The proportion of propane and butane in LPG (liquefied petroleum gas) cylinders can vary depending on the specific country, supplier, and intended use.
In general, LPG cylinders commonly contain a mix of propane and butane, with the proportion of each gas varying according to the season and climate conditions.
During winter, when temperatures are lower, the proportion of propane is usually higher as it has a lower boiling point than butane and can maintain its vapor pressure in colder temperatures.
In contrast, during summer, when temperatures are higher, the proportion of butane is typically higher, as it has a higher vapor pressure than propane and is more suitable for use in warmer conditions.
The exact proportion of propane and butane can also depend on the intended use of the LPG, such as for household or industrial purposes. In general, the typical proportion range for LPG cylinders is 40% to 60% propane and 60% to 40% butane