Alkylate (petrochemicals)
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| Surname |
Alkylate |
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| CAS number |
64741-64-6 |
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In petrochemicals, the term alkylate is used to describe a fraction produced by the alkylation of isobutane , which essentially consists of isoheptanes and isooctanes, i.e. branched hydrocarbons with seven or eight carbon atoms.
The sulfur content is a maximum of 1.5 g / kg.
Manufacturing
The alkylation, i.e. H. Alkyl side chains (e.g. propyl , etc.) are added using low molecular weight alkenes (e.g. propene ). It is carried out at temperatures between 0 ° C and 30 ° C and requires cooling as the process is exothermic .
Physical Properties
At room and normal outside temperatures, the alkylate mixture is a colorless to yellowish liquid with a density at 15 ° C of less than 0.74 g / ml.
At 38 ° C the vapor pressure is below 960 hPa.
The boiling points of the various alkylate molecules are between 29 ° C and 195 ° C, depending on the size of the molecule (number of carbon atoms).
The water solubility is low at 20 ° C, the octanol-water partition coefficient between the lipophilic n- octanol and water is 2.8–6 log P ow . Since it is thus predominantly above 3 log P ow , an accumulation in living beings and food chains is to be expected ( bioaccumulation potential).
use
The alkylate component in fuels increases the knock resistance . It replaces the previously common aromatic additives.
Individual evidence
- ↑ a b Safety data sheet : alkylate (PDF; 693 kB) from Eni, accessed on July 11, 2016.
- ^ Reforming , Aral Research.
- ↑ J. Randall Peterson (StratCo): Alkylate is key for cleaner burning gasoline ., 1996