CN116286089A - Device and method for removing organic sulfur from dry gas - Google Patents

Abstract

The invention discloses a dry gas organic sulfur removal device and a method thereof, wherein the device comprises a mercaptan conversion tower, the mercaptan conversion tower is connected with an agent alkali tank, and the mercaptan conversion tower is connected with a diesel oil absorption desulfurization tower; a mercaptan conversion agent is arranged in the mercaptan conversion tower, a first dry gas inlet is arranged below the mercaptan conversion agent, and a first dry gas outlet is arranged at the top of the mercaptan conversion tower; the diesel oil absorption desulfurizing tower is internally provided with absorption desulfurizing tower filler, the upper side part of the diesel oil absorption desulfurizing tower is provided with a diesel oil inlet, the lower part of the absorption desulfurizing tower filler is provided with a second dry gas inlet, and the second dry gas inlet is connected with the first dry gas outlet. According to the invention, the mercaptan conversion tower and the diesel oil absorption desulfurization tower are arranged, the mercaptan conversion agent is arranged in the mercaptan conversion tower, and the absorption desulfurization tower filler, the coalescence separator and the liquid distributor are arranged in the diesel oil absorption desulfurization tower, so that the dry gas containing organic sulfur is subjected to two-step desulfurization, and the organic sulfur of the dry gas is efficiently removed.

Description

A device and method for removing organic sulfur from dry gas

technical field

The invention relates to the field of petrochemical industry, in particular to a device for removing organic sulfur from dry gas and a method thereof.

Background technique

The survey found that after the dry gas (also known as fuel gas) produced by some refineries was extracted with MDEA amine liquid to remove hydrogen sulfide, it also contained a small amount of methyl mercaptan, dimethyl disulfide, and trace amounts of methyl sulfide and Carbon disulfide, the total content ranges from 100-1000mg/ ^Nm3 . Dry gas is generally used as fuel in oil refineries, and the SO ₂ content in the exhaust gas after combustion is required to be no more than 100 mg/Nm ³ , and some cities or regions require no more than 50 mg/Nm ³ , so most companies require that the dry gas be desulfurized to Below 50mg/Nm ³ , even below 20mg/Nm ³ .

Domestic oil refining companies generally have MDEA amine extraction to remove hydrogen sulfide from dry gas, and most of them can remove hydrogen sulfide to below 20-50mg/Nm ³ , but MDEA amine extraction basically has no effect on organic sulfur removal. At present, there are few technologies for removing organic sulfur from dry gas.

Contents of the invention

Aiming at the above-mentioned technical problems in the related art, the present invention proposes a dry gas organic sulfur removal device and method thereof. By setting a mercaptan conversion tower and a diesel absorption desulfurization tower, and setting a mercaptan conversion agent in the mercaptan conversion tower, the The diesel absorption desulfurization tower is equipped with absorption desulfurization tower packing, coalescing separator and liquid distributor, and performs two-step desulfurization on the dry gas containing organic sulfur, and removes the total sulfur content of the dry gas to below 20mg/Nm ³ , which solves the existing technology There are few technical problems in dry gas removal of organic sulfur in China, and the technical effect of efficient dry gas removal of organic sulfur is achieved.

In order to achieve the above-mentioned technical purpose, on the one hand, the present invention provides a dry gas organic sulfur removal device, comprising a mercaptan conversion tower, the mercaptan conversion tower is connected with an alkali tank, and the mercaptan conversion tower is connected with a diesel absorption desulfurization tower Connected, the mercaptan conversion tower is connected with the external dry gas input unit, and the diesel absorption desulfurization tower is connected with the external dry gas output unit;

The mercaptan conversion tower is provided with a mercaptan conversion agent, the top of the mercaptan conversion tower is provided with a first dry gas outlet, and the top side of the mercaptan conversion tower is provided with an alkali liquor inlet, and the mercaptan conversion tower is provided with a lye inlet. The bottom side of the conversion tower is provided with a first dry gas inlet, the first dry gas inlet is located below the mercaptan conversion agent, the bottom of the mercaptan conversion tower is provided with an alkali outlet, and the first dry gas The gas inlet is connected to the external dry gas input unit, the lye inlet is connected to the bottom outlet of the alkali agent tank through the lye pump, and the bottom outlet of the alkali agent tank is also connected to the lye outlet;

