A fuel ethanol plant in the Midwestern United States was experiencing significant evaporator fouling due to calcium oxalate scale. In an effort to reduce scale formation, clean-in-place (CIP) treatments were run every two weeks and hydroblastings were performed twice a year during cleaning outages. Plant management recognized the lost profit potential caused by cleaning outages and the potential to reduce its steam usage if evaporator efficiency could be improved. Consequently, plant management agreed to evaluate a Polystabil scale inhibitor and recorded the following benefits during the trial:

• Scaling rates were significantly reduced
• 12 CIP treatments were eliminated per year
• Hydroblastings were completely eliminated
• Steam usage was reduced by 6,000 pounds per hour
• Sulfuric acid use was reduced by $200,000 per year

Since permanently converting to the scale inhibitor program, the efficiency of the plant’s evaporator has significantly improved. Notably, the plant’s return on investment for the program is over 900%.