Recycling system for purifying natural gas by-product carbon dioxide and decomposing sodium phenolate
By designing a recycling system for purifying natural gas by-product carbon dioxide decomposition sodium phenol, and using a circulating gas fan and detector to adjust the carbon dioxide concentration, the problems of waste of carbon dioxide resources and carbon emissions after natural gas decarbonization are solved, and effective carbon dioxide recovery and sodium phenol salts are achieved. The decomposition and preparation improves environmental protection.
Patent Information
- Application Number
- CN202420927387.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-29
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-04-29
AI Technical Summary
In the existing natural gas decarbonization process, most of the carbon dioxide gases are directly emptied after separation, resulting in waste of resources and an increase in carbon emissions, and lack of effective recycling methods.
A recycling system for purifying natural gas by-product carbon dioxide decomposition of sodium phenol was designed, and through the MDEA liquid-rich regeneration tower, acid gas cooler, acid gas separator, CO2 gas storage tank, inert gas storage tank and net phenol sodium salt decomposition device. The recycling gas fan and carbon dioxide concentration detector are used to realize the recovery and utilization of carbon dioxide, and are used to purify the decomposition of phenol sodium salt to prepare crude phenol.
The recycling and utilization of carbon dioxide gas is achieved, resource waste is avoided, carbon emissions is reduced, and environmental protection is improved.
Smart Images
Figure CN222226282U_ABST
Abstract
Description
Technical field:
[0001] The utility model relates to a carbon dioxide recovery and utilization system, in particular to a recovery and utilization system for purifying carbon dioxide decomposition sodium phenol which is a byproduct of natural gas. Background technology:
[0002] Synthesis gas and natural gas extracted from formations usually contain some acidic gases such as CO2. According to my country's commodity natural gas index requirements, the CO2 content must be less than 3% (mole%) before it can be exported to civilian users. Therefore, high-CO2 natural gas needs to be decarbonized.
[0003] Solvent absorption is still one of the most mature and widely used decarbonization methods. Solvent absorption is divided into chemical absorption, physical absorption and mixed solvent. Among various solvent absorption methods, the amine method is the most widely used. Among various amine methods, the activated MDEA (N-Methyldiethanolamine) process is the most popular because of its high concentration, high acid gas load, low corrosiveness, low degradation and low volatile loss.
[0004] The activated MDEA (N-methyldiethanolamine) process includes the MDEA rich solution heating regeneration process, and the specific process is as follows: Figure 1 As shown, the MDEA rich liquid flowing out from the bottom of the flash tank passes through the liquid level control valve, and then the MDEA rich liquid enters the upper part of the MDEA rich liquid regeneration tower 1 for desorption and regeneration. The MDEA solution drawn from the middle of the MDEA rich liquid regeneration tower 1 enters the lean liquid-semi-lean liquid heat exchanger 3 and the semi-lean liquid heater 4 through the semi-lean liquid pump 2, and then enters the middle of the MDEA rich liquid regeneration tower 1 for desorption and regeneration. The MDEA lean liquid at the bottom of the MDEA rich liquid regeneration tower is cooled to 400°C by the lean liquid-semi-lean liquid heat exchanger 3 and the lean liquid evaporative air cooler, and then pressurized by the turbine pump side. The pressurized lean liquid enters the lean liquid cooler for cooling and then enters the top of the absorption tower for recycling. The acid gas at the top of the MDEA rich liquid regeneration tower 1 is cooled by the acid gas cooler 5 and then enters the acid gas separator 6. The separated CO2 gas is safely discharged to the highest point, and the separated condensate is pressurized by the reflux pump 7 and then circulated back to the top of the MDEA rich liquid regeneration tower 1. The concentration of separated CO2 is ≥99.5% (dry basis). Direct discharge is a waste of resources and increases the burden on the environment.
[0005] In the phenol oil fractions of high, medium and low temperature coal tar, biomass tar, coal gasification tar and direct or indirect coal liquefaction, all are rich in phenolic compounds and have a wide range of application value. These phenols can be converted into sodium phenolate solution by alkali washing phenol oil, and then decomposed by methods such as sulfuric acid process or carbon dioxide process, thereby obtaining crude phenol. At present, carbon dioxide process is more commonly used to utilize carbon dioxide in flue gas to decompose sodium phenolate to prepare crude phenol. Utility model content:
[0006] The utility model aims to provide a recycling system for purifying the byproduct of natural gas carbon dioxide decomposition sodium phenol, which can realize the recycling of carbon dioxide gas and avoid waste of resources. At the same time, it reduces carbon emissions and is more environmentally friendly.
