The assessment of the economics of an industrial cleaning operation is very difficult and depends on a vast number of factors. However, certain considerations based on solvent properties may give some indication for comparison:
To recover 100 liters/h of fluid the required energy is:
Perchloroethylene 4.1 kW
(Energy required for drying parts from adhering solvents show equal efficiency)
Cost of Cleaning Media
For comparison purposes, one must keep in mind that aqueous cleaning requires up to one kilogram of cleaner (surfactants) per kilogram of removed oil.
Waste Disposal Cost
Waste residues from modern solvent distillation are highly concentrated and, depending on the ease of separation, often contain only minor amounts of solvents.
Aqueous cleaning operations waste residue is generally much larger and contains, besides the removed contaminant, large amounts of non-recyclable surfactants and water.
The high and nearly complete solvent recycling is one of the major advantages of solvent cleaning systems compared to aqueous cleaning operations.