Basil flavour for BASF process
20 Oct 2004
A process involving the world's first commercial use of ionic liquid technology has won an Innovation Award from the journal European Chemical News for BASF.
The technique, originally developed to boost production yields for a compound used in inks and coatings, is now the basis of a new range of products and a licensed process.
BASF produces an alkoxyphenylphosphine called DEPP, which it then uses to make products such as photoinitiators for inks and coatings.
However, the manufacturing process was extremely tricky - the final reaction step produced hydrochloric acid, which had to be removed by adding a tertiary amine. This created a highly viscous suspension which was difficult to separate from the reaction mixture to isolate the DEPP.
The team leader of the project, Matthias Maase, decided that the best option was to add a base which reacted with the acid to produce an ionic liquid, which could then be taken off via gravity phase separation. Ionic liquids are very polar, so will not mix with organic phases; moreover, as they have no vapour pressure and are not flammable, they are safe reagents.
Maase quickly found that one particular base, 1-methylimidazole, would be a suitable candidate: it forms an ionic chloride when it reacts with HCl, which melts at 75°C and so is liquid at ambient temperatures. The base can be regenerated from the salt for recycling. Even better, the base acts as a catalyst for the reaction. And as luck would have it, BASF already produced the compound - it is an intermediate in pharmaceutical production.
BASF dubbed the system Basil - biphasic acid scavenging using ionic liquids - and brought it into service at its Ludwigshafen headquarters after only five months of development in its laboratories. It improved the output of the process by 600%, says Maase, who is now developing a continuous process using Basil in a jet reactor.
BASF is now offering to license the process, and is producing a range of ionic liquids, called Basionics, for companies to use in their own processes.
