NOVELTY - Producing ethanol, involves performing liquefaction step by disposing untreated carbon-containing material within first vessel, adding at least one enzyme to the vessel, and incubating the vessel at first temperature, performing saccharification step by adding at least one enzyme to the vessel, and incubating the vessel to form liquefact, and performing fermentation step by removing the liquefact from the vessel, disposing the liquefact in second vessel, adding at least one enzyme, adding several yeast cells to the second vessel, and incubating the second vessel.    USE - The method and system are useful for producing ethanol (all claimed) which is useful as fuel sources for transportation fleets, and biofuel, and in feedstock.    ADVANTAGE - The ethanol produced by the method improves sustainability and reduces green house gas emissions.    DETAILED DESCRIPTION - Method for producing ethanol, involves (a) (i) performing liquefaction step by disposing an untreated carbon-containing material within first vessel, adding at least one enzyme to the first vessel, and incubating the first vessel at a first temperature, (ii) performing saccharification step by adding at least one enzyme to the first vessel, and incubating the first vessel at a second temperature to form a liquefact within the first vessel, and (iii) performing fermentation step by removing the liquefact from the first vessel, disposing the liquefact in second vessel, adding at least one enzyme, adding several yeast cells to the second vessel, and incubating the second vessel at third temperature, or (b) (i) performing liquefaction step by disposing untreated carbon-containing material within first vessel, adding a volume of a liquid to the first vessel, adding at least one enzyme to the first vessel, and incubating the first vessel at a first temperature to form slurry, (ii) performing saccharification step simultaneous to the liquefaction step by adding at least one enzyme to the first vessel, stirring the slurry, and incubating the first vessel at second temperature to form a liquefact within the first vessel, and (iii) performing fermentation step by removing the liquefact from the first vessel, disposing the liquefact in a second vessel, adding at least one enzyme to the second vessel, adding at least one nutrient to the second vessel, adding several yeast cells to the second vessel, and incubating the second vessel at a third temperature. An INDEPENDENT CLAIM is included for system for producing ethanol, which has first vessel having mechanical actuating apparatus operated at first temperature and second temperature for performing liquefaction and saccharification, and second vessel connected to the first vessel and operated at third temperature for performing fermentation, where untreated carbon-containing material is disposed in the first vessel with several enzymes and incubated at the first and second temperatures to form liquefact, and the liquefact is disposed in the second vessel with at least one enzyme, at least one nutrient, and several yeast cells, and incubated at the third temperature.