microns, the length of the channel is 650 microns, and the height of the modified microchannel is 1.5 cm. The modified microchannel is made of metal 316L. The silanization treatment adopts a flow modification method. First, the inner surface of the microchannel is polished with a chemical polishing solution, and then it is successively washed with deionized water, acetone, alkali solution, rinsed with deionized water, and dried with nitrogen. Subsequently, a silane reagent (γ-aminopropyltriethoxysilane) solution is used for cyclic silanization, and then dried and cured to obtain a silane film with a molar ratio of siloxyl group to silicon carbide group of 1.0 and a thickness of 25 microns. Among them, the silanization treatment conditions are as follows: the chemical polishing solution, by mass content, nitric acid is 4.5%, hydrogen fluoride is 3.5%, hydrogen peroxide is 5%, the volume ratio of the chemical polishing solution to the microchannel is 3, the polishing temperature is 55°C, and the polishing time is 50 seconds; the cleaning temperature of deionized water is 35°C, and the cleaning time is 28 minutes; the flowing cleaning temperature of acetone is 35°C, and the cleaning time is 28 minutes; the composition of the alkali solution, by mass content, sodium hydroxide is 6.5%, sodium phosphate is 0.9%, the alkali washing temperature is 85°C, and the alkali washing time is 28 minutes; the microchannel after alkali washing is rinsed with deionized water 6 times and dried with nitrogen at 35°C; the composition of the silanization reagent solution, by volume fraction, silane reagent: deionized water: absolute ethanol = 3.5:14:84, the pH value is 8.8, the pre-hydrolysis time is 17 hours; the cyclic silanization temperature is 55°C, and the silanization time is 18 minutes; the drying and curing temperature is 115°C, and the drying atmosphere is nitrogen.

[0098] The modifier is a pretreatment agent, toluene, and zinc chloride. The preparation process of the pretreatment agent is as follows: p-chlorodiphenylmethyl chloride reacts with fuming sulfuric acid to obtain a reaction product, and the reaction product is extracted with ether. The reaction conditions of p-chlorodiphenylmethyl chloride and fuming sulfuric acid are as follows: p-chlorodiphenylmethyl chloride and fuming sulfuric acid, by mass fraction, p-chlorodiphenylmethyl chloride: fuming sulfuric acid = 25:75, the reaction temperature is 85°C, and the treatment time is 5.5 hours. The process conditions for ether extraction are as follows: the reaction product and ether, by volume, reaction product: ether = 1:18, the extraction temperature is 28°C, and continuous extraction is carried out for 2.7 hours. The extraction liquids are combined, and then the ether is evaporated at 65°C to obtain the pretreatment agent.

[0099] The composition of the modifier is, by mass parts, pretreatment agent: zinc chloride: toluene = 9.5: 7: 190. The zinc chloride used is anhydrous zinc chloride. After passing through a buffer tank, the modifier is transported to the inlet of the microchannel by a material pump. After flowing through the interior of the channel and flowing out from the outlet of the microchannel, it returns to the modifier buffer tank at the inlet of the material pump. The fluid linear velocity on the inner surface of the channel is 0.15 m / s, the circulating modification temperature is 65 °C, and the modification time is 7 hours. After treating the microchannel with the modifier, a modified microchannel intermediate is obtained. After the microchannel coated with a silane film is treated with the modifier, the content of sulfonic acid groups introduced into the modified microchannel is 0.55 mol / m 2 , and the content of secondary amino groups is 0.38 mol / m 2 .

[0100] The modified microchannel intermediate is further surface-treated with a surface treatment agent. The surface treatment agent includes N-(carbamoylmethyl)-2-aminoethanesulfonic acid, 3,5-dichloro-2-methoxyaniline, zinc chloride, and toluene. By mass parts, N-(carbamoylmethyl)-2-aminoethanesulfonic acid: 3,5-dichloro-2-methoxyaniline: zinc chloride: toluene = 7: 13: 9: 160. The surface treatment conditions are as follows: Nitrogen is used to purge the modifier in the microchannel until no free liquid flows out. The fluid linear velocity of the surface treatment agent on the inner surface of the microchannel is controlled to be 0.48 m / s, the surface treatment temperature is 42 °C, and the modification time is 1.2 hours. After being treated with the surface treatment agent, the content of sulfonic acid groups introduced into the modified microchannel by the surface treatment agent is 16 mmol / m 2 , the content of secondary amino groups is 31 mmol / m 2 , and the content of methoxy groups is 87 mmol / m 2 .

[0101] The modified microchannel intermediate is subjected to post-modification treatment to obtain a modified microchannel. The solvent used for the post-modification treatment is anhydrous ethanol. The post-modification treatment conditions are as follows: After passing through a buffer tank, anhydrous ethanol is transported to the inlet of the microchannel by a material pump. After flowing through the interior of the channel and flowing out from the outlet of the microchannel, it returns to the anhydrous ethanol buffer tank at the inlet of the material pump. The fluid linear velocity on the inner surface of the channel is 0.25 m / s, the circulating post-modification treatment temperature is 75 °C, and the modification time is 2.5 hours. After the ethanol treatment, it is purged with nitrogen at 125 °C for 0.9 hours.

[0102] In the microchannel refiner, the dry gas feed volume space velocity of the microchannel refiner pretreatment is 1300 h -1, the adsorption temperature is 45 °C, and the adsorption pressure (gauge pressure) is 1100 kPa. The regenerant solution is tartaric acid, acetic acid succinic acid, methanesulfonic acid, and demineralized water. Among them, in terms of the mass composition percentage of the regenerant solution, tartaric acid is 25%, acetic acid succinic acid is 3.5%, methanesulfonic acid is 2.5%, and the rest is demineralized water. Among them, the feed ratio of the raw material dry gas to the regenerant solution is 450 by volume.

