Waste gas treatment and heat recovery system of acrylic acid device
By designing the waste gas treatment and heat recovery system, using the combination of waste gas heat exchanger and waste heat boiler, the problem of high temperature after the waste gas treatment of the acrylic device is solved, heat recovery and steam output are achieved, and energy costs are saved.
Patent Information
- Application Number
- CN202323639138.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2033-12-29
AI Technical Summary
The temperature of the waste gas generated by the acrylic device is high after treatment, and there is a problem of energy waste.
A system consisting of exhaust gas heat exchanger, electric heater, exhaust gas reactor, steam superheater and waste heat boiler is designed. The heat of exhaust gas is recovered through the combination of exhaust gas heat exchanger and waste heat boiler, and the waste gas is purified by catalytic combustion. , generate carbon dioxide and water vapor, and increase steam production.
Reducing the temperature of the exhaust gas from 170℃ to 140℃ increases the inlet temperature of the exhaust gas reactor, increases steam production, and saves 1.688 million yuan in steam costs per year.
Smart Images
Figure CN222298594U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of chemical waste gas treatment, and in particular relates to a waste gas treatment and heat recovery system for an acrylic acid device. Background Art
[0002] Acrylic acid units generate waste gas during the production process, which mainly comes from the acrylic acid tail gas discharged from the top of the tail gas absorption tower. These waste gases contain volatile organic compounds (VOCs) such as propylene, propane, formaldehyde, acetaldehyde, acrylic acid, acrolein, acetic acid and ethyl acetate, as well as combustible components such as carbon monoxide. The waste gas generated by the acrylic acid unit can be treated in a variety of ways, such as catalytic combustion technology, adsorption method, condensation recovery method, biological purification method, and plasma purification method; among them, catalytic combustion technology is a commonly used method. Through the action of the catalyst, the organic matter in the waste gas is oxidized and burned at a lower temperature to generate carbon dioxide and water vapor, thereby achieving the purpose of purifying the waste gas and generating steam for recycling. However, the temperature of the treated waste gas is as high as 170°C when it is discharged into the atmosphere through the chimney, which causes energy waste. Utility Model Content
[0003] In order to solve the above technical problems, the utility model provides a waste gas treatment and heat recovery system for an acrylic acid device, which recovers the heat of the waste gas while treating the waste gas, increases steam production and saves energy.
[0004] The utility model adopts the following technical solutions:
[0005] The waste gas treatment and heat recovery system of the acrylic acid device described in the utility model comprises a waste gas heat exchanger, an electric heater, a waste gas reactor, a steam superheater, a waste heat boiler and a chimney. The waste gas heat exchanger is provided with a waste gas inlet and a waste gas outlet. The waste gas inlet is connected to the tail gas outlet of the acrylic acid device. The tail gas outlet of the acrylic acid device is connected in sequence to the waste gas inlet of the waste gas heat exchanger, the electric heater, the waste gas reactor, the steam superheater, the waste heat boiler, the waste gas outlet of the waste gas heat exchanger and the chimney through a waste gas pipeline.
[0006] Preferably, a fan is provided at the tail gas outlet of the acrylic acid device to communicate with the external environment, and the fan is provided with a valve to adjust the air volume entering the system.
[0007] Preferably, the exhaust gas heat exchanger is provided with a bypass pipe, and the bypass pipe is provided with a valve. The temperature of the exhaust gas outlet of the exhaust gas heat exchanger is adjusted by adjusting the air volume of the exhaust gas heat exchanger. The greater the air volume passing through the exhaust gas heat exchanger, the higher the temperature of the exhaust gas outlet.
[0008] Preferably, a second exhaust gas heat exchanger is provided between the exhaust gas outlet of the exhaust gas heat exchanger and the chimney.
[0009] Preferably, the waste heat boiler is provided with a water inlet and a steam outlet, both of which are provided with valves; the waste heat boiler is provided with a bypass pipe, the bypass pipe is provided with a valve, and the exhaust gas outlet of the waste heat boiler is provided with a valve; by adjusting the valve of the waste heat boiler, the steam production of the waste heat boiler is adjusted according to the temperature of the exhaust gas reactor.
[0010] Electric heater: when the exhaust gas temperature of the exhaust gas heat exchanger is low, the electric heater can be used for auxiliary heating.
[0011] The exhaust gas reactor performs catalytic combustion of the exhaust gas to generate carbon dioxide and water vapor, purifies the exhaust gas, and generates heat at the same time.
[0012] Compared with the prior art, the beneficial effects of the utility model are:
[0013] The utility model reduces the temperature of the exhaust gas from 170°C to 140°C, recovers this part of heat, and at the same time increases the inlet temperature of the exhaust gas reactor from 280°C to 309°C. The heat recovery system can increase the system steam production by 0.627kg / h, saving 1.688 million yuan in steam costs each year. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 , schematic diagram of the structure of the waste gas treatment and heat recovery system of the acrylic acid unit;
[0015] In the figure: 1. Waste gas heat exchanger; 2. Electric heater; 3. Waste gas reactor; 4. Steam superheater; 5. Waste heat boiler; 6. Chimney; 7. Acrylic acid device tail gas outlet; 8. Fan. DETAILED DESCRIPTION
[0016] The utility model will be further described below in conjunction with the accompanying drawings.
