CN107243242A - Refinery's amine liquid desulphurization system and its sulfur method - Google Patents

Abstract

The invention discloses a refinery amine liquid desulfurization system, comprising a first refinery gas desulfurization tower, a second refinery gas desulfurization tower, a rich liquid flash tank and a solvent regeneration tower, the first refinery gas desulfurization tower and the second refinery gas desulfurization tower The bottom inlets of the refinery gas desulfurization tower are used to feed catalytic dry gas and catalytic liquefied gas respectively, and the tower kettles of the first refinery gas desulfurization tower and the second refinery gas desulfurization tower are connected to the liquid-rich flash tank through pipelines. The inlet is connected to flash the rich liquid, the outlet of the rich liquid flash tank is connected to the inlet of the solvent regeneration tower through a pipeline, and the outlet of the first regenerated lean liquid of the solvent regeneration tower is connected to the outlet of the first refinery gas desulfurization tower through a pipeline. The inlet of the desulfurizer is connected, the outlet of the second regenerated lean liquid of the solvent regeneration tower is connected with the inlet of the desulfurizer of the second refinery gas desulfurization tower through a pipeline, and the regeneration depth of the outlet of the second regenerated lean liquid is higher than that of the outlet of the first regenerated lean liquid regeneration depth. The refinery amine liquid desulfurization system and the desulfurization method proposed by the invention reduce the load of the regeneration tower and improve the regeneration efficiency.

Description

Refinery amine liquid desulfurization system and its desulfurization method

technical field

The invention relates to the technical field of petroleum refining, in particular to a refinery amine liquid desulfurization system and a desulfurization method thereof.

Background technique

In the process of refining and chemical production, raw oil undergoes primary and secondary processing, and part of the sulfide in the raw oil is converted into H ₂ S, and H ₂ S finally enters dry gas, gasoline, liquefied petroleum gas and other products. If the desulfurization of these sulfur-containing products does not meet the standard, when used as petrochemical raw materials or fuels, it will cause corrosion of equipment and pipelines, eventually causing environmental pollution and endangering human health. In recent years, with the development of the national economy, the demand for oil is increasing, which makes domestic refineries continue to increase the processing capacity of high-sulfur crude oil and low-quality crude oil, and a large number of sulfur-containing products are produced by-products in production, which increases the desulfurization. load. On the other hand, in order to reduce the environmental pollution caused by emissions, the country has increasingly stringent requirements on the quality of fuel products.

The commonly used desulfurizer is usually a renewable water-containing absorbent. At present, the process structure of amine liquid desulfurization in refineries can be roughly divided into two categories: one is to disperse the desulfurization absorption part in various supporting devices, and the solvent regeneration is in each The device performs decentralized regeneration. The other is to disperse the desulfurization absorption part in various supporting devices, and concentrate the rich solvent in the same regeneration tower for centralized regeneration. Although the method of concentrating rich solvents in the same regeneration tower can reduce equipment investment costs, the load on the regeneration tower is too large, which shortens its life, and it is easy to pollute the amine liquid. Once the amine liquid system appears such as belt It is very difficult to find problems such as hydrocarbons in oil and foaming of amine liquid.

Contents of the invention

The main purpose of the present invention is to provide a refinery amine liquid desulfurization system and a desulfurization method thereof, aiming at reducing the load of the regeneration tower while improving its regeneration efficiency.

In order to achieve the above object, the present invention provides a refinery amine liquid desulfurization system, comprising a first refinery gas desulfurization tower, a second refinery gas desulfurization tower, a rich liquid flash tank and a solvent regeneration tower, wherein,

The bottom inlets of the first refinery gas desulfurization tower and the second refinery gas desulfurization tower are respectively used to feed catalytic dry gas and catalytic liquefied gas, and the first refinery gas desulfurization tower and the second refinery gas desulfurization tower The tower stills are all connected to the inlet of the rich liquid flash tank through pipelines to flash the rich liquid, and the outlet of the rich liquid flash tank is connected with the inlet of the solvent regeneration tower through pipelines, and the solvent regeneration tower The first regeneration lean liquid outlet is connected to the desulfurizer inlet of the first refinery gas desulfurization tower through a pipeline, and the second regeneration lean liquid outlet of the solvent regeneration tower is connected to the desulfurizer inlet of the second refinery gas desulfurization tower through a pipeline connected, the regeneration depth of the second regeneration lean liquid outlet is higher than the regeneration depth of the first regeneration lean liquid outlet.

