CN112159695A - Energy-saving natural gas MDEA decarburization device and method - Google Patents
Energy-saving natural gas MDEA decarburization device and method Download PDFInfo
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- CN112159695A CN112159695A CN202011171092.1A CN202011171092A CN112159695A CN 112159695 A CN112159695 A CN 112159695A CN 202011171092 A CN202011171092 A CN 202011171092A CN 112159695 A CN112159695 A CN 112159695A
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
- C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
- C10L3/10—Working-up natural gas or synthetic natural gas
- C10L3/101—Removal of contaminants
- C10L3/102—Removal of contaminants of acid contaminants
- C10L3/104—Carbon dioxide
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- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/1456—Removing acid components
- B01D53/1475—Removing carbon dioxide
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/18—Absorbing units; Liquid distributors therefor
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Abstract
The invention discloses an energy-saving natural gas MDEA decarburization device and a method, the device comprises an absorption tower, a regeneration tower, a carbon dioxide compressor, a purified gas cooler, a lean/rich amine liquid heat exchanger, a lean amine liquid cooler, a rich liquid/carbon dioxide heat exchanger, an amine liquid reboiler, an amine liquid booster pump, a regeneration tower reflux pump, a feed pump, a purified gas-liquid separator, a rich amine liquid flash tank, a carbon dioxide gas-liquid separator, a feed tank, a solution buffer tank and an adjusting valve, wherein the lean amine liquid becomes rich amine liquid after the raw gas is purified by the absorption tower, the rich amine liquid enters the regeneration tower for desorption after being heated by the lean/rich amine liquid heat exchanger and the rich liquid/carbon dioxide heat exchanger, the desorption gas output from the tower top is pressurized and cooled and then subjected to gas separation, the obtained gas is discharged, the liquid returns to the regeneration tower, the lean amine liquid output from the tower bottom returns to the absorption tower for purifying the raw gas, the invention does not need to additionally arrange a tower top cooler of the regeneration tower, greatly reduces the consumption of the refrigerant and reduces the energy consumption.
Description
Technical Field
The invention belongs to the field of natural gas decarburization, and particularly relates to an energy-saving type natural gas MDEA decarburization device and method, which are suitable for CO in natural gas or synthetic gas2Gas decarbonizing process with CO content not lower than 1.5% (mole%) and purified gas2The level may be as low as 50ppm or less or other ranges tailored as desired.
Background
Syngas and natural gas produced from subterranean formations typically contain some CO2And the like. According to the index requirements of commodity natural gas in China, CO2The content is less than 3 percent (mole percent) and can be externally exported to civil users; in addition, to prevent CO2Freezing blockage caused by low temperature, natural gas CO for preparing LNG2The content of CO is required to be lower than 50ppm, so that the content of CO is high2The natural gas needs to be decarbonized. At present, the common decarburization methods at home and abroad include a low-temperature separation method, a membrane separation method, an adsorption separation method, a solvent absorption method, a combined separation method of the above methods, and the like.
The low-temperature separation method is suitable for occasions with high acid gas content but low purification degree requirement, and has complex process and high energy consumption caused by great temperature reduction. The membrane separation method is suitable for removing acid gas and water from high carbon-containing natural gas in a rough way, and generally industrially, the membrane separation method is firstly applied to carry out rough removal on the high carbon-containing natural gas, and then a chemical solvent method is applied to carry out fine removal, so that high purification degree can be achieved, and the method is economical. Although the membrane separation method has the advantages of low energy consumption, small occupied area, convenient maintenance, high efficiency, environmental protection, energy conservation and the like, the hydrocarbon loss rate is higher by adopting the method. The adsorption separation method is suitable for occasions with small treatment capacity, low carbon content and high purification requirement.
The solvent absorption method is still one of the most mature and extensive decarburization methods in current application. The solvent absorption method is further classified into a chemical absorption method, a physical absorption method and a mixed solvent method. Among various solvent absorption methods, the alcohol amine method is most widely used. Among various alcohol amine methods, the activated MDEA process is most advocated because of the characteristics of high use concentration, high acid gas load, low corrosivity, difficult degradation, small volatilization loss and the like. The existing alcohol amine method decarbonization device has the defects of high energy consumption, small equipment load, high investment and the like.
Disclosure of Invention
Aiming at the technical problems existing in the decarbonization by the alcohol amine method in the prior art and the characteristics of mainly reducing pressure and assisting in heating during MDEA regeneration, the invention provides the energy-saving natural gas MDEA decarbonization device and method. The energy-saving natural gas MDEA decarburization device provided by the invention is suitable for CO in natural gas or synthetic gas2Decarbonizing gas with content not less than 1.5% (mole%), purifying gas CO2The level may be as low as 50ppm or less or other ranges tailored as desired. The energy-saving natural gas MDEA decarburization device is provided with a carbon dioxide compressor, a rich liquid/carbon dioxide heat exchanger behind a lean/rich amine liquid heat exchanger, and is not provided with CO2A cooler.
