Fatty acids Esterification
The Davy esterification system is a simple continuous process that is used for
esterification of natural and petrochemical acids. the process uses reactive
distillation to produce an ester product that can be hydrogenated directly
without any further processing. The solid resin catalyst is retained on the
reaction trays, and so does not contaminate the methyl ester product. The
catalyst can also be replaced while the plant is online.
Methyl esters are pumped to the hydrogenation reaction pressure of around 40 bar
and fed into the hydrogenation vaporiser. The feed liquid is vaporised by a
hydrogen-rich gas stream which passes up through the vaporiser.
The overheads from the hydrogenation vaporiser are fed to the hydrogenation
reactor containing a fixed bed of catalyst. The reaction occurs in the vapour
phase in a stream of excess hydrogen. The mild operating conditions of the Davy
hydro-genation process along with uniform temperature and short residence in the
reactor results in a very highly selective process. This high process
selectivity results in minimal byproduct formation and hence high quality
Fatty Alcohol Refining
Unconverted esters are separated and recycled back to the hydrogenation section.
Residual methanol is recovered and recycled, and a light ends purge is taken if
necessary to achieve the required product alkane specification. The column is
run under vacuum and a falling film vaporiser used for the reboiler to prevent
thermal degradation of the product. Heavy boiling bottom stream is recycled back
to the hydrogenation section.