Gas addition module for continuous flow reactors

Dec 29, 2011 | Flow & Level

A gas addition module has been introduced for the Uniqsis FlowSyn and other continuous flow reactors. Enabling fast, controllable pre-saturation of liquid reagents with a wide range of gases, it promotes efficient gas dependent reactions in flow such as hydrogenation, ozonolysis, carbonylation and direct synthesis of carboxylic acids.

The pressurised tube-in-tube design of the gas addition module ensures continuous interaction between the gas and liquid at every point along its length. The tube-in-tube design is based on semi-permeable membrane technology whereby the semi-permeable inner tube containing the liquid (typically a solvent) is bathed by a stream of pressurised gas which is enclosed within a thick-walled impermeable outer tube.

The pressurised gas is able to cross the semi-permeable membrane of the inner tube and dissolve into the liquid carried within. However, because of the semi-permeable nature of the inner tube material, the liquid is unable to cross in the opposite direction. The module is compatible with a wide range of reactive gases (eg CO, CO2, H2, D2, ethene, ethyne, SO2) and organic solvents (eg THF, MeCN, MeOH, PrOH). Capable of generating a continuous gas-saturated solvent stream in typically less than 10 seconds, the module enables flow chemists to carry out a wide variety of applications with minimum effort including heterogeneous and homogeneous gas-liquid reactions such as hydrogenation, ozonolysis, carbonylation and direct synthesis of carboxylic acids.

A particularly convenient feature of the gas addition module is the availability of an optional portable gas reservoir.

This space-saving device is easy and safe to charge with gas from a larger reservoir and obviates the need to bring bulky pressurised gas cylinders into the immediate experimental area.

The gas addition module can be added in-line to any FlowSyn system and other continuous flow reactors to provide a solvent feed stream pre-saturated with gas, although it can also be used as a reactor in its own right.