According to a first embodiment of the present invention, there is provided an energy-saving natural gas MDEA decarbonization apparatus comprising an absorption tower for purifying a raw gas, a regeneration tower for desorbing a rich amine liquid (an amine liquid absorbing an acid gas), a carbon dioxide compressor for pressurizing a desorption gas, a purified gas cooler for cooling a purified gas, a lean/rich amine liquid heat exchanger for preliminarily heating the rich amine liquid and preliminarily cooling a lean amine liquid (an amine liquid after desorption), a lean amine liquid cooler for secondarily cooling the lean amine liquid, a rich liquid/carbon dioxide heat exchanger for reheating the rich amine liquid and cooling the desorption gas, an amine liquid reboiler for heating the amine liquid, an amine liquid filter for purifying the lean amine liquid entering the absorption tower, an amine liquid booster pump for pumping the lean amine liquid in a solution tank into the absorption tower, a regeneration tower reflux pump for feeding a liquid stripped of carbon dioxide from a carbon dioxide gas-liquid separator to the regeneration tower, a regeneration tower reflux pump for feeding the liquid to the regeneration tower, a regeneration tower, and a method for regenerating a process gas, A purified gas-liquid separator for separating free water carried by purified gas, an amine-rich liquid flash evaporation tank for flash evaporation and purification of the amine-rich liquid, a carbon dioxide gas-liquid separator for separating carbon dioxide in the analyzed gas, a solution buffer tank for temporarily storing the amine-poor liquid,
a gas-phase inlet of the absorption tower is connected with a feed gas input pipeline, a gas-phase outlet at the top of the absorption tower is connected with a hot channel inlet of the purified gas cooler through a pipeline, a hot channel outlet of the purified gas cooler is connected with an inlet of the purified gas-liquid separator through a pipeline, a gas-phase outlet at the top of the purified gas-liquid separator is connected to a pipeline of a purified gas outlet device through a first regulating valve, and a liquid-phase outlet at the bottom of the purified gas-liquid separator is connected to an inlet of the amine-rich liquid flash tank through a;
a liquid phase outlet at the bottom of the absorption tower is also connected to an inlet of the rich amine liquid flash tank after passing through a third regulating valve, a liquid phase outlet at the bottom of the rich amine liquid flash tank is connected to an inlet of a cold flow channel of the lean/rich liquid heat exchanger after passing through a fourth regulating valve, a cold flow channel outlet of the lean/rich liquid heat exchanger is connected to an inlet of the cold flow channel of the rich liquid/carbon dioxide heat exchanger through a pipeline, and a cold flow channel outlet of the rich liquid/carbon dioxide heat exchanger is connected to a liquid phase inlet of the regeneration tower (preferably the upper part) through;
a liquid phase output pipeline at the bottom of the regeneration tower is divided into two paths, one path of the liquid phase output pipeline is connected to a lean amine liquid inlet of the solution buffer tank after sequentially passing through a hot flow channel of the lean/rich amine liquid heat exchanger and a hot flow channel of the lean amine liquid cooler, and the other path of the liquid phase output pipeline is connected to a gas-liquid phase return inlet of a tower kettle of the regeneration tower after passing through a cold flow channel of an amine liquid reboiler; an outlet of the solution buffer tank is connected with an inlet of the amine liquid booster pump through a pipeline, namely an inlet pipeline of the amine liquid booster pump, an outlet pipeline of the amine liquid booster pump is divided into two paths, one path of the outlet pipeline is connected to a liquid input pipeline of the amine liquid booster pump after passing through a fifth regulating valve and an amine liquid filter, and the other path of the outlet pipeline is connected to a liquid phase inlet at the upper part of the absorption tower;
a gas phase outlet pipeline at the top of the regeneration tower is connected to an inlet of a heat flow channel of the rich liquid/carbon dioxide heat exchanger after passing through a carbon dioxide compressor, an outlet of the heat flow channel of the rich liquid/carbon dioxide heat exchanger is connected with an inlet of a carbon dioxide gas-liquid separator, and a gas phase output pipeline of the carbon dioxide gas-liquid separator is discharged to a high point of a safety position after passing through a sixth regulating valve; and a liquid phase output pipeline of the carbon dioxide gas-liquid separator is connected to a liquid phase inlet of the regeneration tower after passing through a reflux pump of the regeneration tower (independently or combined with a liquid conveying pipeline between the rich liquid/carbon dioxide heat exchanger and the regeneration tower).
Further, the solution buffer tank is connected with a feeding tank for storing the defoaming agent or the absorbent through a feeding pump, and the feeding pump is used for pumping the defoaming agent and/or the absorbent in the feeding tank into the solution buffer tank.
And further, a gas phase output pipeline at the top of the rich amine liquid flash tank is connected with a flash gas outlet device pipeline after passing through a seventh regulating valve.
Further, the gas phase inlet of the absorption tower is positioned at the bottom of the absorption tower, and the liquid phase inlet of the absorption tower is positioned at the upper part of the absorption tower.
Further, the feed pump is preferably an air operated diaphragm pump.
Further, the purified gas cooler, the lean/rich amine liquid heat exchanger, the lean amine liquid cooler, and the rich liquid/carbon dioxide heat exchanger are plate-type or shell-and-tube heat exchangers using a circulating water cooling system or an air cooling system.
