Methanol heat recovery system of distillation atmospheric tower

Abstract

The utility model relates to a methanol heat recovery system of a rectification atmospheric tower, and belongs to the technical field of energy recovery. The methanol heat recovery system for the rectification atmospheric tower comprises an atmospheric tower, the atmospheric tower is connected with the ORC power generation module; the ORC power generation module is connected with the reflux tank; an outlet of the reflux tank is connected with an inlet of the atmospheric tower; a reflux pump and a reflux valve are arranged between the outlet of the reflux tank and the inlet of the atmospheric tower; an extraction pipeline is connected between the reflux pump and the reflux valve, and an extraction valve is arranged on the extraction pipeline. The normal pressure tower top methanol steam is introduced into the ORC power generation module, the problem of 67 DEG C methanol steam heat recovery can be solved, the methanol steam is used for power generation, and the energy utilization efficiency can be remarkably improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy recovery, in particular to a methanol heat recovery system of a rectification atmospheric pressure tower. Background Art

[0002] Methanol is an important basic organic chemical raw material with a wide range of applications. It can be used to produce a series of organic chemical products such as olefins, formaldehyde, dimethyl ether, acetic acid, methyl tert-butyl ether, dimethylformamide, methylamine, methyl chloride, dimethyl terephthalate, methyl methacrylate, synthetic rubber, etc. Methanol is not only an important chemical raw material, but also an excellent energy source and vehicle fuel. It can be added to gasoline or used as a power fuel instead of gasoline. In addition to chemical raw materials and fuels, methanol can also be used as a good solvent in chemical production.

[0003] In the traditional methanol preparation process, the last step is to purify methanol by distillation. In the distillation device, crude methanol is removed from light components by a pre-tower, and then distilled in a high-pressure tower, a pressure tower, and an atmospheric tower to remove heavy components. In order to save steam consumption, the methanol vapor at the top of the high-pressure tower is used as the heat source for the reboiler of the pressure tower, and the methanol vapor at the top of the pressure tower is used as the heat source for the reboiler of the atmospheric tower. The heat coupling of the high-pressure tower and the pressure tower further reduces the energy consumption of distillation. The specific heat and vaporization heat of methanol are 1.32 J / (kg·℃) (25℃) and 35.259 kJ / mol (temperature is 64.7℃), respectively. The methanol vapor at the top of the atmospheric tower (pressure 5 kpa, temperature 67℃) is cooled by a circulating water cooler, which not only causes energy waste, but also consumes a large amount of circulating water. If the heat in the methanol vapor can be further utilized, energy can be saved, emissions can be reduced, and clean energy utilization can be achieved. Utility Model Content

[0004] In view of the problem of insufficient utilization of methanol vapor in the prior art, the utility model provides a methanol heat recovery system for a distillation atmospheric tower to solve the above problem. The utility model introduces the methanol vapor cooled by circulating water in the original distillation atmospheric tower into the ORC power generation device, saving energy, reducing emissions, and realizing clean utilization of energy.

[0005] The technical solution of the utility model is as follows:

[0006] A distillation atmospheric tower methanol heat recovery system comprises an atmospheric tower; the atmospheric tower is connected to an ORC power generation module; the ORC power generation module is connected to a reflux tank; the outlet of the reflux tank is connected to the inlet of the atmospheric tower; a reflux pump and a reflux valve are provided between the outlet of the reflux tank and the inlet of the atmospheric tower; an extraction pipeline is connected between the reflux pump and the reflux valve, and the extraction pipeline is provided with the extraction valve.

[0007] Furthermore, the ORC power generation module includes an evaporator, which is connected to the atmospheric pressure tower, and an evaporator inlet valve is provided between the evaporator and the atmospheric pressure tower; the evaporator is connected to the reflux tank, and an evaporator outlet valve is provided between the evaporator and the reflux tank; the evaporator is connected to the turbine generator; the turbine generator is connected to the condenser; the condenser is connected to the evaporator; and a working fluid feed pump is provided between the condenser and the evaporator.

[0008] When the methanol vapor coming out of the atmospheric pressure tower passes through the evaporator, it exchanges heat with the working fluid in the evaporator. The heated working fluid R245fa (pentafluoropropane) enters the turbine generator to generate electricity. After the turbine generator generates electricity, the working fluid enters the condenser and is then pressurized by the working fluid pump and sent to the evaporator, completing a Rankine cycle.

[0009] Furthermore, the outlet of the atmospheric tower is connected to the inlet of the reflux tank, and a cooler and a cooler inlet valve are provided between the outlet of the atmospheric tower and the inlet of the reflux tank. When the ORC power generation module needs to be shut down or fails, the cooler inlet valve is opened to allow methanol vapor to enter the cooler for condensation, thereby preventing methanol vapor from damaging the ORC power generation module.

[0010] Furthermore, the bottom of the atmospheric tower is connected to the recovery tower. The heavy components separated by atmospheric distillation will accumulate at the bottom of the tower, which will cause the temperature of the atmospheric tower to rise over time, affecting the separation effect of the distillation section. Therefore, a recovery tower is set up to collect the heavy components in time, which effectively improves the distillation efficiency.

[0011] Furthermore, the atmospheric tower is connected to the atmospheric tower reboiler.

