Separate fractions of the natural gas mixture such as NGL, LPG or heavier condensates tend to have higher sales values than the pipeline gas itself. Certain single components such as methane, ethane, propane and butane can also represent added value over regular pipeline gas. Therefore these fractions are often extracted in tailor made processing plants to meet requirements of specific markets and customers. Cryogenic processes are the most economical solution to extract these fractions from a natural gas mixture.
Condensate is the C5+ fraction and, as such, is the heaviest fraction of a natural gas mixture. Among other things it can be used as gasoline or steam cracker feedstock. Furthermore removing the condensate fraction of the natural gas mixture is required to meet the dewpoint specifications of the pipeline gas.
LPG (Liquefied Petroleum Gas) is widely used as alternative fuel for cars, but is also suitable as a chemical feedstock. LPG consists of propane and butane (C3/C4).
For the recovery of LPG/C3+ Linde Engineering offers an advanced expander process which guarantees recovery rates as high as 99.9 %, while minimizing specific energy consumption. Additionally Linde's advanced expander process allows for a higher CO2 content of the feed gas than the conventional expander processes.
