RPC-Overview

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A major problem in hydrocarbon processing systems is the buildup of carbon on the surface of steel or
stainless steel components—coking. Coking often is initiated by catalytic action of nickel or carbon impu-
rities or additives in the steel used to construct the processing system components.
Restek chemists are working in conjunction with the Fuel Science Program at the Pennsylvania State
University to quantify the effects of Siltek™ and Silcosteel® treatments on the formation of coke.1 A
Silcosteel®-treated system exhibits a 4-fold reduction in coke formation, com-
pared to untreated stainless steel, but a modified Silcosteel® treatment,
Silcosteel®-AC, can provide an 8-fold reduction. The Silcosteel®-AC or
Silcosteel® layer forms a barrier between the hot hydrocarbon stream and the
coking-susceptible steel substrate, and eliminates catalytic breakdown in the
hydrocarbon stream. With the elimination of surface catalytic activity, carbon
will not chemically adhere to the surface.
Current work indicates that the only mechanism of carbon formation in a Restek-treated system is the
result of coking within the fluid phase. This material settles on the surface without adhering, and is easi-
ly removed by agitating the surface. Now, instead of “burning” out coke with oxygen at high temperatures,
deposited carbon can simply be rinsed away.
Applications for Silcosteel®-AC coking control treatment include fuel injection nozzles, jet engine noz-
zles, engine valves, and engine cylinders.
Reduce coking
up to 8-fold
Restek Performance Coatings • 800-356-1688 • 814-353-1300 • 21
1Altin, O.; Venkataraman,
A.; Eser, S. Analysis of Solid
Deposits from Thermal
Stressing of a JP-8 Fuel on
Different Surfaces in a Flow
Reactor Symposium on
Structure of Jet Fuel V,
Division of Petroleum
Chemistry, Inc., 216th
National Meeting, ACS,
August 23-27, 1998).