Heat pump as a key step in CO2 reduction

Sustainability is an important pillar for Aviko Rixona. By installing an industrial heat pump in one of its factories, the manufacturer of dried potato products has taken a major step towards halving its CO2 emissions by 2030.

Combine heating and cooling needs

Jeroen Zwietering, the energy process engineer at Aviko Rixona, says: "To achieve the reduction target, we analysed our production processes for heat consumption and heat recovery potential. For blanching the potatoes, we heated the process water indirectly with natural gas. For re-cooling the potatoes, we used a traditional cooling system (chiller). This meant a double loss of energy, as most of the heat released during the cooling process was discharged outside, and the chiller consumed a lot of electricity. Combining this heat and cooling demand was therefore one of the possibilities. We asked Equans to design a system that would bring the energy supply and demand together, with the highest possible efficiency and for an acceptable investment. Then you quickly end up with a heat pump."

Design requirements

Equans started designing the installation in February 2022. Project manager Gert Boersma: “The heat pump had to meet the requirements for an SDE++ subsidy, have the shortest possible payback period and be reliable, as the granulate production runs day and night. The pump also had to fit into Aviko Rixona’s newly built machine room. The final result is a machine the size of an average living room that uses four times less energy than a traditional heating system.”

Easy to clean

Boersma also thought about the cleanability of the system. He explains: “The water that comes out of the boiler with blanch water is contaminated. To prevent the shell-and-tube heat exchangers from clogging, the water pipes have to be cleaned several times a year. Folding covers on the heat exchanger ensure that the water pipes are easily accessible. We have also increased the diameter of the tubes in the heat exchanger to make it easier to brush them clean. The material that comes into contact with the water in the heat exchangers is made of stainless steel to prevent corrosion. An in-line filter is installed to minimise fouling. Aviko Rixona can also monitor the water supply so that they know in time when cleaning is needed.”

One-day switchover

A big advantage for Aviko Rixona was that Equans was able to build the heat pump at its production site in Panningen. This meant that the production of granulate in Warffum could continue uninterrupted. Once built, the installation was transported by truck. When the cold and hot water pipes were connected to the heat pump and the heat pump was filled with the natural refrigerant ammonia, the installation could be commissioned in November 2022. Switching from the old system to the heat pump took just one day.