You Should Know about LNG/LPG/CNG in Petroleum Industry

LPG carrier, which refers to liquid petrol gas carrier, transports liquefied petroleum gas. In most cases, petroleum gas are to be liquefied directly at a relatively high temperature or through compression. Usually the liquefied gas would be kept in cold storage when being shipped, say, at about -60℃. Or it can be stored in pressure tank and shipped.

LPG differs from LNG, liquefied natural gas. Major ingredient is propane occupying over 95% of LPG, whereas a small quantity of butane also exists in it. LPG liquefied is stored in tanks under an appropriate pressure and thus becomes a kind of fuel for cooking. For many years LPG has been used as the fuel of lightweight vehicles in some countries.

LNG carrier, as indicated above, means liquefied natural gas carrier. LNG liquefaction adopts no pressure related processing. LNG carrier ships liquefied natural gas whose temperature stays at lower than -163℃. Due to a low temperature and high volatility, it could cause huge risks once leaked and ignited.

LNG is produced a type of clean and highly efficient energy after natural gas, whose main component is methane, has been extracted from gas fields. The liquefaction of natural gas helps save storage space and costs, while also leads to a high burning efficiency.

CNG carrier is another sort to ship compressed natural gas. CNG appears as gas with just 1/200 times the standard volume of natural gas on the condition that the pressure ranges from 80 to 313bar. No expensive facilities are needed for liquefaction and regasification, generating obviously lower costs compared to LNG. This makes it increasingly welcomed by the market.

CNG is normally applied to vehicles traveling short distances and neighborhoods with less sound infrastructure. CNG used by vehicles are stored in high-tenacity tanks since the proper pressure for natural gas storage is at around 20Mpa.