Preferably, the pipeline at the outlet of the rich liquid flash tank is also equipped with a regeneration tower feed pump for boosting the rich liquid, and the rich liquid is regenerated after the rich liquid flash tank removes part of the light hydrocarbons The tower feed pump is pressurized, and a rich liquid mixer for mixing the rich liquid is also installed on the pipeline at the inlet of the rich liquid flash tank.

Preferably, the refinery amine liquid desulfurization system also includes a first heat exchanger, the first heat exchanger is provided with a first flow channel and a second flow channel for mutual heat exchange, the first flow channel of the first heat exchanger The inlet is connected to the outlet of the rich liquid flash tank, the outlet of the first flow channel of the first heat exchanger is connected to the inlet of the solvent regeneration tower, the inlet of the second flow channel of the first heat exchanger is connected to the outlet of the first regenerated lean liquid, and the first heat exchanger The outlet of the second flow channel of the heater is connected with the desulfurizer inlet of the first refinery gas desulfurization tower.

Preferably, the refinery amine liquid desulfurization system also includes a second heat exchanger, the second heat exchanger is provided with a first flow channel and a second flow channel for mutual heat exchange, and the first flow channel of the second heat exchanger The inlet is connected to the first heat exchanger, the outlet of the first channel of the second heat exchanger is connected to the inlet of the solvent regeneration tower, the inlet of the second channel of the second heat exchanger is connected to the outlet of the second regeneration lean liquid, and the second heat exchanger The outlet of the second flow channel of the device is connected with the desulfurizer inlet of the second refinery gas desulfurization tower.

Preferably, a first cooler is also installed on the pipeline at the outlet of the second flow channel of the second heat exchanger.

Preferably, the bottom of the solvent regeneration tower is also provided with a reboiler for maintaining the bottom temperature.

Preferably, the amine liquid desulfurization system of the refinery also includes a second cooler and an acid gas liquid separation tank sequentially connected to the solvent regeneration tower, and the acidic water separated by the acid gas liquid separation tank is returned to the upper part of the solvent regeneration tower for reflux, and the The acid gas separated by the gas separation tank is sent to the sulfur recovery unit.

The present invention further proposes a desulfurization method based on the above-mentioned refinery amine liquid desulfurization system, comprising the following steps:

The catalytic dry gas enters the lower part of the first refinery gas desulfurization tower, and contacts with the renewable desulfurization agent from the upper part of the first refinery gas desulfurization tower to obtain a rich liquid that purifies the first refinery gas stream and high _H2S load , at the same time, the catalytic liquefied gas enters the lower part of the second refinery gas desulfurization tower, and countercurrently contacts with the renewable desulfurizer from the upper part of the second refinery gas desulfurization tower to obtain the purification of the _second refinery gas stream and low H2S load rich liquid;

The rich liquid in the tower kettle of the first refinery gas desulfurization tower and the second refinery gas desulfurization tower is mixed, and after being degassed by the rich liquid flash tank, it enters the solvent regeneration tower, and the lean liquid flowing out of the first regeneration lean liquid outlet of the solvent regeneration tower is sent to To the first refinery gas desulfurization tower for recycling as a desulfurizing agent, and the lean liquid flowing out of the second regeneration lean liquid outlet of the solvent regeneration tower is sent to the second refinery gas desulfurization tower for recycling as a desulfurizing agent.

Preferably, the feed temperature of catalytic dry gas entering the first refinery gas desulfurization tower is controlled to be 15°C-50°C, and the feed temperature of catalytic liquefied gas entering the second refinery gas desulfurization tower is controlled to be 15°C-50°C. The operating temperature of the first refinery gas desulfurization tower and the second refinery gas desulfurization tower is 20°C~65°C, and the operating pressure of the first refinery gas desulfurization tower and the second refinery gas desulfurization tower is 0.1MPa~10MPa.

