zknarc said:
... "virtually free from sulphur, benzene and aromatics" seems to indicate there are still amounts of these.
See point 3) below
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This is a 2009 thread btw, but nice too see it, I never thought of alkylate being available to the mass. But it's not pure alkylate if you think so, just 85 - 95%:
Aspen fuel said:
...The alkylate is then mixed with a number of other components and we now have a finished product - the Aspen alyklate petrol...
This is their SDS sheet:
The "other" 5 - 15 % is not alkylate but CAS No.: 64741-70-4
The "other" 5 - 15 % said:
Preparation Description:
A complex combination of hydrocarbons obtained from catalytic isomerization of straight chain paraffinic C4 through C6 hydrocarbons. It consists predominantly of saturated hydrocarbons such as isobutane, isopentane, 2,2-dimethylbutane, 2-methylpentane, and 3-methylpentane. Product is not a mixture according regulation 1907/2006/EC.
That doesn't sound too bad either. No aromatics here.
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What's so special about alkylate?
Other than typical distilling and cracking [already existing longer molecules] into smaller bits by high heat, the alkylation is like you take smaller molecules and "glue" them together to obtain a larger molecule of desired length, a typical length to be used in engines. It is the "odd" production plant within a refinery, small in size compared to the others, with higher risks because of relative pure HF used.
Alkylate has 3 main advantages:
1) a way to get still $$$engine-naptha$$$ from your (propane/butane-sized) smaller molecules that otherwise had to be sold as lesser $LiquidPetrolGas$ or burned as a gas in ovens;
2) its incredible high octane number is
THE substitute for the environmentally disastrous lead that in early days was the ordinary octane agent. They mix alkylate in fuels to get the octane number right;
3) Interesting for us: because it is composed from components that are furthest away from the crude-oil streams that carry sulphur and aromatics. The C3's and C4's to make alkylate with, are treated to the best of industrial norms (not lab grade norms!) to have them "pure". So alkylate is a nice C7 naptha from glueing together a C4 and a C3 molecule. We could say alky is the better (strict - pure) of non-lab grade, still mass produced naptha.
Will it out-beat the classical "wasbenzine" for us here? No, but a very good alternative. That trace of potential aromatics in Wasbenzine is not going to ruin our day at all. Thinking of the freeze precip now.
So I would not trade my wasbenzine for it, but if I did use Alkylate as an alternative I would give it an extra cautic (NaOH) or carbonate shake-wash treatment, before use. Why? The alkylate "synthesizing" (?) happens under very acidic medium, like H2SO4 or HF. The industrial way to get rid of their absorbed traces is a like KOH wash, but any potential shortcomings on that behalf I would take care for at home with an extra basic wash. One had to be in this industry to get paranoia enough
.