Method to inhibit polymerization in a process water

A method of reducing fouling in a water recycling loop, the method comprising:

• selecting a first polymerization inhibitor having a a pygas-water partition coefficient of about 0.0001 to 9 and a second polymerization inhibitor having a pygas-water partition coefficient of about 1000 to 50,000, wherein the pygas-water partition coefficient is determined in water and either a pygas obtained from a process water or a simulated pygas comprising toluene, styrene, cyclohexane, n-hexane, and dicyclopentadiene;
• applying the first polymerization inhibitor and the second polymerization inhibitor to a process water within the water recycling loop to form a treated process water, wherein the total concentration of the first and second polymerization inhibitors in the treated process water is about 5 ppm to 500 ppm;
• and
• contacting the treated process water with an interior surface of the water recycling loop.