Preferably, after the rich liquid is degassed by the flash tank, it is boosted by the feed pump of the regeneration tower to a pressure of 0.1MPa~6MPa, and the temperature of the boosted rich liquid is controlled at 75°C~ 115°C; the bottom temperature of the solvent regeneration tower is maintained at 90°C~150°C.

The refinery amine liquid desulfurization system proposed by the present invention divides the solvent regeneration tower into two lines for output, so that the solvent regeneration tower is divided into upper and lower parts, the lean liquid in the upper part is regenerated at a low depth, and the lean liquid in the lower part The purpose of reducing the reboiler load is achieved by using complete regeneration and reducing the regeneration depth of the lean liquid. At the same time, high-temperature and low-pressure flash evaporation is carried out by using the rich liquid flash tank to reduce the content of regenerated acid gas hydrocarbons and reduce the waste of effective resources. In addition, through concentrated regeneration of rich absorbents with the same H ₂ S load, the regeneration efficiency is high, and equipment investment is reduced at the same time.

Description of drawings

Fig. 1 is a structural schematic diagram of the refinery amine liquid desulfurization system of the present invention.

In the figure, C101-first refinery gas desulfurization tower, C102-second refinery gas desulfurization tower, C103-solvent regeneration tower, D101-liquid removal tank, D102-rich liquid mixer, D103-rich liquid flash tank, D104-acid gas separator tank, D105-solvent storage tank, D106-condenser, E101-second heat exchanger, E102-first cooler, E103-second cooler, E104-reboiler, E105-first One heat exchanger, P101-regeneration tower feed pump, P102-acid liquid reflux pump, P103-second feed pump, P104-first feed pump.

The realization of the purpose of the present invention, functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

detailed description

It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

It should be noted that, in the description of the present invention, the terms "horizontal", "vertical", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientation or positional relationship indicated by "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, and It is not to indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, or operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first", "second", etc. are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

The invention proposes a refinery amine liquid desulfurization system.

Referring to Fig. 1, in this preferred embodiment, a refinery amine liquid desulfurization system includes a first refinery gas desulfurization tower C101, a second refinery gas desulfurization tower C102, a rich liquid flash tank D103 and a solvent regeneration tower C103, in,

The bottom inlets of the first refinery gas desulfurization tower C101 and the second refinery gas desulfurization tower C102 are respectively used to feed catalytic dry gas and catalytic liquefied gas, and the first refinery gas desulfurization tower C101 and the second refinery gas desulfurization tower C102 The tower stills are all connected to the inlet of the rich liquid flash tank D103 through pipelines to flash the rich liquid, and the outlet of the rich liquid flash tank D103 is connected with the inlet of the solvent regeneration tower C103 through pipelines, and the solvent regeneration tower C103 The outlet of the first regeneration lean liquid is connected with the desulfurizer inlet of the first refinery gas desulfurization tower C101 through a pipeline, and the outlet of the second regeneration lean liquid of the solvent regeneration tower C103 is connected with the desulfurizer of the second refinery gas desulfurization tower C102 through a pipeline The inlets are connected, and the regeneration depth of the second regeneration lean liquid outlet is higher than the regeneration depth of the first regeneration lean liquid outlet.

There is also a liquid removal tank D101 at the bottom inlet of the first refinery gas desulfurization tower C101. The catalytic dry gas enters any position in the lower part of the first refinery gas desulfurization tower C101. The catalytic liquefied gas enters any position in the lower part of the second refinery gas desulfurization tower C102. The desulfurizer inlets of the first refinery gas desulfurization tower C101 and the second refinery gas desulfurization tower C102 are arranged at any position above them. A first feed pump P104 and a second feed pump P103 are respectively installed on the pipelines at the inlets of the desulfurizers of the first refinery gas desulfurization tower C101 and the second refinery gas desulfurization tower C102 . The desulfurizing agent in the first refinery gas desulfurization tower C101 and the second refinery gas desulfurization tower C102 is an aqueous mixture containing a weak base, and other components can also be added therein as required, and the weak base can be an alkanolamine, such as Monoethanolamine, diethanolamine, methyldiethanolamine, etc. The desulfurizer usually contains 10%~50% (mass fraction) of alkali components, 10%~90% (mass fraction) of water and 0~50% (mass fraction) of other components. The first refinery gas desulfurization tower C101, the second refinery gas desulfurization tower C102 and the solvent regeneration tower C103 can be any effective mass transfer tower structure, such as packed tower, bubble cap tower, sieve plate tower, valve tower, etc. . The pump in the amine liquid desulfurization system of this refinery adopts an energy-saving chemical process pump and is equipped with an energy-saving motor to improve the efficiency of the pump and motor.

