Example of Pipe Scaling

The overall objective of this project, conducted by Nalco Company in partnership with Argonne National Laboratory, is to develop advanced-scale control technologies to enable coal-based power plants to use impaired water in recirculating cooling systems. The use of impaired water is currently challenged technically and economically due to additional physical and chemical treatment requirements to address scaling, corrosion, and biofouling. Nalco's research focuses on methods to economically manage scaling issues (see Figure 1). The overall approach uses synergistic combinations of physical and chemical technologies with separations to reduce the scaling potential and scale inhibitors extending the safe operating range of the system, to maximize water utilization efficiency and minimize waste discharge.

Research is conducted in three parts with laboratory research and development and small pilot scale field demonstration. Initially researchers establish quantitative technical targets, develop scale inhibitor chemistries for high stress conditions, and determine the feasibility of the membrane separation technologies to minimize scaling. Subsequently, researchers develop additional novel scale inhibitor chemistries, develop selected separation processes, and optimize the compatibility of technology components at the laboratory scale. Finally, integrated technologies are tested using selected pilot scale model sites to validate the performance.

The technology developed makes the use of impaired waters by coal-fired power plants more feasible. Potential benefits of the new technologies include the following: reducing the volume of make-up water required for recirculating cooling systems; reducing the volume of water generated from cooling tower blowdown; and lowering the cost of impaired water use to a point that is as cost efficient as using fresh water.