[0103] In the desulfurization contact tower, the desulfurizer is N-methyldiethanolamine. The conditions for the raw material dry gas to contact the desulfurizer are as follows: the temperature is 47 °C, the pressure is 1200 kPa by gauge pressure, and the number of theoretical plates in the desulfurization contact tower is 10. The usage ratio of the raw material dry gas to the desulfurizer is 65 by volume, and the mass concentration of the desulfurizer is 38%. In the dry gas scrubber, the scrubbing medium is demineralized water. The conditions for the desulfurized purified dry gas to contact the demineralized water are as follows: the temperature is 25 °C, the pressure is 1200 kPa by gauge pressure, and the gas-liquid ratio is 12 by volume.

[0104] A mist separation layer is provided in the microchannel, and the separation accuracy is 4 microns. The cyclone separator is a cyclone, and the separation accuracy is 300 microns.

[0105] In the depropylene contact tower, the depropylene agent is benzene. The conditions for the raw material dry gas to contact the depropylene agent are as follows: the temperature is 12 °C, the pressure is 1400 kPa by gauge pressure, and the number of theoretical plates in the depropylene contact tower is 15. The usage ratio of the raw material dry gas to the depropylene agent is 95 by volume.

[0106] The total nitrogen volume content in the depropylene purified dry gas obtained in this example is 0.8 ppm.

[0107]

Example 3

[0108] The dry gas raw material described in this example is the same as that in Example 1, and the separation process is as Figure 1 shown, and the local microchannel gas-liquid micro-flow is as Figure 2 shown.

[0109] The microchannel refiner is a dynamic adsorption bed with a modified microchannel with an adsorption function, that is, a de-alkali refiner, and the regenerant solution flows in parallel with the dry gas in the microchannel to continuously regenerate the adsorption active centers.

[0110] The preparation method of the modified microchannel includes: the microchannel is first subjected to silanization treatment to obtain a microchannel coated with a silane film, and then the microchannel coated with the silane film is treated with a modifier. After being treated with a surface treatment agent, it is then subjected to a post-modification treatment to obtain a modified microchannel.

[0111] The microchannel refiner is filled with 600 microchannel modules, and each microchannel module is provided with 1300 modified microchannels. The interval between two adjacent parallel modified microchannels is 450 microns. The modified microchannel is a tooth-shaped baffle microchannel, and the bending angle is 120°. The span of each tooth-shaped baffle is 8.9 cm. In each modified microchannel, the width of the channel cross-section is 800 microns, the length of the channel is 4500 microns, and the height of the modified microchannel is 2.5 cm. The modified microchannel is made of metal 316L material.

[0112] The preparation of the modified microchannel is as follows: The silanization treatment of the microchannel adopts the flow modification method. First, the inner surface of the microchannel is polished with a chemical polishing solution, and then sequentially washed with deionized water, acetone, alkali solution, rinsed with deionized water, and dried with nitrogen. Subsequently, a silane reagent (γ-aminopropyltriethoxysilane) solution is used for cyclic silanization, and then dried and cured to obtain a silane film with a molar ratio of siloxyl group to silicon carbide group of 0.7 and a thickness of 15 microns. Among them, the silanization treatment conditions are as follows: The chemical polishing solution contains 3.5% nitric acid, 2.5% hydrogen fluoride, and 4% hydrogen peroxide by mass content. The volume ratio of the chemical polishing solution to the microchannel is 2, the polishing temperature is 45 °C, and the polishing time is 40 seconds; the deionized water washing temperature is 25 °C, and the washing time is 22 minutes; the acetone flow washing temperature is 25 °C, and the washing time is 22 minutes; the alkali solution composition contains 5.5% sodium hydroxide and 0.6% sodium phosphate by mass content. The alkali washing temperature is 65 °C, and the alkali washing time is 23 minutes; the microchannel after alkali washing is rinsed with deionized water in a flowing state 5 times and dried with nitrogen at 25 °C; the composition of the silanization reagent solution is 2.5 parts by volume of silane reagent: 11 parts by volume of deionized water: 96 parts by volume of absolute ethanol, the pH value is 8.2, and the pre-hydrolysis time is 13 hours; the cyclic silanization temperature is 45 °C, and the silanization time is 12 minutes; the drying and curing temperature is 105 °C, and the drying atmosphere is nitrogen.

[0113] The modifier is a pretreatment agent, toluene, and zinc chloride. The preparation process of the pretreatment agent is as follows: p-chlorodiphenylmethyl chloride reacts with fuming sulfuric acid to obtain a reaction product, and the reaction product is extracted with ether. The reaction conditions of p-chlorodiphenylmethyl chloride and fuming sulfuric acid are as follows: p-chlorodiphenylmethyl chloride and fuming sulfuric acid, by mass, p-chlorodiphenylmethyl chloride: fuming sulfuric acid = 35:55, the reaction temperature is 65 °C, and the treatment time is 3.5 hours. The process conditions for ether extraction are as follows: The reaction product and ether, by volume, reaction product: ether = 1:11, the extraction temperature is 21 °C, and continuous extraction is carried out for 2.2 hours. The extraction liquids are combined, and then the ether is evaporated to dryness at 55 °C to obtain the pretreatment agent.

[0114] The composition of the modifier is, by mass parts, pretreatment agent: zinc chloride: toluene = 5.5:5:350. The zinc chloride used is anhydrous zinc chloride. After passing through the buffer tank, the modifier is transported to the inlet of the microchannel by a material pump. After flowing through the inside of the channel and flowing out from the outlet of the microchannel, it returns to the modifier buffer tank at the inlet of the material pump. The fluid linear velocity on the inner surface of the pore is 0.25 m / s, the circulating modification temperature is 55 °C, and the modification time is 5 hours. After treating the microchannel with the modifier, a modified microchannel intermediate is obtained. After the microchannel coated with a silane film is treated with the modifier, the content of sulfonic acid groups introduced into the modified microchannel is 0.3 mol / m 2 , and the content of secondary amino groups is 0.13 mol / m 2 .