The interior of the diesel absorption desulfurization tower is provided with a coalescing separator, a liquid separator and an absorption desulfurization tower packing in sequence from top to bottom, and the top of the diesel absorption desulfurization tower is provided with a second dry gas outlet, and the diesel absorption desulfurization tower The upper side of the diesel absorption desulfurization tower is provided with a diesel inlet, the bottom side of the diesel absorption desulfurization tower is provided with a second dry gas inlet, the second dry gas inlet is located below the packing of the absorption desulfurization tower, and the diesel absorption desulfurization tower The bottom of the tank is provided with a diesel outlet, the second dry gas inlet is connected with the first dry gas outlet of the mercaptan conversion tower, the second dry gas outlet is connected with the external dry gas output unit, the The diesel outlet is connected with the diesel inlet through a circulation diesel pump and a diesel cooler in sequence.

Further, the coalescing separator includes a coalescing separator distribution orifice, the upper part of the coalescing separator distribution orifice is fixedly connected to the coalescing separator mixed wire mesh, and the coalescing separator distribution orifice The material is stainless steel, and the mixed wire mesh of the coalescence separator is braided by stainless steel wire and polymer fiber. The stainless steel wire is linear, and the diameter of the stainless steel wire is 0.05-0.2mm. The surface hydrophilic angle is less than or equal to 5°, the polymer fiber is modified polytetrafluoroethylene or polyphenylene sulfide fiber, and the diameter of the polymer fiber is 0.1-0.3mm.

Further, the mercaptan conversion agent is activated carbon with a demercaptan catalyst and sodium hydroxide solidly loaded thereon, the demercaptan catalyst is sulfonated cyanine cobalt or ammonium cyanine cobalt sulfonate, and the activated carbon is coconut shell, light Microporous spheres, blocks or round rods made of high quality wood or coal, the sulfur adsorption value of the mercaptan conversion agent is greater than 1000mg/g, and the compressive strength of the mercaptan conversion agent is greater than 50N/cm.

Further, the packing of the absorption desulfurization tower is random packing or structured packing, and the packing material of the packing of the absorption desulfurization tower is stainless steel or ceramics.

Further, the liquid separator is evenly provided with several nozzles with downward nozzles, and the liquid separator is connected with the diesel oil inlet.

Further, the diesel oil cooler is connected to the refined diesel oil pipe, and a sulfur-containing diesel oil pipe is connected to the pipeline between the circulating diesel oil pump and the diesel oil cooler.

In another aspect, the present invention provides a method for removing organic sulfur from dry gas, comprising the following steps:

Step S1, making the dry gas containing organic sulfur pass through the mercaptan conversion agent in the mercaptan conversion tower, and under the action of oxygen and the mercaptan conversion agent, the methyl mercaptan in the dry gas containing organic sulfur is converted into Dimethyl disulfide, while the hydrogen sulfide in the dry gas containing organic sulfur is converted into elemental sulfur, and the elemental sulfur is adsorbed in the tiny gaps of the mercaptan conversion agent to complete the mercaptan conversion and hydrogen sulfide removal; The elemental sulfur in the tiny pores of the mercaptan conversion agent is eluted, and at the same time, the mercaptan conversion agent is re-immobilized with sodium hydroxide and the sweetening catalyst to be regenerated; dimethyl disulfide continues to flow into the diesel oil with the dry gas Absorption and desulfurization tower, wherein the height-to-diameter ratio of the mercaptan conversion tower is (3-6):1, the space velocity of dry gas containing organic sulfur is 100-1000h ^-1 , and the temperature inside the mercaptan conversion tower is 20 -50°C;

Step S2, making the dry gas containing dimethyl disulfide pass through the packing of the absorption desulfurization tower of the diesel oil absorption desulfurization tower, and at the same time, washing the diesel oil through the liquid separator to the packing of the absorption desulfurization tower from top to bottom , making dimethyl disulfide and diesel oil contact in the packing of the absorption desulfurization tower, so that the diesel oil can elute dimethyl disulfide, and the dry gas after desulfurization is output to the diesel absorption desulfurization tower after passing through the coalescence separator , complete dry gas desulfurization.

Further, when the lye is used to elute the elemental sulfur in the tiny gaps of the mercaptan conversion agent, the lye in the alkali tank is allowed to pass through the lye inlet under the action of the lye pump Entering the mercaptan conversion tower, soaking the mercaptan conversion agent with alkali to replenish sodium hydroxide and the mercaptan removal catalyst and to elute elemental sulfur.

