Centrisys/CNP, a North American manufacturer of decanter centrifuges and biosolids treatment technologies, has announced the successful start-up and operation of its PONDUS Thermal Hydrolysis Process (TCHP) at Capital Region Water’s Advanced Wastewater Treatment Facility (AWTF) in Harrisburg, Pennsylvania.
As part of the utility’s Energy Recovery Improvement Project, the system is helping to increase renewable natural gas (RNG) production, improve biosolids dewatering and maximise the capacity of existing anaerobic digesters, supporting Capital Region Water’s long-term sustainability and energy recovery goals.
Serving approximately 300,000 people across the Harrisburg region, Capital Region Water implemented the PONDUS system to increase biogas production for conversion into pipeline-quality RNG. The upgraded process also allows the utility to generate additional revenue through renewable energy credits and natural gas sales while improving biosolids management.
“Capital Region Water had a clear vision of transforming wastewater solids into a valuable renewable energy resource while reducing operating costs,” said Gerhard Forstner, president of CNP. “PONDUS helps accomplish both objectives by increasing biogas production, improving dewaterability and enabling the utility to maximise its existing digester infrastructure through a simple, operator-friendly process.”
Before the upgrade, poor dewatering performance resulted in lower cake solids and higher biosolids disposal costs. Since start-up, the facility has recorded approximately 30% higher biogas production than before installation, alongside improved dewatering performance. This has helped reduce the volume of biosolids requiring transport and disposal.
The process also provides additional digester capacity, enabling the utility to make better use of existing assets while providing greater operational flexibility.
Unlike conventional thermal hydrolysis systems, PONDUS operates at atmospheric pressure and does not require pressure vessels or complex steam systems. Its compact footprint allowed it to be integrated into Capital Region Water’s existing facility while providing a simpler solution for plant operators.
“One of Capital Region Water’s priorities was implementing technology that could be readily operated and maintained by its existing staff,” Forstner added. “PONDUS delivers the proven benefits of thermal hydrolysis through a straightforward design that minimises operational complexity while maximising long-term value.”
The project was developed in collaboration with engineering firm Arcadis, whose design incorporated the PONDUS process to support the facility’s renewable energy and biosolids management objectives. Brown and Caldwell served as programme manager, with McCossin as general contractor.
During start-up and commissioning, the Centrisys/CNP team worked closely with Capital Region Water’s operators to optimise system performance and support the transition to full operation.
“Working alongside the Capital Region Water team throughout commissioning has been extremely rewarding,” Forstner said. “Their commitment to innovation, combined with the strong collaboration among the utility, Arcadis, B&C, McCossin and our team, has resulted in a system that is already delivering meaningful operational improvements.”
“PONDUS TCHP has been quick and easy to start up,” added Raymond Hoke, operations supervisor at CRWRF. “We immediately saw a significant increase in biogas production after starting up the PONDUS system. The increase in biogas production and generation of revenue from the sale of the gas will be a huge benefit to the taxpayers of Harrisburg.”
The PONDUS installation demonstrates how utilities can use biosolids treatment technologies to increase renewable energy production, reduce disposal costs and improve the performance of existing treatment infrastructure without adding unnecessary operational complexity.
