Carbon dioxide reduction high pressure

Products Obtained by Electrochemical Reduction of Carbon Dioxide under High Pressure of 10 kg/cm2 Gagea... 

Hara K, Kudo A, Sakata T (1995) Electrochemical reduction of carbon-dioxide under high-pressure on various electrodes in an aqueous-electrolyte. J Electroanal Chem 391(1-2) 141-147... 

Direct-oxidation processes can conveniently remove H2S from the process gas to levels of 100 ppm. At significantly greater cost, levels of perhaps 10 ppm can be achieved. The systems are characterized by relatively low sulfur-carrying capacities and, therefore, high liquor recirculation rates. They are not generally applicable to gas streams with high partial pressures of carbon dioxide the carbon dioxide also dissolves in the solution, causing a pinch in the column and a reduction of sulfur purification capability. 

The second, much more often applied, method of foam manufacture, is the generation of gas bubbles within the liquid. This requires the presence of blowing agents, which exist in two types physical and chemical ones. To the first category belong substances which are soluble in the polymer at a high pressure or at a lower temperature, but which leave the polymer upon pressure reduction and/or temperature increase (for comparison carbon dioxide gas escapes from beer when... 

Transport of iron in carbonate waters, mainly in the form of Fe " bicarbonate, is more common. The decrease in COj due to the overall reduction in pressure when ground waters come to the surface, when carbon dioxide is consumed as a result of photosynthetic activity of plants or even, as Mokiyevskaya (1959) mentions, when the temperature rises, leads to deposition of FeCOj. In Strakhov s opinion such a process could lead to the formation of oolitic hydrogoethite-chamosite-siderite ores. The iron migrated in mobile form as Fe, which accumulated in solution in a reducing environment. Formation of the ores was related to the draining of high-iron waters formed in swampy regions. The near-shore parts of the sea with... 

A number of new or modified syntheses have recently been reported. Catalytic reduction of CO2 at high pressures has been employed to give excellent yields of isotopic methanol. Carbon dioxide can be easily converted to CO by a catalytic exchange method. Excellent yields of CO are readily obtained in this manner. The conversion of CO2 to KCN has been improved with yields of 90-96 per cent reported. "... 

An alternative method is to use a gas that is actually liquefied at the storage temperature and pressure, such as carbon dioxide. This has the advantage that some loss of gas from the container does not cause any reduction in the pressure. However, the pressure in such containers is highly sensitive to temperature with the pressure doubling between 0 and 40° C. This makes for a substantial difference in performance if a wide operating temperature range is desired. This may not be problematic for hospital use or if a pressure regulator is employed, which can be an option in a reusable device. 

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