Increased Evaporator Performance: Stubborn Scale Removal using Hydrogen Peroxide

Project Scope

USP Technologies and a sugar beet processing plant in the US developed a cleaning strategy to use high concentrations of hydrogen peroxide to remove year-over-year burnt on scale inside multi-phase plate pack evaporators. This scale had caused reduced evaporation performance which resulted in evaporation becoming the rate limiting step in the sugar production process. Five plate pack evaporators were cleaned over a two-year period, resulting in increased sugar production. USP provided turn-key solution including chemical supply & inventory management, custom-built equipment, and local & remote technical support.

Background

Scale deposition in evaporators impedes heat transfer, slows processing, and can lead to degradation of product. Even after standard cleaning methods have been used (caustic wash, back-boiling, mild acid wash, and physical scrubbing), scale can persist and accumulate to make evaporation the rate limiting step of sugar beet processing and can require the replacement of the fouled heat exchange units.  Plate pack evaporator fouling has limited mechanical cleaning methods and requires aggressive chemical cleaning methods that are effective in low or no flow conditions.  To supplement caustic cleanings, a novel cleaning strategy using hydrogen peroxide in combination with surfactants/solvents was evaluated as a non-capital solution to remove scale buildup inside the evaporators.

Results

Over a comparable period, average evaporation rates in 2020, 2021, and 2022 were 579, 625, and 638 tons/hr, respectively; a 10% increase in a two-year period. In 2021, these improvements were used to realize a 6.5% increase in slice rate and in 2022 these improvements are helping to extract a higher percentage of sugar from existing beet crop with high water evaporation rates.

Conclusion

The use of hydrogen peroxide in the evaporator cleaning process proved to be an effective solution for the sugar beet processing plant. By removing organic scale from the evaporators, the plant was able to increase efficiency and sugar recovery, leading to significant financial benefits. This case study demonstrates the potential benefits of utilizing hydrogen peroxide in cleaning processes for organic scale buildup. Because of the significant safety & operational considerations associated with this cleaning strategy,
USP and our sugar factory partners believe it is critical that anyone wanting to do a similar cleaning to use a supplier intimately aware of the use of high concentrations of hydrogen peroxide

Read More For the full case study, Evaporator Cleaning – Stubborn Scale Removal