CO2 recovery solution?
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Which method is more suitable for recovering CO2 from industrial gas sources? Chemical absorption, pressure swing adsorption, adsorption distillation, or some other method? The chemical adsorption method using liquid ammonia is generally suitable for CO2 concentrations of 10-20%. Is it feasible to use gas sources with such high concentrations? If combustion is carried out with an excess of air first, CH4, CO, and H2 are converted into CO2 and H2O; by condensing the water, the final gas composition can be adjusted to approximately 15% CO2, 9% O2, and 76% N2. CO2 can then be separated using chemical adsorption, while the heat generated by the combustion process can be used for solvent regeneration. Is this method viable on an industrial scale? Can CH4, CO, and H2 be completely burned? Raw gas flow rate: 5000 Nm3/h; composition (mol%): CH4: 19.2, CO: 8.45, CO2: 48.38, water: 0.86, H2: 23.10
We use pressure swing adsorption, and a recovery and replacement process is employed in this technique, which increases the CO2 concentration from 87% to around 98%; the results are quite good and stable.
I wonder what the pressure of the gas is? The choice of decarbonization technology is closely related to the total pressure and CO2 partial pressure, as well as the intended use of the purified gas. While methods based on alcohol amines are not greatly affected by temperature and pressure, other physicochemical methods are very sensitive to pressure; otherwise, they are not economical. The minimum adsorption pressure of the pressure swing adsorption unit is 0.7 MPa.
Pressure swing adsorption: We use pressure swing adsorption, and this process incorporates a recovery and replacement mechanism that increases the CO2 concentration from 87% to around 98%. The results are quite good, and the performance is stable. Where does your gas supply come from? Have H2, CO, and CH4 been recycled?
I heard that there is now a type of semipermeable membrane that can selectively separate different gases, but it seems to still be in the research phase... It won’t be possible to use it on a large scale in the near future!
What process do you use? With such high levels of CH4:H2:CO being produced, why isn’t it utilized? Isn’t that too much of a waste? Chemical production relies on these several effective gases! ! !
Thank you so much for your suggestion! If considered from two aspects, on the one hand recovering CO2 and on the other hand not disrupting the other gas components, then CO, H2, and CH4 can also be recovered simultaneously. The use of alcohol amines (MEA, MDEA, etc.) as solvents for CO2 adsorption is already quite mature, but could alcohol amines also adsorb CH4, H2, and CO???
It is recommended to have pressure swing adsorption and small Prins separation units, so as to recover CO2 and H2CH4. Are you a designer?
I work on the research and development of CO2 capture from power plant exhaust gases. I’m not very good at design, but I do some as well.
Could you explain pressure swing adsorption and Prinsen separation in more detail? What adsorbent is used for pressure swing adsorption? . ?
Currently, CO2 capture technology is not yet mature, and its cost is too high. But as a technical reserve, Europe has been conducting relevant research; we have just started, and Beihua University and Tsinghua University seem to be working on this. It is recommended that the original poster take a look at materials on this topic.
Europe does place a high emphasis on environmental protection. Although China and the United States are currently major CO2 emitters, the level of CO2 in the atmosphere is primarily the result of a cumulative process, especially during Europe’s Industrial Revolution; therefore, I believe it is only right for them to do more now. In Europe, power plants use post-combustion CO2 capture; the more mature technology for this purpose is chemical adsorption, with MEA or more advanced composite solutions being primarily used. What they value first are environmental factors, followed by economic factors. However, it is not likely that such a solution will become widespread in China at present; we mainly need to consider economic factors, as well as environmental protection considerations.
Does anyone know if MEA has the ability to adsorb CH4?
Pressure swing adsorption, abbreviated as PSA, utilizes the property of adsorbents to have different adsorption capacities for adsorbates at various pressures, as well as their selectivity toward the gas mixtures to be separated at certain adsorption pressures, in order to remove impurity components from the feed gas through pressure-driven adsorption. The adsorbent can be regenerated. We use alumina as the adsorbent.
Using a combustion effect may not yield good results; it’s better to increase CO2 directly.
This post was last edited by eddy-8280103 on 2009-5-16 at 13:44. Ethanolamine solution is used to absorb and regenerate CO2, and for the remaining gas, a methanol production plant with a capacity of nearly two tons per hour can be designed.
It seems we also have carbon dioxide gas sources, but we need to focus on the costs associated with handling it
It is recommended that the gas be absorbed directly; the combustible gas resulting from this absorption is sent to a boiler for combustion, and the steam generated is used in part to heat the solution for regeneration. It’s better to recycle the boiler flue gas directly rather than recycling it after combustion. If the gas source has a pressure of 0.5 MPa or higher, PSA can be used; physical absorption methods are also an option, involving pressure reduction for regeneration and the combustion of the separated gas.
Ideally, CO2 can be separated directly, while the remaining components H2, CO, and CH4 can be used as fuel. The key question is: what solvent can selectively adsorb CO2? Or what method can be used to selectively separate CO2?
Is there a detailed flowchart? If there is one, please send me a copy to take a look