TP25-10 Replacing 12.5% Hypochlorite with On-site Generated Hypochlorite - Creston Water Solutions

Many industrial cooling towers in North America utilize bulk sodium hypochlorite (12.5% w/w) as biocide to prevent biofouling in cooling systems; however, significant increases in price have prompted plant managers to look for cost-effective alternatives that minimize changes in cooling tower chemistry. On-site generation of hypochlorite (OSHG) has been widely used in municipal applications to replace bulk sodium hypochlorite or chlorine gas because it produces a low concentration (<1%) hypochlorite solution utilizing only salt, water and power through a process known as brine electrolysis. Conventional OSHG technology requires high purity salt and potable water, making it less suitable for industrial cooling tower applications; however, a novel electrolyzer design allows for the use of lower quality salt/brine and non-potable water without impacting performance.  A pilot utilizing this technology was conducted at a Florida power plant, replacing bulk hypochlorite for its cooling tower. The pilot unit utilized industrial brine and cooling water to generate a 0.5% hypochlorite solution that replaced bulk hypochlorite achieving the same biofilm control performance at 25% of the cost.