CN211644593U - Based on CO before burning2Isothermal conversion system of trapping system - Google Patents

Abstract

The utility model discloses an isothermal transformation system based on a pre-combustion _CO2 capture system, comprising a synthesis gas input pipeline, a synthesis gas water separator, a buffer filter, a synthesis gas preheater, an electric heater, a humidifier, Isothermal shift furnace, steam generator, desalted water preheater, shift gas cooler, shift gas water separator, stripper and desalted water buffer tank, this system can effectively solve various problems caused by adiabatic shift, and can The consumption and investment cost are low, the system is relatively simple, and the phenomenon of catalyst bed flying temperature will not occur.

Description

An isothermal shift system based on pre-combustion CO2 capture system

technical field

The utility model relates to an isothermal transformation system, in particular to an isothermal transformation system based on a pre-combustion _CO2 capture system.

Background technique

In recent years, the massive exploitation and use of fossil energy such as coal and oil has greatly increased the amount of carbon dioxide emitted into the atmosphere. In order to reduce CO ₂ emissions, low carbon emission energy should be used to replace high carbon emission energy, which is an important strategic idea for China to establish a non-carbon energy system. Therefore, developing technologies for clean and efficient utilization of energy, improving energy efficiency, and on the other hand capturing and storing CO ₂ to reduce or stabilize the concentration of CO ₂ in the atmosphere are of particular significance for alleviating global warming.

Pre-combustion CO ₂ capture technology is a new type of technology for conversion capture before synthesis gas combustion, and it is an important route for hydrogen production, storage, and coal chemical product production. At present, the first domestic pre-combustion CO ₂ capture system is based on IGCC pre-combustion carbon capture, and adopts processes such as sulfur-tolerant shift, MDEA decarbonization, and wet desulfurization. The transformation system is adiabatic transformation. Due to the high content of CO in the syngas from IGCC, three-stage transformation is adopted, the system is complicated, and the investment and energy consumption are high. During the operation, the catalyst bed is overheated, and the process index is difficult to control.

Utility model content

The purpose of this utility model is to overcome the shortcomings of the above-mentioned prior art, and to provide an isothermal transformation system based on the _CO2 capture system before combustion, which can effectively solve various problems brought about by adiabatic transformation, and reduce energy consumption and investment. The cost is low, the system is relatively simple, and at the same time, the phenomenon of the catalyst bed flying over does not occur.

In order to achieve the above purpose, the isothermal shift system based on the pre-combustion _CO2 capture system described in the present invention includes a synthesis gas input pipeline, a synthesis gas water separator, a buffer filter, a synthesis gas preheater, an electric heater, a Humidifier, isothermal shift furnace, steam generator, desalted water preheater, shift gas cooler, shift gas water separator, stripper and desalted water buffer tank;

The synthesis gas input pipeline is communicated with the inlet of the synthesis gas water separator, and the gas outlet of the synthesis gas water separator is communicated with the inlet of the humidifier through the buffer filter, the heat absorption side of the synthesis gas preheater and the electric heater in turn. , the outlet of the heat-absorbing side of the steam generator is communicated with the inlet of the humidifier, the outlet of the humidifier is communicated with the synthesis gas inlet of the isothermal shift furnace, and the shift gas outlet of the isothermal shift furnace is successively discharged through the syngas preheater. The hot side, the exothermic side of the demineralized preheater and the shift gas cooler are communicated with the inlet of the shift gas water separator, and the shift gas outlet of the shift gas water separator is communicated with the subsequent _CO2 capture and absorption system. The water outlet of the gas water separator, the water outlet of the synthesis gas water separator and the outlet of the low-pressure steam pipeline are all connected with the inlet of the stripping tower, and the outlet of the stripping tower is connected with the inlet of the desalted buffer tank, and the desalted water buffer The outlet of the tank is communicated with the inlet of the endothermic side of the steam generator through the endothermic side of the desalinated preheater, the outlet of the exothermic side of the steam generator is communicated with the inlet of the cold working medium of the isothermal shift furnace, and the cold working medium of the isothermal shift furnace is connected. The outlet of the working medium is communicated with the inlet of the exothermic side of the steam generator.