[0115] The modified microchannel intermediate is further surface-treated with a surface treatment agent. The surface treatment agent includes N-(carbamoylmethyl)-2-aminoethanesulfonic acid, 3,5-dichloro-2-methoxyaniline, zinc chloride, and toluene. By mass parts, N-(carbamoylmethyl)-2-aminoethanesulfonic acid: 3,5-dichloro-2-methoxyaniline: zinc chloride: toluene = 5:8:6:340. The surface treatment conditions are as follows: Nitrogen is used to purge the modifier in the microchannel until no free liquid flows out. The fluid linear velocity of the surface treatment agent on the inner surface of the microchannel is controlled to be 0.35 m / s, the surface treatment temperature is 55 °C, and the modification time is 1.8 hours. After being treated with the surface treatment agent, the content of sulfonic acid groups introduced into the modified microchannel by the surface treatment agent is 8 mmol / m 2 , the content of secondary amino groups is 12 mmol / m 2 , and the content of methoxy groups is 25 mmol / m 2 .

[0116] The modified microchannel intermediate is subjected to post-modification treatment to obtain a modified microchannel. The solvent used for the post-modification treatment is anhydrous ethanol. The post-modification treatment conditions are as follows: After passing through the buffer tank, anhydrous ethanol is transported to the inlet of the microchannel by a material pump. After flowing through the inside of the channel and flowing out from the outlet of the microchannel, it returns to the anhydrous ethanol buffer tank at the inlet of the material pump. The fluid linear velocity on the inner surface of the pore is 0.35 m / s, the circulating post-modification treatment temperature is 65 °C, and the modification time is 1.5 hours. After ethanol treatment, it is purged with nitrogen at 115 °C for 0.6 hours.

[0117] In the microchannel refiner, the volume hourly space velocity of the pretreated dry gas feed is 2600 h -1 , the adsorption temperature is 25 °C, and the adsorption pressure (gauge pressure) is 600 kPa. The regenerant solution is tartaric acid, acetic acid-based succinic acid, methanesulfonic acid, and demineralized water. By mass composition percentage, tartaric acid is 15%, acetic acid-based succinic acid is 2.5%, methanesulfonic acid is 1.5%, and the rest is demineralized water. Among them, the volume ratio of the dry gas to the regenerant solution is 550.

[0118] In the desulfurization contact tower, the desulfurizing agent is N-methyldiethanolamine. The conditions for the raw material dry gas to contact with the desulfurizing agent are as follows: the temperature is 23°C, the pressure is, in gauge pressure, 700 kPa, and the number of theoretical plates in the desulfurization contact tower is 7. The volume ratio of the raw material dry gas to the desulfurizing agent is, by volume, 104, and the mass concentration of the desulfurizing agent is 27%. In the dry gas scrubber, the scrubbing medium is demineralized water. The conditions for the desulfurized and purified dry gas to contact with the demineralized water are as follows: the temperature is 45°C, the pressure is, in gauge pressure, 700 kPa, and the gas-liquid ratio is, by volume, 26.

[0119] A mist separation layer is provided in the microchannel, and the separation accuracy is 8 μm. The cyclone separator is a cyclone, and the separation accuracy is 400 μm.

[0120] In the depropylene contact tower, the depropylene agent is benzene. The conditions for the raw material dry gas to contact with the depropylene agent are as follows: the temperature is 18°C, the pressure is, in gauge pressure, 1000 kPa, and the number of theoretical plates in the depropylene contact tower is 10. The volume ratio of the raw material dry gas to the depropylene agent is, by volume, 115.

[0121] The total nitrogen volume content in the depropylene-purified dry gas obtained in this example is 3.9 ppm.

[0122]

Example 4

[0123] The modified microchannel, i.e., the de-alkalization refining agent, used in this example is the same as that in Example 2.

[0124] The separation process for the dry gas raw material used in this example is the same as that in Example 2. This example is different from Example 2 only in that the dry gas raw materials used are different. Among them, the dry gas composition is by volume ratio, including: methane 17.8682%, ethane 8.1077%, N-methyldiethanolamine 0.0038%, propane 0.1858%, propylene 0.8411%, isobutane 0.0811%, n-butane 0.0156%, N,N-dimethylformamide 0.0038%, trans-butene 0.0067%, isobutene 0.0380%, cis-butene 0.0002%, ammonia 0.0624%, cyclopropanemethylamine 0.0067%, nitrogen 13.5356%, hydrogen 29.4381%, N-methylmethylamine 0.0048%, carbon monoxide 1.4964%, aminocyclobutane 0.0077%, carbon dioxide 3.3252%, aminomethane 0.0067%, acetylene 0.0053%, 1,3-butadiene 0.0001%, hydrogen sulfide 6.6700%, paraffins or olefins with more than five carbons 1.1932%, and other components 0.9498%. The volume content of basic impurities in terms of total nitrogen element is 650 ppm.

[0125] The total nitrogen volume content in the depropylene-purified dry gas obtained is 1.4 ppm.

[0126]

Example 5

[0127] The modified microchannel, i.e., the de-alkali refining agent used in this example is the same as that in Example 2.

