Sustainable solution helps drive industrial circular economy loop for Air Products

KOH Regen


Air Products and Chemicals, Inc. (Air Products) contracts to supply a feedstock for Veolia’s proprietary potassium hydroxide (KOH) manufacturing process, resulting in an economic and environmentally sustainable solution. Veolia North America (Veolia) designed, engineered and constructed an inorganic chemical processing facility located near Air Products’ Hometown, Pennsylvania plant. By owning and operating the dedicated KOH manufacturing facility, Veolia’s comprehensive services help the client meet production and financial goals.


For more than 70 years, Air Products as been continuously improving its environmental performance by minimizing the impacts of its operations and products, and enabling its customers to do the same. That’s why it sought a sustainable solution for the KF produced at its Hometown, Pennsylvania manufacturing facility. The plant uses potassium hydroxide (KOH) to neutralize material in certain processing units. The neutralization process produces potassium fluoride (KF). If disposed, this byproduct would be considered hazardous waste, and needs to be safely managed to protect people and the environment.


Veolia offered Air Products a solution that would use the KF waste as feedstock for KOH regeneration through Veolia’s HARDTAC® crystallization technology. HARDTAC enables Veolia to use KF as an ingredient to produce KOH that can be re-used in the client’s production process. The unique design allows larger particles than conventional crystallization (40-60 microns versus 2 microns) and higher solids concentration in the crystallization process, thereby reducing operating expenses. In this application, the HARDTAC system uses KF and calcium hydroxide as ingredients to produce KOH and calcium fluoride (CaF2), via the following process:
  • The ingredients are pumped to Veolia’s HARDTAC reactor where they are mixed and reacted.
  • From the HARDTAC unit, the resulting KOH and CaF2 slurry is separated in a clarifier and filter press arrangement. Typical solids concentrations from dewatering are 85-90% by weight.
  • The KOH product is collected in tanks, adjusted for concentration if required, and returned to the client.


Veolia constructed its KOH manufacturing facility four miles away from the Air Products’ Hometown plant, and began operating in July 1999. Veolia owns the system and provides associated services under a long-term contract. These include supervision, labor, chemicals, operation, maintenance and utilities associated with the HARDTAC facility. The sustainable, closed loop system has been running smoothly for nearly 20 years, and directly supports the customer's operational, financial and environmental goals. 
Cost Savings
Veolia’s solution has provided a more sustainable solution for KF management, and allows the customer to limit its purchase of virgin KOH. This helps reduce the total volume of raw materials that would otherwise be required to produce the virgin KOH, thereby helping to save natural resources. The KOH produced in the Veolia process is less expensive than the commercial price for virgin material. Additionally, because the KF is employed as a feedstock in the KOH manufacturing process, the customer's raw material costs are reduced significantly each year. 

The cost savings also impacts the end users of the client’s products. “In essence, the value of the service we provide continues down the supply chain and impacts the cost savings to those manufacturers, reducing prices of virtually anything with a chip in it, from computers to phones to games,” says Gail Deppen, Veolia North America’s Project Manager. “I am proud of the role we play in providing this service and value to our client. It’s exactly why I entered the field of environmental engineering.”

Environmental Rewards
The immeasurable environmental benefits associated with this process earned Air Products the 2002 Pennsylvania State Governor’s Award for Environmental Excellence. The result is a win-win for Veolia and its client, whose goal is to “make the world more productive, energy efficient and sustainable.” 



Click here to learn more about Veolia's commitment to resource sustainability.