[0007] The utility model is implemented by the following technical scheme: a recycling system for purifying the sodium phenolate decomposition of the byproduct carbon dioxide of natural gas, which comprises: an MDEA rich liquid regeneration tower 1, an acid gas cooler, an acid gas separator, a CO2 gas storage tank, an inert gas storage tank, a circulating gas fan and a clean sodium phenolate decomposition device; the acid gas outlet at the top of the MDEA rich liquid regeneration tower is connected to the acid gas inlet of the acid gas cooler, the acid gas outlet of the acid gas cooler is connected to the inlet of the acid gas separator; the gas outlet of the acid gas separator is connected to the inlet of the CO2 gas storage tank; the outlet of the CO2 gas storage tank and the outlet of the inert gas storage tank are both connected to the inlet of the circulating gas fan; the outlet of the circulating gas fan is connected to the CO2 inlet of the clean sodium phenolate decomposition device.
[0008] Furthermore, a carbon dioxide concentration detector is provided at the outlet of the circulating air fan, and a regulating valve is provided on the connecting pipe between the outlet of the CO2 gas storage tank and the inlet of the circulating air fan. The carbon dioxide concentration detector is used to detect whether the carbon dioxide in the gas at the outlet of the circulating air fan reaches the carbon dioxide concentration required by the process, and the amount of carbon dioxide added is adjusted by adjusting the opening of the regulating valve so that the carbon dioxide concentration in the gas at the outlet of the circulating air fan reaches the process requirement.
[0009] Furthermore, the net phenol sodium salt decomposition device includes a CO2 decomposition tower, a primary decomposition intermediate tank, a crude phenol acidification feed pump, an acidification decomposition tower, an acidification decomposition intermediate tank, a crude phenol discharge pump, a sulfuric acid acidification unit, a sodium carbonate intermediate tank and a circulating gas buffer tank; the crude phenol primary product outlet of the CO2 decomposition tower is connected to the inlet of the primary decomposition intermediate tank; the outlet of the primary decomposition intermediate tank is connected to the inlet of the crude phenol acidification feed pump; the outlet of the crude phenol acidification feed pump is connected to the feed port of the acidification decomposition tower; the crude phenol outlet of the acidification decomposition tower is connected to the inlet of the acidification decomposition intermediate tank; the outlet of the acidification decomposition intermediate tank is connected to the inlet of the crude phenol discharge pump, and the The outlet of the crude phenol discharge pump is connected to the feed port of the sulfuric acid acidification unit; the bottom sodium carbonate outlet of the CO2 decomposition tower and the bottom sodium carbonate outlet of the acidification decomposition tower are both connected to the inlet of the sodium carbonate intermediate tank; the top lean carbon dioxide gas outlet of the CO2 decomposition tower and the top lean carbon dioxide gas outlet of the acidification decomposition tower are both connected to the air inlet of the circulating gas cooler, the air outlet of the circulating gas cooler is connected to the inlet of the circulating gas buffer tank, and the outlet of the circulating gas buffer tank is connected to the inlet of the circulating gas fan; the outlet of the circulating gas fan is respectively connected to the upper air inlet and the lower air inlet of the CO2 decomposition tower; the outlet of the circulating gas fan is connected to the air inlet of the acidification decomposition tower.
[0010] The utility model has the advantages of a recycling system for purifying the carbon dioxide by-product of natural gas decomposition of sodium phenol, which recovers the carbon dioxide gas separated from natural gas by using the activated MDEA (N-methyldiethanolamine) process and uses it to decompose the pure sodium phenol salt to prepare crude phenol, thus realizing the recycling of carbon dioxide gas and avoiding waste of resources. At the same time, it reduces carbon emissions and is more environmentally friendly. Description of the drawings:
[0011] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0012] Figure 1 This is a schematic diagram of the structure of the MDEA rich liquid heating regeneration process system.
[0013] Figure 2 Schematic diagram of the recovery and utilization system for the decomposition of sodium phenol for purifying the by-product carbon dioxide of natural gas.