Further, the sweetening catalyst content in the lye is 200-500 μg/g, and the concentration of sodium hydroxide in the lye is 5-15%wt.

Further, when the diesel oil is washed from top to bottom to the packing of the absorption desulfurization tower through the liquid separator, the diesel oil is cooled through the diesel oil outlet of the diesel absorption desulfurization tower, the diesel circulation pump, and the diesel oil The device cools the diesel oil entering the absorption desulfurization tower to 5-10°C, and at the same time replenishes refined diesel oil through the refined diesel oil pipe, wherein the flow volume ratio of organic sulfur-containing dry gas to diesel oil in the diesel absorption desulfurization tower is 300-1500 : 1, the sulfur content of supplemented refined diesel is less than or equal to 10μg/g.

Beneficial effect of the present invention: by setting mercaptan conversion tower and diesel oil absorption desulfurization tower, and setting mercaptan conversion agent in mercaptan conversion tower, setting absorption desulfurization tower packing, coalescing separator and liquid distribution in diesel oil absorption desulfurization tower The dry gas containing organic sulfur passes through the mercaptan conversion tower from bottom to top. The mercaptan conversion agent in the tower is microporous activated carbon with solid sodium hydroxide and desulfurization agent catalyst. Methyl mercaptan in the process is converted into dimethyl disulfide, hydrogen sulfide is converted into elemental sulfur and adsorbed in the tiny pores of the mercaptan conversion agent, and the dry gas containing dimethyl disulfide passes through the diesel absorption desulfurization tower from bottom to top. After cooling, the diesel oil is sprayed from top to bottom by the liquid distributor and evenly distributed in the cross section of the desulfurization tower. The gas phase and the two phases are fully contacted when they flow through the packing in the desulfurization tower in reverse, and the dimethyl disulfide in the dry gas is extracted and absorbed into the diesel oil. In the above-mentioned two-step desulfurization, the total sulfur in the dry gas can be removed to below 20mg/ ^Nm3 . According to the level of sulfur in the dry gas, the mercaptan conversion agent in the mercaptan conversion tower passes through the dissolved desulfurization every 3-6 months. Alcohol catalyst is soaked and regenerated in lye circulation, and the diesel oil absorbs the circulating diesel oil from the desulfurization tower and is cooled to 5-10°C through a cold medium to reduce the content of diesel components in the purified dry gas, and at the same time reduce the total sulfur content of the purified dry gas, and finally achieve dry gas The purpose of desulfurization.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is a schematic structural view of a dry gas organic sulfur removal device according to an embodiment of the present invention;

Fig. 2 is a bottom view of the structure of the liquid distributor in the dry gas organic sulfur removal device according to an embodiment of the present invention;

Fig. 3 is a schematic structural view of the distribution orifice plate of the coalescing separator in the device for removing organic sulfur from dry gas according to an embodiment of the present invention;

Fig. 4 is a schematic diagram of the structure and hinge points of the mixed wire mesh of the coalescer separator in the device for removing organic sulfur from dry gas according to an embodiment of the present invention;

Fig. 5 is a simplified flow chart of the method for removing organic sulfur from dry gas according to an embodiment of the present invention;

In the figure: 1-mercaptan conversion tower; 2-mercaptan conversion agent; 3-soda alkali tank; 4-lye pump; 5-diesel oil absorption desulfurization tower; 6-absorption desulfurization tower packing; 7-coalescence separator; 71-distribution orifice plate of coalescer separator; 72-mixed wire mesh of coalescer separator; 73-stainless steel wire; 74-polymer fiber; 8-liquid distributor; 9-diesel cooler; 10-circulation diesel pump; 21-Sulphur-containing dry gas pipe; 22-Dry gas pipe after primary desulfurization; 23-Purified dry gas pipe; 24-Agent alkali pipe; 25-Alkaline liquid pipe; Diesel pipe.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention belong to the protection scope of the present invention.

