LNG fine desulfurization production coal gas recovery device

Abstract

The utility model discloses a kind of LNG fine desulfurization production coal gas recovery device, including nitrogen cooler, the first pipeline of communication desulfurization total vent pipeline, second pipeline, the third pipeline of communication resolving gas pipeline, flow regulating valve, the outlet of first pipeline is communicated with the shell side import of nitrogen cooler, the shell side export of nitrogen cooler is communicated with second pipeline, second pipeline is communicated with third pipeline, and flow regulating valve is installed on third pipeline.The utility model realizes the recycling of coke oven gas in the process of opening and stopping, reduces environmental pollution, reduces carbon emission, and saves fuel cost.

Description

Technical Field

[0001] This utility model relates to the field of liquefied natural gas technology, and in particular to a gas recovery device for LNG desulfurization production. Background Technology

[0002] LNG is a liquefied form of natural gas. In the production of LNG from coke oven gas, the desulfurization system is a critical process. The desulfurization system removes sulfides from the feed gas to prevent corrosion of subsequent equipment and catalyst poisoning. During system start-up, the desulfurization catalyst needs to be heated to 280℃, which takes 3 days. During shutdown, catalyst replacement requires cooling, which takes 1 day. The system consumes approximately 15,000 Nm³ of coke oven gas per hour, and approximately 2.52 million Nm³ of coke oven gas is consumed annually during the two start-up and shutdown cycles. 3 This portion of the gas cannot be immediately sent to downstream processes, resulting in it being sent to the flare for combustion and release, causing resource waste and environmental pollution.

[0003] The current method is to directly burn and release the unprocessable gas during the system start-up phase. This not only wastes valuable gas resources but also increases the risk of environmental pollution. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a gas recovery device for LNG desulfurization production, which solves the problem of waste of coke oven gas during start-up and shutdown in the prior art.

[0005] The purpose of this utility model is achieved through the following technical solution: a gas recovery device for LNG desulfurization production, comprising a nitrogen cooler, a first pipe connected to the desulfurization main vent pipeline, a second pipe, a third pipe connected to the desorbed gas pipeline, and a flow regulating valve. The outlet of the first pipe is connected to the shell-side inlet of the nitrogen cooler, the shell-side outlet of the nitrogen cooler is connected to the second pipe, the second pipe is connected to the third pipe, and the flow regulating valve is installed on the third pipe.

[0006] Furthermore, a safety valve is provided between the desulfurization main vent pipeline and the nitrogen cooler.

[0007] Furthermore, the first pipeline is equipped with a first drain valve, the second pipeline is equipped with a second drain valve, and the third pipeline is equipped with a third drain valve.

[0008] This invention has the following advantages: The coke oven gas to LNG co-production hydrogen unit is started and stopped twice a year. During the start-up and shutdown process, the approximately 2.52 million Nm³ of coke oven gas consumed in the heating and cooling of the desulfurization system is replaced by the existing direct flare combustion and release of the gas. Instead, the gas is fed into the recovery device of this invention. After being cooled by a nitrogen cooler, the coke oven gas enters the desorption gas return pipeline after the system pressure and flow are regulated by a regulating valve. This achieves the recovery and utilization of coke oven gas, realizes zero release during the system start-up phase, reduces environmental pollution, lowers carbon emissions, and saves more than 2.016 million yuan in fuel costs annually. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the installation and connection of this utility model.

[0010] In the diagram, 1 is the main desulfurization vent pipeline; 2 is the first pipeline; 3 is the nitrogen cooler; 4 is the second pipeline; 5 is the third pipeline; 6 is the flow regulating valve; 7 is the desorbed gas pipeline; 8 is the coke oven gas heating pipeline; 9 is the safety valve; 10 is the first drain valve; 11 is the second drain valve; and 12 is the third drain valve. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0012] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0013] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0014] like Figure 1As shown, a gas recovery device for LNG desulfurization production includes a nitrogen cooler 3, a first pipeline 2 and a second pipeline 4 connected to the main desulfurization vent pipeline 1, a third pipeline 5 connected to the desorbed gas pipeline 7, a flow regulating valve 6, and a safety valve 9. The main desulfurization vent pipeline 1 is numbered VT0201-400, the first pipeline 2 is numbered VT0208-200, the nitrogen cooler 3 is numbered E0202, the second pipeline 4 is numbered VT0209-200, the flow regulating valve 6 is numbered HV-0204, and the third pipeline 5 is numbered VT02. 10-200. 15000 Nm³ / h of gas used in the start-up and shutdown of the desulfurization system for LNG production from coke oven gas is cooled to 40°C in the shell side of nitrogen cooler 3 through the main desulfurization vent pipeline 1 and the first pipeline 2. After passing through the second pipeline 4 and the third pipeline 5, the flow rate is regulated by the automatic flow regulating valve 6 and then converges to the outlet of the PSA system's desorbed gas pipeline 7. The PSA system is a pressure swing adsorption system used for gas adsorption, separation and purification. The pipeline number in the attached diagram is FG8303-200, which is recovered to the coke oven gas heating pipeline 8 for coke oven heating.

[0015] The shell side of nitrogen cooler 3 contains process gas, while the tube side contains circulating water for cooling.

[0016] A safety valve 9 (PSV0201 in the attached diagram) is installed between the nitrogen cooler 3 and the sulfur vent line 1. The valve has a tripping pressure of 0.9 MPa and can ensure the safety of the equipment and pipeline under this process condition.

[0017] A first drain valve 10 is installed on the first pipeline 2, a second drain valve 11 is installed on the second pipeline 4, and a third drain valve 12 is installed on the third pipeline 5. The first drain valve 10, the second drain valve 11, and the third drain valve 12 are used to drain the condensate generated in the process, which can meet the requirements of the heating process and prevent the condensate from entering the desorption gas pipeline.

[0018] The flow regulating valve 6 can be an automated control valve. The flow regulating valve 6 is electrically connected to the enterprise's DCS system. The DCS system regulates the flow regulating valve 6 to control the flow of the system gas. The DCS system is the enterprise's automated distributed control system. The DCS system realizes real-time monitoring, operation optimization and safety assurance of the whole process through "distributed control and centralized management".

[0019] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gas recovery device for LNG desulfurization production, characterized in that: The system includes a nitrogen cooler (3), a first pipe (2) connected to the desulfurization main venting pipeline (1), a second pipe (4), a third pipe (5) connected to the desorbed gas pipeline (7), and a flow regulating valve (6). The outlet of the first pipe (2) is connected to the shell-side inlet of the nitrogen cooler (3), the shell-side outlet of the nitrogen cooler (3) is connected to the second pipe (4), the second pipe (4) is connected to the third pipe (5), and the flow regulating valve (6) is installed on the third pipe (5).

2. The gas recovery device for LNG desulfurization production according to claim 1, characterized in that: A safety valve (9) is provided between the desulfurization main vent pipeline (1) and the nitrogen cooler (3).

3. The gas recovery device for LNG desulfurization production according to claim 1, characterized in that: The first pipe (2) is provided with a first drain valve (10), the second pipe (4) is provided with a second drain valve (11), and the third pipe (5) is provided with a third drain valve (12).

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