An eighth damper valve may be provided on the cold path outlet conduit of the purge gas cooler, the eighth damper valve being modulated by a temperature indicating controller provided on the hot path outlet conduit of the purge gas cooler. And a ninth regulating valve can be arranged on the cold flow channel of the lean amine liquid cooler and is regulated by a temperature indication controller arranged on the outlet pipeline of the hot flow channel of the lean amine liquid cooler. In addition, the first regulating valve can be regulated by a pressure indication controller arranged on a gas phase outlet pipeline at the top of the purified gas-liquid separator tank, the second regulating valve can be regulated by a liquid level indication controller arranged in the purified gas-liquid separator tank, the third regulating valve is regulated by a liquid level indication controller arranged in the absorption tower, the fourth regulating valve is regulated by a liquid level indication controller arranged in the regeneration tower, the fifth regulating valve is regulated by a flow indication controller arranged on a branch entering the amine liquid filter, the sixth regulating valve is regulated by a pressure indication controller arranged on a gas phase output pipeline of the carbon dioxide gas-liquid separator, and the seventh regulating valve is regulated by a pressure indication controller arranged on a gas phase outlet pipeline at the top of the rich amine liquid flash tank.
According to a second embodiment of the invention, there is provided a method of decarbonizing using the energy efficient natural gas MDEA decarbonization apparatus of the invention the method comprising CO2Absorption and amine liquid regeneration are carried out in two parts, specifically as follows:
(1)CO2absorption: raw material gas with carbon content more than or equal to 1.5% (mole%) and temperature of 30-50 deg.C (preferably 38-42 deg.C, for example about 40 deg.C) enters from the bottom of absorption tower and flows from bottom to top; amine liquid (20-40% wt aqueous MEDA solution) at 40-55 ℃ (preferably 44-50 ℃, for example about 46 ℃), is sprayed from the upper part of the absorption tower (the volume flow ratio of raw material gas to amine liquid is 20-40: 1)), and passes through the absorption tower from top to bottom, and after lean amine liquid and raw material gas which flow in opposite directions are fully contacted in the tower to transfer heat and mass, CO in the raw material gas2Absorption by amine liquid, CO2The concentration is reduced to the desired value (below 50ppm (mole%) or other desired value),
conveying the purified gas from the top of the absorption tower to a purified gas cooler, cooling to about 40 ℃, allowing the purified gas to enter a purified gas-liquid separator, separating out carried free water, conveying the purified gas output from the top of the purified gas-liquid separator out of a device as a product, and collecting a liquid phase separated from the bottom of the purified gas-liquid separator to an amine-rich liquid flash tank for flash evaporation;
(2) amine liquid regeneration: the rich amine liquid absorbing the acid gas is output from the bottom of the absorption tower, is throttled and depressurized to 0.2-0.6MPa (G), preferably 0.3-0.5MPa (G), then enters an rich amine liquid flash tank for flash evaporation, the rich amine liquid output from the bottom of the rich amine liquid flash tank sequentially passes through a lean/rich amine liquid heat exchanger and a rich liquid/carbon dioxide heat exchanger to be heated to about 90-109 ℃, then enters the upper part of a regeneration tower for regeneration, the regeneration tower is provided with an amine liquid reboiler, heat can be properly supplied according to the temperature of the tower bottom, the amine liquid after full desorption is output from the bottom of the regeneration tower, is sequentially cooled to 40-55 ℃ (preferably about 45 ℃) by the lean/rich amine liquid heat exchanger and the lean amine liquid cooler and then is sent to a solution buffer tank,
the amine liquid pumped from the bottom of the solution buffer tank is pressurized by an amine liquid booster pump and then divided into two paths, wherein the first path, namely most of the amine liquid (such as 55-80 wt% of all lean amine liquid, such as 60-80 wt%), is directly pumped to the upper part of the absorption tower after being pressurized, and the other path returns to an inlet pipeline of the amine liquid booster pump after being filtered,
(3) CO-rich discharged from the top of the regeneration tower2The gas (the temperature of the gas is 98-110 deg.C, such as about 100-108 deg.C or such as about 105 deg.C, the pressure is such as about 0.04MPa (G), the content of carbon dioxide in the gas is about 20 mol%) is pressurized by a carbon dioxide compressor (such as to 0.1-0.4 MPa (G), preferably 0.2MPa (G)), and then sent to a rich liquid/carbon dioxide heat exchanger for cooling (such as to 100-120 deg.C, such as about 105 deg.C), and then separated by a carbon dioxide gas-liquid separator, and the top gas phase (the gas phase is CO) is separated by a gas-liquid separator2And water) is emptied at a high point at a safe place; bottom liquid phase (liquid phase composition with small amount of dissolved CO)2Aqueous solution of (a) is pressurized by a regeneration tower reflux pump and then returned to the regeneration tower amine liquid inlet pipeline as tower top reflux.
The feed gas in this application is typically a pipeline gas from a natural gas pipeline network or coke oven gas as a by-product of coking.
Further, considering that improper operation, substandard amine liquid filtration or raw material gas component change may cause amine liquid foaming, in order to prevent amine liquid foaming and supplement amine liquid loss in the operation process, a solution buffer tank needs to be supplemented with a defoaming agent or an absorbent (MDEA) through a feeding tank and a feeding pump.
The invention has the advantages that:
1. compared with the traditional process that the desorption gas at the top of the regeneration tower is cooled, separated and then emptied, the method has the advantages that the desorption gas output from the top of the regeneration tower is pressurized, the heat level is improved, the method is used for heating the rich amine liquid entering the regeneration tower, and the low-level heat is reasonably recycled;
2. before the rich amine liquid after the lean/rich amine liquid heat exchanger enters the regeneration tower for analysis, the temperature is further increased after the rich amine liquid is heated by the carbon dioxide pressurized at the top of the regeneration tower, so that the load of a reboiler of the regeneration tower can be obviously reduced;
3. after the pressurized high-temperature carbon dioxide is condensed and separated, the high-temperature carbon dioxide is discharged at a high point at a safe position, and a carbon dioxide cooler is not required to be additionally arranged, so that the energy consumption of the device is further reduced;
4. suitable for CO in natural gas or synthetic gas2Gas decarbonizing process with CO content not lower than 1.5% (mole%) and purified gas2The content can be as low as below 50ppm or other customized ranges according to requirements, and the acid gas load elasticity is larger.