[0012] The working principle of the utility model is as follows: the methanol from the atmospheric tower reboiler enters the atmospheric tower, overflows from the top of the atmospheric tower and enters the evaporator in the ORC power generation module, and heats the working fluid in the ORC power generation module in the evaporator. The heated working fluid enters the turbine generator to generate electricity, and the working fluid enters the condenser after the turbine generator generates electricity, and then is pressurized by the working fluid pump and sent to the evaporator to complete a Rankine cycle. The methanol after heat conversion enters the reflux tank, and then passes through the reflux pump, a part of it returns to the atmospheric tower, and a part of it is sent to the refined methanol tank as a methanol product.

[0013] The beneficial effects of the utility model are:

[0014] (1) The utility model introduces the atmospheric pressure tower top methanol vapor into the ORC power generation module, which can solve the problem of heat recovery of 67°C methanol vapor. The use of methanol vapor to generate electricity can significantly improve energy utilization efficiency.

[0015] (2) The ORC power generation module of the utility model is designed in parallel with the original process. When one set fails, it can be switched to another set for operation, which can ensure the normal operation of the distillation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] In the figure, 1-atmospheric pressure tower, 2-evaporator inlet valve, 3-ORC power generation module, 4-cooler inlet valve, 5-evaporator, 6-turbine generator, 7-condenser, 8-working fluid feed pump, 9-cooler, 10-evaporator outlet valve, 11-reflux tank, 12-reflux pump, 13-reflux valve, 14-production valve, 15-atmospheric pressure tower reboiler, 16-recovery tower. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0020] Example 1

[0021] A distillation atmospheric tower methanol heat recovery system comprises an atmospheric tower 1; the atmospheric tower 1 is connected to an ORC power generation module 3; the ORC power generation module 3 is connected to a reflux tank 11; the outlet of the reflux tank 11 is connected to the inlet of the atmospheric tower 1; a reflux pump 12 and a reflux valve 13 are provided between the outlet of the reflux tank 11 and the inlet of the atmospheric tower 1; an extraction pipeline is connected between the reflux pump 12 and the reflux valve 13, and an extraction valve 14 is provided on the extraction pipeline.

[0022] Example 2

[0023] A distillation atmospheric tower methanol heat recovery system comprises an atmospheric tower 1; the atmospheric tower 1 is connected to an ORC power generation module 3; the ORC power generation module 3 comprises an evaporator 5, the evaporator 5 is connected to the atmospheric tower 1, an evaporator inlet valve 2 is arranged between the evaporator 5 and the atmospheric tower 1; the evaporator 5 is connected to a reflux tank 11, an evaporator outlet valve 10 is arranged between the evaporator 5 and the reflux tank 11; the evaporator 5 is connected to a turbine generator 6; the turbine generator 6 is connected to a condenser 7; the condenser 7 is connected to the evaporator 5; a working fluid feed pump 8 is arranged between the condenser 7 and the evaporator 5, The working fluid of the RC power generation module 3 is pentafluoropropane; the outlet of the reflux tank 11 is connected to the inlet of the atmospheric pressure tower 1; a reflux pump 12 and a reflux valve 13 are provided between the outlet of the reflux tank 11 and the inlet of the atmospheric pressure tower 1; the outlet of the atmospheric pressure tower 1 is connected to the inlet of the reflux tank 11, and a cooler 9 and a cooler inlet valve 4 are provided between the outlet of the atmospheric pressure tower 1 and the inlet of the reflux tank 11; an extraction pipeline is connected between the reflux pump 12 and the reflux valve 13, and an extraction valve 14 is provided on the extraction pipeline; the bottom of the atmospheric pressure tower 1 is connected to the recovery tower 16; the atmospheric pressure tower 1 is connected to the atmospheric pressure tower reboiler 15.

[0024] Although the present invention is described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person skilled in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person skilled in the art who is familiar with the present technical field may easily think of changes or substitutions within the technical scope disclosed in the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A distillation atmospheric tower methanol heat recovery system, comprising an atmospheric tower; characterized in that: The atmospheric tower is connected to the ORC power generation module; the ORC power generation module is connected to the reflux tank; the outlet of the reflux tank is connected to the inlet of the atmospheric tower; a reflux pump and a reflux valve are provided between the outlet of the reflux tank and the inlet of the atmospheric tower; a production pipeline is connected between the reflux pump and the reflux valve, and a production valve is provided on the production pipeline.

2. The methanol heat recovery system of the atmospheric distillation tower according to claim 1, characterized in that: The ORC power generation module includes an evaporator, which is connected to a normal pressure tower, and an evaporator inlet valve is provided between the evaporator and the normal pressure tower; the evaporator is connected to a reflux tank, and an evaporator outlet valve is provided between the evaporator and the reflux tank; the evaporator is connected to a turbine generator; the turbine generator is connected to a condenser; the condenser is connected to the evaporator; and a working fluid feed pump is provided between the condenser and the evaporator.

3. The methanol heat recovery system of the atmospheric distillation tower according to claim 2, characterized in that: The working fluid used in the ORC power generation module is pentafluoropropane.

4. The methanol heat recovery system of the atmospheric distillation tower according to claim 1, characterized in that: The outlet of the atmospheric tower is connected with the inlet of the reflux tank, and a cooler and a cooler inlet valve are arranged between the outlet of the atmospheric tower and the inlet of the reflux tank.

5. The methanol heat recovery system of the atmospheric distillation tower according to claim 1, characterized in that: The bottom of the atmospheric tower is connected to the recovery tower.

6. The methanol heat recovery system of the atmospheric distillation tower according to claim 1, characterized in that: The atmospheric tower is connected to the atmospheric tower reboiler.

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