Method and device for recovering C2 components in dry gas

A two-component, dry gas technology, used in separation methods, chemical instruments and methods, and gas mixture processing, etc. It can reduce the desorption energy consumption, save the energy consumption of the device, and save the steam consumption.

CN112725032AActive Publication Date: 2021-04-30CHINA PETROLEUM & CHEM CORP +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2021-04-30

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Abstract

The invention relates to the field of dry gas treatment, and discloses a method and a device for recovering C2 components in dry gas. The method comprises the following steps: (1) compressing raw material dry gas, cooling the obtained compressed gas, and carrying out gas-liquid separation to obtain a gas phase and a liquid phase; (2) contacting the gas phase with an absorbent for C2 component absorption to obtain absorption tail gas and absorption pregnant solution, returning the absorption pregnant solution and mixing the absorption pregnant solution with the compressed gas; (3) reducing the pressure of the liquid phase, performing methane desorption to obtain desorbed gas and a rich absorbent, and returning the desorbed gas to the step (1) for compression or discharge; and (4) desorbing and separating the rich absorbent to obtain a lean absorbent and concentrated gas mainly comprising C2 components, and returning the lean absorbent and mixing the lean absorbent with the absorbent. The C2 component obtained by adopting the method provided by the invention is high in recovery rate, and the total energy consumption of the device is low.
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Description

technical field

[0001] The invention relates to the technical field of dry gas treatment, in particular to a method and a device for recovering carbon components in dry gas. Background technique

[0002] At present, the methods for recovering ethane and ethylene components from dry gas that have been industrialized mainly include:

[0003] (1) The cryogenic separation method has a mature process, high ethylene recovery rate and high purity, but requires a drier and a propylene refrigeration device or an ethylene-propylene composite refrigeration device, which requires a large investment and high energy consumption;

[0004] (2) The pressure swing adsorption method is simple in operation and generally low in energy consumption, but the product purity is low and the recovery rate of carbon two components is low. When the scale of raw material dry gas treatment is large, the equipment investment and land occupation are large;

[0005] (3) Shallow cold oil absorption method, th...

Examples

Embodiment approach

[0048] According to a preferred embodiment of the present invention, when the dry gas includes refinery dry gas with carbon six and above component content less than 0.1% mol, it is more conducive to the recovery of carbon two components in the dry gas and the overall plant performance. Lowest consumption.

[0049] According to the present invention, there is no special limitation on the compression, generally stepwise compression is used to increase the pressure of the raw material dry gas to 2.5-4.6MPaG, preferably 3-4.2MPaG, that is, the pressure of the compressed gas is 2.5-4.6MPaG , preferably 3-4.2MPaG. Further preferably, the compression is multi-stage compression, and the present invention has no special limitation on the number of stages of compression processing, for example, it may be two-stage compression or three-stage compression.

[0050] According to the present invention, the cooling is not particularly limited, preferably, the cooling temperature is 5-40°C, ...

Embodiment 1

[0086] This example is used to illustrate the method and device for recovering carbon dioxide from oil absorption, separation and dry gas of the present invention.

[0087] The device comprises: a compressor 2, a cooler 3, a separatory tank 4, an absorption tower 5, a methane desorption tower 7, a desorption tower 9 and a methane desorption tower reboiler 15;

[0088] The compressor 2, the cooler 3 and the separator tank 4 are connected in sequence; the compressor 2 is connected to the refinery dry gas 1 pipeline;

[0089] The bottom of the absorption tower 5 communicates with the top of the liquid separation tank 4 and the cooler 3 respectively, for countercurrently contacting the gas phase produced by the liquid separation tank with the absorbent, and the top of the absorption tower 5 discharges Absorb the tail gas 14, the tower kettle of the absorption tower 5 discharges the absorption rich liquid and returns to the cooler 3 after being boosted by the absorption tower kettl...