NOVELTY - The gas handling system includes a LNG carrier that receives natural gas from an offshore facility or a land-based facility, and LNG process plant (10) provided on the LNG carrier. The LNG carrier includes cargo handling system, LNG tanks and propulsion system. The LNG process plant has a cooling unit (40) has a closed Brayton cooling cycle unit comprising of compressor units and at least one expander unit. The compressor and expander units are mechanically coupled to a gear box, thus forming a single compander unit. Nitrogen gas is used as cooling fluid in the Brayton cooling cycle unit.    USE - Natural gas handling system for liquefying, storing and transporting natural gas such as LNG.    ADVANTAGE - Provides an alternative system for liquefying, storing and transporting natural gas in an efficient way, and which uses LNG carrier to liquefy, store and transport natural gas from the gas production facility to the market. Ensures that the recovered energy from the gas expansion is utilized in the process plant total energy balance, or in the energy balance of the LNG carrier itself. Ensures that the process plant is installed and integrated in the LNG carrier's auxiliary systems, in which the integration can be carried out without disrupting the LNG carrier's normal functions such as passage at full speed, berthing, mooring and cargo offloading.    DETAILED DESCRIPTION - The LNG process plant also includes a gas expanding unit (20) for recovering work from natural gas and providing initial cooling of the natural gas, and a heat exchanging unit (30) for cooling and liquefaction of the natural gas. The fooling unit provides further cooling and facilitates liquefaction and sub-cooling of the natural gas. An expansion valve (50) is provided for final cooling, and performs reduction of the pressure of the liquefied gas before storing it in the LNG tanks using the cargo handling system. An INDEPENDENT CLAIM is also included for the natural gas handling method.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic illustration showing the details of the gas processing system of the LNG carrier.    LNG process plant (10)    Gas expanding unit (20)    Heat exchanging unit (30)    Cooling unit (40)    Expansion valve (50)