Nutrex is a food producer specialized on vinegar and part of the Swiss holding COOP. In 2008 COOP took the decision to achieve CO2 neutrality within 15 years. Nutrex managed to achieve this goal already in 2009 by applying modern heat pump technology in its production site.
For the quality production of vinegar two processes are used: fermentation and pasteurization. These two processes fit perfectly for the application of a heat pump and serve as its source and sink.
Vinegar fermentation occurs as the alcohol is being converted into acid by bacteria. It is an exothermic reaction and stops working when the mixture is getting too warm. To stabilize the process over 10 days at 30°C, the large tanks need to be cooled. On the other side, vinegar pasteurization takes place above 70°C to obtain a non-perishable food. At Nutrex a heat pump was installed with a cooling capacity of 136 kW and a heating capacity of 194 kW. This runs with a COP of 3,4. Beside of the pasteurization, the produced heat is used for heating of the laboratory and of the building.
Since the replacement of conventional oil heating in 2009, Nutrex has achieved a CO2-free production. The use of the heat pumps has reduced the CO2 emissions by approximately 310 000 kg/year and saves up to 65 000 liter of fuel/year.
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