<p>It is shown that the gas flow in the Laval supersonic nozzle differs from throttling by transition of potential and thermal energy expressed with the value of enthalpy into kinetic energy. As a result, the temperature and enthalpy of the gas in the Laval nozzle diffuser decrease, facilitating gas liquefaction. Using this approach, a natural gas liquefaction scheme is proposed, including a supersonic Laval nozzle and a remote cyclone separator for a condensing liquid. A mathematical model for natural gas liquefaction in a Laval nozzle and an algorithm for numerically calculating the process are developed. The maximum yield of liquefied gas is estimated for various initial gas parameters. The obtained results are analyzed, and the efficiency of the proposed process is compared with natural gas liquefaction processes using isenthalpic throttling (the Linde–Hampson cycle) and isentropic expansion in a turboexpander (the Claude cycle).</p>