Drawings
FIG. 1 is a schematic diagram of an energy-saving MDEA natural gas decarbonization device.
Description of reference numerals:
t-1, an absorption tower; t-2, a regeneration tower; c-1, a carbon dioxide compressor; e-1, a purified gas cooler; e-2, a lean/rich amine liquid heat exchanger; e-3, a lean amine liquid cooler; e-4, a rich liquid/carbon dioxide heat exchanger; e-5, an amine liquid reboiler; f-1, an amine liquid filter; P-1A/B, amine liquid booster pump; P-2A/B, a regeneration tower reflux pump; P-3A/B and a charging pump; v-1, a purified gas-liquid separator; v-2, an amine-rich liquid flash tank; v-3, a carbon dioxide gas-liquid separator; v-4, a feeding tank; v-5, a solution buffer tank; x-10, hand valve; x-1, eighth governing valve; x-2, a first regulating valve; x-3, a second regulating valve; x-4, a third regulating valve; x-5 and a fourth regulating valve; x-9, a fifth regulating valve; x-6 and a seventh regulating valve; x-7 and a sixth regulating valve; x-8 and a ninth regulating valve.
Detailed Description
The invention is further illustrated by the following figures and examples.
As shown in figure 1, the energy-saving natural gas MDEA decarburization device is suitable for CO in natural gas or synthetic gas2Gas decarbonizing process with CO content not lower than 1.5% (mole%) and purified gas2The level may be as low as 50ppm or less or other ranges tailored as desired. The device is provided with a carbon dioxide booster set, a rich liquid/carbon dioxide heat exchanger behind a lean/rich amine liquid heat exchanger, and no CO2A cooler.
The invention relates to an energy-saving natural gas MDEA decarburization device, which comprises an absorption tower T-1 for purifying raw gas, a regeneration tower T-2 for desorbing an amine-rich liquid (an amine liquid for absorbing acid gas), a carbon dioxide compressor C-1 for pressurizing desorption gas, a purified gas cooler E-1 for cooling purified gas, a lean/rich liquid heat exchanger E-2 for primarily heating the amine-rich liquid and primarily cooling a lean amine liquid (the amine liquid after desorption), a lean amine liquid cooler E-3 for secondarily cooling the lean amine liquid, a rich liquid/carbon dioxide heat exchanger E-4 for secondarily heating the rich amine liquid and cooling the desorption gas, an amine liquid E-5 for heating the amine liquid, an amine liquid filter F-1 for purifying the lean amine liquid entering the absorption tower T-1, a reboiler, The system comprises an amine liquid booster pump P-1A/B for pumping lean amine liquid in a solution buffer tank into an absorption tower, a regeneration tower reflux pump P-2A/B for conveying liquid without carbon dioxide in a carbon dioxide gas-liquid separator to a regeneration tower, a feeding pump P-3A/B for providing power for a defoaming agent or an absorbent and pumping the liquid into the solution buffer tank, a purified gas-liquid separator V-1 for separating free water carried by purified gas, a rich amine liquid flash tank V-2 for flash evaporation and purification of rich amine liquid, a carbon dioxide gas-liquid separator V-3 for separating carbon dioxide in decomposed gas, a feeding tank V-4 for storing the defoaming agent or the absorbent and a solution buffer tank V-5 for temporarily storing the lean amine liquid;
a gas-phase inlet of an absorption tower T-1 is connected with a feed gas input pipeline, a gas-phase outlet at the top of the absorption tower T-1 is connected with a hot channel inlet of a purified gas cooler E-1 through a pipeline, a hot channel outlet of the purified gas cooler E-1 is connected with an inlet of a purified gas-liquid separator V-1 through a pipeline, a gas-phase outlet at the top of the purified gas-liquid separator V-1 is connected to a purified gas outlet device pipeline through a first regulating valve X-2, and a liquid-phase outlet at the bottom of the purified gas-liquid separator V-1 is connected to an inlet of an amine-enriched liquid flash tank V-2 through a second regulating valve X-3;
a liquid phase outlet at the bottom of the absorption tower T-1 is also connected to an inlet of an amine-rich liquid flash tank V-2 after passing through a third regulating valve X-4, a liquid phase outlet at the bottom of the amine-rich liquid flash tank V-2 is connected to a cold flow channel inlet of a lean/rich liquid heat exchanger E-2 after passing through a fourth regulating valve X-5, a cold flow channel outlet of the lean/rich liquid heat exchanger E-2 is connected to a cold flow channel inlet of a rich liquid/carbon dioxide heat exchanger E-4 through a pipeline, and a cold flow channel outlet of the rich liquid/carbon dioxide heat exchanger E-4 is connected to an upper liquid phase inlet of a regeneration tower T-2 through a pipeline;
a liquid phase output pipeline at the bottom of the regeneration tower T-2 is divided into two paths, one path of the liquid phase output pipeline is connected to a lean amine liquid inlet of a solution buffer tank V-5 after sequentially passing through a hot flow channel of a lean/rich amine liquid heat exchanger E-2 and a hot flow channel of a lean amine liquid cooler E-3, and the other path of the liquid phase output pipeline is connected to a gas-liquid phase return inlet of a tower kettle of the regeneration tower T-2 after passing through a cold flow channel of an amine liquid reboiler E-5; an outlet (a liquid phase outlet at the bottom) of the feeding tank V-4 is connected to an inlet of a solution buffer tank V-5 through a feeding pump P-3A/B, an outlet of the solution buffer tank V-5 is connected to an inlet of an amine liquid booster pump P-1A/B through a pipeline (an amine liquid booster pump inlet pipeline), an outlet pipeline of the amine liquid booster pump P-1A/B is divided into two paths, one path is connected to an inlet pipeline of the amine liquid booster pump P-1A/B through a fifth regulating valve X-9 and an amine liquid filter F-1, and the other path is connected to a liquid phase inlet at the upper part of an absorption tower T-1;
