Method for efficiently recycling light components in light component removal tower

Abstract

The invention provides a method for efficiently recycling light components in a light component removal tower, which comprises the following steps: introducing a gas phase discharged from the top of the light component removal tower into a cryogenic heat exchanger for cooling to obtain cooling liquid and high-purity synthesis gas; conveying the cooling liquid to a reflux tank, and circularly returning the cooling liquid to the light component removal tower; high-purity synthesis gas enters the gas buffer tank and is subjected to defoaming treatment through the defoaming net in the gas buffer tank, the defoamed gas is fed into the compressor to be pressurized, and the pressurized gas is introduced into the micro-interface reactor. According to the invention, the gas phase discharged from the top of the light component removal tower is subjected to cryogenic heat exchange treatment, high-purity synthesis gas and cooling liquid in the gas phase are effectively separated, and are respectively introduced into the gas buffer tank and the reflux tank to form a circulating reflux system, so that high-value gas components are efficiently recovered and reutilized, and the production cost is reduced. And the resource waste caused by direct emission to a torch or a fuel gas pipe network in the traditional process is obviously reduced.

Description

Technical Field

[0001] The invention relates to a method, in particular to a method for efficiently recycling light components in a light component removal tower, and belongs to the technical field of light component recovery. Background Art

[0002] In the polyol carbonyl synthesis process, a light-constituent removal tower is typically used to separate low-boiling-point impurities and light components from the pre-reaction feed gas to improve the stability of subsequent reactions and product purity. The gaseous components discharged from the top of the light-constituent removal tower still contain a large amount of high-purity synthesis gas, primarily composed of carbon monoxide and hydrogen, which has high chemical reaction value.

[0003] However, in existing technologies, this gas is typically not recycled but instead discharged directly into the flare system or introduced into the fuel gas pipeline network as fuel gas. This treatment method not only wastes high-value gas resources but also may lead to increased fuel gas system load and increased risk of liquid carryover. Summary of the Invention

[0004] Based on the above background, the purpose of the present invention is to provide a method for efficiently recovering and utilizing light components in a light component removal tower with high recovery rate and stable operation, so as to solve the problems described in the background technology.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A method for efficiently recycling light components in a light component removal tower, comprising:

[0007] The gas phase discharged from the top of the light component removal tower is introduced into a cryogenic heat exchanger for cooling to obtain coolant and high-purity synthesis gas;

[0008] The cooling liquid is transported to the reflux tank and circulated back to the light component removal tower;

[0009] The high-purity synthesis gas enters the gas buffer tank and is defoamed by the defoaming net in the gas buffer tank. The defoamed gas is sent to the compressor for pressurization, and the pressurized gas is introduced into the micro-interface reactor;

[0010] The accumulated liquid at the bottom of the gas buffer tank is transported to the reflux tank and circulated back to the light component removal tower.

[0011] Preferably, the operating conditions of the light component removal tower include: a bottom temperature of 135 to 140° C., and a top pressure of 0.43 to 0.46 MPa.

[0012] Preferably, the high-purity synthesis gas comprises the following components in mass percentage: a total content of carbon monoxide and hydrogen of 87.5-88.5%, propylene of 2.5-3.5%, and a total content of n-butyraldehyde and isobutyraldehyde of 2-3%.

[0013] Preferably, the operating conditions of the cryogenic heat exchanger include: the cooling temperature of the cryogenic heat exchanger is less than 5°C.

[0014] Preferably, a carbon monoxide infrared detector is provided on the top of the microinterface reactor.

[0015] Preferably, the gas buffer tank adopts a vertical structure, and the defoaming net inside the gas buffer tank is located between the inlet and outlet of the gas buffer tank.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The present invention provides a method for efficiently recovering and utilizing light components in a light component removal tower. The method performs cryogenic heat exchange treatment on the gas phase discharged from the top of the light component removal tower, effectively separates the high-purity synthesis gas and the coolant therein, and introduces them into a gas buffer tank and a reflux tank to form a circulating reflux system, thereby achieving efficient recovery and reuse of high-value gas components and significantly reducing the waste of resources caused by direct discharge to a flare or a fuel gas pipeline network in traditional processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0019] Figure 1 It is a schematic flow chart of the method of the present invention.

[0020] In the figure: 1. Light component removal tower; 2. Cryogenic heat exchanger; 3. Reflux tank; 4. Gas buffer tank; 5. Compressor; 6. Micro-interface reactor. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the scope of protection of the present invention.

[0022] In the present invention, unless otherwise specified, all components and percentages are by weight. The equipment and raw materials used are commercially available or commonly used in the art. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art. The components or equipment in the following embodiments, unless otherwise specified, are all universal standard parts or components known to those skilled in the art. Their structures and principles are known to those skilled in the art through technical manuals or routine experimental methods.

[0023] The following detailed description of the embodiments of the present invention is made in conjunction with the accompanying drawings. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, one or more embodiments may be implemented by those skilled in the art without these specific details.

