From cheese makers to cement makers, businesses need heat and cool to produce their wares. Oil and gas are essential fuels for industry. Climate reasons aside, with these fossil fuels so cheap for so long, industries had little incentive to install more sustainable technologies.
But the war in Ukraine and soaring gas prices are forcing companies to rethink their energy sources. This is where heat pumps come in. Manufacturers of environmentally friendly heating systems report receiving more and more requests from companies.
The devices work by extracting heat from air, ground, water or waste heat created in industrial processes. They can be used to heat buildings or for heat required in industrial manufacturing processes.
Regular heat pumps that you might use to keep your home warm in the winter can reach temperatures of up to 95 degrees Celsius or 203 degrees Fahrenheit. But these temperatures are not high enough for many manufacturing processes.
Currently, special high-temperature heat pumps reach 165 degrees Celsius, with some pilot installations reaching the 300 degree mark. In the future, heat pumps could provide 30% of process heat up to 400 degrees Celsius, according to a recent study by the International Energy Agency (IEA).
Yet, some industries are already using heat pumps on a large scale with positive results.
Heat pumps to release the aroma of chocolate
Have you ever wondered why chocolate smells so good? Well, the delicious aroma comes from a process called conching, during which the chocolate mass is stirred at 60 degrees for several hours. All chocolate companies use heating and cooling processes to make the beloved product from cocoa beans and most still use gas to do so.
The Swiss company Maestrani does things a little differently. To maintain stable conching temperatures, he switched to using a heat pump powered by waste heat from his own cooling machinery that would otherwise have been wasted.
Since heat pumps and refrigerators work on the same principle, the new machines combine heating and cooling processes. Energy consumption has fallen by 20% at the factory, reducing the amount of CO2 emitted annually by 170 tonnes, say the chocolatiers.
A megabyte of cheese
A data center in Switzerland helps serve cheese with waste heat from cooling its servers. It is associated with the Gais mountain cheese dairy where heat pumps heat the water to 85 degrees Celsius. This is used to pasteurize up to 50,000 liters (13,208 gallons) of milk for cheese production each day.
Nestled high in the Alps of northeastern Switzerland, the dairy saves around 2 million kilowatt hours of gas per year, according to its own calculations. The company will only use gas heating in an emergency or if repair work is in progress so as not to interrupt production.
Use heat pumps to dry bricks
Brick production is energy-intensive work. It involves mixing loam, clay and sand with water, shaping the bricks and then drying them. After that, they are baked in an oven at temperatures up to 1000 degrees Celsius.
But since 2019, a brick kiln in the Austrian municipality of Uttendorf has been using the hot exhaust air from the kiln to power a high-temperature heat pump that dries the bricks before firing. This decision reduced their gas consumption by 30% and led to a reduction of 2,000 to 3,000 tonnes of CO2 emissions per year.
The plant is operated by Wienerberger AG, the world’s largest brick producer with over 200 locations in 28 countries. Wienerberger also plans to install high temperature heat pumps in Poland, the UK and the Netherlands. At the Uttendorf plant, an electric oven will replace the gas oven.
The world’s largest heat pump will be built in Germany
The German chemical multinational BASF plans to install one of the world’s largest heat pumps with an output of 120,000 kilowatts at its main plant in Ludwigshafen.
The pump would use waste heat from the plant’s cooling water system. According to BASF, it could produce up to 150 tons of steam per hour, which would significantly reduce natural gas consumption and CO2 emissions by up to 390,000 tons per year.
Heat pumps could help decarbonize production
At its food and feed plant in Pischelsdorf, Austria, the international food group AGRANA uses a high-temperature heat pump to extract water from wheat starch at up to 160 degrees.
The dry powder is used in the food industry as a binder and thickener for sauces, soups and puddings.
According to the Austrian research institute AIT, the heat pump supplies around 10% of the heating power of the drying installation. This saves up to 3.2 million kilowatt hours of gas and around 600 tons of CO2 emissions per year.
High-temperature pumps like this could be integrated into existing installations in many places, according to Veronika Wilk, an expert in industrial heat pumps at AIT. More than a third of production processes worldwide could use this technology in the future, for example in the paper, food and chemical industries.
“Recovering unused waste heat dramatically reduces the need for fossil fuels and leads to process decarbonization,” Wilk said.
This article was originally written in German.