Sulfur as a Fuel Source in a Combined Power Cycle Equipped with a Dry Flue Gas Desulfurization System

Abstract

This paper investigates the novel use of elemental sulfur as a fuel in a combined cycle power plant, wherein sulfur is oxidized in the combustion chamber to produce work from a gas turbine. Produced sulfur dioxide is then reacted with calcite to produce anhydrite (CaSO4) in a flue gas desulfurization unit. The desulfurization reaction is exothermic, producing heat that can be converted to electricity by passing the exhaust gas through a heat recovery steam generator. The cases studied in this work are a 410 MW natural gas combined cycle, used as a reference case, a sulfur combined cycle (SCC) consisting of a typical industrial gas turbine with heat recovery followed by desulfurization, and a third case of a SCC followed by desulfurization before the heat recovery, thereby producing power from the exothermic desulfurization reaction. Energy calculations of the last case show promising results for converting sulfur to anhydrite through a combined cycle that produces 615 MW of electrical power with CO2 emission of 0.584 kg/kWh, a value lower than the representative value of a new, supercritical coal power plant.