To transport natural gas by ship its density must be increased. This can be done by decreasing temperature and/or increasing pressure. Decreasing the temperature to -162°C causes it to condense to a liquid (LNG) with 1/600th the volume. Compressing the gas (CNG) reduces the volume 300-fold.

Floating or Marine CNG (FCNG) is the transportation of CNG by ship. CNG does not require complex and expensive refrigeration. As a result, while the energy density of CNG is about half that of LNG and therefore requires more shipping capacity, CNG loading and discharge facilities are much simpler and far less expensive. CNG thus has a comparative advantage for the transportation of smaller volumes of gas over shorter distances. CNG has the added benefit that the majority of investment is in the ships (not in onshore terminals), allowing ultimate redeployment to other projects. (CONTINUED - 830 WORDS)