[0128] The separation process for the dry gas raw material in this example is the same as that in Example 2. Compared with Example 2, the only difference is the dry gas raw material used. Among them, the dry gas composition by volume percentage includes: methane 17.8853%, ethane 8.1154%, methylamine 0.0001%, ethylene 16.0057%, propane 0.1860%, propylene 0.8419%, isobutane 0.0812%, n-butane 0.0157%, trans-butene 0.0067%, ammonia 0.0008%, n-butene 0.0185%, isobutene 0.0381%, N-methylmethylamine 0.0001%, cis-butene 0.0002%, aminocyclobutane 0.0001%, oxygen 0.1371%, nitrogen 13.5486%, hydrogen 29.4662%, cyclopropanemethylamine 0.0001%, carbon monoxide 1.4978%, carbon dioxide 3.3284%, acetylene 0.0053%, 1,3-butadiene 0.0001%, hydrogen sulfide 6.6764%, alkanes or alkenes with more than five carbons 1.1943%, and other components 0.9500%. The volume content of basic impurities calculated by total nitrogen element is 8 ppm.

[0129] The total nitrogen volume content in the obtained de-propylene purified dry gas is 0.03 ppm.

[0130]

Example 6

[0131] The modified microchannel, i.e., the de-alkali refining agent used in this example is the same as that in Example 2.

[0132] The separation process for the dry gas raw material in this example is the same as that in Example 2. Compared with Example 2, the only difference is that the regenerant solution used in the packing refiner is citric acid with a mass concentration of 25%.

[0133] The total nitrogen volume content in the obtained de-propylene purified dry gas is 4.3 ppm.

[0134]

Example 7

[0135] Compared with Example 2, the microchannel refiner used in this example only differs in the pretreatment raw material, and 4,4'-dichlorodiphenylmethanol is used to replace an equal mass of p-chlorobenzhydryl chloride.

[0136] The separation process for the dry gas raw material in this example is the same as that in Example 2.

[0137] The total nitrogen volume content in the obtained de-propylene purified dry gas is 4.3 ppm.

[0138]

Example 8

[0139] The microchannel refiner used in this embodiment is only different from that in Embodiment 2 in that the pretreated raw material is different, and 4-chlorodiphenylchloromethane is used to replace an equal mass of p-chlorobenzhydryl chloride.

[0140] The separation process for the dry gas raw material in this embodiment is the same as that in Embodiment 2.

[0141] The volume content of total nitrogen in the obtained depropylenized purified dry gas is 4.1 ppm.

[0142]

Example 9

[0143] The modified microchannel used in this embodiment is only different from that in Embodiment 3 in that the surface treatment agent and its treatment are omitted.

[0144] The dry gas raw material used in this embodiment and the separation process for the dry gas raw material are the same as those in Embodiment 3.

[0145] The volume content of total nitrogen in the obtained depropylenized purified dry gas is 12.1 ppm.

[0146]

Example 10

[0147] The modified microchannel, i.e., the de-alkalization refiner, used in this embodiment is only different from that in Embodiment 3 in that the surface treatment agent and its treatment are omitted.

[0148] The separation process for the dry gas raw material in this embodiment is the same as that in Embodiment 3. The composition of the raw material dry gas by volume percentage includes: methane 17.8853%, ethane 8.1154%, methylamine 0.0001%, ethylene 16.0057%, propane 0.1860%, propylene 0.8419%, isobutane 0.0812%, n-butane 0.0157%, trans-butene 0.0067%, ammonia 0.0008%, n-butene 0.0185%, isobutene 0.0381%, N-methylmethylamine 0.0001%, cis-butene 0.0002%, aminocyclobutane 0.0001%, oxygen 0.1371%, nitrogen 13.5486%, hydrogen 29.4662%, cyclopropanemethylamine 0.0001%, carbon monoxide 1.4978%, carbon dioxide 3.3284%, acetylene 0.0053%, 1,3-butadiene 0.0001%, hydrogen sulfide 6.6764%, alkanes or alkenes with five or more carbon atoms 1.1943%, other components 0.9500%. The volume content of basic impurities in terms of total nitrogen element is 8 ppm.

[0149] The volume content of total nitrogen in the obtained depropylenized purified dry gas is 1.7 ppm.

[0150]

Example 11

[0151] The dry gas raw material described in this embodiment is the same as that in Embodiment 1, and the separation flow is asFigure 1 As shown, the local microchannel gas-liquid micro-flow is as Figure 2 shown.

[0152] The microchannel refiner is a dynamic adsorption bed with modified microchannels having an adsorption function, i.e., a de-alkalization refiner, in which a regenerant solution flows in parallel with dry gas in the microchannels to continuously regenerate the adsorption active centers.

[0153] The preparation method of the modified microchannels includes: first, the microchannels are subjected to silanization treatment to obtain microchannels coated with a silane film, and then the microchannels coated with the silane film are treated with a modifier. After being treated with a surface treatment agent, modified microchannels are obtained.

[0154] The microchannel refiner is filled with 600 microchannel modules, and each microchannel module is provided with 1300 modified microchannels. The interval between two adjacent parallel modified microchannels is 450 microns. The modified microchannels are tooth-shaped baffle microchannels, the bending angle is 120°, and the span of each tooth-shaped baffle is 8.9 cm. In each modified microchannel, the width of the channel cross-section is 800 microns, the length of the channel is 4500 microns, and the height of the modified microchannel is 2.5 cm. The modified microchannels are made of metal 316L.

[0155] The preparation of the modified microchannels is as follows: The silanization treatment of the microchannels adopts a flowing modification method. First, the inner surface of the microchannels is polished with a chemical polishing solution, and then successively washed with deionized water, acetone, alkali solution, rinsed with deionized water, and dried with nitrogen. Subsequently, a silane reagent (γ-aminopropyltriethoxysilane) solution is used for cyclic silanization, and then dried and cured to obtain a silane film with a molar ratio of siloxane group to silicon-carbon group of 0.7 and a thickness of 15 microns. Among them, the silanization treatment conditions are as follows: The chemical polishing solution contains 3.5% nitric acid, 2.5% hydrogen fluoride, and 4% hydrogen peroxide by mass content. The volume ratio of the chemical polishing solution to the microchannels is 2, the polishing temperature is 45 °C, and the polishing time is 40 seconds; the deionized water washing temperature is 25 °C, and the washing time is 22 minutes; the acetone flowing washing temperature is 25 °C, and the washing time is 22 minutes; the composition of the alkali solution contains 5.5% sodium hydroxide and 0.6% sodium phosphate by mass content, the alkali washing temperature is 65 °C, and the alkali washing time is 23 minutes; the microchannels after alkali washing are rinsed with deionized water flowing 5 times and dried with nitrogen at 25 °C; the composition of the silanization reagent solution is 2.5 parts by volume of silane reagent: 11 parts by volume of deionized water: 96 parts by volume of absolute ethanol, the pH value is 8.2, and the pre-hydrolysis time is 13 hours; the cyclic silanization temperature is 45 °C, and the silanization time is 12 minutes; the drying and curing temperature is 105 °C, and the drying atmosphere is nitrogen.

