A Swiss paper mill has installed a retrofit system that introduces a heat recovery step for heating its process water by capturing steam. The system at Sappi Schweiz AG in Biberist, Switzerland, recovers exhaust air from its PM 9 dryer section, saving money and reducing CO2 emissions.

Designed by Voith Paper Air Systems, Appleton, Wis., the process-water heating step made the already existing multi-stage heat recovery system more efficient by saving a good portion of the steam application, according to Voith. The dryer section’s waste air is used by another consumer.

Return on investment was quick, according to Stefan Probst, Sappi’s project manager, saying the process-water heat recovery paid off in “the shortest time.”