NOVELTY - Carbonaceous feedstocks are converted into energy by converting carbonaceous feedstock and greenhouse gas stream in gasification unit to produce a synthesis gas. At least a portion of synthesis gas is electrochemically oxidized in a first half-cell, and an oxygen-containing gas is electrochemically reduced in second half-cell of fuel cell to produce an electrical energy.    USE - The method is for converting carbonaceous feedstock such as carbonaceous-containing hazardous waste, and/or carbonaceous-containing medical waste into energy. It is used in electric power producing fossil fuel plant, petroleum refinery, and petrochemical plant. (All claimed).    ADVANTAGE - The process provides energy from carbonaceous feedstock without the production of unwanted greenhouse gas emissions.    DETAILED DESCRIPTION - Conversion of carbonaceous feedstocks into energy comprises converting a carbonaceous feedstock and greenhouse gas stream in a gasification unit (12) to synthesis gas comprising carbon monoxide and hydrogen.    The gasification unit is a non-catalytic high temperature, gas-phase rector operating at conditions to achieve a gas exit temperature of 700-1600degreesC. At least a portion of synthesis gas from the gasification unit is electrochemically oxidized in a first half-cell of fuel cell to first half-cell exit gas comprising carbon dioxide and water. The carbon dioxide is recovered from the first half-cell exit gas to serve as at least20% of greenhouse gas stream in the first step. An oxygen-containing gas is electrochemically reduced in a second half-cell of fuel cell completing the circuit and resulting in production of electrical energy.    An INDEPENDENT CLAIM is also included for a system for converting carbonaceous feedstocks into energy comprising gasification unit, fuel cell (26) and passage member. The gasification unit comprises non-catalytic high temperature, gas-phase reactor (30) and has carbonaceous feedstock inlet. The fuel cell produces electrical energy and comprises first half-cell and second half-cell. The first half-cell has inlet in fluid communication with synthesis gas and first mechanism for electrochemically oxidizing synthesis gas into a first half-cell exit gas of carbon dioxide and water. The second half-cell has second mechanism for electrochemically reducing an oxygen-containing gas, and a membrane separating the first and second half cells that will not allow passage of components from the respective half-cells.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic flow diagram of the process and system.    Gasification unit (12)    Fuel cell (26)    Gas-phase reactor (30)    Condenser (50)