Atlas Copco offers certified ‘net zero energy consumption’ compressors

Atlas Copco’s Oil-free Air division has announced that the company’s ZR series of water-cooled oil-free air compressors, with built-in energy recovery systems, is the first in the world to be TÜV certified for ‘net zero energy consumption’ at specific design conditions. It has been proved that 100% of the electrical power input could be recovered in the form of hot water. With these ‘carbon zero’ compressors, industries using a great deal of hot water and steam, such as food and beverage, dairy, pulp and paper, pharmaceutical, textile, chemical and petrochemical, and power plants and clean rooms can dramatically cut down on their energy bills.

Energy savings in compressed air systems are very important as energy consumption typically represents over 80% of a compressor’s life-cycle cost. While compressed air systems on average account for about 10% of industrial electricity consumption, it can be as high as 40% of a plant’s electricity bill.

“We are very pleased to offer our customers a compressed air solution which can recover 100% of the input energy,” says Stephan Kuhn, President of Atlas Copco’s Compressor Technique business area. “Today, our customers face stringent targets to reduce carbon dioxide emissions. With the carbon zero compressor, customers can get compressed air virtually for free, which has significant impact towards preserving the environment and also on their bottom line.”

Earlier this year, TÜV supervised the type testing of Atlas Copco’s ZR 55-750 water-cooled oil-free screw compressors, equipped with built-in energy recovery systems . The testing process involved real-time measurement of the electrical power input and the output power as hot water. The two measurements were then compared. It was proved that under the specific design conditions of 40 °C and 70% relative humidity, 100% of the input electrical power could be recovered.

While the carbon zero compressor compresses air, all the input electrical energy is converted into heat. This heat appears at different compressor components. The challenge is really to pick up this heat from all the components which are the compression elements, the oil cooler, intercooler and aftercooler. The built-in energy recovery system circulates cooling water through all these components and, as a result of the heat transfer, yields hot water at up to 90 °C. This hot water can find several applications in the industry.