a gas phase outlet at the top of the amine-rich liquid flash tank V-2 is connected to a flash gas outlet device pipeline after passing through a seventh regulating valve X-6;
a gas phase outlet at the top of the regeneration tower T-2 is connected to an inlet of a carbon dioxide compressor C-1 through a pipeline, an outlet of the carbon dioxide compressor C-1 is connected to an inlet of a heat flow channel of a rich liquid/carbon dioxide heat exchanger E-4, an outlet of the heat flow channel of the rich liquid/carbon dioxide heat exchanger E-4 is connected with an inlet of a carbon dioxide gas-liquid separator V-3, and a gas phase output pipeline of the carbon dioxide gas-liquid separator V-3 is discharged to a high point of a safety position after passing through a sixth regulating valve X-7; the liquid phase output pipeline of the carbon dioxide gas-liquid separator V-3 is connected to the liquid phase inlet of the regeneration tower T-2 through a regeneration tower reflux pump P-2A/B (is merged with the liquid conveying pipeline between the rich liquid/carbon dioxide heat exchanger E-4 and the regeneration tower or is independently connected to the upper liquid phase inlet of the regeneration tower T-2).
The gas phase inlet of the absorption tower T-1 is positioned at the bottom of the absorption tower, and the liquid phase inlet of the absorption tower T-1 is positioned at the upper part of the absorption tower.
The feed pump P-3A/B is preferably a pneumatic diaphragm pump.
The purified gas cooler E-1, the lean/rich amine liquid heat exchanger E-2, the lean amine liquid cooler E-3 and the rich liquid/carbon dioxide heat exchanger E-4 are plate type or shell-and-tube type heat exchangers which adopt a circulating water cooling system or an air cooling system.
A hand valve X-10 is arranged on a liquid conveying pipeline between the lean/rich amine liquid heat exchanger E-2 and the regeneration tower T-2 and is used for adjusting the flow rate of lean amine liquid entering the solution buffer tank V-5.
An eighth damper valve X-1 may be provided in the cold aisle outlet duct of the purge gas cooler E-1, which eighth damper valve X-1 is modulated by a temperature indicating control provided in the hot aisle outlet duct of the purge gas cooler E-1. The cold flow channel of the lean amine liquid cooler E-3 can be provided with a ninth regulating valve X-8, and the ninth regulating valve X-8 is regulated by a temperature indication controller arranged on the outlet pipeline of the hot flow channel of the lean amine liquid cooler E-3. Further, the first regulating valve X-2 is regulated by a pressure indicating controller provided on the top gas phase outlet pipe of the purified gas-liquid separator V-1, the second regulating valve X-3 is regulated by a liquid level indicating controller provided in the purified gas-liquid separator V-1, the third regulating valve X-4 is regulated by a liquid level indicating controller provided inside the absorption column T-1, the fourth regulating valve X-5 is regulated by a liquid level indicating controller provided in the regeneration column T-2, the fifth regulating valve X-9 is regulated by a flow indicating controller provided on the branch into the amine liquid filter F-1, the sixth regulating valve X-7 is regulated by a pressure indicating controller provided on the gas phase outlet pipe of the carbon dioxide gas-liquid separator V-3, the seventh regulator valve X-6 is regulated by a pressure indicating control on the vapor phase outlet line at the top of the rich amine liquid flash drum V-2.
Example 1
(1)CO2Absorption: raw material gas with carbon content more than or equal to 1.5 percent (mole%) and temperature of about 40 ℃ enters from the bottom of the absorption tower T-1 and flows from bottom to top; amine liquid (about 30% wt of aqueous MEDA solution) at about 46 ℃ is poured from the upper part of the absorption tower T-1 and passes through the absorption tower T-1 from top to bottom. After the amine liquid and the feed gas which flow in the reverse directions are fully contacted with each other in the tower to transfer heat and mass, CO in the feed gas2Absorption by amine liquid, CO2The concentration is reduced to below 50ppm (mole%).
The purified gas is conveyed from the top of the absorption tower T-1 to a purified gas cooler E-1 to be cooled to about 40 ℃, enters a purified gas-liquid separator V-1 to separate out the carried free water, and the purified gas output from the top of the purified gas-liquid separator V-1 is used as a product (CO in the purified gas)2The content is lower than 50ppm) is sent out of the device, and the liquid phase separated from the bottom of the purified gas-liquid separator V-1 is converged to the rich amine liquid flash tank V-2 for flash evaporation.
