FIELD: conversion of hydrocarbon gas into reformed gas containing hydrogen and carbon monoxide. SUBSTANCE: method involves compressing supplied gas in primary compressor for producing primary gas with following dividing it into two portions, with first portion being primary combustion air; dividing primary hydrocarbon gas into two portions before supplying it into mixing chamber; combusting first portion together with primary combustion air in combustion zone of primary combustion chamber to produce primary combustion gas; feeding second portion of primary hydrocarbon gas to reforming zone and providing reaction thereof with primary combustion gas for producing reformed gas, which is used for actuation of primary power turbine and compressor; feeding portion of primary air together with secondary hydrocarbon gas into secondary combustion chamber for producing off gas used for actuation of secondary power turbine and gas compressor. First version of combustion system is substantially similar to that of second version except that compressors and power turbine are reconfigured and second system comprises auxiliary secondary power turbine. Second version of method is carried out in the same manner as first one and is accompanied with production of reformed gas and actuation of primary power turbine and compressor. Off gas is used to actuate secondary turbine, however secondary turbine actuates auxiliary primary compressor, which is adapted for compressing supplied gas upstream of primary compressor by energetically self-adequate method. Off gas is adapted for additional actuation of secondary power turbine for providing alternative energy consumers with additional power. Method and system for converting hydrocarbon gas into reformed hydrogen-containing gas are profitable as compared to conventional hydrocarbon gas conversion systems. EFFECT: reduced costs of equipment employed for carrying out process, reduced labor intensity and increased product output. 6 cl, 3 dwg