The outlet of the desalted buffer tank is communicated with the inlet of the absorption side of the desalted preheater through the desalted water pump.

The outlet of the exothermic side of the steam generator is communicated with the inlet of the cold working medium of the isothermal shift furnace through a circulating water pump.

The buffer filter is filled with anti-toxic protective agent.

The syngas preheater is a shell and tube heat exchanger.

A sub-line for temperature regulation is arranged between the heat-absorbing side inlet and the heat-absorbing side outlet of the syngas preheater.

A depth-adjusting sub-line is arranged between the heat-absorbing side inlet and the heat-releasing side outlet of the syngas preheater.

A venting auxiliary line is connected to the syngas outlet of the isothermal shift furnace.

The utility model has the following beneficial effects:

During the specific operation of the isothermal shift system based on the _CO2 capture system before combustion, the syngas is first dried and filtered through the syngas water separator and the buffer filter, so as to filter out the carbon dioxide in the syngas. Impurities such as heavy metals and oxygen-containing substances that make the shift catalyst poisoning and invalid, then enter the isothermal shift furnace, and the syngas is shifted through the isothermal shift furnace. The steam generator is absorbed by the cold medium desalinated water, and the desalted water is vaporized into steam to avoid the phenomenon of overheating of the catalyst bed, and effectively solve various problems caused by adiabatic transformation. Then, it enters the subsequent CO ₂ capture and absorption system after being separated and dried by the shift gas water separator. The system is relatively simple, and the energy consumption and investment cost are low.

Description of drawings

Figure 1 is a schematic structural diagram of the utility model.

Among them, 1 is a syngas water separator, 2 is a buffer filter, 3 is a syngas preheater, 4 is an electric heater, 5 is a humidifier, 6 is an isothermal shift furnace, 7 is a circulating water pump, and 8 is a steam Generator, 9 is a desalted water preheater, 10 is a shift gas cooler, 11 is a shift gas water separator, 12 is a stripper, 13 is a desalted water buffer tank, and 14 is a desalted water pump.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail:

Referring to Figure 1, the isothermal shift system based on the _CO2 capture system before combustion according to the present invention includes a synthesis gas input pipeline, a synthesis gas water separator 1, a buffer filter 2, a synthesis gas preheater 3, an electric heater 4. Humidifier 5, isothermal shift furnace 6, steam generator 8, desalted water preheater 9, shift gas cooler 10, shift gas water separator 11, stripper 12 and desalted water buffer tank 13; syngas The input pipeline is communicated with the inlet of the syngas water separator 1, and the gas outlet of the syngas water separator 1 passes through the buffer filter 2, the heat absorption side of the syngas preheater 3, the electric heater 4 and the humidifier 5 in turn. The inlet of the steam generator 8 is communicated with the inlet of the humidifier 5, the outlet of the humidifier 5 is communicated with the synthesis gas inlet of the isothermal shift furnace 6, and the shift gas outlet of the isothermal shift furnace 6 is communicated with each other. Through the exothermic side of the syngas preheater 3, the exothermic side of the desalinated water preheater 9, and the shift gas cooler 10 in turn, it is communicated with the inlet of the shift gas water separator 11, and the shift gas of the shift gas water separator 11 is connected. The outlet is communicated with the subsequent _CO2 capture and absorption system, the water outlet of the shift gas water separator 11, the water outlet of the synthesis gas water separator 1 and the outlet of the low-pressure steam pipeline are all communicated with the inlet of the stripper 12, and the steam The outlet of the stripping tower 12 is communicated with the inlet of the desalted buffer tank 13, and the outlet of the desalted buffer tank 13 is communicated with the inlet of the endothermic side of the steam generator 8 through the endothermic side of the demineralized preheater 9, and the steam generator The exothermic side outlet of 8 is communicated with the cold working medium inlet of the isothermal shift furnace 6 , and the cold working medium outlet of the isothermal shift furnace 6 is communicated with the exothermic side inlet of the steam generator 8 .