(2) Amine liquid regeneration: the rich amine liquid absorbing the acid gas is discharged from the bottom of the absorption tower T-1, and is reduced in pressure to about 0.3-0.5MPa (G) through throttling, then enters an amine-rich liquid flash tank V-2 for flash evaporation, the amine-rich liquid output from the bottom of the amine-rich liquid flash tank passes through a lean/rich amine liquid heat exchanger E-2 and a rich liquid/carbon dioxide heat exchanger E-3 in sequence and is heated to about 100 ℃, then enters the upper part of a regeneration tower T-2 for regeneration, the regeneration tower T-2 is provided with an amine liquid reboiler E-5, when the temperature of the tower bottom is lower than 98 ℃, heat is supplied (reaching or maintaining about 108 ℃), the amine liquid after sufficient desorption is output from the bottom of the regeneration tower T-2, and is sent to a solution buffer tank V-5 after being sequentially cooled to about 45 ℃ by a lean/rich amine liquid heat exchanger E-2 and a lean amine liquid cooler E-3.
In order to prevent amine liquid from foaming and supplement amine liquid loss in the operation process, a defoaming agent or an absorbent (specifically a 20-40 wt% MEDA aqueous solution) is supplemented into a solution buffer tank V-5 through a feeding tank V-4 and a feeding pump P-3A/B.
The amine liquid pumped out from the bottom of the solution buffer tank V-5 is pressurized by an amine liquid booster pump P-1A/B and then divided into two paths, wherein the first path is about 60 percent of the total amine liquid which is pressurized and then directly pumped to the upper part of an absorption tower T-1, and the other path is filtered by an amine liquid filter F-1 and then returns to an inlet pipeline of the amine liquid booster pump P-1A/B to be converged with the amine liquid which is input into the amine liquid booster pump P-1A/B from the solution buffer tank V-5.
(3) CO-rich stream from the top of the T-2 regenerator2The temperature of the analysis gas is about 108 ℃, the pressure is about 0.04MPa (G), the content of carbon dioxide in the analysis gas is about 20 mol percent, the analysis gas is pressurized to about 0.2MPa (G) by a carbon dioxide compressor C-1, then the analysis gas is conveyed to a rich liquid/carbon dioxide heat exchanger E-4 for cooling, the temperature is reduced to about 105 ℃, then the analysis gas is separated by a carbon dioxide gas-liquid separator V-3, and the gas phase at the top is discharged at a high point at a safe place; the liquid phase at the bottom is pressurized by a regeneration tower reflux pump P-2A/B and then is sent to a regeneration tower T-2 amine liquid inlet pipeline as tower top reflux.
Claims (10)
1. An energy-saving natural gas MDEA decarburization device is characterized by comprising an absorption tower (T-1) for purifying raw gas, a regeneration tower (T-2) for desorbing rich amine liquid, a carbon dioxide compressor (C-1) for pressurizing desorption gas, a purified gas cooler (E-1) for cooling purified gas, a lean/rich amine liquid heat exchanger (E-2) for primarily heating the rich amine liquid and primarily cooling the lean amine liquid, a lean amine liquid cooler (E-3) for secondarily cooling the lean amine liquid, a rich liquid/carbon dioxide heat exchanger (E-4) for reheating the rich amine liquid and cooling desorption gas, an amine liquid reboiler (E-5) for heating the amine liquid, an amine liquid filter (F-1) for purifying the lean amine liquid entering the absorption tower, and an amine liquid filter (F-1) for purifying the lean amine liquid entering the absorption tower, An amine liquid booster pump (P-1A/B) for pumping the lean amine liquid in the solution buffer tank into the absorption tower, a regeneration tower reflux pump (P-2A/B) for conveying the liquid without carbon dioxide in the carbon dioxide gas-liquid separator to the regeneration tower, a purified gas-liquid separator (V-1) for separating free water carried by purified gas, an amine rich liquid flash evaporation tank (V-2) for flash evaporation and purification of the amine rich liquid, a carbon dioxide gas-liquid separator (V-3) for separating the carbon dioxide in the analyzed gas, and a solution buffer tank (V-5) for temporarily storing the lean amine liquid,
a gas-phase inlet of the absorption tower (T-1) is connected with a feed gas input pipeline, a gas-phase outlet at the top of the absorption tower (T-1) is connected with a hot channel inlet of the purified gas cooler (E-1) through a pipeline, a hot channel outlet of the purified gas cooler (E-1) is connected with an inlet of the purified gas-liquid separator (V-1) through a pipeline, a gas-phase outlet at the top of the purified gas-liquid separator is connected with a purified gas outlet device pipeline after passing through a first regulating valve (X-2), and a liquid-phase outlet at the bottom of the purified gas-liquid separator (V-1) is connected with an inlet of the amine-rich liquid flash tank (V-2) after passing through a second regulating valve (X;
a liquid phase outlet at the bottom of the absorption tower (T-1) is also connected to an inlet of the amine-rich liquid flash tank (V-2) after passing through a third regulating valve (X-4), a liquid phase outlet at the bottom of the amine-rich liquid flash tank (V-2) is connected to a cold flow channel inlet of the lean/rich liquid heat exchanger (E-2) after passing through a fourth regulating valve (X-5), a cold flow channel outlet of the lean/rich liquid heat exchanger (E-2) is connected to a cold flow channel inlet of the rich liquid/carbon dioxide heat exchanger (E-4) through a pipeline, and a cold flow channel outlet of the rich liquid/carbon dioxide heat exchanger (E-4) is connected to a liquid phase inlet of the regeneration tower (T-2) through a pipeline;
