Patent FR-2921055-A1 (FR)
Title: Reduction of carbon dioxide solution into carbon monoxide and dihydrogen, by continuously generating carbon dioxide enriched plasma at a terminal of carbon electrode immersed in the solution under the action of an alternative current
Inventor: UGOLIN NICOLAS
IPC: C01B32/40
Filed: 2007-09-14
Abstract: The process to reduce carbon dioxide solution into carbon monoxide and dihydrogen, comprises continuously generating a carbon dioxide enriched plasma at a terminal of carbon electrode (1) immersed in the solution under the action of an alternative current (6). The carbon dioxide is flowed at a pressure of 1-10000 bars to enrich the plasma. The current is applied with the electrodes immersed in a reactor filled with an electrolyte solution at a frequency of 0.5-1000 Hz, a voltage of 1-100 KV and an intensity of 1-1000 A. The electrodes are maintained at a constant distance of 0.01 mm to 3 cm. The process to reduce carbon dioxide solution into carbon monoxide and dihydrogen, comprises continuously generating a carbon dioxide enriched plasma at a terminal of carbon electrode (1) immersed in the solution under the action of an alternative current (6). The carbon dioxide is flowed at a pressure of 1-10000 bars to enrich the plasma. The current is applied with the electrodes immersed in a reactor filled with an electrolyte solution at a frequency of 0.5-1000 Hz, a voltage of 1-100 KV and an intensity of 1-1000 A. The electrodes are maintained at a constant distance of 0.01 mm to 3 cm by an electrically neutral ceramic interlayer (3), and a spring system. The interlayer having holes or pores is optionally drilled to allow the circulation of solvent, gas, electrolytes and electrical current thus enhancing the formation of plasma. The interlayer is constituted of a ring or a frame with a calibrated thickness of 0.01 mm and 3 cm. A spring is placed on each electrode opposite to the interlayer to push the electrodes against the interlayer and to measure the wear out of two electrodes by maintaining a constant distance from one another. The electrical conduction is ensured by an electrically conducting wire that is placed at the end of each electrode opposite to the interlayer. A guide is connected to the interlayer to eventually ensure the correct positioning of the electrodes. The output of reactions in solution is improved by the introduction of catalysts in the reactor. The catalysts are present in the form of nanoparticles or microparticles having a size of 1 nm to 3 mu m. The particles are isolated from plasma by sequestration of electrodes in a quartz enclosure letting the solute and gas to pass. Walls of the enclosure allow to pass the visible and invisible plasma radiation and the heat generated by it. The passage of solutes and gas through the enclosure wall is performed by apertures in the enclosure plugged by sieve of which the pores are smaller than the particles. The sieve or filters are optionally constituted of calibrated synthetic foam. The carbon electrodes are metallized by gallium and aluminum alloys in a proportion of 1-75% of gallium or aluminum alone. The inner face of electrodes is covered by a sheet or an aluminum deposit having a thickness of 2-500 mu m. An electrically neutral synthetic material layer is optionally intercalated, of which a side is covered with a few microns of plastic or synthetic material such as polyimide. The aluminum or gallium-aluminum alloy is structured by sealing, pressing, gluing and fusing two sheets to prepare sandwich defining tightly enclosed alloy reservoirs deposited in rows. The length of the reservoir is 500 mu m. Sizable spacings are introduced between the reservoirs. Synthesis gas produced by the reactor are separated by differential solubilization of aqueous solvents and then degassed by ultrasound and/or heat shock in vacuum. All or part of the reactor is coupled with carbon dioxide sequestering systems in which the operating power is provided by renewable energies such as wind, sun or recovery of thermal energy by heat exchange systems.