Non-toxic, high-performance heat transfer fluid

Non-toxic, high-performance heat transfer fluid

Non-toxic, high-performance heat transfer fluid

Keywords: Heat transfer, Fluids, Non-toxic

Thermera, a new non-toxic, high- performance heat transfer fluid for use in heat-recovery units, air conditioning, heat pumps and industrial applications, has been developed by Fortum Oil and Gas Oy of Porvoo, Finland. The basis of Thermera is natural, water-soluble, biodegradable betaine, a by-product of sugar beet processing, which is separated from molasses using a method developed by a leading supplier of betaine, Finnfeeds Finland Oy, a subsidiary of Danisco.

Fortum supply two standard grades: Thermera-15 and Thermera-35, which are designed for use in closed circuits operating in the temperature ranges −15°C to +110°C and −35°C to +110°C, respectively. However, we are informed that special grades can be produced with the freezing protection customised to meet end-users’ requirements. Thermera thermal performance is said to equal or exceed that of conventional heat transfer fluids like glycols; life-cycle costs are considered competitive with those of glycols, because used Thermera is not toxic waste.

Because betaine is a biodegradable product, Thermera is reported to have an extremely low environmental impact and can be disposed of like ordinary waste water, unlike glycol-based heat-transfer fluids which need to be disposed of in a hazardous waste incinerator. The constituents of standard Thermera grades are 35 or 50 per cent betaine (trimethyiglycine), 64 or 49 per cent purified water, <1 per cent corrosion inhibitor, and <1 per cent odorant.

Additional advantages claimed of Thermera include excellent cold-flow and anti-corrosion characteristics, which have been further enhanced by the inclusion of environmentally benign additives.

Thorough independent corrosion-rate tests were carried out to establish the speed of change in the metal thickness of pipes and vessels, expressed as micrometers per annum (ASTM 1384 equivalent test). Using a Thermera - 15 solution, it was reportedly shown that the corrosion rate for steel and copper was as low as 0.3 μm p.a. (mass loss 0.2 mg).

Thermera is always supplied as a ready- to-use solution in containers according to customer requirements. Local availability of Thermera and other information can be obtained from thermera@fortum.com

Prior to its launch, independent physical tests were carried out on the product at Lappeenranta University of Technology, stability tests at the University of Jyväskylä, circuit analyses at VTT - The Technical Research Centre of Finland and biochemical analyses at Danisco.

Two Nokia office buildings equipped with ABB Fläkt air-conditioning systems are the largest office sites currently using Thermera. To date, the most significant user of Thermera for industrial processes is Finnfeeds Finland’s production plant in Naantali, Finland.

According to its manufacturer, in most cases Thermera can successfully replace conventional heat transfer fluids without the need for changes to operating parameters or the physical dimensions of the heat transfer system. However, all existing fluid should be removed and the pipework rinsed with water before Thermera is used in the system.

According to Janne Jokinen, product manager at Fortum: “There is no comparable non-toxic alternative to Thermera currently available, so we expect to achieve at least a 10 per cent share of Finland’s heat-transfer market within 2-3 years. But our goal is, of course, to market Thermera world-wide.”

Thermera has already been patented in the EU, USA, Canada, Japan, China and Russia by Fortum, which is an ISO 9001 certified company.

Details available from: Fortum Oil and Gas Oy, Tel: +35 810 4511; E-mail: thermera@fortum.com; Web site: www.fortum.com