[0014] MDEA rich liquid regeneration tower 1, semi-lean liquid pump 2, lean liquid-semi-lean liquid heat exchanger 3, semi-lean liquid heater 4, acid gas cooler 5, acid gas separator 6, reflux pump 7, CO2 gas storage tank 8, inert gas storage tank 9, circulating gas fan 10, carbon dioxide concentration detector 11, regulating valve 12, CO2 decomposition tower 13, primary decomposition intermediate tank 14, crude phenol acidification feed pump 15, acidification decomposition tower 16, acidification decomposition intermediate tank 17, crude phenol discharge pump 18, sulfuric acid acidification unit 19, sodium carbonate intermediate tank 20, circulating gas buffer tank 21, circulating gas cooler 22. Specific implementation method:
[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0016] Example 1: Figure 2 As shown, a recycling system for purifying sodium phenolate produced by decomposing carbon dioxide as a byproduct of natural gas comprises: an MDEA rich liquid regeneration tower 1, an acid gas cooler 5, an acid gas separator 6, a CO2 gas storage tank 8, an inert gas storage tank 9, a circulating gas blower 10 and a clean sodium phenolate decomposition device; the acid gas outlet at the top of the MDEA rich liquid regeneration tower 1 is connected to the acid gas inlet of the acid gas cooler 5, and the acid gas outlet of the acid gas cooler 5 is connected to the inlet of the acid gas separator 6; the gas outlet of the acid gas separator 6 is connected to the inlet of the CO2 gas storage tank 8; the outlet of the CO2 gas storage tank 8 and the outlet of the inert gas storage tank 9 are both connected to the inlet of the circulating gas blower 10.
[0017] A carbon dioxide concentration detector 11 is provided at the outlet of the circulating air fan 10, and a regulating valve 12 is provided on the connecting pipe between the outlet of the CO2 gas storage tank 8 and the inlet of the circulating air fan 10. The carbon dioxide concentration detector 11 is used to detect whether the carbon dioxide in the gas at the outlet of the circulating air fan 10 reaches the carbon dioxide concentration required by the process, and the amount of carbon dioxide added is adjusted by adjusting the opening of the regulating valve 12, so that the carbon dioxide concentration in the gas at the outlet of the circulating air fan 10 reaches the process requirement.
[0018] The net phenol sodium salt decomposition device comprises a CO2 decomposition tower 13, a primary decomposition intermediate tank 14, a crude phenol acidification feed pump 15, an acidification decomposition tower 16, an acidification decomposition intermediate tank 17, a crude phenol discharge pump 18, a sulfuric acid acidification unit 19, a sodium carbonate intermediate tank 20 and a circulating gas buffer tank 21; the crude phenol primary product outlet of the CO2 decomposition tower 13 is connected to the inlet of the primary decomposition intermediate tank 14; the outlet of the primary decomposition intermediate tank 14 is connected to the inlet of the crude phenol acidification feed pump 15; the outlet of the crude phenol acidification feed pump 15 is connected to the feed port of the acidification decomposition tower 16; the crude phenol outlet of the acidification decomposition tower 16 is connected to the inlet of the acidification decomposition intermediate tank 17; the outlet of the acidification decomposition intermediate tank 17 is connected to the inlet of the crude phenol discharge pump 18, and the crude phenol discharge The outlet of the pump 18 is connected to the feed port of the sulfuric acid acidification unit 19; the bottom sodium carbonate outlet of the CO2 decomposition tower 13 and the bottom sodium carbonate outlet of the acidification decomposition tower 16 are both connected to the inlet of the sodium carbonate intermediate tank 20; the top lean carbon dioxide gas outlet of the CO2 decomposition tower 13 and the top lean carbon dioxide gas outlet of the acidification decomposition tower 16 are both connected to the air inlet of the circulating gas cooler 22, the air outlet of the circulating gas cooler 22 is connected to the inlet of the circulating gas buffer tank 21, and the outlet of the circulating gas buffer tank 21 is connected to the inlet of the circulating gas fan 10; the outlet of the circulating gas fan 10 is respectively connected to the upper air inlet and the lower air inlet of the CO2 decomposition tower 13; the outlet of the circulating gas fan 10 is connected to the air inlet of the acidification decomposition tower 16.
