Pall products are used to purify final product streams in refineries, chemical, petrochemical and polymer plants removing corrosion products and liquid contaminants such as water and caustic, treat high temperature and high viscosity melt polymers, recover expensive catalyst for reuse and remove liquid aerosols to protect process equipment such as turbines and compressors. These filters and coalescers are used to prepare feedstocks and utilities for use in production of intermediate and final products. Free water or other dispersed contaminants cause haze, process equipment fouling, poison catalysts and lead to off-specification product. Removal of these contaminants can improve the economy of plant operation and ensure on-specification product is shipped every time. This dual nature greatly increases the surfactant's tendency to adsorb at interfaces and increases the tendency for emulsion formation.
Surfactants act to reduce interfacial tension between two liquids.
IFT exists because the molecules in a liquid have different energies in the bulk phase as compared to close to the interface between a hydrocarbon liquid and an aqueous liquid. Petroleum and chemical streams can contain surfactants as a natural part of the process or as performance enhancer additives. Some of the surfactants present are sodium naphthasulfonates, cresylic acids, naphthenic acids, corrosion inhibitors, biocides, metal scavengers, and emulsion breakers. The higher the viscosity the more difficult the separation. Fine solids can stabilize emulsions or plug the separating device.