Alkylation unit

[Hamzaali1999]

Sir I want some guidline about Alkylation unit. First of I want to ask it’s feasibility in Pakistan. Can we install the project in pakistan’s refineries. If yes then why refineries doesn’t install that unit even this unit give high octane component of gasoline blending even there is zero sulphur aromatics which are toxic?

Second question is about it’s process selected how can I choose one processes ? What are practical parameters for that particular selection ?

Third questions is about it’s feed. I am totally confused about it’s feedstock(olefins and isobutane). Basic feedstock is coming from FCC unit and also several other unit like hydrocracking coming olefins. In some literature’s there is feed pretreatment step why because olefin contains impurities like butadiene oxygen nitrogen compounds usually FCC feed is deethanized and macraptan is formed in reaction and aslo acid soluble oils. So what we do in pretreatment ?

Fourth questions is about it’s reaction and reactor design. Who it’s reaction going on means I understand main reaction but some sides reaction are there like polymerization hydride transfer like these how we know that are formed and these sides reaction will produce for any reactants means like we use isobutylene and isobutane or butylene and isobutane or 1 butene and isobutane for these different reaction the side reactions remain same or it may be different ?

[Nasir Hussain]

The feed required for Alkylation unit is normally from FCC unit.
While FCC unit is not installed in Pakistan region.
FCC unit is normally in those regions where is is the high demand of gasoline.
In Pakistan region diesel and kero are on high demand thats why hydrocracking unit are installed to convert heavy bottom to boost the production of diesel.
In addition, we had great demand of furnace oil as well. Those refineries which do not have hydrocracking units, they produce furnace oil and Asphalt.
But for some years might be since 2017, due to heavy smog furnace oil power plants remains shutdown from Nov. To February. So some refineries had to shut down due to sale issue of furnace oil and others had to reduce refinery loads.
Now refiners are thinking to convert VDU bottom to some valuable product. So in the near future might be FCC unit and Alkylation unit installed.

[Nasir Hussain]

For process selection ;
https://www.digitalrefining.com/article/1000242,A_flexible_approach_to_refinery_olefin_alkylation.html#.XpX9LLdRVPz

[Nasir Hussain]

Further comparison between HF and H2SO4 process; by Dupont
https://www.dupont.com/content/dam/dupont/products-and-services/consulting-services-and-process-technologies/consulting-services-and-process-technologies-landing/documents/H2SO4_vs._HF.pdf

Another reason for the preference of H2SO4 process is the availability of raw material of H2SO4. Sulfur is available in the refineries and is separated in the Sulfur Recovery unit which can be converted to H2SO4.
Some engineering companies like Haldor Topsoe is offering the wet process of H2SO4 making.

[Author]

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