Vaporisation and Product Collection Core Separations

We understand people are continuously looking to push the boundaries in their field of research.

At Core Separations we want to help you explore those boundaries and help you to deliver your goals.

We work on a number of “special projects” that deliver results for our customers.

One such project was to help one of our customers explore the effect of temperature and CO2 vaporisation on the yield of their product.

When performing an supercritical extraction with CO2, we set conditions in the extractor that produces a suitably soluble medium (i.e. the CO2 stream) that dissolves the products of interest from our biomass.  Upon leaving the extractor we reduce the pressure to help separate the extract away from the CO2 stream.  Now the added complication in this process is the JouleThomson effect, which occurs as a result of depressurisation of CO2 resulting in a rapid decrease in temperature.

If your first collector is set at a pressure above 45 – 50 bar and the temperature of the in coming CO2 is below 5 °C then the CO2 remains a liquid.  The lack of phase change from Liquid to gas can significantly affect the collection of your product.  More so if you are recycling at these pressures as it can result in your extract recycling back round the system.

We compensate for this by heating the stream to vaporise the CO2, turning it from a liquid to a gas.  The heating starts with what is commonly known as the vaporiser.  This is a heat exchanger located directly after the automatic back-pressure regulator, heating the CO2 stream before it enters the separator.  We then further heat the separator to maintain the temperature.

Our customer found that when using the vaporiser for a particular process there was a small loss in yield, because of the product coating the inside of the vaporiser when heated.   Their aim was to move the product into the collector suspended in the liquid CO2 while ensure the liquid level didn’t exceed the volume of the first separator resulting in a carryover of their product.

To do this they wanted to start with a visual aid to watch the level of liquid CO2 rise and fall within the separator.  They needed a vessel with a long glass window capable of withstanding 100 bar of vessel.  At Core Separations we produce the majority of our equipment ourselves but working together with our partners we look for solutions to assist our customers with their problems.

PARR instruments company based in Moline, US have over 100 years of experience producing high quality pressure vessels into a range of applications.  They have a compatible product for this application with an oblong window allowing us to observe the CO2 liquid level as well as the product collection.

By working closely with PARR instruments, we integrated this vessel into our SFE system to create a customised system to aid our customer in their research.

We are always keen to work with researchers looking for engineering solutions to application problems.  Please get in touch if you want to talk to us further about your supercritical or subcritical CO2 extraction requirements.