The outlet of the desalted buffer tank 13 is connected to the inlet of the heat absorption side of the desalted water preheater 9 through the desalted water pump 14; the outlet of the heat release side of the steam generator 8 is connected to the inlet of the cold working medium of the isothermal shift furnace 6 through the circulating water pump 7 Pass.

A temperature adjustment sub-line L1 is arranged between the heat-absorbing side inlet and the heat-absorbing side outlet of the syngas preheater 3; L2; the outlet of the synthesis gas of the isothermal shift furnace 6 is connected with a venting sub-line L3, and the depth-adjusting sub-line L2 can lead some or all of the synthesis gas at the inlet of the synthesis gas preheater 3 to the shell side outlet of the synthesis gas preheater 3 , by controlling the flow rate of the synthesis gas flowing into the sub-line L2 for adjusting the depth to control the flow rate of the synthesis gas entering the isothermal shift furnace 6, so as to achieve the required transformation depth; Reach the required furnace temperature.

The buffer filter 2 is filled with an anti-toxic protective agent, and the anti-toxic protective agent can adsorb and filter out impurities such as heavy metals in the syngas that can poison the shift catalyst and fail.

The syngas preheater 3, the steam generator 8 and the desalted water preheater 9 are shell and tube heat exchangers.

The concrete working process of the present utility model is:

The syngas enters the syngas water separator 1 from the boundary area for water separation and drying, wherein the separated syngas enters the buffer filter 2 for filtration, and the filtered syngas enters the syngas preheater 3 and is filtered from the isothermal source. The high temperature shift gas of the shift furnace 6 is heated, and then enters the electric heater 4 for heating. The synthesis gas output by the electric heater 4 is mixed with the medium pressure steam output by the steam generator 8 and then enters the isothermal shift furnace 6 to generate a shift reaction, In order to produce the shift gas, the shift gas enters the syngas preheater 3 for a heat exchange and cooling, and the cooled shift gas enters the desalinated water preheater 9 for secondary heat exchange and cooling, and then enters the shift gas cooler. 10 Carry out three heat exchange and cooling, and then enter the subsequent CO ₂ capture and absorption system after being separated and dried by the shifted gas water separator 11.

The process water separated by the syngas water separator 1 and the shift gas water separator 11 enters the stripper 12, and is mixed with low-pressure steam to extract the acid gas in the water, and the stripped process water enters the desalinated buffer tank 13 For intermediate reuse, the process water in the desalinated buffer tank 13 is pressurized by the desalted water pump 14 and sent to the desalted water preheater 9 to exchange heat with the shift gas output from the syngas preheater 3 and then enter the steam generator 8, Then, it exchanges heat with the boiler feed water output from the isothermal shift furnace 6 to generate intermediate pressure steam, wherein the generated intermediate pressure steam enters the humidifier 5 and mixes with the syngas output from the electric heater 4 and enters the isothermal shift furnace 6 .

In addition, in the initial stage of start-up, the electric heater 4 is put into operation, that is, when the temperature of the syngas output from the syngas preheater 3 does not reach the activation temperature of the shift catalyst, the electric heater 4 turns on the electric heating function. Once the high temperature shift gas is generated in the isothermal shift furnace 6, the low temperature syngas from the buffer filter 2 can be heated by the syngas preheater 3 to make the temperature reach the activation temperature of the shift catalyst, and the electric heating can be turned off at this time. device 4.

