Dry natural gas liquefaction method

A method of liquefying a dry natural gas comprising water, methane and less than 1% by mole of hydrocarbons heavier than methane, wherein the following stages are carried out:

• a) passing the dry natural gas through a water-adsorbent solid so as to obtain a water-depleted natural gas and a water-laden adsorbent solid, the water-adsorbent solid being selected from among 3A, 4A and 5A sieves, b) passing the water-depleted natural gas through a solid adsorbing heavy hydrocarbons comprising at least five carbon atoms so as to obtain a heavy hydrocarbon-depleted natural gas and a heavy hydrocarbon-laden adsorbent solid, the heavy hydrocarbon-adsorbent solid being selected from among the X and Y faujasite zeolites, and activated charcoals, c) liquefying the heavy hydrocarbon-depleted natural gas at a pressure above 40 bar abs so as to obtain a liquid natural gas under pressure, and d) expanding the liquid natural gas under pressure obtained in stage c) to atmospheric pressure so as to obtain a liquid natural gas and a gas fraction.