A chloroform distillation tower energy-saving production system

Abstract

The utility model relates to the technical field of methane chloride product production, and specifically to an energy-saving production system for a chloroform distillation tower, including a feed preheater, a distillation tower, a gas compressor, a waste heat reboiler, a steam reboiler, a tower top material cooler, a tower bottom material cooler, a reflux tank, a discharge pump and a reflux pump. The utility model heats and pressurizes the tower top material steam through the compression effect of the gas compressor, and then uses it as a heat source for the waste heat reboiler at the bottom of the distillation tower, so that the high latent heat carried in the material steam is effectively utilized, while saving the external steam consumption, it also reduces the consumption of circulating water of the tower top condenser. In addition, the tower top material that releases the latent heat continues to preheat the feed material of the distillation tower, increases the feed temperature, and realizes the gradient utilization of energy.

Description

Technical Field

[0001] The utility model relates to the technical field of methane chloride product production, in particular to an energy-saving production system for a chloroform distillation tower. Background Art

[0002] Chloroform is a commonly used organic solvent and industrial raw material, widely used in organic synthesis and chemical production, such as the manufacture of Freon refrigerants. It is also used in the production of dyes, pharmaceuticals, and other chlorine-containing compounds, and is in high market demand. In the medical field, chloroform is used as an inhalation anesthetic due to its low toxicity and good permeability. The anesthetic effect is rapid and the depth is easily controlled, making surgical procedures smoother and safer. In addition, chloroform can be used as a drug solvent or carrier, helping drugs penetrate tissues or organs better and improving their efficacy.

[0003] In industrial production, polychloromethanes are commonly produced through a thermal chlorination reaction between chlorine and monochloromethane. These polychloromethanes are then separated and purified in subsequent refining units to yield dichloromethane, chloroform, and carbon tetrachloride. This process offers a simple process, high yield, and high product purity. Currently, the chloroform distillation towers in refining units are generally conventional, energy-intensive, and their steam consumption accounts for a significant portion of product costs. Therefore, effectively reducing steam consumption in these towers is crucial for lowering production costs and improving enterprise competitiveness.

[0004] Chinese patent CN214181843U discloses a chloroform distillation device. The device adopts a dual-tower thermal coupling method of a low-pressure distillation tower and a pressurized distillation tower. The overhead steam of the pressurized distillation tower is used as the heat source for the reboiler of the low-pressure distillation tower, achieving energy saving. However, this method has the problems of complex process, large equipment investment and high operation difficulty. Therefore, how to efficiently achieve energy saving and emission reduction of chloroform distillation tower has become a common concern of many companies. Utility Model Content

[0005] In order to overcome the deficiencies of the above-mentioned prior art, the utility model provides an energy-saving production system for a chloroform distillation tower. The temperature and pressure of the tower top material vapor are increased by the compression action of a gas compressor 5, and then the vapor is used as a heat source for a waste heat reboiler 3 at the bottom of the distillation tower. After the tower top material vapor releases latent heat in the waste heat reboiler 3, it is used to preheat a feed preheater 1, thereby realizing effective utilization of the energy gradient and reducing the amount of circulating water used in the tower top material cooler 6, thereby achieving the purpose of energy conservation and emission reduction.

[0006] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0007] A chloroform distillation tower energy-saving production system comprises a feed preheater 1, a distillation tower 2, a waste heat reboiler 3, a gas compressor 5, a tower top material cooler 6, and a reflux tank 7.

[0008] The top outlet of the distillation tower 2 is connected to the inlet of the gas compressor 5, the outlet of the gas compressor 5 is connected to the heat source inlet of the waste heat reboiler 3, the heat source outlet of the waste heat reboiler 3 is connected to the heat source inlet of the feed preheater 1, the heat source outlet of the feed preheater 1 is connected to the material inlet of the top material cooler 6, and the material outlet of the top material cooler 6 is connected to the inlet of the reflux tank 7; the liquid phase outlet of the reflux tank 7 is respectively connected to the reflux inlet of the distillation tower 2 and the external equipment through a reflux pump 8, so that part of the chloroform is refluxed to the distillation tower 2, and the qualified chloroform product is output outside the boundary;

[0009] The material outlet of the feed preheater 1 is connected to the material inlet of the distillation tower 2.

[0010] Furthermore, the bottom material outlet of the distillation tower 2 is connected to the material inlet of the waste heat reboiler 3, the material inlet of the steam reboiler 4, and the material inlet of the bottom material cooler 9 respectively;

[0011] The material outlet of the waste heat reboiler 3 and the material outlet of the steam reboiler 4 are respectively connected to the material inlet of the bottom of the distillation tower 2;

[0012] The material outlet of the tower bottom material cooler 9 is connected to a discharge pump 10 for discharging the heavy components at the tower bottom.

[0013] Furthermore, the heat source inlet and the heat source outlet of the steam reboiler 4 are both connected to an external heat source system.

[0014] Furthermore, the reflux tank 7 is provided with a top gas phase outlet for discharging non-condensable gas.

[0015] Furthermore, the refrigerant inlets and outlets of the tower top material cooler 6 and the tower bottom material cooler 9 are connected to a public utility circulating water system.

