【Alkylation】Several problems encountered in Rumsfeld alkylation
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This post was last edited by Xiao Gong 1985 on 2016-4-3 at 09:54. Our plant’s alkylation unit uses the Rumms process, with tetrahydrofuran as the raw material. Due to issues with the activity of the MTBE catalyst, the content of isobutylene in the raw material is high. What impact does this have on the alkylate oil? Will it cause the dry point to rise? Currently, the dry point is around 205, whereas it used to be below 200.
Also, during the disassembly and inspection of the pump casing in the distillation system, many honeycomb-shaped sand holes were found inside. Have you encountered such a situation? What type of corrosion is this?
I hope the experts here can give some advice – what effects will the presence of sulfates in the distillation system have? Does it affect the sulfur content of the product?
An increase in isobutylene content leads to more condensation side reactions, thereby raising the dry point? As for the cellular sand defects at the pump casing outlet in the mechanical pump, it is likely cavitation; clean the filter at the pump inlet.
Cavitation has occurred; the required net positive suction head of the pump is too high. Consider cutting the impeller, or replace it with a pump that requires a lower net positive suction head!
The entry of sulfatides into the distillation system can lead to salt deposition in the reboiler, affecting the thermal efficiency of the bottom reboiler
An increase in isobutylene content is not a problem; it simply means an increase in the olefin content, and what’s needed is an corresponding increase in the alkene-to-olefin ratio. When our plant stops producing MTBE, it’s fine to use straight C4 fractions from the gas separation process, although the acid consumption may be higher than usual.
It’s best to measure the wall thickness of the distillation system, as corrosion caused by impurities is quite severe; measuring the thickness is necessary to ensure safety!
Original poster, which company is responsible for the design and manufacturing? Could you please tell us?