A method for producing ¾-rich synthesis gas comprises the following steps: decomposing a hydrocarbon-containing fluid into an H2/C-aerosol in a first hydrocarbon converter by supplying energy which is at least partly provided in the form of heat; introducing at least a first stream of the H2/C-aerosol into a first sub-process which comprises the following steps: directing at least a part of the H2/C-aerosol from the first hydrocarbon converter into a first C-converter; introducing CO2 into the first C-converter and mixing the CO2 with the H2/C-aerosol introduced into the first C-converter; converting the mixture of H2/C-aerosol and CO2 into a synthesis gas at a temperature of 800 to 1700° C.; mixing additional H2 with the synthesis gas for the production of H2-rich synthesis gas. In a second sub-process running in parallel with the first sub-process, hydrogen H2 and carbon dioxide CO2 are produced from a hydrocarbon-containing fluid, wherein at least a portion of the CO2 produced in the second sub-process is introduced into the first C-converter; and wherein at least a portion of the H2 produced in the second sub-process is mixed with the synthesis gas from the first C-converter. The CO2 which is needed for the conversion of C in the first C-converter can thereby be provided independently of an external source, and the entire operational sequence is easily controllable.