Synthesis gas production process for the implementation of a natural gas liquefaction

A process for the liquefaction of natural gas in combination with a process for the production of synthesis gas, the liquefaction process comprising the following stages:

• Stage a):
• pretreatment of a feed natural gas in order to remove the impurities liable to freeze during the liquefaction process;
• Stage b):
• extraction, from the gas stream resulting from stage a), of a stream enriched in hydrocarbons having more than two carbon atoms;
• Stage c):
• liquefaction of the gas stream depleted in hydrocarbons having more than two carbon atoms resulting from stage b);
• the process for the production of synthesis gas comprising the following stages:
• Stage a′):
• desulfurization at a temperature of greater than 350° C. of a natural gas feed stream;
• Stage b′):
• optional prereforming, at a temperature of greater than 500° C., in order to convert the hydrocarbon chains containing at least two carbon atoms of the gas stream resulting from stage a′) into methane;
• Stage c′):
• reforming consisting in reacting, at a temperature of greater than 800° C., the gas stream resulting from stage a′) or b′) with steam in order to produce hydrogen, carbon dioxide and carbon monoxide;
• wherein the steam resulting from the process for the production of synthesis gas is used as source of heating for the implementation of stage a);
• and wherein stage a) comprises a pretreatment by adsorption by means of an adsorption system comprising between two and five containers of at least one bed of adsorbent and at least one device for heating and/or cooling an adsorption and/or regeneration stream circulating in said adsorption system and wherein the steam resulting from the process for the production of synthesis gas is employed to reheat said regeneration stream.