TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The process comprises catalyzing and synthesizing low carbon (1-5C) mixed alcohol or high-carbon (6-18C) mixed alcohol with modified FischeruTropsch (F-T) catalyst of sulfur tolerant catalyst like molybdenum disulfide (MoS2) or cobalt-lanthanum-zirconium/actinium; performing heat transfer heating for the gas of mixed alcohol liquid product through cooling, condensating and separating, where the carbon monoxide, carbon dioxide, hydrogen are catalyzed and synthesized into methane hydrocarbon as city gas through cooling, condensating and separating and further processing into synthetic natural gas, compressed natural gas and liquefied natural gas. The process comprises: purifying fresh synthesis gas to remove noxious substance harmful to catalyst like sulfur, catalyzing and synthesizing low carbon mixed alcohol with copper-zinc-actinium or zinc/chromium modified methyl alcohol by heating and heat exchange and catalyzing and synthesizing methane hydrocarbon; and separating mixed alcohol products by circulator returns to the state before synthol and converges with fresh synthesis gas, catalyzing and synthesizing mixed alcohol and performing methanation reaction for the rest of gas in later process. In the process, a part of methane gas returns to methanation reaction by raising pressure with circulator and the rest of gas is conveyed out after cooling and separating moisture. The molar ratio of hydrogen/carbon monoxide in fresh synthesis gas is 0.5-3. The process comprises preparing gas mixture with the unreacted gas of fresh synthesis gas as well as separated mixed alcohol and replenished fresh hydrogen rich gas (coke-oven gas, methyl alcohol or ammonia synthesis purge gas) according to hydrogen-carbon dioxide (CO2)/carbon monoxide; adopting the gas mixture to catalyze and synthesize hydrocarbon product with nickel catalyst, where CO2 zero release is realized in producing process. The process comprises adopting coal as raw material or dry coal gasification to obtain rich carbon syngas of which hydrogen/carbon monoxide is less than 1, improving hydrogen/carbon monoxide without changing carbon monoxide, where rich carbon syngas is synthesized into mixed alcohol with sulfur tolerant catalyst like molybdenum disulfide.