[0016] Preferably, the distillation tower 2 is a plate tower, and the tower tray type is an F1 float valve tower tray.

[0017] The utility model provides an energy-saving production system for a chloroform distillation tower. The material vapor produced at the top of the chloroform distillation tower 2 contains a large amount of latent heat, but the temperature of the material vapor is low and cannot be used directly. The material vapor at the top of the tower is heated and pressurized by the compression action of a gas compressor 5, and then used as a heat source for a waste heat reboiler 3 at the bottom of the distillation tower. This effectively utilizes the high latent heat carried in the material vapor at the top of the tower, reduces the amount of external steam used, and simultaneously, after the material vapor at the top of the tower releases the latent heat in the waste heat reboiler 3, preheats the feed to the distillation tower 2, thereby realizing effective utilization of the energy gradient and achieving the purpose of energy saving.

[0018] Preferably, the raw material inlet temperature of the feed preheater 1 is 30-40°C, the top temperature of the distillation tower 2 is 60-68°C, and the top pressure of the distillation tower 2 is 10-18KPa (gauge pressure); after the material vapor is compressed, the outlet pressure of the gas compressor 5 is 0.51-0.64MPa (gauge pressure) and the outlet temperature is 164-176°C; the temperature at the material outlet of the top material cooler 6 and the bottom material cooler 9 is 40-50°C; the mass reflux ratio of the distillation tower 2 is 2.2-2.6.

[0019] The beneficial effects of the utility model are:

[0020] 1. The utility model provides an energy-saving production system for a chloroform distillation tower. The temperature and pressure of the overhead material vapor are increased by the compression action of a gas compressor 5, and then the vapor is used as a heat source for a waste heat reboiler 3 at the bottom of a distillation tower 2. This effectively utilizes the high latent heat carried in the overhead material vapor, reduces the amount of external steam, and also reduces the amount of circulating water used in the overhead material cooler 6. Compared with conventional distillation tower separation processes, the utility model saves steam consumption by approximately 60%-75%.

[0021] 2. The utility model adds a feed preheater 1. The steam of the material at the top of the distillation tower 2 releases latent heat in the waste heat reboiler 3 and then enters the feed preheater 1, and then preheats the feed of the distillation tower 2, thereby realizing the effective utilization of energy gradient. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the energy-saving production system of chloroform distillation tower provided by the utility model;

[0023] Among them, 1. Feed preheater; 2. Distillation tower; 3. Waste heat reboiler; 4. Steam reboiler; 5. Gas compressor; 6. Top material cooler; 7. Reflux tank; 8. Reflux pump; 9. Bottom material cooler; 10. Discharge pump. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Example 1:

[0026] like Figure 1 As shown, a chloroform distillation tower energy-saving production system includes an inlet and outlet feed preheater 1, a distillation tower 2, a waste heat reboiler 3, a steam reboiler 4, a gas compressor 5, a tower top material cooler 6, a reflux tank 7, a reflux pump 8, a tower bottom material cooler 9 and a discharge pump 10. The chloroform distillation tower 2 is a plate tower, and the tower tray type is an F1 float valve tower tray.

[0027] The top outlet of the distillation tower 2 is connected to the inlet of the gas compressor 5, the outlet of the gas compressor 5 is connected to the inlet of the heat source of the waste heat reboiler 3, the heat source outlet of the waste heat reboiler 3 is connected to the inlet of the heat source of the feed preheater 1, the outlet of the heat source 1 of the feed preheater is connected to the material inlet of the top material cooler 6, the material outlet of the top material cooler 6 is connected to the inlet of the reflux tank 7, the liquid phase outlet of the reflux tank 7 is connected to the inlet of the reflux pump 8, and the outlet of the reflux pump 8 is respectively connected to the reflux inlet of the distillation tower 2 and external equipment, so that part of the chloroform is refluxed to the distillation tower 2, and the qualified chloroform product is output outside the boundary, and the non-condensable gas inside the system is discharged from the top gas phase outlet of the reflux tank 7.

[0028] The raw materials are fed into the distillation tower 2 through the feed preheater 1 and the material inlet of the distillation tower 2 .

[0029] The material outlet at the bottom of the distillation tower 2 is connected to the material inlet of the waste heat reboiler 3 and the material inlet of the steam reboiler 4, respectively. The material outlet of the waste heat reboiler 3 and the material outlet of the steam reboiler 4 are respectively connected to the material inlet at the bottom of the distillation tower 2. The temperature and pressure of the material vapor at the top of the distillation tower 2 are increased by the compression action of the gas compressor 5, and then used as the heat source for the waste heat reboiler 3 at the bottom of the distillation tower 2. After releasing the latent heat in the waste heat reboiler 3, the material vapor at the top of the distillation tower 2 is used to preheat the feed of the distillation tower 2, thereby realizing the effective utilization of the energy gradient and reducing the amount of circulating water used in the top material cooler 6.

[0030] The material outlet at the bottom of the distillation tower 2 is also connected to the material inlet of the bottom material cooler 9 , and the material outlet of the bottom material cooler 9 is connected to the inlet of the discharge pump 10 .

