LPG desulfurization
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In a delayed coking unit, during liquefied gas desulfurization and denaturation, the concentration of the alkaline solution is fine, but the total sulfur content after desulfurization is above the specified limit. What usually causes this?
This post was last edited by ylb913 on 2015-12-18 20:28: alkali solution concentration, catalyst concentration, air injection volume, and back-extraction efficiency. Alkali solution circulation volume. The size of the equipment (both of our previous expansions of the installation **improved the efficiency of desulfurization or removal, as well as my own performance). Generally, a high COS level makes it impossible for the liquefied gas desulfurization unit to function properly.
The magnitude of the main air flow; furthermore, some of the thiols produced in coking cannot be removed using conventional methods
There can be various reasons; each case needs to be analyzed on its own. The total sulfur content in coker liquefied gas is already relatively high, and if there are issues with aspects such as the air injection volume in the desulfurization system or its regeneration efficiency, these will further affect the quality of the liquefied gas product.
Back-extraction oil, air injection volume, and the temperature after the alkali solution heater all affect the regeneration process. Initially, the levels in our process after dehydration were also above the specified limits; no matter how we adjusted the air injection volume, the temperature after the alkali solution heater remained somewhat too high. Things improved once back-extraction oil was used. The sulfur content in the raw material also affects these parameters
Did you pull it back out? Was it turned on? ? ? Alkali solution concentration, amount of titanium cyanocobalt sulfonate added, air injection volume, alkali solution circulation volume, regeneration efficiency, etc. Raw materials: sulfur content, desulfurization efficiency
Are you referring to disulfide back-extraction? ? We don’t have back-extraction here; it’s just a sedimentation tank, with the disulfides going to the heating furnace.
It definitely affects the quality of liquefied gas products
We conducted a full component analysis; the thiol content is almost zero, while the sulfide content is high. Is there any solution? Thioethers are mainly at carbon 5? ? We have appropriately reduced the stabilizer tower top temperature, but the effect is not very significant.
If it’s all thioethers, then there’s no need to go through the double-dehydration process; it’s because the upstream cutting of C5 isn’t done cleanly enough. Control the upstream processes properly to separate the thioethers.