LPG

Liquid gas, abbreviated as LPG, usually consists of two hydrocarbon compounds, propane and butane, with the chemical formula C4H10, C3H8. Butane itself consists of two compounds, isobutane and normal butane. LPG, which is usually called propane in some parts of the world, can also be produced as a byproduct of natural gas production and crude oil refining processes.

LPG in America consists of 90% propane, 2.5% butane and heavy hydrocarbons and a small amount of ethane and propylene. LPG compositions are different for different places and in different seasons. For example, liquid gas provided to consumers in Iran in different seasons has between 50-90% butane and 10-50% propane and up to 2% heavier compounds such as pentane.

LPG is not to be confused with LNG (liquefied natural gas) because LNG is actually natural gas (mainly methane and ethane) that has been liquefied for easier and more economical transport, and CNG is natural gas that has been compressed to volume. Occupy a third.

Understanding Liquefied Natural Gas (LNG) Units
Liquefied natural gas, commonly called LNG, has become an important part of the EU’s natural gas supply/demand picture, with LNG exports growing over the past two years.

Fortunately, the above graph is in easy to understand units of million cubic feet. But often digging into LNG data can be confusing since different units are used to measure natural gas in its gaseous and liquid forms. And since LNG is a global business, both metric and English units are used.

LNG is typically measured in volumetric units. When in liquid form, LNG is commonly measured in metric tonnes. But you will sometimes see it measured in the amount of gas that it will provide when converted back to gaseous form. In this case, common units are billions of cubic meters (bcm) or billions of cubic feet (Bcf). Annual capacities of flow rates of facilities are often described in million tonnes per annum or millions of tonnes per year (these are the same thing). Various abbreviations are used including MMtpa, mtpa, MMty/y, or million mt/yr. Tanker capacities are sometimes stated in cubic meters, but this can be confusing because this is cubic meters of liquid not gas.

Converting volumetric units to energy content is complicated by the fact that different cargos of LNG have different heating values depending on how it was processed and the requirements of the country to which it is being delivered. Heating values in Asia tend to be higher than in other countries due to local specifications. Here are various conversions:

1 million tonnes (LNG) = 48.7 Bcf* (gas) = 1.379 bcm (gas)
1 Bcf (gas) = 45,000 cubic meters (LNG)
1 million tonnes per year (mtpa) (LNG) = 48.7 Bcf/year* (gas) = 1.379 bcm/year (gas)
1 cubic meter (m3) = 35.315 Cubic feet (cf)
1 tonne (LNG) = 53.57 MMBtu**
1 kilocalorie (kcal) = 4.187 kilojoule (kJ) = 3.968 Btu
1 Dth = 1 MMBtu = 10 therms = 1,000,000 Btu
Assumes a specific gravity of LNG at .45
** Assumes a natural gas heating value of 1,100 Btu/cf

We hope the above explanation helps you organize the LNG data you are reviewing. Because natural gas use around the world is likely to continue to grow given the volume of cheap LNG available, you need to understand LNG units to understand the global supply/demand picture.