As shown in Figures 1-4, the dry gas removal device for organic sulfur provided by the embodiment of the present invention includes:

The mercaptan conversion tower 1, the mercaptan conversion tower 1 is connected with the caustic soda tank 3, the mercaptan conversion tower 1 is connected with the diesel absorption desulfurization tower 5, and the mercaptan conversion tower 1 is connected with the external dry gas input unit, The diesel absorption desulfurization tower 5 is connected with an external dry gas output unit;

The mercaptan conversion tower 1 is provided with a mercaptan conversion agent 2, the top of the mercaptan conversion tower 1 is provided with a first dry gas outlet, and the top side of the mercaptan conversion tower 1 is provided with a lye inlet, The bottom side of the mercaptan conversion tower 1 is provided with a first dry gas inlet, the first dry gas inlet is located below the mercaptan conversion agent 2, and the bottom of the mercaptan conversion tower 1 is provided with a lye outlet, the first dry gas inlet is connected to the external dry gas input unit, the lye inlet is connected to the bottom outlet of the agent alkali tank 3 through the lye pump 4, and the lye outlet is connected to the agent alkali tank 3 The bottom outlet connection of alkali tank 3;

The upper part of the diesel oil absorption and desulfurization tower 5 is provided with a coalescence separator 7, and the bottom of the coalescence separator 7 is provided with a liquid separator 8, and the bottom of the liquid separator 8 is provided with an absorption desulfurization tower packing 6, The top of the diesel absorption desulfurization tower 5 is provided with a second dry gas outlet, the upper side of the diesel absorption desulfurization tower 5 is provided with a diesel inlet, and the bottom side of the diesel absorption desulfurization tower 5 is provided with a second dry gas outlet. Inlet, the second dry gas inlet is located below the packing 6 of the absorption desulfurization tower, the bottom of the diesel absorption desulfurization tower 5 is provided with a diesel outlet, the second dry gas inlet is connected to the mercaptan conversion tower 1 The first dry gas outlet is connected, the second dry gas outlet is connected to the external dry gas output unit, and the diesel outlet is connected to the diesel inlet through a circulating diesel pump 10 and a diesel cooler 9 in sequence.

Specifically, the coalescing separator 7 includes a coalescing separator distribution orifice 71, the upper part of the coalescing separator distributing orifice 71 is fixedly connected to the coalescing separator mixed wire mesh 72, and the coalescing and separating The material of the device distribution orifice 71 is stainless steel, and the mixed weaving wire mesh 72 of the coalescence separator is woven by stainless steel wire 73 and polymer fiber 74, and the stainless steel wire 73 is uniform linear, and the stainless steel wire 73 The diameter is 0.05-0.2mm, the surface hydrophilic angle of the stainless steel wire 73 is less than or equal to 5°, the polymer fiber 74 is a modified polytetrafluoroethylene or polyphenylene sulfide fiber material, and the polymer fiber 74 The diameter is 0.1-0.3mm.

Specifically, the mercaptan conversion agent 2 is activated carbon with a sweetening catalyst and sodium hydroxide solidly loaded thereon, the sweetening catalyst is sulfonated cyanine cobalt or ammonium cyanine cobalt sulfonate, and the activated carbon is coconut shell , microporous spheres, blocks or round rods made of light wood or coal, the sulfur adsorption value of the mercaptan conversion agent 2 is greater than 1000mg/g, and the compressive strength of the mercaptan conversion agent 2 is greater than 50N /cm.

Specifically, the packing 6 of the absorption desulfurization tower is random packing or structured packing, and the packing material of the packing 6 of the absorption desulfurization tower is stainless steel or ceramics.

Specifically, the liquid separator 8 is evenly provided with several nozzles with downward nozzles, and the liquid separator 8 is connected to the diesel oil inlet.

Specifically, the diesel oil cooler 9 is connected to the refined diesel oil pipe 27 , and a sulfur-containing diesel oil pipe 28 is connected between the circulating diesel oil pump 10 and the diesel oil cooler 9 .

As shown in Figure 5, the method for removing organic sulfur from dry gas provided by the embodiment of the present invention includes:

Step S1, making the organic sulfur-containing dry gas pass through the mercaptan conversion agent 2 in the mercaptan conversion tower 1, and under the action of a small amount of oxygen and the mercaptan conversion agent 2, formaldehyde in the organic sulfur dry gas is The mercaptan is converted into dimethyl disulfide, and the hydrogen sulfide in the organic sulfur-containing dry gas is converted into elemental sulfur at the same time, and the elemental sulfur is adsorbed in the tiny voids of the mercaptan conversion agent 2 to complete the mercaptan conversion and hydrogen sulfide removal , using a caustic soda to elute the elemental sulfur in the tiny voids of the mercaptan conversion agent 2, and at the same time make the mercaptan conversion agent re-immobilize sodium hydroxide and the demercaptan catalyst to be regenerated, and the dimethyl disulfide is The dry gas continues to flow to enter the diesel absorption desulfurization tower 5, wherein the mercaptan conversion tower 1 has an aspect ratio of 3-6:1, and the space velocity of the dry gas containing organic sulfur is 100-1000h ^-1 , so The temperature in the mercaptan conversion tower 1 is 20-50°C;

