Newest green technology in South Africa

Natex’s 5 litres/1 000 bar R&D pilot unit, similar to the one that will be installed at the DTI Centre of ExcellenceThe first Supercritical Fluid Extraction (SCFE) pilot plant in Africa will officially be opened at the end of October 2012. It will be situated in the Bio Beneficiation Systems Lab on the Potchefstroom Campus of the North-West University (NWU) as part of the Department of Trade and Industry’s dti Centre of Excellence in Advanced Manufacturing.

The plant will be funded by the dti’s Division of Advanced Manufacturing, under the leadership of Nomfuneko Majaja. The order for the pilot plant was placed with Natex in Austria in January 2012 and the plant will be delivered and commissioned in October.

‘I am extremely excited about the new SCFE pilot plant and the introduction of the latest technology in the country, which will open completely new opportunities to our economy for agro-processing, pharmaceuticals and cosmetology industries,’ states Majaja. ‘This technology will be able to replace old and sometimes not so healthy alternatives, thus ushering great opportunities for those who have knowledge on the indigenous medicinal plants by the use of new, scientific, appropriately measured dosages, and better and healthier means of providing herbal medicines to the communities.’

The SCFE lab will make use of supercritical carbon dioxide, which is the latest, safest extraction technology. Supercritical carbon dioxide is a fluid phase of carbon dioxide which is held at or above its critical temperature and critical pressure. Carbon dioxide is usually used as a gas in the air or as a solid, called dry ice. If the temperature and pressure of the carbon dioxide are increased in a certain way, it can adopt properties of something midway between a gas and a liquid, and act as a solvent, used for the extraction of compounds by means of a separation technique.

There are many advantages in using Co2 as a solvent for supercritical fluid extraction. It is environmentally friendly, easily available and easily recycled. It is also tasteless and odourless, which means that extracted compounds will not have a bad scent or changed flavour. This technology will also make it possible to extract more compounds from raw materials, for example, extracting the caffeine and aroma out of coffee beans. Carbon dioxide is free of bacteria and germicidal, which makes extracted samples safer to use and consume.

Components that can be extracted are stimulants (caffeine and nicotine), oils (soybean oil, natural oils and animal oils), flavours (hops, fruit extracts and spice extracts), fragrances and aromas, pharmaceuticals, polymers, natural pesticides and natural antioxidants.

The plant will be available to local businesses and industries to use for research and development. It will also be available for short, free processing runs where businesses could test the market with newly developed products.