Molecular sieve desulfurization of coking liquefied gas
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In the delayed coking unit, in the liquefied gas desulfurization section, the dual-desorption method is currently used to remove hydrogen sulfide and thiol compounds; however, recently the total sulfur level has exceeded the specified limits, and analysis has shown that it is due to sulfides. Can molecular sieves be used to remove them? How should the process be designed?
Does the author mean the content of sulfides in total sulfur after double desulfurization? So, what are the amounts of hydrogen sulfide and organic sulfur in the total sulfur content after the liquefied gas desulfurization tower? Is the concentration of the alkali solution used for desulfurizing the fiber membrane normal? Try changing the alkali solution. Also, what type of tray is used in the liquefied gas desulfurization tower?
What is the standard? Is it 343 mg/Nm3 for total sulfur or some other parameter? What type of thioether is it: a disulfide, or a monothioether? It would be best to analyze the sulfur morphology, oh! Molecular sieves can certainly be used for removal, though the cost is higher.
It also depends on what the target value is; perhaps the molecular sieve method won’t be necessary. It needs to be analyzed in detail!
What catalyst are you using? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
The standard is 343; it should be a monothioether
It is after double dehydration; the hydrogen sulfide level is 0. The catalyst we use is cobalt titanium cyanosulfide, and the concentration of the alkaline solution used as a catalyst is around 13–15
It would be better to briefly explain the analysis methods – were it GC-SCD, FPD, or AED analysis? Is quantification possible? It is recommended to compare the liquefied vapor form of sulfur after amine washing and after alkali washing. If it is confirmed to be a monothiether, make adjustments from the absorption stabilization system. Alkali washing cannot remove monothiols. The adsorption method is costly, and waste gas is also generated during the regeneration of the adsorbent.
The alkali washing method indeed cannot remove components such as thioethers; therefore, a gas separation unit is needed for separation. If the coking liquefied gas is to be sold externally, separation operations must be carried out upstream to remove the heavier components more thoroughly.
After catalytic desulfurization of liquefied gas, both hydrogen sulfide and thiol are at 0 levels, while the total sulfur content is above 20, ranging from 50 to 60 at most. Is it mainly sulfur ethers that are present? How to adjust from absorption stability?