Liquefied petroleum gas supplied for export as a technical propane–butane blend (SPBT), produced to TÜ 022224689-01-2019. Cargoes are supplied in a certified propane/butane ratio — most commonly propane 40% with butane 60%, or propane 60% with butane 40% — with the actual ratio stated on the laboratory certificate for each lot.
Specification
- Product: technical propane–butane mix (SPBT)
- Standard: TÜ 022224689-01-2019
- Ratios supplied: propane 40% / butane 60%, propane 60% / butane 40%, or as certified per cargo
- Saturated vapour pressure at +45 °C: max 1.6 MPa
- Hydrogen sulfide and mercaptan sulfur: max 0.013%, of which hydrogen sulfide max 0.003%
- Loading: pressurised rail tank cars and road tankers
Ratios
Propane 40% / Butane 60%
The most commonly contracted export blend, and the standard specification for overland cargoes to regional destinations.
Propane 60% / Butane 40%
The propane-rich blend, specified where colder-weather vaporisation matters. Corresponds to the SPBT variant permitted at not less than 60% propane and propylene by agreement between producer and buyer.
Per laboratory certificate
The ratio is set per cargo and stated on the certificate of analysis rather than fixed in advance. This basis accounts for a large share of shipped volume.
Component grades — TDS 829-2016
The blend is made from the technical grades below. TDS 829-2016 is the domestic-use standard; the export blend is supplied to TÜ 022224689-01-2019.
| Parameter | PT (propane technical) | SPBT (propane-butane mix) | BT (butane technical) |
|---|
| Sum of methane, ethane and ethylene, % | Not rated | Not rated | Not rated |
| Sum of propane and propylene, %, min | 75 | Not rated | — |
| Sum of butanes and butylenes, %, min | — | 60 | 60 |
| Volume fraction of liquid residue at 20 °C, %, max | 0.7 | 1.6 | 1.8 |
| Saturated vapour pressure, gauge, MPa, at +45 °C, max | 1.6 | 1.6 | 1.6 |
| Saturated vapour pressure, gauge, MPa, at −20 °C, min | 0.16 | — | — |
| Hydrogen sulfide and mercaptan sulfur, %, max | 0.013 | 0.013 | 0.013 |
| — of which hydrogen sulfide, %, max | 0.003 | 0.003 | 0.003 |
| Free water and alkali | None | None | None |
| Odour intensity, points, min | 3 | 3 | 3 |
By agreement between producer and buyer, SPBT may be produced with a propane and propylene content of not less than 60%.
Applications
Domestic and commercial heating and cooking, autogas, and petrochemical feedstock.
Commercial basis
Exchange pricing references Platts FOB Arab Gulf propane and butane quotations in the certified ratio, less a differential with a floor price.
Related
Loading and delivery
Loaded at the Naip and Sarahs storage and dispatch terminals, and at the Türkmenbaşy refinery. Rail dispatch to Afghanistan, Uzbekistan, Tajikistan, Iran and Türkiye.