Further, a regeneration tower feed pump P101 for boosting the pressure of the rich liquid is also installed on the pipeline at the outlet of the rich liquid flash tank D103, and the rich liquid is flashed to remove part of the light hydrocarbons by the rich liquid The feed pump P101 of the regeneration tower boosts the pressure, and a rich liquid mixer D102 for mixing the rich liquid is installed on the pipeline at the inlet of the rich liquid flash tank D103.

Further, the amine liquid desulfurization system of this refinery also includes a first heat exchanger E105, and the first heat exchanger E105 is provided with a first flow channel and a second flow channel for mutual heat exchange, and the first flow channel of the first heat exchanger E105 The inlet of the channel is connected to the outlet of the rich liquid flash tank D103, the outlet of the first channel of the first heat exchanger E105 is connected to the inlet of the solvent regeneration tower C103, the inlet of the second channel of the first heat exchanger E105 is connected to the first regeneration lean liquid The outlet is connected, and the outlet of the second flow channel of the first heat exchanger E105 is connected with the desulfurizer inlet of the first refinery gas desulfurization tower C101.

Further, the amine liquid desulfurization system of this refinery also includes a second heat exchanger E101, which is provided with a first flow channel and a second flow channel for mutual heat exchange, and the first flow channel of the second heat exchanger E101 The inlet of the channel is connected to the first heat exchanger E105, the outlet of the first channel of the second heat exchanger E101 is connected to the inlet of the solvent regeneration tower C103, the inlet of the second channel of the second heat exchanger E101 is connected to the outlet of the second regeneration lean liquid The outlet of the second flow channel of the second heat exchanger E101 is connected with the desulfurizer inlet of the second refinery gas desulfurization tower C102. A heat exchange network is formed by the first heat exchanger E105 and the second heat exchanger E101, thereby effectively reducing energy consumption.

A first cooler E102 is also installed on the pipeline at the outlet of the second flow channel of the second heat exchanger E101. A solvent storage tank D105 is also installed between the second feed pump P103 and the first cooler E102.

Further, a reboiler E104 for maintaining the bottom temperature is also installed at the bottom of the solvent regeneration tower C103. The heat source of the reboiler E104 is provided by steam (the steam is set at 0.4MPa) to prevent the temperature of the tube bundle wall of the reboiler from being too high, resulting in thermal degradation of the solvent. In addition, the reboiler E104 uses low-pressure steam as the heat source, fully utilizes the existing heat source and cold source, and has low energy consumption.

Further, the amine liquid desulfurization system of this refinery also includes the second cooler E103 and the acid gas liquid separation tank D104 connected in sequence with the solvent regeneration tower C103, and the acid water separated by the acid gas liquid separation tank D104 returns to the upper part of the solvent regeneration tower C103 As reflux, the acid gas separated by the acid gas separator tank D104 is sent to the sulfur recovery unit.

In the refinery amine liquid desulfurization system proposed by the present invention, the solvent regeneration tower C103 is divided into two lines for output. In this way, the solvent regeneration tower C103 is divided into upper and lower parts. The lean liquid in the upper part is regenerated at a low depth, and the lower part The lean liquid is completely regenerated, and the purpose of reducing the load of the reboiler E104 is achieved by reducing the regeneration depth of the lean liquid. At the same time, use the rich liquid flash tank D103 to perform high-temperature and low-pressure flash evaporation to reduce the content of regenerated acid gas hydrocarbons and reduce the waste of effective resources. In addition, through concentrated regeneration of rich absorbents with the same H ₂ S load, the regeneration efficiency is high, and equipment investment is reduced at the same time.

