Is there any use of limestone slurry for desulfurizing natural gas?

I would like to ask everyone: 1. Has anyone encountered the use of limestone slurry for removing H2S from natural gas? 2. Should the disposal of such waste be considered as hazardous waste? What are the main components of its waste residue? 3. Is the substance CaSx stable? Does anyone know? Thank you all!

I would like to know whether desulfurization using limestone slurry produces CaSx, and if there are any other components as well Is the substance CaSx stable? Does it have severe environmental pollution characteristics? I couldn’t find any relevant information online, so I came here to ask everyone for help.

Your desulfurization process is incorrect. If only a small amount is involved, treating it with limestone slurry will naturally result in waste residue; if the quantity is large, it is recommended to use the CLAUS desulfurization process to produce sulfur, which is in high demand these days.

I’ve never heard of using limestone slurry to remove H2S. The common methods are to use MDEA, MEA, mannitol, or NaOH to remove hydrogen sulfide. I’ve never come across the method you mentioned!

H2S is generally removed using the Claus process, right?

However, the operator did use limestone slurry to remove H2S from the natural gas, and the H2S concentration at its highest level was over 10 g/m3; it is likely that the removal was not thorough. Now waste residue needs to be dealt with, but the composition of this residue is unknown.

It’s not the time to consider what process to use for desulfurization; limestone slurry desulfurization has already been employed, and waste residue has been generated. Now we need to deal with this waste residue, but I’m not sure of its exact composition.

It’s impossible to form CaSx, and sulfur in natural gas isn’t in its elemental form either. Calcium sulfide. Chemical name: Calcium sulfide (CaS). Chemical description: Chemical formula CaS. Molecular weight 72.14. White cubic crystal system. The one containing impurities is light yellow. Relative density 2.5, refractive index 2.137. It dissolves in water or undergoes hydrolysis upon contact with moisture. Slightly soluble in alcohol. It decomposes in humid air and is oxidized in dry air. It decomposes rapidly in the presence of acids, releasing H2S. It reacts with chlorine and iodine to yield elemental sulfur. Uses: Used to make luminous paints, as well as in the pharmaceutical industry, heavy metal treatment, and environmental protection. Production method: It is produced by heating calcium sulfate powder with coke or wood chips at high temperatures. Alternatively, it is prepared by passing a mixture of H2S and H2 at 1000 degrees Celsius over calcium carbonate until no water vapor is produced, then continuing to pass the same gas mixture with H2 for a few more minutes and subsequently cooling it. So it can’t be CaSx. The equations for the desulfurization reaction are: SO2 + H2O → H2SO3; CaCO3 + 2H2SO3 → Ca(HSO3)2 + CO2 + H2O; Ca(HSO3)2 + O2 + 2H2O → CaSO4·2H2O + H2SO4; CaCO3 + H2SO4 + H2O → CaSO4·2H2O + CO2. This post was last edited by terry921 on 2008-1-25 at 16:54

In the coal used by power plants, mixing quicklime with the coal can achieve sulfur removal

However, natural gas contains H2S and SO2; H2S is a weak acid that can react with Ca(OH)2 in the limestone slurry to form CaS or CaSx. It is preliminarily assumed that after using limestone slurry to remove H2S and SO2 from natural gas, the waste residue will contain substances such as CaS, CaSx, CaSO3, and Ca(OH)2 that did not participate fully in the reaction. The problem I am facing is that these mixed substances have very small particles; although their surfaces are solidified, the material beneath the surface still has a high moisture content, giving it good fluidity (slipperiness). I am considering using landfilling as a disposal method, but if these materials are simply dumped there, their stability will likely be poor. Landfilling machinery or vehicles will slip when moving over them, which poses difficulties for the landfilling process. Therefore, I am currently testing the use of fly ash to solidify these materials (mainly by removing the moisture from them and increasing internal friction). I would like to ask if anyone can recommend other curing agents, what their components are, and what their prices are

Exactly, because the H2S removal method I’ve been researching also does not involve limestone slurry; however, they might have already started using limestone slurry for H2S removal before a scientific method was found.

Excuse me, friend on the second floor, what kind of curing agent should be used to cure this type of waste residue? Are there any recommendations? Could you please explain its ingredients and price?

Sulfur-containing natural gas contains hydrogen sulfide, organic sulfur (thiols), carbon dioxide, saturated water, and other impurities; therefore, it is necessary to remove these harmful components. The commonly used methods for desulfurization and dewaxing include liquid desulfurization and fixed-bed desulfurization. The currently more mature and viable liquid desulfurization process in China is the alcohol amine method; since mercaptans are also present in sulfur-containing natural gas, the sulfone amine method can be used to remove hydrogen sulfide and mercaptans. This process is relatively mature; it can remove hydrogen sulfide from natural gas to levels of ≤7 mg/m3. Meanwhile, the average removal rate of thiols in natural gas is 75%, resulting in a thiol sulfur content in the resulting natural gas of 125 mg/m3. This level does not meet the technical requirement of thiol sulfur levels ≤16 mg/m3. In such cases, a fixed-bed desulfurization process, such as a molecular sieve desulfurization process, can be used to remove the remaining thiols from natural gas.

Check the information on IGCC; generally, the limestone-gypsum method is not used for removal

We handle waste gas treatment from power plant boilers; we only remove sulfur dioxide, as it’s difficult to deal with hydrogen sulfide

They have become accustomed to it; these days many property owners do choose lime desulfurization, and one of our clients is exactly that. The effect is still quite good; it meets the requirements. The key issue is the waste disposal problem you mentioned, as well as whether CAS is stable and safe; please look up more information on this.