A method for producing H 2 -rich synthesis gas comprising the following steps: decomposing a hydrocarbon-containing fluid into an H 2 /C-aerosol in a first hydrocarbon converter (9, 9') by supplying energy which is at least partly provided in the form of heat; introducing at least a first stream of the H 2 /C-aerosol into a first sub-process which comprises the following steps: directing at least a part of the H 2 /C-aerosol from the first hydrocarbon converter (9, 9') into a first C-converter; introducing CO 2 into the first C-converter and mixing the CO 2 with the H 2 /C-aerosol introduced into the first C-converter; converting the mixture of H 2 /C-aerosol and CO 2 into a synthesis gas at a temperature of 800 to 1700°C; mixing additional H 2 with the synthesis gas for producing H 2 -rich synthesis gas; producing the additional hydrogen H 2 and the carbon dioxide CO 2 from a hydrocarbon-containing fluid in a second sub-process running in parallel with the first sub-process, wherein the CO 2 and a portion of the additional H 2 produced in the second sub-process are produced from CO and H 2 O by a water-gas-shift-reaction, and wherein the CO which is introduced into the water-gas-shift-reaction is produced in a second C-converter from carbon C and water H 2 O at a temperature of 800 to 1700°C; wherein the CO 2 produced in the second sub-process is introduced into the first C-converter; and wherein only a portion of the additional H 2 produced in the second sub-process is mixed with the synthesis gas from the first C-converter. decomposing a hydrocarbon-containing fluid into an H 2 /C-aerosol in a first hydrocarbon converter (9, 9') by supplying energy which is at least partly provided in the form of heat; introducing at least a first stream of the H 2 /C-aerosol into a first sub-process which comprises the following steps: directing at least a part of the H 2 /C-aerosol from the first hydrocarbon converter (9, 9') into a first C-converter; introducing CO 2 into the first C-converter and mixing the CO 2 with the H 2 /C-aerosol introduced into the first C-converter; converting the mixture of H 2 /C-aerosol and CO 2 into a synthesis gas at a temperature of 800 to 1700°C; mixing additional H 2 with the synthesis gas for producing H 2 -rich synthesis gas; producing the additional hydrogen H 2 and the carbon dioxide CO 2 from a hydrocarbon-containing fluid in a second sub-process running in parallel with the first sub-process, wherein the CO 2 and a portion of the additional H 2 produced in the second sub-process are produced from CO and H 2 O by a water-gas-shift-reaction, and wherein the CO which is introduced into the water-gas-shift-reaction is produced in a second C-converter from carbon C and water H 2 O at a temperature of 800 to 1700°C; directing at least a part of the H 2 /C-aerosol from the first hydrocarbon converter (9, 9') into a first C-converter; introducing CO 2 into the first C-converter and mixing the CO 2 with the H 2 /C-aerosol introduced into the first C-converter; converting the mixture of H 2 /C-aerosol and CO 2 into a synthesis gas at a temperature of 800 to 1700°C; mixing additional H 2 with the synthesis gas for producing H 2 -rich synthesis gas; producing the additional hydrogen H 2 and the carbon dioxide CO 2 from a hydrocarbon-containing fluid in a second sub-process running in parallel with the first sub-process, wherein the CO 2 and a portion of the additional H 2 produced in the second sub-process are produced from CO and H 2 O by a water-gas-shift-reaction, and wherein the CO which is introduced into the water-gas-shift-reaction is produced in a second C-converter from carbon C and water H 2 O at a temperature of 800 to 1700°C; wherein the CO 2 produced in the second sub-process is introduced into the first C-converter; and wherein only a portion of the additional H 2 produced in the second sub-process is mixed with the synthesis gas from the first C-converter.