a liquid phase output pipeline at the bottom of the regeneration tower (T-2) is divided into two paths, one path of the liquid phase output pipeline is connected to a lean amine liquid inlet of a solution buffer tank (V-5) after sequentially passing through a hot flow channel of a lean/rich amine liquid heat exchanger (E-2) and a hot flow channel of a lean amine liquid cooler (E-3), and the other path of the liquid phase output pipeline is connected to a gas-liquid phase return inlet of a tower kettle of the regeneration tower (T-2) after passing through a cold flow channel of an amine liquid reboiler (E-5); an outlet of the solution buffer tank (V-5) is connected to an inlet of the amine liquid booster pump (P-1A/B) through a pipeline, namely an inlet pipeline of the amine liquid booster pump, an outlet pipeline of the amine liquid booster pump (P-1A/B) is divided into two paths, one path of the outlet pipeline passes through a fifth regulating valve (X-9) and an amine liquid filter (F-1) and then is connected to an inlet pipeline of the amine liquid booster pump (P-1A/B), and the other path of the outlet pipeline is connected to a liquid phase inlet at the upper part of the absorption tower (T-1);
a gas phase outlet at the top of the regeneration tower (T-2) is connected to an inlet of a carbon dioxide compressor (C-1) through a pipeline, an outlet of the carbon dioxide compressor (C-1) is connected to an inlet of a heat flow channel of a rich liquid/carbon dioxide heat exchanger (E-4), an outlet of the heat flow channel of the rich liquid/carbon dioxide heat exchanger (E-4) is connected with an inlet of a carbon dioxide gas-liquid separator (V-3), and a gas phase output pipeline of the carbon dioxide gas-liquid separator (V-3) is discharged to a high point at a safety position through a sixth regulating valve (X-7); a liquid phase output pipeline of the carbon dioxide gas-liquid separator (V-3) is connected to a liquid phase inlet of the regeneration tower (T-2) after passing through a regeneration tower reflux pump (P-2A/B).
2. The energy-saving natural gas MDEA decarburization device as claimed in claim 1, wherein the gas phase outlet at the top of the rich amine liquid flash tank (V-2) is connected to the flash gas takeoff line after passing through a seventh adjusting valve (X-6).
3. The energy-saving natural gas MDEA decarbonization device according to the claim 1 or 2, characterized in that the solution buffer tank (V-5) is connected with a feeding tank (V-4) for storing the antifoaming agent or the absorbent through a feeding pump (P-3A/B).
4. The energy-saving natural gas MDEA decarburization device as claimed in claim 1 or 2, wherein the gas phase inlet of the absorption column (T-1) is located at the bottom of the absorption column and the liquid phase inlet of the absorption column (T-1) is located at the upper part of the absorption column.
5. The energy-saving natural gas MDEA decarburization device as claimed in claim 1, wherein the feed pump (P-3A/B) is an air operated diaphragm pump.
6. The energy-saving natural gas MDEA decarburization device as recited in claim 1, wherein the purge gas cooler (E-1), the lean/rich amine liquid heat exchanger (E-2), the lean amine liquid cooler (E-3) and the rich liquid/carbon dioxide heat exchanger (E-4) are plate-type or shell-and-tube heat exchangers using a circulating water cooling system or an air cooling system.
7. A method for decarbonization by using the energy-saving natural gas MDEA decarbonization device of any one of claims 1 to 6, which is characterized by comprising the following steps:
(1) the raw gas enters from the bottom of the absorption tower, flows from bottom to top, the amine liquid is sprayed from the upper part of the absorption tower and passes through the absorption tower from top to bottom, the amine liquid and the raw gas flowing in opposite directions are fully contacted in the tower to transfer heat and mass, and then CO in the raw gas2Absorbed by amine liquid, and CO is output from the top of the absorption tower2Purified gas with concentration below 50ppm is cooled by a purified gas cooler and then is conveyed to a purified gas-liquid separator to separate carried free water, and the gas output from the top of the purified gas-liquid separator is used as a productThe liquid phase obtained by the separation at the bottom is conveyed to an amine-rich liquid flash tank for flash evaporation after being output from the device;
(2) the method comprises the steps that rich amine liquid absorbing acid gas is output from the bottom of an absorption tower, enters an rich amine liquid flash tank for flash evaporation after throttling and pressure reduction (the temperature of the rich amine liquid flash tank is 55-70 ℃, and the pressure is 0.3-0.5Mpa (G)), the rich amine liquid output from the rich amine liquid flash tank sequentially passes through a lean/rich amine liquid heat exchanger and a rich liquid/carbon dioxide heat exchanger to be heated to 90-109 ℃, then enters the upper part of a regeneration tower for regeneration, the fully desorbed amine liquid is output from the bottom of the regeneration tower, is sequentially cooled to 40-55 ℃ (preferably about 45 ℃) by the lean/rich amine liquid heat exchanger and a lean amine liquid cooler and then is sent to a solution buffer tank, the amine liquid output from the bottom of the solution buffer tank is pressurized by the amine liquid and then divided into two paths, the first path is directly pumped to the absorption tower after being pressurized, and the other path is filtered and then returns to an inlet;
(3) after being pressurized by a carbon dioxide compressor, the analytic gas discharged from the top of the regeneration tower is conveyed to a rich liquid/carbon dioxide heat exchanger for cooling, then liquid is separated by a carbon dioxide gas-liquid separator, and the top gas phase is discharged at a high point of safety; and the liquid phase at the bottom is pressurized by a reflux pump of the regeneration tower and then returned to an amine-rich liquid inlet pipeline of the regeneration tower as the reflux of the tower top.
