Reflux system of isothermal transformation furnace
By using the reflux system of the isothermal shift reactor, the temperature of the catalyst bed is reduced by mixing the refluxed syngas with steam, and the temperature of the catalyst bed is adjusted by the quench gas. This solves the problem of local high temperature in the shift reactor, and achieves catalyst protection and methanol production capacity improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2026-03-27
AI Technical Summary
In existing shift reactors, a localized high-temperature core zone easily forms in the middle of the upper bed, leading to catalyst deactivation, reduced reaction rate, and decreased shift gas production, thus affecting methanol synthesis gas supply and production capacity.
An isothermal shift furnace reflux system is adopted to reduce the catalyst bed temperature by mixing refluxed syngas with steam, and to regulate the catalyst bed temperature by using quench gas, thereby protecting the catalyst and enhancing reaction efficiency.
It effectively protects the catalyst, increases the gas volume of the shift reactor, increases the production of methanol synthesis gas, and improves methanol production capacity.
Smart Images
Figure CN224040884U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to calcium carbide furnace gas methanol field, specifically related to a kind of isothermal shift converter backflow system. BACKGROUND
[0002] Calcium carbide furnace gas is typical industrial byproduct gas in calcium carbide (calcium carbide, CaC2) production process, its component composition mainly includes carbon monoxide (CO, 70-90%), hydrogen (H2, 5-20%), methane (CH4, 1-5%) and carbon dioxide (CO2, 1-3%), and contains trace nitrogen and oxygen. Based on the CO component characteristics of its high calorific value, calcium carbide furnace gas catalytic conversion process is generally used to prepare methanol in industry.
[0003] In calcium carbide furnace gas methanol synthesis gas process, gas after purification is handled into shift reactor, CO and water vapor occur reversible water-gas shift reaction under the action of catalyst In view of the high carbon and low hydrogen characteristics of raw material gas, improving CO conversion rate can effectively increase H2 / CO2 molar ratio, and then improve methanol synthesis gas yield. However, limited by the structure characteristics of existing shift reactor, local high-temperature core zone is easily formed in the middle of upper bed layer, if the temperature in the middle of upper bed layer is too high, catalyst deactivation may be caused due to heat accumulation, reaction rate is reduced, shift gas (containing H2 and CO2) generation amount is reduced, and then the supply of methanol synthesis gas is affected, which limits the process gas intake amount per unit time, and finally causes methanol synthesis gas generation efficiency to be reduced, and methanol production capacity is restricted. UTILITY MODEL CONTENTS
[0004] The utility model aims at providing a kind of isothermal shift converter backflow system.
[0005] The utility model is implemented by the following technical solutions:
[0006] A kind of isothermal shift converter backflow system, including humidifier and shift converter, the inlet of the humidifier is connected with calcium carbide furnace gas pipe, the outlet of the humidifier is connected with the top gas inlet of the shift converter by pipeline, the exhaust port of the shift converter is connected with synthesis gas pipe;It further includes an ejector, the synthesis gas inlet of the ejector is connected with the synthesis gas pipe by pipeline, the steam inlet of the ejector is connected with steam pipe, the exhaust port of the ejector is connected with the inlet of the humidifier;Backflow synthesis gas regulating valve is installed on the pipeline between the ejector and the synthesis gas pipe, steam regulating valve is installed on the steam pipe;The calcium carbide furnace gas pipe is also connected with the cold blast gas inlet of the shift converter by pipeline, cold blast gas regulating valve is installed on the pipeline between the calcium carbide furnace gas pipe and the shift converter.
[0007] Preferably, a reflux syngas flow meter is installed at the outlet of the reflux syngas regulating valve, a steam flow meter is installed at the outlet of the steam regulating valve, and a quench gas flow meter is installed at the outlet of the quench gas regulating valve. The signal output terminals of the syngas flow meter, steam flow meter, and quench gas flow meter are all electrically connected to the signal input terminal of the controller. The signal output terminal of the controller is electrically connected to the signal input terminals of the reflux syngas regulating valve, steam regulating valve, and quench gas regulating valve, respectively.
[0008] The advantages of this invention are as follows: a portion of the synthesis gas is refluxed and mixed with steam in the ejector, so that the circulating gas carries water vapor, which can reduce the amount of steam required for the shift reaction in the shift reactor. A portion of the calcium carbide furnace gas is sent into the shift reactor from the catalyst quench gas inlet to reduce the local temperature of the catalyst bed, protect the catalyst, and extend the catalyst's service life. This increases the gas volume in the shift reactor, which in turn increases the production of methanol synthesis gas and consequently increases the methanol production. Attached image description:
[0009] Figure 1 This is a schematic diagram of the structure of this utility model.
