Flow Chemistry Delivers: Fast Scale Up of Challenging Chemistry
Andre de Vries,
Commercial Director,
InnoSyn B.V.
The continuous tubular reactor is a well-known concept, which is applied
broadly and has proven its value to the chemical industry. A micro reactor is essentially
a tubular reactor with an unusual small diameter. Its excellent performance
originates from the fact that the characteristic time for heat and mass
transfer scales quadratic with the length scale: a ten times smaller diameter results in a
hundred times faster transfer. The latter characteristic, combined with relatively
small hold-up volumes makes
continuous flow reactors the ideal asset for any demanding type of chemistry.
Typical applications are the ones where hazardous reagents and exotherms would
hamper batch operations: e.g.
nitrations, cyclopropanations, azide chemistry, catalytic oxidations with air
and low temperature organometallic reactions.
In this
presentation two relevant examples will be presented in detail.
1. Matteson
boronic ester homologation. It will be demonstrated that the
excellent heat and mass transfer of continuous flow reactors, calls for lower
cooling capacity, while enabling significantly increased productivity combined
with higher selectivities as compared to the corresponding batch processes. The
process has been scaled up successfully from lab, to pilot, to full plant scale
in collaboration with partners. 2. A second
example where the application of hazardous reagents and exotherms would hamper
batch operations, involves catalytic oxidations with air. The latter has been investigated
in a flow set-up successfully, both with Taylor flow regime and a so-called ‘single phase’
for various substrates, e.g. sterically hindered secondary alcohols . Details of this study will be
disclosed.
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