The invention further proposes a desulfurization method for an amine liquid desulfurization system in a refinery.

A kind of desulfurization method based on above-mentioned refinery amine liquid desulfurization system, comprises the following steps:

Catalytic dry gas enters the lower part of the first refinery gas desulfurization tower C101, and contacts with the renewable desulfurizer from the upper part of the first refinery gas desulfurization tower C101 countercurrently, and obtains purification of the first refinery gas stream and high _H2S load Rich liquid, while the catalytic liquefied gas enters the lower part of the second refinery gas desulfurization tower C102, and countercurrently contacts with the renewable desulfurizer from the upper part of the second refinery gas desulfurization tower C102 to obtain a purified second refinery gas stream and low H ₂ S loaded rich solution;

The rich liquid in the tower kettle of the first refinery gas desulfurization tower C101 and the second refinery gas desulfurization tower C102 is mixed and then degassed by the rich liquid flash tank D103 and then enters the solvent regeneration tower C103, and the first regeneration lean liquid outlet of the solvent regeneration tower C103 The lean liquid flowing out is sent to the first refinery gas desulfurization tower C101 for recycling as a desulfurizing agent, and the lean liquid flowing out of the second regeneration lean liquid outlet of the solvent regeneration tower C103 is sent to the second refinery gas desulfurization tower C102 for recycling as a desulfurizing agent.

Specifically, the feed temperature of catalytic dry gas entering the first refinery gas desulfurization tower C101 is controlled to be 15°C~50°C, and the feed temperature of catalytic liquefied gas entering the second refinery gas desulfurization tower C102 is controlled to be 15°C~50°C (preferably 33°C), the operating temperatures of the first refinery gas desulfurization tower C101 and the second refinery gas desulfurization tower C102 are both 20°C~65°C (preferably 30°C), the first refinery gas desulfurization tower C101 and the second refinery gas desulfurization tower C101 and the second The operating pressure of refinery gas desulfurization tower C102 is 0.1MPa~10MPa (preferably 1.2MPa). Under these conditions, the sulfur content in the purified gas from the first and second refineries can meet the discharge requirements.

Specifically, after the rich liquid is degassed by the flash tank, it is boosted by the feed pump P101 of the regeneration tower, and the pressure is 0.1MPa~6MPa. The temperature of the boosted rich liquid is controlled to 75 ℃~115℃; the bottom temperature of solvent regeneration tower C103 is maintained at 90℃~150℃. Under these conditions, the heat load of the reboiler can be reduced, the hydrocarbon content of the regenerated acid gas can be reduced, and the waste of effective resources can be reduced.

The present invention proposes the following several embodiments here.

Example 1

The desulfurization process is as follows: the dry gas is sent to the lower part of the first refinery gas desulfurization tower C101 with a feed rate of 4900m ³ /h, a feed temperature of 38°C, and a feed pressure of 1.0MPa, and the operating temperature of the tower is 36°C , the operating pressure is 0.85MPa, the low-depth regeneration absorbent N-methyldiethanolamine (MDEA) extracted from the side line of the solvent regeneration tower C103 is sent to the upper part of the first refinery gas desulfurization tower C101, and the two are in countercurrent contact for mass transfer. The acidic substances (H ₂ S, CO ₂ ) in the dry gas are absorbed by the desulfurizer to obtain the purified dry gas stream (H ₂ S=10mg/m ³ ≤150mg/m ³ ) and rich liquid with high H ₂ S load .

The liquefied gas is sent to the lower part of the second refinery gas desulfurization tower C102 with a feed rate of 30,000kg/h, a feed temperature of 35°C, and a feed pressure of 1.3MPa. The operating temperature of the tower is 35°C and the operating pressure is 1.112MPa , make it countercurrently contact with the fully regenerated absorbent MDEA (N-methyldiethanolamine) from the bottom of the solvent regeneration tower C103 at a concentration of 30wt%, and obtain a purified liquefied gas stream (H2S=5mg/m ³ ≤50mg /m ³ ) and low H ₂ S loading rich solution.

