Study On Carbon Fuel And Anode Material Of Direct Carbon Fuel Cell

A Direct Carbon Fuel Cell is a fuel cell that uses a carbon rich material as a fuel. Direct carbon-electricity conversion by a fuel cell (FC) is a high efficient process, say,2-3 times of efficiency of coal-fired power plants. Direct Carbon Fuel Cell have the advantage of theoretical efficiency is around 100%, high energy per unit volume, rich carbon fuels (including coal, petroleum coke, biomass and organic garbage), releases pure carbon dioxide as by-produce which is easily stored, simple structure. Half cell reaction at anode is very important for the performance of the direct carbon fuel cell system. The anode reaction is depending on the structure and the properties of the carbon fuels and the anode morphology. This paper is based on the single cell of direct carbon fuel cell using the hybrid fuel cells coupling the mechanism of the solid oxide fuel cell and fluidic bed, which also can be operated under the coupling mechanism of the solid oxide fuel cell and molten carbon fuel cell which made by author himself, study the carbon fuels and anode modify.A direct carbon fuel cell which based on the solid oxide fuel cell, have a high reaction temperature normally around 1000℃ to be required. The Boudouard reaction happens as the temperature reaches up to 700℃. Reducing the reaction temperature is, therefore, required to make the process more efficient and economic. In this paper, modification of the carbon fuels is focused to improve their activity. Physical and chemical methods were used to enhance the electro-oxidation ability of charcoal and graphite. In the physical treatment the high-energy ball milling technology was used to treat the carbon fuels. In the chemical treatment the nitric acid oxide treatment was applied for charcoal and graphite. The graphite was also treated with the intercalated oxidation method. The experimental results show that the surface area (specific surface area) of charcoal firstly increases with the high-energy ball milling and then drops with further milling. The charcoal particles become smaller and smaller when suffering long time milling. The thermo-gravimetric analysis of the charcoal samples in the air shows that their electro-oxidation property can be improved by the treatment. Graphite has higher specific surface area after being treated with the high-energy ball milling. The crystal array of the graphite has trend to change from order to disorder. After the nitric acid treatment, the level of the graphite becomes loose. The graphite oxide with a high specific surface area and high reaction ability can be obtained by the intercalated oxidation treatment. The thermo-gravimetric analysis show that the chemical oxidation activated order is intercalated oxidation higher then ball milling higher then the initial graphite.The needle-like and net-like structure of anodes were fabricated by electrospinning technology and chemical vapour deposition mechanism, in order to solve the poor contacting problem between the carbon fuel and the anode. The NiO/CeO2 composite nanofibers was made for the net-like anode by fabricated PVP/NiO/CeO2 organic-inorganic composite nanofibers first then sintered them in the tubular furnace under 1000oC, with air. The dimension of the novel composite ceramic nanofibers is around 100nm, with net structure. Tin dioxide was used the grown needle-like anode. The dimension of the tin dioxide is under lOOnm, was made by vapour-liquid-solid mechanism. The core-shell structure of the tin dioxide nanofibers was made by vapour-solid mechanism. Hopefully, this structure can transfer the electronic and the oxygen ionic at the same time. In the design of a single cell of Direct carbon fuel cell section, I try to design a cell that can running base on hybrid fuel cells coupling the mechanism of the solid oxide fuel cell and fluidic bed, which also can be operated under the coupling mechanism of the solid oxide fuel cell and molten carbon fuel cell. COMSOL 3.5a was used for the computer simulation the result of the modification of the anode and the pre-treatment of the carbon fuel. The computer test qualitative analysis the single cell performance.