Questions regarding the gas-liquid ratio and acid gas load in MDEA desulfurization? ? ?

This post was last edited by ylb913 on 2016-4-22 at 11:27. The acid gas load of the lean amine solution and the hydrogen sulfide content in the gas are also required. Also, if there is carbon dioxide in the raw materials, it becomes difficult to calculate.

How can it be calculated without sulfur dioxide? A beginner seeking guidance

The acid gas load on the lean liquid is set at 0.4 mol/mol. The hydrogen sulfide content in the feed gas varies, ranging approximately between (0–1.54%), and there is also CO2 present at levels of (0–7.35%). Please help answer!

Actually, I think MDEA selectively absorbs hydrogen sulfide, so CO2 doesn’t need to be considered. Experts, could you help me do the calculations? I want to know how to calculate it: handshake

@The fire contains highly skilled operators; the load of acid gas in the lean liquid is 0.4 mol/mol, with CO2 being ignored. The quality of the lean liquid is excellent. How should this be calculated? Please provide the calculation process

This post was last edited by ylb913 on 2016-4-28 07:17. 1. Since there are requirements regarding the degree of absorption of hydrogen sulfide, but none for carbon dioxide, it is impossible not to absorb carbon dioxide. 2. The maximum allowable acid gas load for the so-called rich amine solution is generally 0.5 mol (H2S+CO2)/mol (MDEA), and carbon dioxide is included in this value. 3. The acid gas load for the lean amine solution that you provided is 0.4 mol/mol, which is clearly incorrect; it’s an extremely high value. The typical value is in the range of 0.00 several. 4. Let’s talk about how the acid gas load is calculated: The concentration of hydrogen sulfide or carbon dioxide in the amine solution is usually expressed in g/l (grams per liter). The molecular weight of hydrogen sulfide is 34, while that of carbon dioxide is 44. The denominator, “liters,” refers to the aqueous solution of MEDA; of course, the concentration of the amine solution is needed for this calculation, and the value given by the original poster, 50%, is used. The density or specific gravity of the amine solution is also required in the calculations; at 40 degrees, it should be around 1.02, so for simplicity, it can be taken as 1.0. The molecular weight of MDEA, which is 119, also needs to be used. (1) Ignoring CO2 for now, 1 g (H2S)/1 L of MDEA aqueous solution = 1 g (H2S)/(1*0.5) L of MDEA = (1/34) mol H2S/(0.5*1000/119) mol MDEA = 0.007 mol H2S/mol MDEA; this represents the normal order of magnitude for the hydrogen sulfide content in lean amine solutions. 0.5 mol H2S/mol MDEA = 0.5/0.007 = 71.4 g (H2S)/1 L (MDEA aqueous solution). or 71.4 kg (H2S)/1 t (MDEA aqueous solution). The difference in hydrogen sulfide content between this rich liquid and the lean liquid is roughly calculated at 70 kilograms of (H2S) per ton of (MDEA aqueous solution). 30,000 standard cubic feet of gas, containing 1.54% hydrogen sulfide by volume; 30,000*1.54% = 462 standard cubic feet of hydrogen sulfide. Dividing this by 22.4 gives 20.63 moles of hydrogen sulfide, and multiplying by 34 results in 701 kg of hydrogen sulfide. Minimum flow rate of the amine solution = 701/70 = 10 tons/hour.

@ylb913, expert, since you’re being so kind, please also write out for me the calculation process for considering CO2. Ultimately, we want to derive a normalized formula.

Our factory also uses MEDA to absorb carbon dioxide. Our factory has been shut down for a year; now that we want to resume production, we need to determine whether this amine solution is still usable and whether it has been oxidized

I think: if your MDEA has protective measures in place, nitrogen water seal protection should be fine. It’s possible to test how much oxidation product there is You can look up relevant information; I’m a beginner too