[0156] The modifiers are a pretreatment agent, toluene, and zinc chloride. The preparation process of the pretreatment agent is as follows: p-chlorodiphenylmethyl chloride reacts with fuming sulfuric acid to obtain a reaction product, and the reaction product is extracted with ether. The reaction conditions of p-chlorodiphenylmethyl chloride and fuming sulfuric acid are as follows: p-chlorodiphenylmethyl chloride and fuming sulfuric acid, by mass fraction, p-chlorodiphenylmethyl chloride: fuming sulfuric acid = 35:55, the reaction temperature is 65 °C, and the treatment time is 3.5 hours. The process conditions for ether extraction are as follows: the reaction product and ether, by volume, reaction product: ether = 1:11, the extraction temperature is 21 °C, and continuous extraction is carried out for 2.2 hours. The extraction liquids are combined, and then the ether is evaporated to dryness at 55 °C to obtain the pretreatment agent.

[0157] The composition of the modifier is, by mass fraction, pretreatment agent: zinc chloride: toluene = 5.5:5:350. Anhydrous zinc chloride is used for zinc chloride. After passing through a buffer tank, the modifier is transported to the inlet of the microchannel by a material pump. After flowing through the inside of the channel and flowing out from the outlet of the microchannel, it returns to the modifier buffer tank at the inlet of the material pump. The fluid linear velocity on the inner surface of the pore is 0.25 m / s, the circulating modification temperature is 55 °C, and the modification time is 5 hours. After treating the microchannel with the modifier, a modified microchannel intermediate is obtained. After the microchannel coated with a silane film is treated with the modifier, the content of sulfonic acid groups introduced into the modified microchannel is 0.3 mol / m 2 , and the content of secondary amino groups is 0.13 mol / m 2 .

[0158] The modified microchannel intermediate is further surface-treated with a surface treatment agent. The surface treatment agent includes N-(carbamoylmethyl)-2-aminoethanesulfonic acid, 3,5-dichloro-2-methoxyaniline, zinc chloride, and toluene. By mass fraction, N-(carbamoylmethyl)-2-aminoethanesulfonic acid: 3,5-dichloro-2-methoxyaniline: zinc chloride: toluene = 5:8:6:340. The surface treatment conditions are as follows: Nitrogen is used to purge the modifier in the microchannel until no free liquid flows out. The fluid linear velocity of the surface treatment agent on the inner surface of the microchannel is controlled to be 0.35 m / s, the surface treatment temperature is 55 °C, and the modification time is 1.8 hours. After being treated with the surface treatment agent, the content of sulfonic acid groups introduced into the modified microchannel by the surface treatment agent is 8 mmol / m 2 , and the content of secondary amino groups is 12 mmol / m 2 , and the content of methoxy groups is 23 mmol / m 2 .

[0159] In the microchannel refiner, the volume space velocity of the pretreated dry gas feed is 2600 h -1, the adsorption temperature is 25 °C, and the adsorption pressure (gauge pressure) is 600 kPa. The regenerant solution is tartaric acid, acetic acid succinic acid, methanesulfonic acid, and demineralized water. By mass composition percentage, tartaric acid is 15%, acetic acid succinic acid is 2.5%, methanesulfonic acid is 1.5%, and the rest is demineralized water. Among them, the dosage ratio of dry gas to the regenerant solution is 550 by volume.

[0160] In the desulfurization contact tower, the desulfurizer is N-methyldiethanolamine. The conditions for the contact between the raw material dry gas and the desulfurizer are as follows: the temperature is 23 °C, the pressure is 700 kPa by gauge pressure, and the theoretical plate number of the desulfurization contact tower is 7. The dosage ratio of the raw material dry gas to the desulfurizer is 104 by volume, and the mass concentration of the desulfurizer is 27%. In the dry gas scrubber, the scrubbing medium is demineralized water. The conditions for the contact between the desulfurized purified dry gas and the demineralized water are as follows: the temperature is 45 °C, the pressure is 700 kPa by gauge pressure, and the gas-liquid ratio is 26 by volume.

[0161] A mist separation layer is provided in the microchannel, and the separation accuracy is 8 microns. The cyclone is a cyclone separator, and the separation accuracy is 400 microns.

[0162] In the depropylene contact tower, the depropylene agent is benzene. The conditions for the contact between the raw material dry gas and the depropylene agent are as follows: the temperature is 18 °C, the pressure is 1000 kPa by gauge pressure, and the theoretical plate number of the depropylene contact tower is 10. The dosage ratio of the raw material dry gas to the depropylene agent is 115 by volume.

[0163] The total nitrogen volume content in the depropylene purified dry gas obtained in this example is 6.6 ppm.

[0164]

Example 12

[0165] In this example, the dry gas raw material is the same as that in Example 1, and the separation process is as Figure 1 shown, and the local microchannel gas-liquid micro flow is as Figure 2 shown.

[0166] The microchannel refiner is a dynamic adsorption bed with a modified microchannel having an adsorption function, i.e., a de-alkali refining agent, and the regenerant solution flows in parallel with the dry gas in the microchannel to continuously regenerate the adsorption active centers.