[0019] The clean phenol sodium salt from the upstream device is sent to the clean phenol salt tank, and then sent to the upper section of the CO2 decomposition tower 13 by the decomposition feed pump, and the rich CO2 is sent by the circulating gas fan 10 for the first decomposition, and then flows into the lower section, and then decomposed with CO2 for the second time. The generated crude phenol primary product is separated from the Na2CO3 solution in the tower kettle and sent to the primary decomposition intermediate tank 14, and then sent to the acidification decomposition tower 16 by the crude phenol acidification feed pump 15. After carbon dioxide acidification decomposition, it is separated in the separator at the bottom of the acidification decomposition tower 16. The resulting crude phenol is sent to the acidification decomposition intermediate tank 17, and sent to the sulfuric acid acidification unit 19 by the crude phenol discharge pump 18. The Na2CO3 solution separated at the bottom of the two towers enters the sodium carbonate intermediate tank 20, flows to the sodium carbonate storage tank by gravity, and then is sent out of the device by the sodium carbonate discharge pump. The lean CO2 gas escaping from the CO2 decomposition tower 13 and the acidification decomposition tower 16 is cooled to about 45°C by the circulating gas cooler 22 and enters the circulating gas buffer tank 21, and then returns to the inlet of the circulating gas fan 10 for recycling.
[0020] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A system for purifying the carbon dioxide byproduct of natural gas and recycling sodium phenolate by decomposition, characterized in that: It comprises: an MDEA rich liquid regeneration tower, an acid gas cooler, an acid gas separator, a CO2 gas storage tank, an inert gas storage tank, a circulating gas fan and a clean phenol sodium salt decomposition device; the acid gas outlet at the top of the MDEA rich liquid regeneration tower is connected to the acid gas inlet of the acid gas cooler, the acid gas outlet of the acid gas cooler is connected to the inlet of the acid gas separator; the gas outlet of the acid gas separator is connected to the inlet of the CO2 gas storage tank; the outlet of the CO2 gas storage tank and the outlet of the inert gas storage tank are both connected to the inlet of the circulating gas fan; the outlet of the circulating gas fan is connected to the CO2 inlet of the clean phenol sodium salt decomposition device.
2. The system for recycling sodium phenolate from the decomposition of carbon dioxide, a byproduct of purified natural gas, according to claim 1, characterized in that: A carbon dioxide concentration detector is provided at the outlet of the circulating air fan, and a regulating valve is provided on the connecting pipeline between the outlet of the CO2 gas storage tank and the inlet of the circulating air fan.
3. The system for recycling sodium phenolate from the decomposition of carbon dioxide, a byproduct of purified natural gas, according to claim 1 or 2, characterized in that: The net phenol sodium salt decomposition device comprises a CO2 decomposition tower, a primary decomposition intermediate tank, a crude phenol acidification feed pump, an acidification decomposition tower, an acidification decomposition intermediate tank, a crude phenol discharge pump, a sulfuric acid acidification unit, a sodium carbonate intermediate tank and a circulating gas buffer tank; the crude phenol primary product outlet of the CO2 decomposition tower is connected to the inlet of the primary decomposition intermediate tank; the outlet of the primary decomposition intermediate tank is connected to the inlet of the crude phenol acidification feed pump; the outlet of the crude phenol acidification feed pump is connected to the feed port of the acidification decomposition tower; the crude phenol outlet of the acidification decomposition tower is connected to the inlet of the acidification decomposition intermediate tank; the outlet of the acidification decomposition intermediate tank is connected to the inlet of the crude phenol discharge pump, and the crude phenol outlet The outlet of the material pump is connected to the feed port of the sulfuric acid acidification unit; the bottom sodium carbonate outlet of the CO2 decomposition tower and the bottom sodium carbonate outlet of the acidification decomposition tower are both connected to the inlet of the sodium carbonate intermediate tank; the top lean carbon dioxide gas outlet of the CO2 decomposition tower and the top lean carbon dioxide gas outlet of the acidification decomposition tower are both connected to the air inlet of the circulating gas cooler, the air outlet of the circulating gas cooler is connected to the inlet of the circulating gas buffer tank, and the outlet of the circulating gas buffer tank is connected to the inlet of the circulating gas fan; the outlet of the circulating gas fan is respectively connected to the upper air inlet and the lower air inlet of the CO2 decomposition tower; the outlet of the circulating gas fan is connected to the air inlet of the acidification decomposition tower.