[0024] like Figure 1 As shown, a method for efficiently recovering light components from a light component removal tower 1 is described. The overhead gaseous product from the light component removal tower 1 is introduced via a pipeline into a cryogenic heat exchanger 2 for low-temperature cooling. The heat exchanger's cooling medium is low-temperature chilled water or another industrially feasible cooling source. The cooling temperature is controlled below 5°C to fully condense the gaseous components. The cooled mixture is divided into two parts: a coolant and uncondensed gas.

[0025] The coolant is introduced into the reflux tank 3 located downstream of the system via a pipeline for storage. It is then pumped back into the light-consumer removal tower 1 via a reflux pump for reflux, enhancing the separation efficiency within the tower. Simultaneously, the uncondensed, high-purity synthesis gas is fed into the gas buffer tank 4 via a gas phase pipeline.

[0026] The gas buffer tank 4 is a vertical structure equipped with a defoaming screen installed between the inlet and outlet of the gas buffer tank 4. The screen is used to intercept any entrained liquid droplets and prevent the liquid phase from entering subsequent equipment. After the gas is defoamed, it is further pipelined to the compressor 5 for pressurization. The compressor 5 can be centrifugal or screw type. The compressed gas has sufficient pressure to be directly supplied to the micro-interface reactor for use in the polyol synthesis reaction process.

[0027] In order to improve the system monitoring and control capabilities, a carbon monoxide infrared detector is installed on the top of the micro-interface reactor, which can realize online real-time monitoring of the carbon monoxide content in the synthesis gas. Its detection range is controlled at 2% to 4% to ensure that the gas composition meets the reaction requirements.

[0028] In addition, part of the accumulated liquid at the bottom of the gas buffer tank 4 is also transported to the reflux tank 3 through a pipeline, and is returned to the light component removal tower 1 together with the above-mentioned condensate, forming a stable and closed gas-liquid circulation system.

[0029] The implementation principle of the method for efficiently recycling light components in a light component removal tower 1 of the present invention is as follows:

[0030] By installing a cryogenic heat exchanger 2 on the gas phase discharge path of the light component removal tower 1, this portion of the gas phase is cooled at low temperatures, achieving gas-liquid separation and producing recyclable condensate and high-purity gas. The condensate is introduced into the reflux tank 3 and returned to the tower to participate in the separation process, achieving closed-loop utilization of liquid resources.

[0031] Meanwhile, the high-purity syngas, after undergoing cryogenic heat exchange, enters gas buffer tank 4, where a defoaming screen is installed to effectively separate entrained liquid droplets, preventing liquid from entering compressor 5 and potentially causing equipment failure. The defoamed syngas is further pressurized by compressor 5 and fed into the micro-interface reactor for subsequent polyol carbonyl synthesis reactions, thereby enabling the reuse of this high-value gas component.

[0032] In addition, a small amount of accumulated liquid at the bottom of the buffer tank is also returned to the reflux tank 3 through the pipeline, and finally returned to the light component removal tower 1, further improving the recycling efficiency of the system.

[0033] Through the above steps, efficient recovery of light component high-purity gas throughout the entire process is achieved, which significantly improves raw material utilization and reduces energy consumption.

[0034] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for efficiently recycling light components in a light component removal tower (1), characterized in that: include: The gas phase discharged from the top of the light component removal tower (1) is introduced into a cryogenic heat exchanger (2) for cooling to obtain a coolant and high-purity synthesis gas; The cooling liquid is transported to the reflux tank (3) and circulated back to the light component removal tower (1); The high-purity synthesis gas enters the gas buffer tank (4) and is defoamed by a defoaming net in the gas buffer tank (4). The defoamed gas is sent to a compressor (5) for pressurization, and the pressurized gas is introduced into a micro-interface reactor; The accumulated liquid at the bottom of the gas buffer tank (4) is transported to the reflux tank (3) and circulated back into the light component removal tower (1).

2. The method according to claim 1, wherein: The operating conditions of the light component removal tower (1) include: a tower bottom temperature of 135-140° C. and a tower top pressure of 0.43-0.46 MPa.

3. The method according to claim 1, wherein: The high-purity synthesis gas comprises the following components in mass percentage: a total content of carbon monoxide and hydrogen of 87.5-88.5%, propylene of 2.5-3.5%, and a total content of normal butyraldehyde and isobutyraldehyde of 2-3%.

4. The method according to claim 1, wherein: The operating conditions of the cryogenic heat exchanger (2) include: the cooling temperature of the cryogenic heat exchanger (2) is less than 5°C.

5. The method according to claim 1, wherein: A carbon monoxide infrared detector is arranged on the top of the micro-interface reactor.

6. The method according to claim 1, wherein: The gas buffer tank (4) adopts a vertical structure, and the defoaming net inside the gas buffer tank (4) is located between the inlet and the outlet of the gas buffer tank (4).

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