[0010] In the diagram: 1. Humidifier; 2. Calcium carbide furnace gas pipe; 3. Syngas pipe; 4. Ejector; 5. Steam pipe; 6. Recirculating syngas regulating valve; 7. Steam regulating valve; 8. Cold quench gas regulating valve; 9. Recirculating syngas flow meter; 10. Steam flow meter; 11. Cold quench gas flow meter; 12. Detailed implementation method:
[0011] like Figure 1 As shown, an isothermal converter reflux system includes a humidifier 1 and a converter 2. The inlet of the humidifier 1 is connected to the calcium carbide furnace gas pipe 3, and the outlet of the humidifier 1 is connected to the top air inlet of the converter 2 via a pipe. The exhaust port of the converter 2 is connected to the syngas pipe 4. It also includes an ejector 5, whose syngas inlet is connected to the syngas pipe 4 via a pipe, whose steam inlet is connected to a steam pipe 6, and whose exhaust port is connected to the inlet of the humidifier 1. A reflux syngas regulating valve 7 is installed on the pipe between the ejector 5 and the syngas pipe 4, and a steam regulating valve 8 is installed on the steam pipe 6. The calcium carbide furnace gas pipe 3 is also connected to the quench gas inlet of the converter 2 via a pipe, and a quench gas regulating valve 9 is installed on the pipe between the calcium carbide furnace gas pipe 3 and the converter 2.
[0012] During production, calcium carbide furnace gas is fed into humidifier 1 from calcium carbide furnace gas pipe 3 to increase its moisture content. After mixing, it is sent to shift reactor 2 to undergo a shift reaction. The resulting syngas is discharged from syngas pipe 4 to the methanol washing process. A portion of the syngas is refluxed and mixed with steam from steam pipe 6 in ejector 5. Then, it is sent back to humidifier 1 along with the calcium carbide furnace gas. The process parameters for the refluxed syngas are: pressure 2.0 MPa, temperature 200℃, and flow rate 20000 Nm³. 3 The steam process parameters are pressure 4.0 MPa, temperature 430℃, and flow rate 14000 kg / h, which allows the circulating gas to carry its own water vapor, reducing the amount of steam required for the conversion reaction in converter 2. The flow rate is regulated by a self-regulating valve group consisting of reflux syngas regulating valve 7 and steam regulating valve 8. A portion of the calcium carbide furnace gas from calcium carbide furnace gas pipe 3 is fed into converter 2 through the catalyst quench gas regulating valve 9 from the catalyst quench gas inlet of converter 2 to reduce the local temperature of the catalyst bed, protect the catalyst, and extend its service life. This increases the gas volume in converter 2, leading to an increase in subsequent methanol synthesis gas production and ultimately an increase in methanol production.
[0013] A reflux syngas flow meter 10 is installed at the outlet of the reflux syngas regulating valve 7, a steam flow meter 11 is installed at the outlet of the steam regulating valve 8, and a quench gas flow meter 12 is installed at the outlet of the quench gas regulating valve 9. The signal output terminals of the syngas flow meter, steam flow meter 11, and quench gas flow meter 12 are all electrically connected to the signal input terminal of the controller. The signal output terminal of the controller is electrically connected to the signal input terminals of the reflux syngas regulating valve 7, steam regulating valve 8, and quench gas regulating valve 9, respectively. The reflux syngas flow rate is detected by the reflux syngas flow meter 10, and the steam flow rate is detected by the steam flow meter 11. The opening of the reflux syngas regulating valve 7 and the steam regulating valve 8 is adjusted by detecting the real-time flow rate to keep their ratio stable. The quench gas flow meter 12 is used to detect the flow rate of calcium carbide furnace gas entering the converter 2 through the quench gas inlet. The opening of the quench gas regulating valve 9 can be adjusted according to the furnace temperature and flow rate.
[0014] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An isothermal reformer reflux system comprising a humidifier and a reformer, the inlet of the humidifier being connected with a calcium carbide furnace gas pipe, the outlet of the humidifier being connected with the top gas inlet of the reformer through a pipe, and the exhaust outlet of the reformer being connected with a synthesis gas pipe, characterized in that, It also includes an ejector, the synthesis gas inlet of the ejector is connected with the synthesis gas pipe through a pipe, the steam inlet of the ejector is connected with a steam pipe, the exhaust port of the ejector is connected with the inlet of the humidifier; a backflow synthesis gas regulating valve is installed on the pipe between the ejector and the synthesis gas pipe, a steam regulating valve is installed on the steam pipe; the calcium carbide furnace gas pipe is also connected with the cold blast inlet of the shift converter through a pipe, a cold blast regulating valve is installed on the pipe between the calcium carbide furnace gas pipe and the shift converter.
2. An isothermal reformer return system according to claim 1, wherein, A backflow synthesis gas flow meter is installed at the outlet of the backflow synthesis gas regulating valve, a steam flow meter is installed at the outlet of the steam regulating valve, a cold blast flow meter is installed at the outlet of the cold blast regulating valve, the signal output ends of the synthesis gas flow meter, the steam flow meter and the cold blast flow meter are electrically connected with the signal input end of the controller, the signal output end of the controller is electrically connected with the signal input ends of the backflow synthesis gas regulating valve, the steam regulating valve and the cold blast regulating valve respectively.