Step S2, make the dry gas containing dimethyl disulfide pass through the absorption desulfurization tower packing 6 of the diesel oil absorption desulfurization tower 5, and simultaneously pass the diesel oil through the liquid separator 8 to the absorption desulfurization tower packing 6 from above And the lower leaching, make dimethyl disulfide and diesel oil contact in described absorption desulfurization tower filler 6, so that diesel oil elutes dimethyl disulfide, and the dry gas after desulfurization passes through described coalescence separator 7 and then output The diesel oil absorbs the desulfurization tower 5 to complete the dry gas desulfurization.

Specifically, when using alkali to elute the elemental sulfur in the tiny gaps of the mercaptan conversion agent 2, the lye in the alkali tank 3 passes through the lye under the action of the lye pump 4. The lye inlet enters the mercaptan conversion tower 1 to soak the mercaptan conversion agent 2 with alkali to replenish sodium hydroxide and mercaptan removal catalyst and to elute elemental sulfur.

Specifically, the sweetening catalyst content in the lye of the alkali tank 3 is 200-500 μg/g, and the concentration of sodium hydroxide in the lye is 5-15%wt.

Specifically, when the diesel oil is washed from top to bottom to the absorption desulfurization tower packing 6 through the liquid separator 8, the diesel oil outlet through the diesel absorption desulfurization tower 5, the diesel circulation pump 10 , the diesel oil cooler 9 cools the diesel oil entering the absorption desulfurization tower to 5-10°C, and at the same time replenishes refined diesel oil through the refined diesel oil pipe 27, wherein the dry gas containing organic sulfur in the diesel absorption desulfurization tower 5 is mixed with The diesel flow volume ratio is 300-1500:1, and the sulfur content of the added refined diesel is less than or equal to 10μg/g.

In order to facilitate the understanding of the above-mentioned technical solution of the present invention, the above-mentioned technical solution of the present invention will be described in detail below through a specific usage mode.

In the actual production environment, the dry gas organic sulfur removal device according to the present invention includes a mercaptan conversion tower 1, a mercaptan conversion agent 2, an alkali tank 3, a lye pump 4, a diesel absorption desulfurization tower 5, an absorption desulfurization tower Packing 6, coalescence separator 7, liquid distributor 8, diesel oil cooler 9, circulating diesel pump 10, the mercaptan conversion agent 2 is packed in the mercaptan conversion tower 1, and the absorption desulfurization tower packing 6 is packed In the middle section of the diesel absorption desulfurization tower 5, the coalescence separator 7 is installed at the top of the diesel absorption desulfurization tower 5, and the liquid distributor 8 is installed above the absorption desulfurization tower packing 6 at the upper part of the diesel absorption desulfurization tower 5.

The dry gas inlet at the bottom side of the mercaptan conversion tower 1 is connected to the sulfur-containing dry gas pipe 21, and the lye outlet at the bottom of the mercaptan conversion tower 1 is connected to the lye pipe 25, and the lye pipe 25 is connected to the alkali On the pipe 24, one end of the agent alkali pipe 24 is connected to the agent alkali tank 3, and the other end of the agent alkali pipe 24 is connected to the lye pump 4 and the lye inlet on the top side of the mercaptan conversion tower 1, and the mercaptan The dry gas outlet at the top of the conversion tower 1 is connected to the dry gas pipe 22 after first-stage desulfurization, and the other end of the dry gas pipe 22 after the first-stage desulfurization is connected to the dry gas inlet at the bottom of the diesel absorption desulfurization tower 5, and the bottom of the diesel absorption desulfurization tower 5 is The diesel oil outlet is connected to the circulating diesel pipe 26, and the other end of the circulating diesel pipe 26 is connected to the circulating diesel pump 10, the diesel oil cooler 9 and the diesel inlet on the upper side of the diesel absorption desulfurization tower 5, and the upper side of the diesel absorption desulfurization tower 5 The diesel oil inlet is connected to the liquid distributor 8, and the circulating diesel oil pipe 26 is connected with a sulfur-containing diesel oil pipe 28 at the outlet of the diesel circulating pump 10, and the described circulating diesel oil pipe 26 is connected with a refined diesel oil pipe 27 at the inlet of the diesel oil cooler, The dry gas outlet at the top of the diesel absorption desulfurization tower 5 is connected to the purified dry gas 23 .

