The sequence of MTBE and alkylation steps
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This post was last edited by jacques0920 on 2017-2-22 at 11:18. Hello everyone, generally, does the gas coming out of the catalytic unit first pass through MTBE and then undergo alkylation, or is it alkylated first? What’s the reason? Thank you!
After MTBE, it goes to the alkylation unit; the M unit consumes isobutylene, and the remaining olefins proceed to the alkylation unit for reaction.
Is it that isobutylene cannot participate in alkylation reactions?
Isobutylene can participate in alkylation reactions; however, feeding isobutylene into M brings greater benefits to the enterprise.
One more question: what is the main reason why the scale of alkylation cannot be increased at present? It seems that abroad, alkylation is the main method used. Thank you!
Alkylation projects are also being launched on a large scale this year, mainly by state-owned enterprises. At present, the main factor restricting the development of alkylation plants remains the issue of raw materials.
Methylation first, followed by alkylation; this makes full use of isobutylene and maximizes efficiency
First, it’s necessary to know the prices of alkylated oil and MTBE. MTBE uses isobutylene, and alkylated oil also uses isobutylene, but MTBE is significantly more expensive than alkylated oil. In that case, the remaining C4 can be used for alkylation, or it can be fed into an OCU as well
What is OCU? Thank you!
OCU is produced by the Lummus process, via butylene disproportionation and reaction with ethylene to yield propylene
It is definitely M that is processed first, followed by alkylation. As for isobutylene, it can be used with methanol to produce MTBE, or it can participate in alkylation reactions to yield alkylated oils; however, in terms of cost-effectiveness, the former is far superior to the latter. There is another important reason as well: after undergoing the MTBE reaction, the impurities and harmful components in the C4 feedstock are removed, and the resulting etherified C4 can be used as a raw material for alkylation, which helps to **extend the operational life of the alkylation units and significantly reduce corrosion in those units.