Petroleum paraffins: properties, types and applications
Petroleum paraffins are a broad group of solid and liquid methane-series hydrocarbons obtained from petroleum processing. They are among the most versatile and in-demand petrochemical products, used in packaging, candle manufacturing, rubber technical goods, cosmetics, pharmaceuticals, paints and coatings, and many other industries. Paraffins combine affordability, chemical inertness, water-repellent properties and the ability to form strong crystalline structures, making them an indispensable component in formulations of varying complexity.
Chemical Nature and Classification
Chemically, paraffins are mixtures of saturated hydrocarbons with straight or branched chains. Solid paraffins are based on normal alkanes with 18 to 40 carbon atoms, while liquid paraffins contain predominantly C10–C18 hydrocarbons. The chain length and the ratio of normal, iso- and cyclic structures determine the melting point, crystallinity and mechanical properties of the material.
Depending on physical state and structure, several main types of paraffin feedstock are distinguished. Solid paraffins are crystalline substances, white or slightly yellowish, with melting points in the range of 45–65 °C (for highly refined grades — up to 70 °C and above). Liquid paraffins (liquid n-alkanes) are mobile liquids under normal conditions with pour points below 20 °C, used as feedstock for organic synthesis and as process fluids. Ceresins occupy an intermediate position between paraffins and microcrystalline waxes: they have higher molecular weight, melting points of 60–85 °C and a fine-crystalline structure, which gives compositions greater flexibility and oil-retention capacity.
By degree of refinement, paraffins are divided into several levels. Slack waxes contain 5 to 20% oil and are the product of dewaxing petroleum fractions. Partial refining yields semi-refined paraffins with 0.5–5% oil content. The highest refinement level is fully refined paraffin, in which the oil mass fraction does not exceed 0.5%. These highly refined grades, subjected to hydro- or adsorbent treatment, are water-clear, odourless and approved for food contact.
Grades and Regulatory Framework
In Russia, requirements for solid petroleum paraffins are established by GOST 23683-89. According to the standard, paraffins are divided by refinement degree into highly refined and refined, with grades determined by application. Highly refined grades P-1 and P-2 are intended for food contact: P-1 is used for rigid containers, packaging materials, adhesives and melts, while P-2 is used for coating and impregnating flexible food packaging that retains elasticity at low temperatures. Grades V2, V3, V4 and V5 are highly refined paraffins for industries with special purity requirements; in particular, V2 is used in rubber technical goods. Refined technical grades T-1, T-2, T-3 and S are used as feedstock: T-1 for household chemicals and candles, T-2 in the chemical and petrochemical industry, T-3 for impregnating technical paper, cardboard, textiles and wooden surfaces, and S for synthetic fatty acid production.
Ceresins are regulated by a separate standard (GOST 2488-79), which establishes requirements for a mixture of solid hydrocarbons obtained by refining petroleum ceresin. Liquid paraffins, depending on fractional composition and application, are supplied under technical specifications that account for normal alkane content and pour point.
Production Technology
Paraffin production is inextricably linked to the dewaxing of petroleum oils and fuels. To obtain oils with low pour points from petroleum fractions, high-pour-point normal alkanes must be removed — these are the feedstock for paraffins. The main technological stages include dewaxing of oil fractions using solvents (ketones, propane, mixtures of chlorinated hydrocarbons), de-oiling and fractional crystallisation of the resulting slack waxes and petrolatums, and purification of crude paraffins.
To obtain high-purity liquid and solid n-alkanes, processes based on urea adduct formation (urea dewaxing) and adsorption using molecular sieves (zeolites) are used. These methods allow normal alkanes to be separated from kerosene and gas oil fractions with high selectivity. The final stage of commercial paraffin production is purification — hydrotreatment or contacting with adsorbents — which removes resins, aromatic compounds and sulfur compounds, giving the product a stable colour, clarity and odourlessness.
Properties Determining Applications
The key characteristics of paraffins are melting point, oil content, penetration, colour and melt viscosity. Solid paraffins have high crystallinity, water-repellent properties, chemical inertness and low melt viscosity, ensuring good impregnation and barrier coating formation. Liquid paraffins are characterised by low viscosity, thermal stability and the ability to dissolve many organic compounds, making them convenient process media. Ceresins, due to their fine-crystalline structure, increase the flexibility of wax compositions, improve oil retention and impart resistance to sweating.
Applications
Candle manufacturing remains one of the largest consumers of paraffin. Paraffin candles are distinguished by shape stability, even burning and the ability to be coloured and scented. Decorative and scented candles use blends of paraffin with ceresin and other additives that regulate melting point and structure.
Packaging industry uses paraffins for impregnating and coating paper, cardboard and flexible packaging materials. Paraffin coatings impart moisture resistance, grease resistance and barrier properties to packaging, and highly refined grades are approved for direct food contact. In corrugated cardboard production, paraffin is used to improve strength and water resistance.
Rubber and tyre industry uses paraffins as a component of rubber compounds and as an antiozonant additive. During vulcanisation, paraffin migrates to the product surface and creates a protective layer that resists ozone and atmospheric attack. Special grades with controlled melting point and oil content are used for these purposes.
Cosmetics and pharmaceuticals are important consumption segments for highly refined paraffins. Paraffin is included in creams, ointments, balms, petroleum jellies and wax bases, where it performs a structuring and moisture-protective function. Pharmacopoeial grades of paraffin and liquid paraffin (mineral oil) are used as ointment bases and excipients.
Paint and coatings industry and hot-melt adhesives use paraffins to modify rheological properties, improve coating water resistance and create matte effects. In hot-melt adhesives, paraffin reduces viscosity, improves wetting and regulates open time.
Other directions include match production, paper cups and beverage packaging, electrical insulation, foundry applications where paraffin is used in investment casting patterns, and agriculture and controlled-release fertilisers.
Market and Trends
The paraffin market shows steady demand, supported by the development of candle production, the packaging industry, construction and the automotive sector. Candles remain the largest consumption segment, followed by packaging, rubber technical goods, cosmetics and hot-melt adhesives. The Asia-Pacific region is the largest producer and consumer of paraffins, driven by large-scale oil refining and a developed manufacturing base.
Key trends include tightening requirements for paraffin purity for food contact and medical applications, the development of bio-based and synthetic alternatives, and growing attention to the carbon footprint of products. Manufacturers are improving hydrotreatment and de-oiling technologies, enabling grades with minimal polycyclic aromatic hydrocarbon content. At the same time, interest is growing in paraffins as phase-change materials for thermal energy storage systems.
Selecting the right paraffin grade for a specific technology — taking into account melting point, oil content, penetration and food-contact requirements — requires an individual approach that includes assessment of melt rheology, compatibility with other components and processing conditions. Organising paraffin supplies, including logistics and financial support, also requires consideration of temperature conditions during storage and transportation, especially for liquid and low-melting grades.