In specific use, the method for removing organic sulfur from dry gas according to the present invention includes:

Step S1, the dry gas containing organic sulfur passes through the mercaptan conversion tower from bottom to top, and the mercaptan conversion agent in the tower is microporous activated carbon with solid sodium hydroxide and desulfurization agent catalyst. Under the action of a small amount of oxygen in the dry gas, the dry gas Methyl mercaptan in the gas is converted into dimethyl disulfide, hydrogen sulfide is converted into elemental sulfur and adsorbed in the tiny pores of the mercaptan conversion agent, and the content of mercaptan and hydrogen sulfide in the dry gas can be removed to below 1mg/ ^Nm3 ;

Step S2, according to the level of sulfur content in the dry gas, the mercaptan conversion agent in the mercaptan conversion tower is regenerated by soaking in the alkali solution dissolved in the demercaptan catalyst every 3-6 months, on the one hand, replenishing the demercaptan catalyst lost on the activated carbon And sodium hydroxide, on the other hand, wash away the elemental sulfur adsorbed in the micropores of activated carbon;

Step S3, the dry gas containing dimethyl disulfide passes through the diesel absorption desulfurization tower from bottom to top, and after cooling, the diesel oil is sprayed from top to bottom through the liquid distributor and evenly distributed in the cross section of the desulfurization tower, and the gas-liquid two-phase reverse When flowing through the packing in the desulfurization tower, it is fully contacted, and the dimethyl disulfide in the dry gas is extracted and absorbed into the diesel oil. The diesel oil absorbed in the desulfurization tower is self-circulating at a large flow rate and continuously replaced at a small flow rate. After the above two steps of desulfurization, the total sulfur in dry gas can be removed to below 20mg/ ^Nm3 . Diesel oil absorption The circulating diesel oil in the desulfurization tower is cooled to 5-10°C by the cooling medium to reduce the content of diesel components in the purified dry gas, and at the same time reduce the total sulfur content of the purified dry gas.

According to the device and method for removing organic sulfur from dry gas in the present invention, the following examples are provided.

Example 1:

Delayed coking unit of a refinery produces dry gas. After extraction with MDEA amine liquid, the hydrogen sulfide content in the dry gas is 5-10mg/Nm ³ , the content of methyl mercaptan is 50-150mg/Nm ³ , and the content of methyl sulfide is less than 5mg/Nm ³ , The content of dimethyl disulfide is 200-350mg/Nm ³ , and the patented technology of the present invention is used in the pilot desulfurization experiment. The content of hydrogen sulfide and mercaptan in the purified dry gas is less than 1mg/Nm ³ , and the total sulfur is less than 10mg/m ³ .

Example 2:

Delayed coking unit of a refinery produces dry gas. After extraction with MDEA amine solution, the hydrogen sulfide content in the dry gas is 5-15mg/Nm ³ , the content of methyl mercaptan is 50-100mg/Nm ³ , and the content of methyl sulfide is less than 5mg/Nm ³ , the content of carbon disulfide is less than 5mg/Nm ³ , the content of dimethyl disulfide is 300-400mg/Nm ³ , and the patented technology of the present invention is used in the pilot desulfurization experiment, and the contents of hydrogen sulfide and mercaptan in the purified dry gas are respectively less than 1mg/Nm ³ , The total sulfur is less than 15 mg/m ³ .

Example 3:

Delayed coking unit of a refinery produces dry gas, the flow rate of dry gas is 30000-40000Nm ³ /h, the operating pressure is 0.6MPa(G), the hydrogen sulfide content in the dry gas after MDEA amine extraction is 5-15mg/Nm ³ , methyl sulfide Alcohol content 50-100mg/Nm ³ , methyl sulfide content less than 5 mg/Nm ³ , carbon disulfide content less than 5 mg/Nm ³ , dimethyl disulfide content 300-400 mg/Nm ³ , using the patented technology of this invention to build a set of dry gas Desulfurization purification device, the content of hydrogen sulfide and mercaptan in the purified dry gas after desulfurization is less than 1mg/Nm ³ , and the total sulfur is 10-20mg/m ³ .