The isothermal shift furnace 6 is provided with a number of heat exchange tubes, the gaps of the heat exchange tubes are filled with shift catalysts, the low temperature working medium flowing inside the heat exchange tubes is boiler feed water, and the heat exchange tubes, the circulating water pump 7 and the steam generator 8 constitute a boiler. The circulation loop of the feed water, the boiler feed water is under-saturated, and its function is to remove the heat released by the shift reaction.

Claims (8)

1. Based on CO before burning₂The isothermal conversion system of the capture system is characterized by comprising a synthesis gas input pipeline, a synthesis gas water separator (1), a buffer filter (2), a synthesis gas preheater (3), an electric heater (4), a humidifier (5), an isothermal conversion furnace (6), a steam generator (8), a desalted water preheater (9), a conversion gas cooler (10), a conversion gas water separator (11), a stripping tower (12) and a desalted water buffer tank (13);

the synthesis gas input pipeline is communicated with an inlet of a synthesis gas water separator (1), an air outlet of the synthesis gas water separator (1) is communicated with an inlet of a humidifier (5) through a buffer filter (2), a heat absorption side of a synthesis gas preheater (3) and an electric heater (4) in sequence, an outlet of a heat absorption side of a steam generator (8) is communicated with an inlet of the humidifier (5), an outlet of the humidifier (5) is communicated with a synthesis gas inlet of an isothermal converter (6), a conversion gas outlet of the isothermal converter (6) is communicated with an inlet of a conversion gas water separator (11) through a heat release side of the synthesis gas preheater (3), a heat release side of a desalted water preheater (9) and a conversion gas cooler (10) in sequence, and a conversion gas outlet of the conversion gas water separator (11) is communicated with a subsequent CO₂The collecting and absorbing system is communicated, the water outlet of the shift gas water separator (11), the water outlet of the synthesis gas water separator (1) and the outlet of the low-pressure steam pipeline are communicated with the inlet of the stripping tower (12), the outlet of the stripping tower (12) is communicated with the inlet of the desalted water buffer tank (13), the outlet of the desalted water buffer tank (13) is communicated with the heat-absorbing side inlet of the steam generator (8) through the heat-absorbing side of the desalted water preheater (9), and the heat-releasing side outlet of the steam generator (8) is communicated with the isothermal shift conversionThe cold working medium inlet of the furnace (6) is communicated, and the cold working medium outlet of the isothermal conversion furnace (6) is communicated with the heat release side inlet of the steam generator (8).

2. The pre-combustion CO-based according to claim 1₂The isothermal transformation system of the capture system is characterized in that the outlet of a desalted water buffer tank (13) is communicated with the heat absorption side inlet of a desalted water preheater (9) through a desalted water pump (14).

3. The pre-combustion CO-based according to claim 1₂The isothermal transformation system of the capture system is characterized in that a heat release side outlet of a steam generator (8) is communicated with a cold working medium inlet of an isothermal transformation furnace (6) through a circulating water pump (7).

4. The pre-combustion CO-based according to claim 1₂The isothermal transformation system of the capture system is characterized in that the interior of the buffer filter (2) is filled with an antitoxic protective agent.

5. The pre-combustion CO-based according to claim 1₂The isothermal transformation system of the capture system is characterized in that the synthesis gas preheater (3) is a shell-and-tube heat exchanger.

6. The pre-combustion CO-based according to claim 1₂The isothermal shift system of the capture system is characterized in that a temperature adjustment subline (L1) is arranged between the heat absorption side inlet and the heat absorption side outlet of the synthesis gas preheater (3).

7. The pre-combustion CO-based according to claim 1₂Isothermal shift system for a capture system, characterized in that a depth-control subline (L2) is arranged between the heat-absorption-side inlet and the heat-release-side outlet of the syngas preheater (3).

8. The pre-combustion CO-based according to claim 1₂The isothermal transformation system of the capture system is characterized in that a synthesis gas outlet of the isothermal transformation furnace (6) is communicatedThere is a vent subline (L3).

Images