[0031] The heat medium inlet and outlet of the steam reboiler 4 are both connected to the external heat source system, and the refrigerant inlets and outlets of the tower top material cooler 6 and the tower bottom material cooler 9 are connected to the public engineering circulating water system.

[0032] In this embodiment, the raw material inlet temperature of the feed preheater 1 is 31°C, the top temperature of the distillation tower 2 is 65°C, and the top pressure of the distillation tower 2 is 13 kPa (gauge pressure); the material outlet pressure after compression by the gas compressor 5 is 0.53 MPa (gauge pressure), and the outlet temperature is 166°C; the top material cooler 6 is cooled by circulating water, and the material outlet temperature of the top material cooler 6 after cooling is 42°C, and the material outlet temperature of the bottom material cooler 9 after cooling is 46°C; the mass reflux ratio of the distillation tower 2 is 2.3.

[0033] Calculations show that the chloroform distillation tower energy-saving production system provided in this embodiment saves steam consumption by approximately 65% ​​compared with a conventional distillation tower separation process (i.e., the feed preheater 1 and the gas compressor 5 are not used; the raw material is added to the distillation tower 2 through the material inlet of the distillation tower 2; the top material vapor of the distillation tower 2 enters the top material cooler 6 through the top outlet of the distillation tower 2 and the material inlet of the top material cooler 6; the heat medium inlet and heat medium outlet of the waste heat reboiler 3 are both connected to an external heat source system; and the remaining processes are the same as those of this embodiment), thereby achieving energy-saving production.

[0034] Example 2:

[0035] A chloroform distillation tower energy-saving production system. This embodiment differs from Example 1 in that a raw material inlet temperature is 38°C, a top temperature of a chloroform distillation tower 2 is 66°C, and a top pressure of the chloroform distillation tower 2 is 17 kPa (gauge pressure); after compression by a gas compressor 5, the material outlet pressure is 0.61 MPa (gauge pressure), and the outlet temperature is 173°C; a top material cooler 6 is cooled by circulating water; after cooling, the material outlet temperature of the top material cooler 6 is 48°C, and the material outlet temperature of the bottom material cooler 9 is 43°C; and a mass reflux ratio of the chloroform distillation tower 2 is 2.5.

[0036] Calculations show that the chloroform distillation energy-saving tower production system provided in this embodiment saves approximately 73% of steam consumption compared with a conventional distillation tower separation process (i.e., the feed preheater 1 and the gas compressor 5 are not used; the raw material is added to the distillation tower 2 through the material inlet of the distillation tower 2; the overhead material vapor of the distillation tower 2 enters the overhead material cooler 6 through the top outlet of the distillation tower 2 and the material inlet of the overhead material cooler 6; the heat medium inlet and heat medium outlet of the waste heat reboiler 3 are both connected to an external heat source system; and the remaining processes are the same as those of this embodiment).

Claims

1. A chloroform distillation tower energy-saving production system, characterized in that: It includes a feed preheater (1), a distillation tower (2), a waste heat reboiler (3), a gas compressor (5), a tower top material cooler (6), and a reflux tank (7); The top outlet of the distillation tower (2) is connected to the inlet of the gas compressor (5), the outlet of the gas compressor (5) is connected to the heat source inlet of the waste heat reboiler (3), the heat source outlet of the waste heat reboiler (3) is connected to the heat source inlet of the feed preheater (1), the heat source outlet of the feed preheater (1) is connected to the material inlet of the top material cooler (6), the material outlet of the top material cooler (6) is connected to the inlet of the reflux tank (7); the liquid phase outlet of the reflux tank (7) is respectively connected to the reflux inlet of the distillation tower (2) and external equipment through a reflux pump (8); The material outlet of the feed preheater (1) is connected to the material inlet of the distillation tower (2); the tower bottom material outlet of the distillation tower (2) is respectively connected to the material inlet of the waste heat reboiler (3), the material inlet of the steam reboiler (4), and the material inlet of the tower bottom material cooler (9); the material outlet of the waste heat reboiler (3) and the material outlet of the steam reboiler (4) are respectively connected to the tower bottom material inlet of the distillation tower (2).

2. The chloroform distillation tower energy-saving production system according to claim 1, characterized in that: The material outlet of the tower bottom material cooler (9) is connected to a discharge pump (10).

3. The chloroform distillation tower energy-saving production system according to claim 1, characterized in that: The heat source inlet and the heat source outlet of the steam reboiler (4) are both connected to an external heat source system.

4. The chloroform distillation tower energy-saving production system according to claim 1, characterized in that: The reflux tank (7) is provided with a top gas phase outlet for discharging non-condensable gas.

5. The chloroform distillation tower energy-saving production system according to claim 1, characterized in that: The refrigerant inlet and outlet of the tower top material cooler (6) and the tower bottom material cooler (9) are connected to a public utility circulating water system.

6. The chloroform distillation tower energy-saving production system according to claim 1, characterized in that: The distillation tower (2) is a plate tower, and the tower tray type is an F1 floating valve tower tray.

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