The rich liquid with low H ₂ S load and the rich liquid with high H ₂ S load are mixed in the mixing tank and then transferred to the first heat exchanger E105 to exchange heat to 90°C, then enter the rich liquid flash tank D103, after flash degassing The pressure of the regeneration tower feed pump P101 is increased to 0.31MPa and enters the solvent regeneration tower C103 for regeneration. The operating temperature of the solvent regeneration tower C103 is 100°C and the operating pressure is 0.06MPa. A reboiler is installed at the bottom of the solvent regeneration tower C103 to maintain the The bottom temperature is 115°C, and the deeply regenerated lean liquid from the bottom of the solvent regeneration tower C103 is sent to the second heat exchanger E101 for heat exchange and cooling to 38°C, then enters the solvent storage tank D105, and then sent to the second refinery gas desulfurization tower C102 as desulfurization Agent recycling. The acid gas from the top of the solvent regeneration tower C103 is cooled by the second cooler E103 and then enters the regenerated acid gas liquid separation tank D104 for gas-liquid separation and then sent to the sulfur recovery unit. The liquid phase at the bottom of the regenerated acid gas liquid separation tank D104 returns to the solvent The upper part of the regeneration tower C103 is refluxed for recycling. The rich liquid with a certain regeneration depth extracted from the side line of the solvent regeneration tower C103 is cooled by a heat exchanger and pumped into the upper part of the first refinery gas desulfurization tower C101 through a booster pump as a desulfurizer for recycling. Lost absorbent is replaced by depleted agent external to the unit.

Example 2

The desulfurization process in this example is the same as in Example 1 except for the operating parameters. The specific parameters are as follows: absorbent concentration 45wt%, liquefied gas feed rate 30000kg/h, feed temperature 30°C, feed pressure 1.1MPa, liquefaction The operating temperature of the gas desulfurization tower is 35°C, the operating pressure is 1MPa, the dry gas feed rate is 4900m ³ /h, the feed temperature is 30°C, the feed pressure is 0.9MPa, the operating temperature of the first refinery gas desulfurization tower C101 is 35°C, and the operating pressure is 0.8MPa, the temperature of the second heat exchanger E101 is 80°C, the pressure of the regeneration tower feed pump P101 is increased to 0.1MPa, the operating temperature of the solvent regeneration tower C103 is 90°C, the operating pressure is 0.03MPa, and the reboiler maintains the bottom temperature of the tower at 110°C. The heat exchange cooling temperature of the second heat exchanger E101 is 30°C.

Example 3

The desulfurization process in this example is the same as in Example 1 except for the operating parameters. The specific parameters are as follows: absorbent concentration 15 wt%, liquefied gas feed rate 30000kg/h, feed temperature 40°C, feed pressure 2.1MPa, The operating temperature of the liquefied gas desulfurization tower is 45°C, the operating pressure is 2 MPa, the dry gas feed rate is 4900m ³ /h, the feed temperature is 40°C, the feed pressure is 1.1MPa, the operating temperature of the first refinery gas desulfurization tower C101 is 45°C , the operating pressure is 1MPa, the temperature of the second heat exchanger E101 is 110°C, the feed pump P101 of the regeneration tower is boosted to 0.3MPa, the operating temperature of the solvent regeneration tower C103 is 110°C, the operating pressure is 0.1MPa, and the reboiler maintains the bottom temperature of the tower at 130°C , The cooling temperature of the second heat exchange is 50°C.

Example 4

The desulfurization process in this example is the same as in Example 1 except for the operating parameters. The specific parameters are as follows: the absorbent concentration is 32 wt%, the feed temperature of the liquefied gas into the liquefied gas desulfurization tower is 33°C, and the feed amount of the liquefied gas is 30000kg/h, feed pressure 1.3MPa, operating temperature of liquefied gas desulfurization tower 32°C, operating pressure 1.2MPa, after full absorption to obtain purified liquefied gas stream (H ₂ S=2mg/m ³ ≤50mg/m ³ ) , the feed temperature of dry gas entering the first refinery gas desulfurization tower C101 is 35°C, the dry gas feed rate is 4900m ³ /h, the operating temperature of the first refinery gas desulfurization tower C101 is 38°C, and the operating pressure is 0.9 MPa, after fully absorbing and desulfurizing, a purified dry gas stream (H ₂ S=3mg/m ³ ≤150mg/m ³ ) is obtained. The heat exchange temperature in the second heat exchanger E101 is 90°C, and the regeneration tower feed pump P101 will After the rich liquid is pressurized to 0.3MPa, it enters the solvent regeneration tower C103 (, and the reboiler maintains the temperature at the bottom of the tower at 120°C.

