An MINLP model for biofouling control in seawater-cooled facilities

The use of seawater as a cooling agent in industrial plants is becoming a common practice in regions with water scarcity. One of the main problems of this approach is the heat transfer reduction due to biofouling in the heat exchangers. Biocide agents and scheduled maintenances are commonly used to control the biofilm growth. Dechlorination agents are also used to reduce the biocide concentration in the water discharge. In this work, a mathematical programming approach to develop optimal policies of biocide continuous dosing, dechlorination agents continuous dosing and maintenance scheduling for a seawater-cooled power desalination plant is presented. The resulting mixed integer nonlinear programming model can be used to test different dosing policies to detect a superior one. For the case study presented, results show that daily dosing policies offer an optimum economic policy, although biweekly and monthly dosing policies might provide a suitable compromise between economic and operating issues.

► Biofouling occurs in heat exchangers that use seawater as cooling agent.
► Biocide agents and scheduled maintenances are used to control the biofilm growth.
► Dechlorination is also needed to reduce the biocide concentration in water discharge.
► An MINLP model for optimal dosing of biocide and dechlorination agents is presented.
► Different dosing policies are tested with the MINLP model.