Fouling in Refineries

Fouling, in petroleum refineries is the deposit formation, encrustation, deposition, scaling, scale formation, slagging, and sludge formation which has an adverse effect on operations. It is the accumulation of unwanted material within a processing unit or on the solid surfaces of the unit to the detriment of function.
The major effects include,

(1) loss of heat transfer as indicated by charge outlet temperature decrease and pressure drop increase,

(2) blocked process pipes,

(3) under-deposit corrosion and pollution, and

(4) localized hot spots in reactors,

All the above factors results in production losses and increased maintenance costs.