A reusable, cheaper, eco-friendly and easy-to-handle alternative to dry ice with food and beverage applications are the claims made for PureTemp -40, launched by Entropy Solutions, based in Minneapolis, US.
PureTemp made from vegetable-based fats and oils is said to protect deep-frozen products to -40 °F (-40 °C) during shipment. The company terms the product a phase change material (PCM) which either melts or freezes to absorb or release significant amounts of latent heat at constant temperatures. “While most traditional PCMs are derived from petroleum, our innovative, bio-based PCMs are 100 per cent environment-friendly and renewable,” said a company spokesperson.
PCMs behave like sensible heat storage (SHS) materials; their temperature rises as they absorb heat, said the company. But, unlike conventional SHS, when PCMs reach the temperature at which they change phase (their melting temperature) they absorb large amounts of heat at an almost constant temperature.
PCMs continue to absorb heat without a significant rise in temperature until all the material is transformed to the liquid phase. When the ambient temperature around a liquid material falls, the PCMs solidify, releasing their stored latent heat. PCMs are said to store up to 14 times more heat per unit volume than do conventional storage materials such as water or masonry.
“While dry ice can be used only once, PureTemp can be used more than 20,000 times with no thermal degradation,” said a company statement. Also, compared with dry ice which emits carbon dioxide, PureTemp produces zero emissions and is renewable, biodegradable with no shipments restrictions.
Incorporating PureTemp in the walls of a coffee cup will cool the beverage quickly from its brewing temperature of 180°F (82 °C) to its optimal drinking temperature of about 135°F (57 °C), according to the company. When the coffee temperature begins to drop below its optimal level, the cup is said to automatically start releasing heat captured when the coffee was too hot; maintaining the right level for up to one hour.
Commenting on the new food and beverage application, Eric Lindquist, the company’s president said: "We are extremely encouraged about the prospects for PureTemp -40 and believe it could do for temperature-sensitive shipping what hybrid cars can do for the automotive industry. Being able to provide customers a safer, more cost-effective and more eco-friendly option for frozen shipments is very rewarding."
Entropy Solutions focuses on the development and commercialization of thermal technology in a range of industries including food, beverage and pharmaceuticals.