Natural gas desulfurization
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Gentlemen, there are many methods for desulfurizing natural gas used in industry. But why hasn’t the method of desulfurization using hydrogen, oxygen, and sodium hydroxide been put into use? Technically, it should work: absorption – 2NaOH + H2S = Na2S + H2O (with excess NaOH); regeneration – 2Na2S + O2 + 2H2O == 4NaOH + S↓. This is just a basic understanding on my part; are there many other side effects or corrosion-related issues as well? I hope some expert will appear and provide an answer!
I remember the oxidation reaction of sodium sulfide does not yield this result. Moreover, even with this result, the sulfur you produce is likely to be unsellable.
It should be this reaction; oxygen is stronger than sulfur. Why does this result in poor sulfur quality?
For other wet oxidation methods (such as the iron-alkali method), the quality of the sulfur produced is also poor!
2Na2S + H2O + 2O2 → Na2S2O3 + 2NaOH
2Na2S + H2O + 2O2 → Na2S2O3 + 2NaOH; I think this is a reaction that occurs when there is an excess of oxygen
It should be during regeneration; due to the alkaline environment, sodium sulfide comes into contact with oxygen and forms various polysulfides, involving numerous side reactions. This is just my humble opinion; I’m not sure what the actual situation is!
I remember that the technical staff from the LPG desulfurization manufacturers said that Na2S could not be regenerated, so H2S had to be removed first before desulfurization in order to reduce the loss of alkaline solution.
This post was last edited by Desert Fish on 2015-8-8 08:50 at http://www.doc88.com/p-442508778760.html. It discusses natural gas dehydration and desulfurization technologies. Hydrogen sulfide does not seem to react with sodium hydroxide under dry conditions; if a sodium hydroxide solution is used, an additional dehydration step is required, and it is difficult to regenerate the absorbent solution back into a sodium hydroxide solution. Compared to physical absorption using organic solvents, this method involves a larger volume of material to be processed but is easier to regenerate, while solid adsorbents are also easier to regenerate than this method
If solid sulfur is produced, mixing it with the solution makes this diversion a problem! It could also be an economic issue!
2Na2S + H2O + 2O2 → Na2S2O3 + 2NaOH. This reaction wasn’t invented by me; it was found in the design documents for the liquefied gas desulfurization unit at Hainan Refining and Chemical Industry Company.