Abstract

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.