[0167] The preparation method of the modified microchannel includes: first, the microchannel is subjected to silanization treatment to obtain a microchannel coated with a silane film, and then the microchannel coated with the silane film is treated with a modifier to obtain a modified microchannel.

[0168] The microchannel refiner is filled with 600 microchannel modules, each microchannel module is provided with 1300 modified microchannels, and the spacing between two adjacent parallel modified microchannels is 450 microns. The modified microchannel is a toothed baffle microchannel, the bending angle is 120°, and the span of each toothed baffle is 8.9 cm. In each modified microchannel, the width of the channel cross-section is 800 microns, the length of the channel is 4500 microns, and the height of the modified microchannel is 2.5 cm. The modified microchannel is made of metal 316L material.

[0169] The preparation of the modified microchannel is as follows: The silanization treatment of the microchannel adopts the flowing modification method. First, the inner surface of the microchannel is polished with a chemical polishing solution, and then it is successively washed with deionized water, acetone, alkali solution, rinsed with deionized water, and dried with nitrogen. Subsequently, it is subjected to cyclic silanization with a silane reagent (γ-aminopropyltriethoxysilane) solution, and then dried and cured to obtain a silane film with a molar ratio of siloxyl group to silicon carbide group of 0.7 and a thickness of 15 microns. Among them, the silanization treatment conditions are as follows: The chemical polishing solution, by mass content, is 3.5% nitric acid, 2.5% hydrogen fluoride, 4% hydrogen peroxide, the volume ratio of the chemical polishing solution to the microchannel is 2, the polishing temperature is 45 °C, and the polishing time is 40 seconds; the deionized water washing temperature is 25 °C, and the washing time is 22 minutes; the acetone flowing washing temperature is 25 °C, and the washing time is 22 minutes; the composition of the alkali solution, by mass content, is 5.5% sodium hydroxide, 0.6% sodium phosphate, the alkali washing temperature is 65 °C, and the alkali washing time is 23 minutes; the microchannel after alkali washing is rinsed with deionized water flowing 5 times and dried with nitrogen at 25 °C; the composition of the silanization reagent solution, by volume fraction, is silane reagent: deionized water: absolute ethanol = 2.5:11:96, the pH value is 8.2, the pre-hydrolysis time is 13 hours; the cyclic silanization temperature is 45 °C, and the silanization time is 12 minutes; the drying and curing temperature is 105 °C, and the drying atmosphere is nitrogen.

[0170] The modifier is a pretreatment agent, toluene, and zinc chloride. The preparation process of the pretreatment agent is as follows: p-chlorodiphenylmethyl chloride reacts with fuming sulfuric acid to obtain a reaction product, and the reaction product is extracted with ether. The reaction conditions of p-chlorodiphenylmethyl chloride and fuming sulfuric acid are as follows: p-chlorodiphenylmethyl chloride and fuming sulfuric acid, by mass fraction, p-chlorodiphenylmethyl chloride: fuming sulfuric acid = 35:55, the reaction temperature is 65 °C, and the treatment time is 3.5 hours. The process conditions for ether extraction are as follows: the reaction product and ether, by volume, reaction product: ether = 1:11, the extraction temperature is 21 °C, and continuous extraction is carried out for 2.2 hours. The extraction liquids are combined, and then the ether is evaporated at 55 °C to obtain the pretreatment agent.

[0171] The composition of the modifier is as follows by mass fraction: pretreatment agent: zinc chloride: toluene = 5.5:5:350. The zinc chloride used is anhydrous zinc chloride. After passing through the buffer tank, the modifier is transported to the inlet of the microchannel by a material pump. After flowing through the interior of the channel and exiting from the outlet of the microchannel, it returns to the modifier buffer tank at the inlet of the material pump. The linear velocity of the fluid on the inner surface of the pore is 0.25 m / s, the circulating modification temperature is 55 °C, and the modification time is 5 hours. After treating the microchannel with the modifier, a modified microchannel intermediate is obtained. After the microchannel coated with a silane film is treated with the modifier, the content of sulfonic acid groups introduced into the modified microchannel is 0.3 mol / m 2 , and the content of secondary amino groups is 0.13 mol / m 2 .

[0172] In the microchannel refiner, the volume space velocity of the pretreated dry gas feed is 2600 h -1 , the adsorption temperature is 25 °C, and the adsorption pressure (gauge pressure) is 600 kPa. The regenerant solution is tartaric acid, acetic acid-based succinic acid, methanesulfonic acid, and demineralized water. By mass composition percentage, tartaric acid is 15%, acetic acid-based succinic acid is 2.5%, methanesulfonic acid is 1.5%, and the rest is demineralized water. Among them, the dosage ratio of dry gas to the regenerant solution is 550 by volume.

[0173] In the desulfurization contact tower, the desulfurizer is N-methyldiethanolamine. The conditions for the contact between the raw material dry gas and the desulfurizer are as follows: the temperature is 23 °C, the pressure is 700 kPa by gauge pressure, and the number of theoretical plates in the desulfurization contact tower is 7. The dosage ratio of the raw material dry gas to the desulfurizer is 104 by volume, and the mass concentration of the desulfurizer is 27%. In the dry gas scrubber, the scrubbing medium is demineralized water. The conditions for the contact between the desulfurized and purified dry gas and the demineralized water are as follows: the temperature is 45 °C, the pressure is 700 kPa by gauge pressure, and the gas-liquid ratio is 26 by volume.

[0174] A mist separation layer is provided in the microchannel, and the separation accuracy is 8 μm. The cyclone separator is a cyclone, and the separation accuracy is 400 μm.