8. The decarburization method according to claim 7, wherein the volume ratio of the raw gas and the amine liquid flowing in the opposite direction is 20:1 to 30: 1.
9. The decarburization process according to claim 7 or 8, wherein the desorption gas discharged from the top of the regeneration tower is pressurized to 0.18 to 0.25MPa (G), preferably 0.2MPa (G), by a carbon dioxide compressor.
10. Decarburization method according to any one of claims 7 to 9, wherein the rich liquor/carbon dioxide heat exchanger cools the desorption gas after compression by the carbon dioxide compressor to 100 to 120 ℃, preferably to 105 ℃.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113980708A (en) * | 2021-11-01 | 2022-01-28 | 中石化中原石油工程设计有限公司 | Ultrahigh CO2Decarburization method for content synthesis gas |
| CN114262635A (en) * | 2021-12-09 | 2022-04-01 | 中国石油大学(北京) | Natural gas reinforced desulfurization and decarburization system and method |
| CN114669167A (en) * | 2022-02-16 | 2022-06-28 | 苏州市兴鲁空分设备科技发展有限公司 | Pressure swing adsorption and desorption gas recycling device |
| WO2022242317A1 (en) * | 2021-05-20 | 2022-11-24 | 中国华电科工集团有限公司 | Carbon dioxide capture system for rich liquid flash-evaporation and regeneration waste heat recovery |
| CN116036838A (en) * | 2023-01-06 | 2023-05-02 | 江苏科技大学 | Carbon dioxide trapping system and method |
| WO2024104091A1 (en) * | 2022-11-15 | 2024-05-23 | 中国石油天然气股份有限公司 | Energy-saving system and process for flue gas decarbonization and deoxygenation |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205011722U (en) * | 2015-09-25 | 2016-02-03 | 新地能源工程技术有限公司 | Device that contains high concentration CO2 natural gas or synthetic gas decarbonization |
| CN206916095U (en) * | 2017-03-29 | 2018-01-23 | 上海治汇环保设备有限公司 | A kind of biogas water elution carbon device of efficient energy-saving |
| CN207161247U (en) * | 2017-09-13 | 2018-03-30 | 新地能源工程技术有限公司 | The device of natural gas decarbonization rich solution pressure energy is reclaimed using hydraulic turbine |
| CN110639335A (en) * | 2019-09-26 | 2020-01-03 | 江苏城乡建设职业学院 | Energy-saving method and system for regeneration tower in deep decarburization of natural gas |
| CN110684574A (en) * | 2018-07-06 | 2020-01-14 | 中国石油化工股份有限公司 | Decarbonization method for preparing liquefied natural gas from high-carbon-content natural gas |
| CN111690449A (en) * | 2020-06-18 | 2020-09-22 | 北京颖泓科技发展有限公司 | Energy-saving natural gas MDEA decarburization system and decarburization process thereof |
-
2020
- 2020-10-28 CN CN202011171092.1A patent/CN112159695A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205011722U (en) * | 2015-09-25 | 2016-02-03 | 新地能源工程技术有限公司 | Device that contains high concentration CO2 natural gas or synthetic gas decarbonization |
| CN206916095U (en) * | 2017-03-29 | 2018-01-23 | 上海治汇环保设备有限公司 | A kind of biogas water elution carbon device of efficient energy-saving |
| CN207161247U (en) * | 2017-09-13 | 2018-03-30 | 新地能源工程技术有限公司 | The device of natural gas decarbonization rich solution pressure energy is reclaimed using hydraulic turbine |
| CN110684574A (en) * | 2018-07-06 | 2020-01-14 | 中国石油化工股份有限公司 | Decarbonization method for preparing liquefied natural gas from high-carbon-content natural gas |
| CN110639335A (en) * | 2019-09-26 | 2020-01-03 | 江苏城乡建设职业学院 | Energy-saving method and system for regeneration tower in deep decarburization of natural gas |
| CN111690449A (en) * | 2020-06-18 | 2020-09-22 | 北京颖泓科技发展有限公司 | Energy-saving natural gas MDEA decarburization system and decarburization process thereof |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022242317A1 (en) * | 2021-05-20 | 2022-11-24 | 中国华电科工集团有限公司 | Carbon dioxide capture system for rich liquid flash-evaporation and regeneration waste heat recovery |
| CN113980708A (en) * | 2021-11-01 | 2022-01-28 | 中石化中原石油工程设计有限公司 | Ultrahigh CO2Decarburization method for content synthesis gas |
| CN114262635A (en) * | 2021-12-09 | 2022-04-01 | 中国石油大学(北京) | Natural gas reinforced desulfurization and decarburization system and method |
| CN114669167A (en) * | 2022-02-16 | 2022-06-28 | 苏州市兴鲁空分设备科技发展有限公司 | Pressure swing adsorption and desorption gas recycling device |
| WO2024104091A1 (en) * | 2022-11-15 | 2024-05-23 | 中国石油天然气股份有限公司 | Energy-saving system and process for flue gas decarbonization and deoxygenation |
| CN116036838A (en) * | 2023-01-06 | 2023-05-02 | 江苏科技大学 | Carbon dioxide trapping system and method |
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