Many petrochemical products found use in the industry, different in terms of physical and chemical properties and the conditions of use. Impurities in these materials are also different in structure and composition, therefore they are classified by aggregate state, chemical composition and other parameters.
Aggregate state classes are solid, liquid and gaseous contaminants.
Solid contaminants include products of wear and corrosion products, dust, salts and other such substances; liquid impurities include water, resins and surfactants; gaseous contaminants are, obviously, various gases, including air.
Chemically, the impurities can be mineral (including water and air) and organic (carbon compounds).
Microbiological impurities (bacteria, fungi, pyrogenic substances) are also present in petrochemicals.
The classification of impurities source and origin from the refinery to the operating equipment has three classes.
Production impurities enter the materials in production. These include crude oil contaminants (metal and silicon oxides, asphalt and tar), technological (resins), atmospheric (metal and silicon oxides and water) and contact (metal oxides) impurities.
Operational contamination forms when the materials are transported and stored. They include atmospheric (metal and silicon oxides and water), residual (metal and silicon oxides and water), contact (metal oxides and particles of seals and gaskets), wear (metals, alloys and plastics), high temperature (resins, asphaltenes and other products of oxidation and polymerization), low temperature (paraffins and ceresins), gaseous (air and other gases) and microbial (bacteria, fungi) impurities.
Contamination accumulated during use enters the materials in the process of operation of machines and engines. These include hydrocarbon (resins, asphaltenes, carbenes, carboids, asphaltogenic and oxyacids, coke, soot etc, residual (hydrocarbon contaminants, metal and silicon oxides and water), atmospheric (metal and silicon oxides and water), contact (metal oxides, particles of seals and construction materials), wear (metals, alloys and plastics) and gaseous (air, vapors, exhaust gases etc).
Such classification allows to comprehensively approach petrochemical material purification, identify and remove the sources of impurities and implement measures to reduce contamination levels.