[0175] In the depropylene contact tower, the depropylene agent is benzene. The conditions for the contact between the raw material dry gas and the depropylene agent are as follows: the temperature is 18 °C, the pressure is 1000 kPa by gauge pressure, and the number of theoretical plates in the depropylene contact tower is 10. The dosage ratio of the raw material dry gas to the depropylene agent is 115 by volume.

[0176] The total nitrogen volume content in the depropylene-purified dry gas obtained in this example is 14.1 ppm.

[0177]

Comparative Example 1

[0178] This comparative example is compared with Example 3, only in that an unmodified microchannel is used. The dry gas raw material used in this comparative example is the same as that in Example 3, and the separation process for the dry gas raw material is the same as that in Example 3.

[0179] The total nitrogen volume content in the purified dry gas after propylene removal is 18 ppm.

[0180]

Comparative Example 2

[0181] The dry gas raw material used in this comparative example is the same as that in Example 3, and the desulfurization and propylene removal are the same as those in Example 3. The removal of basic impurities is carried out by washing with water in a packed tower (model 250Y) to remove basic impurities. The equipment and process operating conditions of the water washing tower are as follows: the temperature is 35 °C, the pressure (gauge pressure) is 1000 kPa, the number of theoretical plates is 18, a dilute sulfuric acid aqueous solution with a pH of 3 is used, and the gas-liquid volume ratio is 40.

[0182] The total nitrogen volume content in the purified dry gas after propylene removal is 43 ppm.

[0183]

Comparative Example 3

[0184] The dry gas raw material used in this comparative example is the same as that in Example 3, and the desulfurization and propylene removal are the same as those in Example 3. The removal of basic impurities uses commercial 002SC H resin (Suqing Resin Company) as the adsorbent, and a conventional fixed bed adsorption process is adopted. The adsorption conditions are as follows: the resin filling volume is 120 cubic meters, the adsorption temperature is 30 °C, and the volume space velocity is 50 h -1 。

[0185] In the initial stage of operation, the total nitrogen volume content in the purified dry gas after propylene removal is 5 ppm. The adsorbent starts to break through in about 11 days, and regeneration needs to use 4% - 6% sulfuric acid for regeneration. The consumption volume of the regeneration liquid per unit volume of the adsorbent is 4 - 5 times.

[0186] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A dealkalization refining agent includes a microchannel, and the inner surface of the microchannel includes a silane film and a modified layer from outside to inside; the modified layer contains a sulfonic acid group and a secondary amino group; The inner surface of the microchannel includes a silane film and a modified layer from outside to inside, which means that the silane film is on the inner surface of the microchannel, and the modified layer is on the inner surface of the silane film; In the silane film, the molar ratio of the siloxyl group to the silicon-carbon group is 0.6 to 1.1; In the modified layer, the content of sulfonic acid groups is 0.2 - 0.6 mol / m 2 , and the content of secondary amino groups is 0.08 - 0.42 mol / m 2 .

2. The de-alkalization refining agent according to claim 1, characterized in that The thickness of the silane film is 10 to 30 micrometers.

3. The de-alkalization refining agent according to claim 1, characterized in that, The microchannel is a baffle microchannel, and the material is metal.

4. The de-alkalization refining agent according to claim 3, characterized in that, The microchannel is a baffle microchannel with a square cross-section and longitudinally serrated or wavy, and the bending angle is 30° to 150°; the cross-section of the microchannel is square, the width is 300 to 1000 micrometers, the aspect ratio is 1.5 to 6, the height of the modified microchannel is 1 to 3 centimeters, and the single-section baffle span is 0.6 centimeters to 23 centimeters.

5. The de-alkalization refining agent according to any one of claims 1-4, characterized in that, The inner surface of the modified layer further includes a surface treatment layer; in the surface treatment layer, the content of sulfonic acid groups is 6 to 20 mmol / m 2 , the content of secondary amino groups is 10 to 36 mmol / m 2 , the content of methoxy groups is 20 to 90 mmol / m 2 .

6. A preparation method of the dealkalization refining agent according to any one of claims 1-4, including: (1) Prepare a microchannel coated with a silane film; (2) Treat the microchannel coated with a silane film in step (1) with a modifier to obtain a dealkalization refining agent.

7. The preparation method according to claim 6, characterized in that, The modifier in step (2) includes a pretreatment agent, a catalyst, and a solvent; the catalyst is selected from one of Lewis acids or Lewis bases; the solvent is selected from at least one of toluene, p-xylene, m-xylene, and o-xylene; the preparation method of the pretreatment agent is as follows: the pretreatment raw material reacts with fuming sulfuric acid to obtain the pretreatment agent, and the pretreatment raw material is selected from at least one of 4,4'-dichlorodiphenylmethanol, p-chlorodibenzyl chloride, and 4-chlorodiphenylchloromethane.

8. The preparation method according to claim 7, characterized in that, In the modifier in step (2), the catalyst is selected from at least one of anhydrous zinc chloride, anhydrous tin tetrachloride, and anhydrous aluminum chloride.

9. The preparation method according to claim 7, characterized in that, In the preparation method of the pretreatment agent in step (2), the pretreatment raw material is p-chlorodibenzyl chloride.

10. The preparation method according to claim 7, characterized in that, In the preparation method of the pretreatment agent in step (2), the reaction conditions are as follows: the pretreatment raw material and fuming sulfuric acid, by mass, the pretreatment raw material: fuming sulfuric acid = (20 to 40): (50 to 80), the reaction temperature is 60°C to 90°C, and the reaction time is 3 to 6 hours.

11. The preparation method according to claim 7, characterized in that, The composition of the modifier in step (2) includes, by mass, the pretreatment agent: the catalyst: the solvent = (5 to 10): (4 to 8): (180 to 360).

