Specification
Composition, vapour pressure, sulphur, water, residues and odourant specification where applicable.
Energy and fuels / Gases
LPG
LPG reviewed through composition, vapour pressure, pressurised storage and delivery channel.
Technical identity
LPG as a pressurised propane-butane product
LPG is a family of liquefied petroleum gases, usually propane, butane or C3/C4 mixtures. It is kept liquid by moderate pressure, not by the cryogenic regime used for LNG.
Composition changes commercial behaviour: vapour pressure, density, cold-weather performance, suitability for cylinders, autogas or industrial bulk supply and safety requirements.
The review should confirm whether the offer is propane, butane, a commercial mix or a specific grade. Without composition and vapour pressure, the LPG name is insufficient.
FamilyPressurised liquefied gas
ComponentsPropane / butane
Key controlVapour pressure
DeliveryCylinder or bulk
Loading published market reference…Automatic reference data; no estimated value is shown if the source is unavailable.
Recovery, fractionation and LPG control
1Recovery
Natural-gas or refinery streams supply light hydrocarbons.
2Separation
Fractionation produces propane, butane or commercial mix.
3Specification
Composition, vapour pressure, sulphur, water and residues are controlled.
4Pressurised storage
Tanks, spheres or cylinders keep the product liquid.
5Distribution
Dispatch by LPG carrier, railcar, bulk truck or cylinder.
Quality and specification
Composition and vapour pressure in LPG
C3/C4 composition decides pressure, vaporisation and use. Butane-rich LPG behaves differently from propane-rich LPG, especially at low ambient temperature.
Vapour pressure must fit the tank, cylinder, transport mode and local regulation. Sulphur, water, residues, corrosion and odourant are also checked where required.
The COA should state method, sample, date, tank and composition. For LPG, a cylinder photograph or volume promise is not enough.
Tanks, cylinders and pressurised transport
LPG logistics use pressure vessels: spheres, horizontal tanks, railcars, road tankers, cylinders or specialised ships. Each channel needs valves, pressure relief and safety procedures.
The buyer should review connection compatibility, unloading capacity, dangerous-goods permits, mass/volume and temperature. Cylinders add tare, periodic inspection and container traceability.
LPG is not managed as LNG. It does not need cryogenic tanks, but pressure, leak detection, ventilation, classified areas and emergency procedures are essential.
Specific controls
| Element | Verification |
|---|---|
| C3/C4 composition | Defines pressure, vaporisation, heating value and end-use suitability. |
| Vapour pressure | Must fit container, transport and regulation. |
| Sulphur and corrosion | Affect safety, equipment and compliance. |
| Water and residues | May cause blockage, corrosion or vaporisation problems. |
| Odourant | Required in many end-user distribution applications. |
LPG demand channels and terminals
LPG context is organised by channels: residential/commercial, autogas, industry, petrochemicals and markets without natural-gas grids. Useful geography is pressurised terminals and bulk or cylinder distribution.
| Market | Role | Context |
|---|---|---|
| Cylinder-distribution regions | RESIDENTIAL / COMMERCIAL DEMAND | Access depends on filling, safety and distribution network. |
| Petrochemical centres | FEEDSTOCK | Propane and butane can feed cracking, alkylation or other processes. |
| Coastal and inland LPG terminals | LOGISTICS | Ships, spheres, railcars and trucks connect supply to users. |
Sources: U.S. EIA - Transporting and storing hydrocarbon gas liquids; U.S. EIA - Hydrocarbon gas liquids explained
Documents for buying LPG
Certificate
COA, SDS, quantity certificate, tank/cylinder record and independent inspection.
Logistics
Permits, transport class, valves, unloading, custody and receiver compatibility.
Buyer questions about LPG
Are LPG and LNG the same?
No. LPG is pressurised propane/butane; LNG is mostly methane liquefied by cryogenic cooling.
Why does the propane/butane ratio matter?
It changes vapour pressure, vaporisation, cold-weather performance and final use.
How is LPG transported?
By LPG carriers, railcars, pressurised road tankers, bulk tanks or cylinders, depending on volume and channel.
What controls vapour pressure?
Composition, temperature and specification; it must be compatible with vessel and regulation.
Which documents are requested?
Composition COA, SDS, quantity, tank or cylinder record, inspection and dangerous-goods transport documents.
Can LPG be used as autogas?
Yes when the mixture, regulation, station and vehicle are compatible with automotive LPG.