Fuel system deposits surfactants

Surfactants are used in fuel applications to prevent fuel injector deposits, intake valve and exhaust valve deposits, combustion chamber deposits [2,3], injector deposits of direct gasoline injector systems [4,5] and high-pressure diesel injector systems [6], and low-temperature intake valve deposits [7]. 

The high content of water and emulsifier in this fuel creates some differences in handling and application compared to conventional diesel fuel. The surfactant quality of the emulsification additive in the fuel can remove existing deposits from the internal surfaces of fuel handling and storage systems. Problems with fuel discoloration and fuel filter plugging may follow. Compared with conventional diesel, fuel economy ratings per tank of fuel will drop because the overall carbon content per unit volume of fuel is lower. This is due to carbon displacement by water. 

Many applications of surfactants in lubricants and fuels have a common purpose, namely to reduce or prevent the formation of deposits by the degradation products of lubricants and fuels. In lubricant applications, surfactants serve in various roles. In crankcase oils, surfactants reduce and prevent sludge formation and deposit formation in pistons, cylinders, and valve train systems [1]. They also reduce and prevent sludge formation in the reservoirs of transmission fluids, gear oils, and industrial oils, and keep parts clean by prevention of deposit formation on metal parts. In addition, they provide friction control in friction interfaces as in automatic transmissions. 

Generally, the only bundles that will be hard to clean will be those between the bottom of the fractionator and the reactor. These units may be coked if the process was upset. The other bundles can be cleaned by first circulating the light cycle oil, which is a cut off the fractionator. Diesel fuel may also be used. The addition of a surfactant to the diesel will help disperse the deposits, but more than one system volume will probably be needed. An emulsion can be used with the last stage to remove iron oxides. If the acid is the inner phase, passivation may not be required. If the cleaning stages are separate, or if the organic is the inner phase, then ammonium citrate is recommended for passivation because sodium is also a catalyst poison. 

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