NOVELTY - The method comprises providing a reactor (10) containing a liquid metal comprising copper (99 mass%), feeding materials, where one of the materials is a carbonaceous material and other material comprises oxygen, to the reactor such that an overall molar ratio of carbon to oxygen in materials is 1:1, and reacting the materials within the reactor to produce synthesis gas comprising carbon monoxide under conditions without active stirring of the liquid metal in the reactor. The reaction occurs within the reactor such that no copper oxide accumulates within the reactor over a period of 30 days.    USE - The method is useful for producing a synthesis gas from a carbonaceous material in a liquid metal gasifier reactor.    ADVANTAGE - The method is capable of reliably and effectively producing the synthesis gas from the carbonaceous material with less energy consumption.    DETAILED DESCRIPTION - The method comprises providing a reactor (10) containing a liquid metal comprising copper (99 mass%), feeding materials, where one of the materials is a carbonaceous material and other material comprises oxygen, to the reactor such that an overall molar ratio of carbon to oxygen in the materials is 1:1, and reacting the materials within the reactor to produce synthesis gas comprising carbon monoxide under conditions without active stirring of the liquid metal in the reactor. The reaction occurs within the reactor such that no copper oxide accumulates within the reactor over a period of 30 days. The reactor comprises a headspace (18) positioned above the liquid metal, and is sized so that the liquid metal contained in the reactor has a weight of 10 tons. The materials are fed to the headspace. One of carbonaceous materials fed to the reactor comprises wood. The oxygen (80%) in the materials is reacted within the reactor. The liquid metal has a temperature of 1500 degrees C, and an overall standard oxidation potential of 0 V. The step of stirring the metal within the reactor is driven by a heat convection process. An INDEPENDENT CLAIM is included for a method for operating a liquid metal gasifier reactor.    DESCRIPTION OF DRAWING(S) - The diagram shows a flow chart of a process for producing a synthesis gas from a carbonaceous material.    Reactor (10)    Headspace (18)    Inlet (20)    Outlet (30)    Conduit. (33)