Regeneration system for carbon-rich amine liquid and application thereof

Abstract

The invention relates to a regeneration system for carbon-rich amine liquid produced by capturing of carbon dioxide in mixed gas and application thereof. The regeneration system consists of a bipolarmembrane electrodialysis device and a carbon dioxide removal device, wherein the bipolar membrane electrodialysis device consists of a bipolar membrane electrodialysis membrane stack which is fixedlyarranged between an anode plate and a cathode plate; the carbon dioxide removal device consists of one or multiple of hollow fiber membrane reactors; an inlet of the carbon dioxide removal device is communicated with an acid chamber outlet of the bipolar membrane electrodialysis device, and an outlet of the carbon dioxide removal device is communicated with an acid liquid storage tank; the carbondioxide gas removed out of the carbon dioxide removal device is collected into the carbon dioxide storage tank. The regeneration system has the advantages that the carbon-rich amine liquid with heat stability is treated by the bipolar membrane electrodialysis and carbon dioxide removal coupling device, so that the independent operation of traditional hot blowing and organic ammonia regeneration isavoided; the energy consumption in carbon capturing is reduced, the technology process is simplified, and the whole carbon dioxide net capturing efficiency is improved.

Description

technical field [0001] The invention belongs to the field of electric-driven membrane separation, and in particular relates to a regeneration system for carbon-rich amine liquid and its application. Background technique [0002] The capture and storage of carbon dioxide is an effective way to control carbon dioxide gas emissions and reduce the concentration of carbon dioxide in the air. The existing carbon dioxide capture and separation methods include solvent absorption method, solid adsorption method, membrane separation method, etc. Among them, the solvent absorption method has higher absorption efficiency for carbon dioxide and is easy to regenerate, so it has been widely used. Common carbon dioxide absorption solvents include organic amines, ionic liquids, and alkali / carbonate absorbents, among which organic amines and alkali / carbonate absorbents are the most common. Solvent absorption method needs to go through four necessary operation units in the process of carbon d...

AI Technical Summary

Problems solved by technology

[0003] Patent US5910611A reports a method for removing heat-stable salts in organic amines by electrodialysis. By adding lye to the carbon-poor amine solution, the heat-stable salts are converted into inorganic salts and neutral organic amines, and then the carbon-poor amines are The liquid is passed into the electrodialysis unit, and the dissociated inorganic salts are removed under the action of the electric field, while the neutral organic amines cannot move under the electric field and are retained. This method usually adopts batch operation until the heat stable salts are completely removed. , but due to the incomplete neutralization of protonated organic amines, material loss will be caused during the electrodialysis process, and at the same time, batch operations will cause changes in pH and ionic strength, causing damage to the ion membrane

[0004] Patent US5292407A reports a production method that utilizes an electrodialysis device with a special structure to convert thermally stable salts into thermally unstable salts, and does not need to add lye to neutralize the process, thereby reducing the loss of organic amines during electrodialysis , but because the thermally unstable anions are usually introduced in the form of acid, the pH of the feed solution is usually very low, which will cause corrosion of the equipment. At the same time, the thermally stable anions will accompany the parasitic migration of the thermally unstable anions, resulting in incomplete removal of thermally stable salts

[0005] Existing studies on the carbon dioxide capture process mostly focus on the process optimization of a single operation unit, without considering how to shorten the entire carbon capture process process, how to reduce the energy consumption in the regeneration of organic amines and the removal of thermally stable salts

Considering the traditional organic amine treatment unit, the disadvantages of poor removal efficiency of thermally stable salts, high organic amine loss rate and secondary pollution

However, the thermal regeneration process of carbon capture agent needs to consume a lot of heat energy, which is an energy-intensive operation, which greatly reduces the net capture efficiency of carbon dioxide. At the same time, the integrated operation of heat stable salt removal and thermal stripping increases the carbon capture process. The technological process improves the operation and maintenance cost of the process

Images