A booster system for increasing pressure of an object gas includes: a first compression unit that compresses the object gas to intermediate pressure equal to or higher than the critical pressure and lower than the target pressure and generates an intermediate supercritical fluid; a cooling unit that cools the intermediate supercritical fluid with a cooling medium and generates an intermediate supercritical pressure liquid; a liquid extracting and pressure reducing unit that extracts a part of the intermediate supercritical pressure liquid; a flow regulating valve that regulates a flow rate of the extracted part of the intermediate supercritical pressure liquid; a second compression unit that increases pressure of the rest of the intermediate supercritical pressure liquid to be equal to or higher than the target pressure; and a pressure sensor that detects pressure of the intermediate supercritical pressure liquid.

Systems and processes for natural gas processing, liquefaction, and storage are described. The systems and processes include one or more arrangements of features which are capable of liquefying all of the gas entering an inlet of the system or a portion of the entering gas. The portion of the entering gas that is liquefied can vary based on the pressure of an outlet of the system, which can be fixed or vary based on usage downstream.

The present invention comprises systems and methods for natural gas liquefaction. In embodiments, the systems comprise a methane-based refrigeration system that also uses a slip stream of LNG for additional cooling.

A natural gas liquefaction system and method for effectively and efficiently removing heavy hydrocarbons and converting natural gas into liquefied natural gas. Natural gas streams entering the system may consist of varied gas compositions, pressures, and temperatures. In embodiments the system may comprise a natural gas (NG)-to-liquefied natural gas (LNG) portion and a closed-loop refrigeration portion comprising a closed-loop single mixed refrigerant system. In other embodiments the system may comprise an NG-to-LNG portion and a closed-loop refrigeration portion comprising a closed-loop gaseous nitrogen expansion refrigeration system. All embodiments utilize an integrated heat exchanger with cold-end and warm-end sections and integrated multi-stage compressor and expander configurations (e.g. compander) in order to increase overall operation flexibility and efficiency. This optimized method and system is capable of more efficiently producing a liquefied natural gas product at a desired capacity using a minimum amount of equipment and a modularized design to reduce construction costs.

In a process of liquefaction and subcooling of a stream rich in CO.sub.2, the stream is liquefied by a closed cycle of refrigerant and subcooled by heat exchange with three streams of liquid CO.sub.2 at different pressures.