In summary, by means of the above-mentioned technical scheme of the present invention, by setting the mercaptan conversion tower and the diesel oil absorption desulfurization tower, and setting the mercaptan conversion agent in the mercaptan conversion tower, the absorption desulfurization tower packing is arranged in the diesel oil absorption desulfurization tower , a coalescing separator and a liquid distributor, so that the dry gas containing organic sulfur passes through the mercaptan conversion tower from bottom to top. Under the action of a small amount of oxygen, the methyl mercaptan in the dry gas is converted into dimethyl disulfide, and the hydrogen sulfide is converted into elemental sulfur and adsorbed in the tiny pores of the mercaptan conversion agent. The diesel oil absorbs the desulfurization tower on the upper side, and after cooling, the diesel oil is sprayed from top to bottom through the liquid distributor and evenly distributed in the cross section of the desulfurization tower. The base disulfide is extracted and absorbed into the diesel oil. After the above two steps of desulfurization, the total sulfur in the dry gas can be removed to below 20mg/ ^Nm3 . According to the sulfur content in the dry gas, the mercaptan conversion agent in the mercaptan conversion tower can -Regenerated by circulating immersion in alkaline solution dissolved with demercaptan catalyst for 6 months, diesel oil absorbs circulating diesel oil from the desulfurization tower and cools it to 5-10°C through a cold medium to reduce the content of diesel components in the purified dry gas, and at the same time reduce the purified dry gas Total sulfur content, and finally achieve the purpose of dry gas desulfurization.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. A device for removing organic sulfur from dry gas, characterized in that it comprises a mercaptan conversion tower (1), the mercaptan conversion tower (1) is connected to the caustic soda tank (3), and the mercaptan conversion tower (1 ) is connected to the diesel absorption desulfurization tower (5), the mercaptan conversion tower (1) is connected to an external dry gas input unit, and the diesel absorption desulfurization tower (5) is connected to an external dry gas output unit; The mercaptan conversion tower (1) is provided with a mercaptan conversion agent (2), the top of the mercaptan conversion tower (1) is provided with a first dry gas outlet, and the top of the mercaptan conversion tower (1) The side is provided with a lye inlet, and the bottom side of the mercaptan conversion tower (1) is provided with a first dry gas inlet, and the first dry gas inlet is located below the mercaptan conversion agent (2). The bottom of the mercaptan conversion tower (1) is provided with a lye outlet, the first dry gas inlet is connected to the external dry gas input unit, and the lye inlet is connected to the alkali agent through the lye pump (4) The bottom outlet of the tank (3) is connected, and the bottom outlet of the alkali tank (3) is also connected with the lye outlet; The diesel absorption desulfurization tower (5) is provided with a coalescence separator (7), a liquid separator (8) and an absorption desulfurization tower packing (6) sequentially from top to bottom, and the diesel absorption desulfurization tower (5) The top is provided with a second dry gas outlet, the upper side of the diesel absorption desulfurization tower (5) is provided with a diesel inlet, and the bottom side of the diesel absorption desulfurization tower (5) is provided with a second dry gas inlet, the The second dry gas inlet is located below the packing (6) of the absorption desulfurization tower, and the bottom of the diesel absorption desulfurization tower (5) is provided with a diesel outlet, and the second dry gas inlet is connected to the mercaptan conversion tower (1 ) is connected to the first dry gas outlet, the second dry gas outlet is connected to the external dry gas output unit, and the diesel oil outlet is connected to the Diesel inlet connection. 2. The dry gas organic sulfur removal device according to claim 1, characterized in that, the coalescer separator (7) comprises a coalescence separator distribution orifice (71), and the coalescence separator distribution orifice The upper part of (71) is fixedly connected to the mixed wire mesh (72) of the coalescing separator. Stainless steel wire (73) and polymer fiber (74) are braided, the stainless steel wire (73) is linear, the diameter of the stainless steel wire (73) is 0.05-0.2mm, and the diameter of the stainless steel wire (73) The surface hydrophilic angle is less than or equal to 5°, the polymer fiber (74) is a modified polytetrafluoroethylene or polyphenylene sulfide fiber, and the diameter of the polymer fiber (74) is 0.1-0.3 mm. 3. The dry gas organic sulfur removal device according to claim 1, characterized in that, the mercaptan conversion agent (2) is activated carbon solidly loaded with a mercaptan catalyst and sodium hydroxide, and the mercaptan catalyst is sulfur Cobalt cyanine or ammonium cyanine cobalt sulfonate, the activated carbon is a microporous spherical, block or round rod made of coconut shell, light wood or coal, the sulfur of the mercaptan conversion agent (2) The adsorption value is greater than 1000mg/g, and the compressive strength of the mercaptan conversion agent (2) is greater than 50N/cm. 4. The device for removing organic sulfur from dry gas according to claim 1, characterized in that the packing (6) of the absorption desulfurization tower is random packing or structured packing, and the packing material of the packing (6) of the absorption desulfurization tower is Stainless steel or ceramic. 