12. The preparation method according to claim 7, characterized in that, The process of treating the microchannel coated with a silane film in step (1) with the modifier in step (2) is as follows: the modifier enters the microchannel from the microchannel inlet and then flows out from the microchannel outlet, and the above process is carried out cyclically. Among them, the linear velocity of the modifier on the inner surface of the microchannel is controlled to be 0.1 to 0.3 m / s, the modification temperature is 50 to 70°C, and the modification time is 4 to 8 hours.

13. The preparation method according to claim 6, characterized in that, In step (2), after treating the microchannel coated with a silane film described in step (1) with a modifier, surface treatment is further carried out using a surface treatment agent; after the surface treatment, the content of sulfonic acid groups introduced into the de-alkalization refining agent is 6 to 20 mmol / m 2 , the content of secondary amino groups is 10 to 36 mmol / m 2 , the content of methoxy groups is 20 to 90 mmol / m 2 .

14. The preparation method according to claim 13, characterized in that, In step (2), the surface treatment agent includes N-(carbamoylmethyl)-2-aminoethanesulfonic acid, 3,5-dichloro-2-methoxyaniline, a catalyst, and a solvent; the catalyst is selected from one of Lewis acids or Lewis bases; the solvent is selected from at least one of toluene, p-xylene, m-xylene, and o-xylene; and / or, by mass parts, N-(carbamoylmethyl)-2-aminoethanesulfonic acid: 3,5-dichloro-2-methoxyaniline: catalyst: solvent = (4 - 8): (7 - 14): (5 - 10): (150 - 350); and / or, the conditions for surface treatment are as follows: controlling the fluid linear velocity of the surface treatment agent on the inner surface of the microchannel to be 0.3 - 0.5 m / s, the surface treatment temperature to be 40 - 60 °C, and the modification time to be 1 - 2 hours.

15. The preparation method according to claim 14, characterized in that, In step (2), the catalyst in the surface treatment agent is selected from at least one of anhydrous zinc chloride, anhydrous stannic chloride, and anhydrous aluminum chloride.

16. The preparation method according to claim 6 or 13, characterized in that, After being treated with the modifier or the surface treatment agent in step (2), post-modification treatment is carried out, wherein the solvent used for the post-modification treatment is at least one of absolute ethanol, absolute methanol, and absolute acetone.

17. The preparation method according to claim 16, characterized in that, In step (2), the solvent used for the post-modification treatment is absolute ethanol.

18. The preparation method according to claim 16, characterized in that, In step (2), the conditions for the post-modification treatment are as follows: the solvent enters the inside of the microchannel from the microchannel inlet and flows out from the microchannel outlet, and the above process is carried out cyclically; wherein, controlling the fluid linear velocity of the solvent used for the post-modification treatment on the inner surface of the micro-through hole channel to be 0.2 - 0.4 m / s, the post-modification treatment temperature to be 60 - 80 °C, and the modification time to be 1 - 3 hours.

19. Use of the de-alkalization refining agent according to any one of claims 1-5 or the de-alkalization refining agent prepared by the preparation method according to any one of claims 6-18 in removing alkaline impurities from dry gas, wherein, The raw material dry gas contacts with the de-alkalization refining agent to obtain purified dry gas with alkaline impurities removed.

20. The application according to claim 19, wherein The application uses a microchannel refiner, which is internally provided with a microchannel module composed of de-alkalization refining agents in parallel and / or in series. The raw material dry gas enters the microchannel module through the inlet dry gas distributor. At the same time, the regenerant solution enters the microchannel module through the inlet regenerant solution distributor. Under the action of power, the regenerant solution is dispersed with the dry gas in the microchannel and passes through the microchannel, realizing adsorption and regeneration simultaneously. The microchannel is provided with a mist separation layer to capture the regenerant solution after coalescence work, thereby obtaining purified dry gas and the regenerant solution after work.

21. The application according to claim 20, characterized in that, The microchannel refiner is filled with 500 - 1000 modified microchannel modules. Each modified microchannel module is provided with 1000 - 2000 modified microchannels, and the interval between two adjacent parallel modified microchannels is 300 - 500 microns.

22. The application according to claim 20, characterized in that, The regenerant is selected from at least one of citric acid, tartaric acid, acetic acid-based succinic acid, methanesulfonic acid, sulfuric acid, and phosphoric acid.

23. The application according to claim 22, characterized in that, By mass composition percentage of the regenerant solution, tartaric acid is 10% - 30%, acetic acid-based succinic acid is 2% - 4%, methanesulfonic acid is 1% - 3%, and the rest is demineralized water.

24. The application according to claim 19, wherein The alkaline impurities contained in the raw material dry gas include at least one of ammonia, methylamine, N-methylmethylamine, cyclopropanemethylamine, N-dimethylmethylamine, monoethanolamine, diethanolamine, aminocyclobutane, diisopropanolamine, and N-methyldiethanolamine; And / or, in the raw dry gas, the volume content based on the total nitrogen element is not less than 5 ppm and not more than 2000 ppm.

25. The application according to claim 24, wherein In the raw dry gas, the volume content based on the total nitrogen element is not less than 50 ppm and not more than 1000 ppm.

26. The application according to claim 24, characterized in that, In the raw dry gas, the volume content based on the total nitrogen element is not less than 500 ppm.

27. The application according to claim 19 or 20, characterized in that, In the described application, the conditions for the de-alkalization refining are as follows: the volume space velocity of the raw material dry gas feed is 600 to 3000 h -1 , the adsorption temperature is 20 to 50 °C, the adsorption pressure gauge pressure is 500 to 1200 kPa, and the feed volume ratio of the raw material dry gas to the regenerant solution is 400 to 600 by volume.

28. The application according to claim 19, wherein Before the raw dry gas contacts the de-alkali refining agent, it first contacts the desulfurization agent to remove sulfide-containing substances, obtaining desulfurized and purified dry gas. And / or, the purified dry gas after removing basic impurities contacts the de-propylene agent to obtain de-propylene purified dry gas.

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