PDI was contracted by a paper mill to aid in wastewater sludge recovery. The waste heat drying system engineered by PDI operates at the rate of about 10 tons per hour and makes the plant more energy efficient and reduces production costs. 

PDI's unique fluidized-bed boiler system design allows efficient drying and utilizes the full energy production of the boiler by using waste heat to create fuel from paper mill waste. The process, which recycles leftover boiler exhaust gases for heat, dries waste from 70% moisture down to 40% to become fuel for the boiler. 

The system’s efficient use of heat and the ability to use paper mill waste as fuel significantly reduces natural gas consumption. Additional savings are realized by eliminating the need for storage, transportation, and the associated record keeping for the waste that would normally be disposed of in a landfill.