In Puerto Rico, Caribbean, Union Engineering has successfully completed the installation of a specially designed plant for carbon dioxide (CO2) production & purification for a local Coca-Cola bottler.

Union Engineering won the project from the local Coca-Cola bottler, where the assignment was to ensure the bottler’s independence from external CO2 suppliers and secure a constant supply of high quality carbon dioxide.

Furthermore, the Coca Cola bottler was facing increased difficulties in purchasing potassium permanganate from the market - a chemical traditionally used as an oxidation agent in the CO2 purification process.

Denmark-based Union Engineering and the Coca-Cola bottler focused on designing a plant that would benefit both operating cost and the environment. The final solution, which uses a range of Union Engineering’s proprietary purification solutions, ended up providing reductions in both fuel and chemical consumption.

Soft drink bottlers typically require both a high purity and stable supply of CO2, with local conditions often seen as an important factor. Not only was Union Engineering able to meet these requirements, but the company also took its installation a step further – with a cleaner, more productive production process.

The company’s Lars Klitgaard Pedersen explained, “Where a conventional combustion-based CO2 plant consumes approx. 350kg diesel/h to produce 1000kg of food grade carbon dioxide, we developed a future-orientated solution in Puerto Rico.”

“By using a part stream of an existing flue gas source, fuel input to the CO2 plant is reduced by up to 45%.”

The flue gas chosen was from the existing steam boilers which, during steam production, produces the CO2-rich flue gas that goes straight into the carbon dioxide plant. When combining the flue gas, the Union Engineering plant automatically adjusts the burner according to the quantity of flue gas. The plant is configured to run based on 100% diesel combustion, however via sensors, the import of the flue gas starts as soon as the steam boilers are working.

This set-up ensures Coca-Cola the best possible CO2 production, and the most effective utilisation of the flue gas available.

Union Engineering also implemented one of its patented technologies, NOxFlash (Patent Pend.) whereby the traditional use of PPM – which is usually a part of the purification steps – was eliminated. In addition, the Coca-Cola plant in Puerto Rico was equipped with a final purification unit – a PUR-D, to ensure improved purity of the CO2.

The combination of the NOxFlash and the PUR-D reduced the 02 in the final product to below 5 ppm.