An apparatus, a system and a method for producing liquefied gas are provided. A liquefaction plant may be coupled to a source of, for example, unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream may pass through an expansion device. The compressed process stream is cooled, such as by a heat exchange process utilizing the expanded cooling stream, by a heat exchanger utilizing a separate, independent refrigerant, or by both. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. A portion of the liquid gas may be used for additional cooling or substantially all of the liquid gas may be collected as product.
 The United States Government has certain rights in this invention pursuant to Contract No. DE-AC07-05ID14517 between the United States Department of Energy and Battelle Energy Alliance, LLC.