Example 5

Products from a catalytic cracking unit of a petrochemical company—dry gas and liquefied gas, were dehydrogen sulfide refined. The dry gas contained 0.25wt%H ₂ S and 0.54wt%CO ₂ , and the liquefied gas contained 0.27wt%H ₂ S. The petrochemical company's quality requirements for desulfurized products are: H ₂ S in purified dry gas≤150mg/m ³ , H ₂ S in purified liquefied gas≤50mg/m ³ .

The desulfurization method of the present invention is used for desulfurization, and the operating conditions are as follows: the absorbent is 30wt% N-methyldiethanolamine (MDEA) aqueous solution, the feed rate of liquefied gas is 24388kg/h, the feed temperature is 32°C, and the feed pressure is 1.4 MPa, operating temperature 32°C, operating pressure 1.213MPa; dry gas feed rate 4366m ³ /h, feed temperature 38°C, feed pressure 1.0MPa, operating temperature 30°C, operating pressure 0.95MPa; second heat exchanger The temperature of E101 is 90°C, the boost pressure is 0.26MPa, the operating temperature of solvent regeneration tower C103 is 105°C, the operating pressure is 0.1MPa, the reboiler maintains the bottom temperature of 123°C, and the heat exchange cooling temperature is 38°C.

For comparison, we desulfurize the same dry gas and liquefied gas under the same operating conditions (the same conditions as in Example 5 above). The required amount of lean liquid is 15000kg/h, the amount of lean liquid required for desulfurization of the liquefied gas desulfurization tower is 3000kg/h, and the regeneration amount of the combined absorbent is 18000kg/h. And adopt the inventive method (adopt appropriate regeneration depth fully), can avoid unnecessary reboiler E104 load, thereby reduce the load of regeneration tower reboiler E104, the load of the reboiler E104 of solvent regeneration tower C103 is by classification The 2602MJ/h before use was reduced to 2028MJ/h, which reduced energy consumption by 22.06% compared with before.

The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural transformations made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technical fields, are all the same. included in the scope of patent protection of the present invention.

Claims (10)

1. a kind of refinery's amine liquid desulphurization system, it is characterised in that including the first refinery gas desulfurizing tower, the second refinery gas desulfurizing tower, Rich solution flash tank and solvent regeneration tower, wherein,

The bottom inlet of the first refinery gas desulfurizing tower and the second refinery gas desulfurizing tower is respectively used to be passed through catalysis drying gas and urged The tower reactor of change liquefied gas, the first refinery gas desulfurizing tower and the second refinery gas desulfurizing tower passes through pipeline and rich solution flash tank Entrance is connected to be flashed to rich solution, and the outlet of the rich solution flash tank is connected by the entrance of pipeline and solvent regeneration tower, First regeneration lean solution outlet of the solvent regeneration tower is connected by pipeline with the desulfurizing agent entrance of the first refinery gas desulfurizing tower, institute The the second regeneration lean solution outlet for stating solvent regeneration tower is connected by pipeline with the desulfurizing agent entrance of the second refinery gas desulfurizing tower, described Regeneration depth of the regeneration depth of second regeneration lean solution outlet higher than the first regeneration lean solution outlet.

2. amine liquid desulphurization system in refinery's as claimed in claim 1, it is characterised in that the pipeline in the rich solution flash tank exit On be also equipped with regenerator feed pump for being boosted to rich solution, rich solution is after rich solution flash tank flash distillation removing part lighter hydrocarbons Boosted by regenerator feed pump, the richness for being mixed to rich solution is also equipped with the pipeline of the rich solution flash tank porch Liquid mixer.