[0017] like Figure 1 As shown, the waste gas treatment and heat recovery system of the acrylic acid device described in the utility model includes a waste gas heat exchanger 1, an electric heater 2, a waste gas reactor 3, a steam superheater 4, a waste heat boiler 5 and a chimney 6. The waste gas heat exchanger 1 is provided with a waste gas inlet and a waste gas outlet. The waste gas inlet is connected to the tail gas outlet 7 of the acrylic acid device. The waste gas inlet of the waste gas heat exchanger 1, the electric heater 2, the waste gas reactor 3, the steam superheater 4, the waste heat boiler 5, the waste gas outlet of the waste gas heat exchanger 1 and the chimney 6 are connected in sequence from the tail gas outlet 7 of the acrylic acid device through a waste gas pipeline.
[0018] The tail gas outlet 7 of the acrylic acid device is provided with a fan 8, which is connected to the external environment. The fan 8 is provided with a valve to adjust the air volume entering the system.
[0019] The exhaust gas heat exchanger 1 is provided with a bypass pipe, and the bypass pipe is provided with a valve. The temperature of the exhaust gas outlet of the exhaust gas heat exchanger 1 is adjusted by adjusting the air volume of the exhaust gas heat exchanger 1. The greater the air volume passing through the exhaust gas heat exchanger 1, the higher the temperature of the exhaust gas outlet.
[0020] A second exhaust gas heat exchanger 1 is provided between the exhaust gas outlet of the exhaust gas heat exchanger 1 and the chimney 6 .
[0021] The waste heat boiler 5 is provided with a water inlet and a steam outlet, both of which are provided with valves; the waste heat boiler 5 is provided with a bypass pipe, the bypass pipe is provided with a valve, and the exhaust gas outlet of the waste heat boiler 5 is provided with a valve; by adjusting the valve of the waste heat boiler 5, the steam production of the waste heat boiler 5 is adjusted according to the temperature of the exhaust gas reactor 3.
[0022] The working process of this utility model:
[0023] The exhaust gas of the acrylic acid device is supplemented with oxygen in fresh air by the fan 8, and is heated by the waste gas through the exhaust gas heat exchanger 1 using the residual gas, and then enters the electric heater 2. When the exhaust gas temperature of the exhaust gas heat exchanger 1 is low, it can be assisted by the electric heater 2 for heating in the initial stage of start-up; then it enters the exhaust gas reactor 3, and catalytic combustion of the exhaust gas is carried out to generate carbon dioxide and water vapor, purify the exhaust gas, and generate heat at the same time. The heat generated by the exhaust gas reaction is used to heat the unreacted low-temperature exhaust gas. The high-pressure steam superheater 4 superheats the high-pressure steam, and the waste heat boiler 5 generates low-pressure steam. When passing through the exhaust gas heat exchanger 1 again, the exhaust gas newly entering the exhaust gas heat exchanger 1 is preheated, and the residual heat is recovered through the second exhaust gas heat exchanger 1 and discharged through the chimney 6.
Claims
1. An exhaust gas treatment and heat recovery system for an acrylic acid device, characterized in that: The invention comprises a waste gas heat exchanger (1), an electric heater (2), a waste gas reactor (3), a steam superheater (4), a waste heat boiler (5) and a chimney (6). The waste gas heat exchanger (1) is provided with a waste gas inlet and a waste gas outlet. The waste gas inlet is connected to an acrylic acid device tail gas outlet (7). The acrylic acid device tail gas outlet (7) is connected in sequence to the waste gas inlet of the waste gas heat exchanger (1), the electric heater (2), the waste gas reactor (3), the steam superheater (4), the waste heat boiler (5), the waste gas outlet of the waste gas heat exchanger (1) and the chimney (6) through a waste gas pipeline.
2. The waste gas treatment and heat recovery system of the acrylic acid device according to claim 1, characterized in that: The tail gas outlet (7) of the acrylic acid device is provided with a fan (8) which is connected to the external environment, and the fan (8) is provided with a valve.
3. The waste gas treatment and heat recovery system of the acrylic acid device according to claim 1, characterized in that: The exhaust gas heat exchanger (1) is provided with a bypass pipe, and the bypass pipe is provided with a valve.
4. The waste gas treatment and heat recovery system of the acrylic acid device according to claim 1, characterized in that: A second exhaust gas heat exchanger (1) is provided between the exhaust gas outlet of the exhaust gas heat exchanger (1) and the chimney (6).
5. The waste gas treatment and heat recovery system of an acrylic acid device according to claim 1, characterized in that: The waste heat boiler (5) is provided with a water inlet and a steam outlet, and both the water inlet and the steam outlet are provided with valves.
6. The waste gas treatment and heat recovery system of an acrylic acid device according to claim 1, characterized in that: The waste heat boiler (5) is provided with a bypass pipe, the bypass pipe is provided with a valve, and the exhaust gas outlet of the waste heat boiler (5) is provided with a valve.