Product

Main Product: Hydrocarbon gas liquids
Segment: Refined Products
Main-Family: Refinery Liquids
Sub-Family: Light Distll. & Proc. Hydroc.
Physical State: Liquid

Product

Refined LPG

Abbreviation

LPG

Names

LPG; Sweetened LPG; Commercial LPG; LP Gas; Autogas; Propane; Butane

Production

Global Production Production Map

Refined LPG, also known as sweetened LPG, is a commercially traded liquefied petroleum gas that has undergone a purification process—most commonly Merox or similar sweetening technology—to remove sulfur compounds and other contaminants. This process reduces hydrogen sulfide and mercaptan concentrations to very low levels, producing an LPG product that is odorless (apart from any added odorant for leak detection), non-corrosive, and compliant with strict regulatory and market specifications required for use in domestic, industrial, and automotive applications. The sweetening process (e.g., Merox) primarily removes sulfur compounds but may be paired with hydrotreating if significant olefins are present and product specification demands are stringent.

Refined LPG is produced from both petroleum refining and natural gas processing. Its constituents are mainly propane, butane and iso-butane and mixtures of these gases. In standard commercial LPG, the olefin content is typically very low or negligible. Only in certain industrial applications or geographic regions might “unsweetened” or partially hydrogenated LPG streams retain measurable butylenes and propylene. The composition of commercial LPG can vary by country—using propane, butane, or blends—according to local standards (for example, LPG in Australia is primarily propane).

Refined vs. Raw LPG Constituents

Constituent	Refined LPG (Sweetened, Commercial)	Raw LPG (Untreated)
Propane	Major (>30–100%)	Major
n-Butane	Major (>0–70%)	Major
Iso-butane	Minor/Variable (up to 20%)	Minor/Variable
Propylene	Trace to very low (<5%)	Minor to moderate
Butylene	Trace to very low (<2%)	Minor to moderate
Sulfur compounds	<0.001 wt% (regulated)	Variable, high possible

Chemical Data

LPG remains liquid under moderate pressure but becomes gaseous at atmospheric pressure and temperature, allowing for safe storage and transport in steel vessels ranging from small gas bottles to large bulk storage tanks.

Property	Value
Chemical Formula	Variable (mainly C₃H₈, C₄H₁₀, includes butanes, propane)
Molecular Weight (g/mol)	44–58 (propane: 44.10; butane: 58.12; blend based on ratios)
Freezing Point °C)	Below −138°C (butane: −138.4°C; propane: −187.7°C; blends: in-between)
Boiling Point (°C)	−0.5°C to −42°C (n-butane: −0.5°C; propane: −42°C; blends: range)
Melting Point (°C)	Below −135°C (similar to freezing point; blend-dependent)
Sulfur Content (wt%)	≤0.001 wt% (sweetened LPG; regulatory/commercial spec; typical value post-Merox process)
Specific Gravity	0.50–0.58 at 15°C (air=1)
Conversion Factor	1 tonne ≈ 1.96 m³ (density ~510 kg/m³; varies by blend)

Notes

All data above refer specifically to refined (sweetened) LPG, after treatment to remove sulfur and other impurities, meeting domestic and commercial product standards.
Properties depend on the ratio of propane, butane, and other light hydrocarbons as per local or national regulations.
Sulfur is reduced to strict specifications: in many markets, <5 ppm by mass, commonly as ≤0.001 wt% in the final product.

References