Discussion on the absorption process approach
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This post was last edited by Cloverb on 2010-12-16 09:34. Sodium hypochlorite solution is used to absorb hydrogen sulfide from acetylene gas, and the Radfrac model is employed for simulation. I have analyzed this process: it is a chemical absorption process that involves electrolytes, as well as dissociation and redox reactions of acidic gases in the solution; there should also be a consideration of Henry’s law constants. There are two issues: one is the property calculation method; the ELECNRTL model is used, but this system also contains hydrocarbons ； Second is the setup of reactions; setting both electrolytic reactions and redox reactions makes the calculations very complex. So I would like to ask the experts here whether my analysis is correct. Please give me some guidance; thank you! The redox reaction in the absorption process is as follows: H2S + 4NaClO = H2SO4 + NaCl
I think you need to figure out which reaction is taking precedence and focus on the main issue! Or you could use two radfrac simulations, one taking into account the electrolyte and the other taking into account redox reactions – I’m not sure if that would work
Reply to 3# superyj: The solubility of hydrogen sulfide in water is quite high, so it should be able to absorb a lot of it. But since sodium hypochlorite has been added, it cannot be ignored. You just said that two radfrac units can be used, which would mean washing twice – wouldn’t that result in inaccurate calculations?
It belongs to both the absorption and reactive distillation types; both types of reactions should be included, as it’s not easy to handle ions
There are two types of equilibria: one is the phase equilibrium of aqueous solutions in absorbing H2S, and the other is the chemical equilibrium of the oxidation reaction between H2S and sodium hypochlorite. The former can be described using a conventional absorption model, while the latter is described through an ionic equilibrium model. In my opinion, an electrolyte model, along with the oxidation reaction and its parameters, can be used to simulate this process