Carbon dioxide gasification

Carbon dioxide gasification gives vigorous atomisation... 

Finally, coke deposits were efficiently removed from the catalyst by steam and carbon dioxide gasification, which restored the initial catalytic activity. 

This mechanism implies catalyst-oxygen interaction and excludes interaction between carbon and catalyst. It was used to explain successfully the observed features of the carbon dioxide gasification, including the deactivation (by oxidation) of the catalyst. Experimental evidence was presented to support the view that the metal acts as a dissociation centre, producing active species that diffuse across the metal to react at the graphite-metal interface. 

Saber, J. M., Falconer, J. L., Brown, L. F. (1984). Carbon dioxide gasification of carbon black isotope study of carbonate catalysis. Journal of Catalysis, 90, 65—74. 

The ratio of hydrogen to carbon monoxide is controlled by shifting only part of the gas stream. After the shift, the carbon dioxide, which is formed in the gasifier and in the water gas reaction, and the sulfur compounds formed during gasification, are removed from the gas. 

Capital costs which foUow the same trend as energy consumption, can be about 1.5 to 2.0 times for partial oxidation and coal gasification, respectively, that for natural gas reforming (41). A naphtha reforming plant would cost about 15—20% more than one based on natural gas because of the requirement for hydrotreatiag faciUties and a larger front-end needed for carbon dioxide removal. 

The processes using physical absorption require a solvent circulation proportional to the quantity of process gas, inversely proportional to the pressure, and nearly independent of the carbon dioxide concentration. Therefore, high pressures could favor the use of these processes. The Recitsol process requires a refrigeration system and more equipment than the other processes. This process is primarily used in coal gasification for simultaneous removal of H2S, COS, and CO2. 

Partial oxidation as carried out in gasification produces carbon monoxide, hydrogen gas, carbon dioxide, and water vapor. The carbon dioxide reacts with hot carbon from the coal to produce carbon monoxide, and steam reacts with the carbon to produce carbon monoxide and hydrogen. The hydrogen can react with carbon through direct hydrogen gasification ... 

Synthetic Natural Gas. Another potentially very large appHcation of coal gasification is the production of synthetic natural gas (SNG). The syngas produced from coal gasification is shifted to produce a H2-to-CO ratio of approximately 3 to 1. The carbon dioxide produced during shifting is removed, and CO and H2 react to produce methane (CH, or SNG, and water in a methanation reactor. 

Direct hydrogen cyanide (HCN) gas in a fuel oil gasification plant to a combustion unit to prevent its release. 4. Consider using purge gases from the synthesis process to fire the reformer strip condensates to reduce ammonia and methanol. 5. Use carbon dioxide removal processes that do not release toxics to the environment. When monoethanolamine (MEA) or other processes, such as hot potassium carbonate, are used in carbon dioxide removal, proper operation and maintenance procedures should be followed to minimize releases to the environment. 

The recycling of PVC by hydrothermal techniques is described, in which PVC is thermally converted in a steam atmosphere into hydrogen chloride, hydrogen, carbon dioxide, carbon monoxide and some gaseous and liquid hydrocarbons. Whilst gasification with only steam is an endothermic reaction, partial combustion of PVC by the addition of small amounts of air, enables autothermic operation of the process to take place. This work deals... 

The composition of a gas derived by the gasification of coal is, volume percentage carbon dioxide 4, carbon monoxide 16, hydrogen 50, methane 15, ethane 3, benzene 2, balance nitrogen. If the gas is burnt in a furnace with 20 per cent excess air, calculate ... 

Shiying L., Michiaki H., Yoshizo S. and Hiroyuki H., Hydrogen Production from Coal by Separating Carbon Dioxide during Gasification, Fuel, 81, 2079-2085, 2002. 

Lin, S. Y. Harada, M. Suzuki, Y. Flatano, FI., Flydrogen production from coal by separating carbon dioxide during gasification. Fuel 2002, 81, 2079-2085. 

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