3. amine liquid desulphurization system in refinery's as claimed in claim 1, it is characterised in that also including First Heat Exchanger, this first is changed The first flow exchanged heat mutually and second flow channel, entrance and the rich solution flash tank of First Heat Exchanger first flow are provided with hot device Outlet connection, the outlet of First Heat Exchanger first flow and the entrance of solvent regeneration tower are connected, and First Heat Exchanger second flow channel enters Mouth is connected with the first regeneration lean solution outlet, the outlet of First Heat Exchanger second flow channel and the desulfurizing agent entrance of the first refinery gas desulfurizing tower Connection.

4. amine liquid desulphurization system in refinery's as claimed in claim 3, it is characterised in that also including the second heat exchanger, this second is changed The first flow exchanged heat mutually and second flow channel, the entrance and First Heat Exchanger of the second heat exchanger first flow are provided with hot device The entrance of connection, the outlet of the second heat exchanger first flow and solvent regeneration tower is connected, the second heat exchanger second flow channel entrance with Second regeneration lean solution outlet connection, the outlet of the second heat exchanger second flow channel and the desulfurizing agent entrance of the second refinery gas desulfurizing tower connect Connect.

5. amine liquid desulphurization system in refinery's as claimed in claim 4, it is characterised in that the second heat exchanger second flow channel outlet The first cooler is also equipped with the pipeline at place.

6. amine liquid desulphurization system in refinery's as claimed in claim 1, it is characterised in that the solvent regeneration tower bottom of towe is additionally provided with use The reboiler of bottom temperature is taken in maintenance.

7. amine liquid desulphurization system in refinery's as claimed in claim 1, it is characterised in that also including being sequentially connected with solvent regeneration tower The second cooler and acid qi leel flow container, the acid water that acid qi leel flow container is isolated returns to solvent regeneration tower top and returns Stream, the sour gas that acid qi leel flow container is isolated delivers to sulfur recovery facility.

8. a kind of sulfur method of refinery's amine liquid desulphurization system based on described in claim 3, it is characterised in that Bao includes Yi Xia Walk Suddenly：

Catalysis drying gas enters the first refinery gas desulfurizing tower bottom, with the reproducible desulfurization come from the first refinery gas desulfurizing tower top Agent counter current contacting, is purified the first refinery gas logistics and high H₂The rich solution of S loads, while catalytic liquefaction gas enters the second refinery Desulfurization tower bottom, the reproducible desulfurizing agent counter current contacting with coming from the second refinery gas desulfurizing tower top, is purified second Refinery gas logistics and low H₂The rich solution of S loads；

Enter after being deaerated after the tower reactor rich solution mixing of first refinery gas desulfurizing tower and the second refinery gas desulfurizing tower through rich solution flash tank Solvent regeneration tower, the lean solution of the regeneration lean solution outlet outflow of solvent regeneration tower first delivers to the first refinery gas desulfurizing tower as desulfurizing agent Recycle, the lean solution of the regeneration lean solution outlet outflow of solvent regeneration tower second is delivered to the second refinery gas desulfurizing tower and followed as desulfurizing agent Ring is used.

9. the sulfur method of amine liquid desulphurization system in refinery's as claimed in claim 8, it is characterised in that control catalysis drying gas enters The feeding temperature of first refinery gas desulfurizing tower is 15 DEG C ~ 50 DEG C, and control catalytic liquefaction gas enters entering for the second refinery gas desulfurizing tower Material temperature degree is 15 DEG C ~ 50 DEG C, and the operation temperature of the first refinery gas desulfurizing tower and the second refinery gas desulfurizing tower is 20 DEG C ~ 65 DEG C, The operating pressure of first refinery gas desulfurizing tower and the second refinery gas desulfurizing tower is 0.1MPa ~ 10MPa.

10. the sulfur method of amine liquid desulphurization system in refinery's as claimed in claim 8, it is characterised in that rich solution is de- through flash tank By being boosted through regenerator feed pump after gas, pressure is 0.1MPa ~ 6MPa, temperature after the rich solution after boosting exchanges heat through First Heat Exchanger Control as 75 DEG C ~ 115 DEG C；Solvent regeneration tower column bottom temperature maintains 90 DEG C ~ 150 DEG C.