A HIGHLY EFFICIENT COMBINED CYCLE FOSSIL AND BIOMASS FUEL POWER GENERATION AND HYDROGEN PRODUCTION PLANT WITH ZERO CO_2 EMISSION

摘要

An advanced combined cycle for fossil and biomass fuel power generation and hydrogen production is described. An electric arc hydrogen plasma black reactor (HPBR) decomposes the carbonaceous fuel (natural gas, oil, coal and biomass) to elemental carbon and hydrogen. When coal and biomass feedstocks are used, the contained oxygen converts to carbon monoxide. Any ash and sulfur present are separated and removed. The elemental carbon is fed to a molten carbonate direct carbon fuel cell (DCFC) to produce electrical power, part of which is fed back to power the hydrogen plasma. The hydrogen produced is used in a solid oxide fuel (SOFC) cell for power generation and the remaining high temperature energy in a back-end steam Rankine cycle (SRC) for additional power. Any CO formed is converted to hydrogen using a water gas shift reactor. The plasma reactor is 60% process efficient, the direct carbon fuel cell is up to 90% thermally efficient, the solid oxide fuel cell is 56% efficient and the steam Rankine cycle is 38% efficient. Depending on the feedstock, the combined cycles have efficiencies ranging from over 70% to exceeding 80% based on the higher heating value of the feedstock and are thus twice as high as conventional plants. The CO_2 emissions are proportionately reduced. Since the CO_2 from the direct carbon fuel cell and the water gas shift is highly concentrated, the CO_2 can be sequestered to reduce emission to zero with much less energy loss than required by conventional plants. Alternatively, the combined cycle plants can produce hydrogen for the FreedomCAR program in combination with electrical power production at total thermal efficiencies greater than obtained with fossil fuel reforming and gasification plants producing hydrogen alone.