Coal-to-methanol conversion gas receiving system

Abstract

The utility model discloses a coal-to-methanol conversion gas receiving system which comprises a gasification process, a first conversion furnace, a second conversion furnace, a third conversion furnace, a purification process, a heat exchanger, a torch process and a PLC (Programmable Logic Controller), according to the method, a gasification process, a first shift converter, a second shift converter, a heat exchanger, a third shift converter and a purification process are sequentially connected in series through pipelines; the torch process is connected to a pipeline between the three-way converter and the purification process, electric valves in all the pipelines are controlled through signals of the PLC, overtemperature damage of an emptying pipeline in the conversion gas connection process is effectively avoided, the gas connection time of a conversion device is effectively shortened, and the safety of the conversion device is improved. And personnel can be prevented from being far away from the high-temperature pipeline under certain abnormal conditions (such as pipeline breakage and equipment failure), and possible safety accidents are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of coal - to - methanol technology, and specifically relates to a coal - to - methanol conversion gas - receiving system. Background Technique

[0002] The coal - to - methanol process is a traditional and mature basic chemical industry with relatively wide applications. In the production of methanol plants, it mainly consists of conversion, purification, synthesis, and rectification processes. The role of conversion is to convert CO in the raw synthesis gas into H2 and CO2 to adjust the hydrogen - carbon ratio for methanol synthesis, recover part of the reaction heat, and convert part of the organic sulfur into inorganic sulfur. Carbon monoxide conversion is a very important unit in chemical operations and is widely used in large chemical enterprises such as petrochemical, coal chemical, and fertilizer plants.

[0003] During the startup process of the coal - to - methanol plant, after the gasifier is ignited, qualified effective gas is sent to the conversion process. The first conversion furnace receives gas first. After the bed temperature is stable, gas is introduced into the second conversion furnace. During the gas - receiving process of the first conversion furnace, the outlet temperature is relatively high (about 500°C), and the high - temperature gas is discharged through the pipeline, causing a certain degree of damage to the discharge pipeline and posing a huge safety hazard; during the pressurization isolation and gas - receiving process, the valves are repeatedly switched, and the workload of on - site personnel is large. The above - mentioned process for the conversion device to receive gas and reach a stable state to enter the purification device takes 4 hours. Before methanol is produced, all synthesis gas is discharged through the flare, which takes a long time and causes a large waste. Content of the Utility Model

[0004] The purpose of the utility model is to provide a coal - to - methanol conversion gas - receiving system to reduce the heat loss caused by the discharge of the flare process, improve the utilization rate of heat, and reduce the damage to the flare process pipeline caused by high - temperature emissions.

[0005] To achieve the above - mentioned purpose, the technical solution adopted by the utility model is:

[0006] A coal - to - methanol conversion gas - receiving system includes a gasification process, a first conversion furnace, a second conversion furnace, a flare process, and a PLC controller; its characteristics are: it also includes a third conversion furnace, a purification process, and a heat exchanger. The gasification process, the first conversion furnace, the second conversion furnace, the heat exchanger, the third conversion furnace, and the purification process are connected in series through pipelines in sequence; a flare process pipeline is connected in the pipeline between the first conversion furnace and the second conversion furnace and is connected to the flare process, and a flare process pipeline two is connected in the pipeline between the third conversion furnace and the purification process and is connected to the flare process.

[0007] An electric valve is installed in the pipeline between the gasification process and the second conversion furnace.

[0008] Electric valves are installed in the pipelines connecting the first conversion furnace to the pipeline between the second conversion furnace and the flare process.

[0009] Electric valves are installed in the pipelines connecting the three-stage converter between the purification process and the flare process.

[0010] All the said electric valves are signal-connected to the PLC controller.

[0011] Compared with the prior art, the beneficial effects of the present utility model are as follows: After changing the gas connection device during the start-up process of the methanol plant, it effectively avoids the problem that the outlet temperature is too high during the gas connection process of the first-stage converter in the prior art. The high-temperature gas is vented through the on-site pipeline, causing a certain degree of damage to the vent pipeline and posing a huge safety hazard. At the same time, during the pressure charging isolation and gas connection process, the valves are repeatedly switched, resulting in a large workload for on-site personnel. It takes 4 hours for the above process transformation device to connect the gas to the stable purification device. Before methanol is produced, all synthesis gas is vented through the flare, which takes a long time and causes a large waste.

