Pionieers in CO2 extraktion

URACA pumps transporte liquid CO2

URACA has been manufacturing liquid CO2 pumps for five decades. As a pioneer in this field, we continuously build on our expertise and our product portfolio so that we can seamlessly adapt our product range to market requirements. As such, we optimised our P3-10 pump for CO2  applications in a development project and launched it on the market this year.

A note on using CO2:

Despite its bad reputation as a greenhouse gas, carbon dioxide is an extremely helpful substance with useful properties in many applications. For example, it is used in the fields of food engineering and laboratory technology to extract flavour or colouring from foods. The benefits of this relatively modern CO2 extraction procedure in comparison to conventional procedures using solvents is quite obvious: instead of using synthetic solvents such as n-hexane, which is hazardous to health, CO2 is used – and it is safe.

This process involves liquid CO2 first being supercooled and fed into the pump. The CO2 is simultaneously heated by heavily compressing it with up to 1,000 bar of pressure and keeping it in a supercritical state. Under these conditions, it possesses the properties of a gas and a liquid and it is known for its excellent dissolving capacities. The high fluidity of the supercritical CO2 means that it can penetrate the tiniest pores in food and extract all kinds of substances, i.e. caffeine from coffee beans, resin from hop cones, nicotine from tobacco or flavourings from spice plants.

Thesupercritical CO2 is then released and warmed, which turns it back into gas and it evaporates without a trace, leaving nothing but the pure extract. As CO2 is inert, it also does not react with the extract or distort its properties.

The difficulty in this pumping technique lies in this use of CO2. It is a gas under normal ambient conditions. In order to keep it in liquid state its process parameters must be closely monitored to protect the pump from cavitation. As it has poor lubrification properties and is highly compressible, liquid CO2 can also only be safely and reliably pumped in pumps developed specifically for this use.

The fluid section of the P3-10 has been fundamentally redesigned for this and the pump now features valves optimised for dead space as well as cooling systems in the stuffing box and valve block.

The first P3-10 pump for CO2 that we supplied is being used in a pilot plant to extract the colour and flavour from tomatoes. It is currently proving itself in continuous operation.