NOVELTY - Preparing (I) liquid fuel, comprises (a) supplying (110) hydrocarbon to heated area of reaction chamber in first controlled volume, (b) supplying (120) carbon dioxide to heated area of reaction chamber in second controlled volume, (c) forming (130) carbon monoxide and hydrogen, (d) transporting (140) carbon monoxide to reactor in third controlled volume, (e) transporting (150) hydrogen to reactor in fourth controlled volume, (f) supplying additional hydrogen to reactor in fifth controlled volume, (g) regulating pressure in reactor, and (h) forming liquid fuel.    USE - The method is useful for preparing liquid fuel comprising methanol (claimed).    ADVANTAGE - The method: provides liquid fuel which reduces cost to store and transport gaseous fuels; controls emission of hydrocarbon and carbon dioxide; provides liquid fuels that are easily accessible for various kinds of users; and maximizes liquid fuel production and minimizes total energy consumption or longest use duration of catalysts used in reaction chamber.    DETAILED DESCRIPTION - Preparing (I) a liquid fuel, comprises (a) supplying (110) a hydrocarbon to a heated area of a reaction chamber in a first controlled volume, (b) supplying (120) a carbon dioxide to the heated area of the reaction chamber in a second controlled volume, (c) forming (130) carbon monoxide and hydrogen from the hydrocarbon and the carbon dioxide by an energy provided by the heated area, (d) transporting (140) the carbon monoxide to an reactor in a third controlled volume, (e) transporting (150) the hydrogen to the reactor in a fourth controlled volume, (f) supplying an additional hydrogen selectively to the reactor in a fifth controlled volume, (g) regulating a pressure in the reactor by adjusting the controlled volumes to achieve a predetermined object, and (h) forming the liquid fuel from the hydrogen and the carbon monoxide in the reactor according to the predetermined object. INDEPENDENT CLAIMS are also included for:    (1) preparing (II) a liquid fuel, comprising steps (a)-(d) as above per se, (d2) transporting a first part of the hydrogen to the reactor in a fourth controlled volume, (d3) transporting a second part of the hydrogen to form ammonia, steps (f)-(h) as above per se, and storing the liquid fuel and the ammonia in a storage device; and    (2) a system for preparing the liquid fuel, comprising a reaction chamber, a heated area which is located in the reaction chamber, receiving the hydrocarbon in the first controlled volume, and receiving the carbon dioxide in a second controlled volume, where the hydrocarbon and the carbon dioxide form the carbon monoxide and the hydrogen by an energy provided by the heated area, and a reactor for receiving the carbon monoxide in the third controlled volume, receiving the hydrogen in the fourth controlled volume, and selectively receiving additional hydrogen in the fifth controlled volume, the reactor forms the liquid fuel from the carbon monoxide and the hydrogen according to the predetermined object, a regulating device for regulating a pressure in the reactor by adjusting the controlled volumes to achieve the predetermined object, and a storage device for storing the liquid fuel.    DESCRIPTION OF DRAWING(S) - The figure shows a process flow diagram for preparing the renewable liquid fuel.    Supplying a hydrocarbon to a heated area of a reaction chamber in a first controlled volume (110)    Supplying a carbon dioxide to the heated area of the reaction chamber in a second controlled volume (120)    Forming carbon monoxide and hydrogen from the hydrocarbon and the carbon dioxide by an energy provided by the heated area (130)    Transporting the carbon monoxide to an reactor in a third controlled volume (140)    Transporting the hydrogen to the reactor in a fourth controlled volume (150)