5. The device for removing organic sulfur from dry gas according to claim 1, characterized in that, the liquid separator (8) is evenly equipped with several nozzles with downward nozzles, and the liquid separator (8) and the Diesel inlet connection. 6. The dry gas organic sulfur removal device according to claim 1, characterized in that, the diesel oil cooler (9) is connected to the refined diesel oil pipe (27), and the circulating diesel pump (10) is connected to the The pipeline between the diesel coolers (9) is connected with a sulfur-containing diesel pipe (28). 7. A method for removing organic sulfur from dry gas, characterized in that using the device for removing organic sulfur from dry gas according to any one of claims 1-7, comprising the steps of: Step S1, making the organic sulfur-containing dry gas pass through the mercaptan conversion agent (2) in the mercaptan conversion tower (1), and under the action of oxygen and the mercaptan conversion agent (2), the organic sulfur The methyl mercaptan in the dry gas is converted into dimethyl disulfide, and the hydrogen sulfide in the dry gas containing organic sulfur is converted into elemental sulfur at the same time, and the elemental sulfur is adsorbed in the tiny pores of the mercaptan conversion agent (2) to complete Mercaptan conversion and dehydrogen sulfide; use a base to elute the elemental sulfur in the tiny pores of the mercaptan conversion agent (2), and at the same time make the mercaptan conversion agent (2) re-immobilize sodium hydroxide and demercaptan catalyst Thereby regeneration is obtained; dimethyl disulfide continues to flow into the diesel absorption desulfurization tower (5) with the dry gas, wherein, the aspect ratio of the mercaptan conversion tower (1) is (3-6):1, containing The space velocity of organic sulfur dry gas is 100-1000h ^-1 , and the temperature inside the mercaptan conversion tower (1) is 20-50°C; Step S2, make the dry gas containing dimethyl disulfide pass through the absorption desulfurization tower packing (6) of the diesel absorption desulfurization tower (5), and at the same time, pass the diesel oil to the absorption desulfurization tower (5) through the liquid separator (8) The desulfurization tower packing (6) is rinsed from top to bottom, so that dimethyl disulfide and diesel oil are in contact with the absorption desulfurization tower packing (6), so that the diesel oil can elute dimethyl disulfide, and the dry gas after desulfurization After passing through the coalescence separator (7), it is output to the diesel absorption desulfurization tower (5) to complete dry gas desulfurization. 8. The method for removing organic sulfur from dry gas according to claim 7, characterized in that, when the elemental sulfur in the tiny voids of the mercaptan conversion agent (2) is eluted with an alkali agent, the alkali agent is used to The caustic soda in the tank (3) enters the mercaptan conversion tower (1) through the lye inlet under the action of the lye pump (4), so that the caustic soda soaks the mercaptan conversion agent (2) To supplement sodium hydroxide and sweetening catalyst and elute elemental sulfur. 9. The method for removing organic sulfur from dry gas according to claim 7, characterized in that the content of the demercaptan catalyst in the lye is 200-500 μg/g, and the concentration of sodium hydroxide in the lye is 5-15%wt. 10. The method for removing organic sulfur from dry gas according to claim 7, characterized in that when the diesel oil is washed from top to bottom by the liquid separator (8) to the absorption desulfurization tower packing (6), The diesel oil entering the absorption desulfurization tower (5) is cooled to 5-10°C through the diesel oil outlet of the diesel oil absorption desulfurization tower (5), the diesel circulation pump (10), and the diesel oil cooler (9), while passing through the The refined diesel oil pipeline (27) supplements refined diesel oil, wherein, the flow volume ratio of organic sulfur-containing dry gas in the diesel oil absorption desulfurization tower (5) to diesel oil is (300-1500):1, and the sulfur content of the supplemented refined diesel oil Less than or equal to 10μg/g.

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