[0012] The present utility model adopts the gasification process, the first-stage converter, the second-stage converter, the heat exchanger, the third-stage converter, and the purification process to be connected in series through pipelines in sequence. During the gas connection process of the first-stage converter, the second-stage converter, the heat exchanger, and the third-stage converter are preheated at the same time, and then the gas is passed through the on-site pipeline and the flare process pipeline. At this time, the temperature of the gas in the pipeline is greatly reduced, which will not cause damage to the flare process pipeline. Moreover, heat exchange is carried out on the second-stage converter and the third-stage converter, and heat exchange is carried out through the heat exchanger. The heat of the high-temperature gas in the gas connection of the first-stage converter is fully utilized, improving the heat utilization efficiency, without waste and without causing damage to the flare process pipeline, achieving multiple benefits at once.

[0013] The pipeline valves of the present utility model are controlled by PLC, enabling personnel to monitor and operate at a safe distance, avoiding the need for personnel to manually operate valves that may be in a dangerous state, reducing the chance of personnel being directly exposed to a dangerous environment, reducing the potential risks faced by personnel, and having strong safety. Brief Description of the Drawings

[0014] Figure 1 It is a schematic diagram of a coal-to-methanol conversion gas connection system related to the present utility model.

[0015] Markings in the figure: 1. Gasification process, 2. First-stage converter, 3. Second-stage converter, 4. Third-stage converter, 5. Purification process, 6. Heat exchanger, 7. Flare process, 8. First flare process pipeline, 9. Second flare process pipeline, 10. PLC controller. Detailed Embodiments

[0016] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present utility model shall fall within the protection scope of the present utility model.

[0017] As Figure 1 shown, a coal-to-methanol conversion gas receiving system of the present utility model includes a gasification process (1), a first conversion furnace (2), a second conversion furnace (3), a third conversion furnace (4), a purification process (5), a heat exchanger (6), a flare process (7), and a PLC controller (10); adopting a method of series-connected first gas introduction for the first, second, and third conversion furnaces, the gasification process (1) is connected in series with the first conversion furnace (2), the second conversion furnace (3), the heat exchanger (6), the third conversion furnace (4), and the purification process (5) in sequence through pipelines; one end of the flare process (7) is connected to the pipeline between the first conversion furnace (2) and the second conversion furnace (3) through a first flare process pipeline (8) and a second flare process pipeline (9), and is also connected to the pipeline between the third conversion furnace (4) and the purification process (5).

[0018] An electric valve is installed in the pipeline between the gasification process (1) and the second conversion furnace (3).

[0019] Electric valves are installed in the pipelines connecting the first conversion furnace (2) to the second conversion furnace (3) and the flare process (7).

[0020] Electric valves are installed in the pipelines connecting the third conversion furnace (4) to the purification process (5) and the flare process (7).

[0021] All the electric valves are signal-connected to the PLC controller (10).

[0022] By changing the coal-to-methanol conversion gas receiving system, the switch valves are controlled by the PLC controller (10), and the raw coal gas from the gasification process (1) enters the first conversion furnace (2), the second conversion furnace (3), the heat exchanger (6), and the third conversion furnace (4) in series in an orderly manner. The converted gas enters the flare process (7) for discharging and optimizing and adjusting various parameters. The converted gas after being cooled by the heat exchanger (6) is sent to the flare process (7) through the second flare process pipeline (9), effectively reducing the phenomenon of high-temperature damage to the pipeline after the catalyst reaction, and ensuring the equipment safety and long-term safe use during the start-up process.

[0023] The present utility model reserves the pipeline standby for directly connecting the first conversion furnace (2) to the flare process (7).

Claims

1. A coal-to-methanol conversion gas receiving system, comprising a gasification process (1), a first conversion furnace (2), a second conversion furnace (3), a flare process (7), and a PLC controller (10); characterized in that: It also includes a three-phase transformer (4), a purification process (5), and a heat exchanger (6). The gasification process (1) is connected in series with the first transformer (2), the second transformer (3), the heat exchanger (6), the third transformer (4), and the purification process (5) in sequence through pipelines; the pipeline between the first transformer (2) and the second transformer (3) is connected to a flare process pipeline 1 (8) and connected to the flare process (7); the pipeline between the third transformer (4) and the purification process (5) is connected to a flare process pipeline 2 (9) and connected to the flare process (7).

2. A coal-to-methanol conversion gas receiving system according to claim 1, characterized in that The pipeline between the gasification process (1) and the second transformer (3) is equipped with an electric valve.

3. A coal-to-methanol conversion gas receiving system according to claim 1, characterized in that Electric valves are installed in the pipelines connecting the first transformer (2) to the second transformer (3) and the torch process (7).

4. A coal-to-methanol shift gas receiving system according to claim 1, characterized in that Electric valves are installed in the pipelines connecting the purification process (5) and the flare process (7) of the three-transformer furnace (4).

5. A coal-to-methanol conversion gas receiving system according to claim 2, characterized in that The electric valves are all connected to the PLC controller (10) via signals.

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