Recycled carbon

In photosynthesis, nature recycles carbon dioxide and water, using the energy of sunlight, into carbohydrates and thus new plant life. The subsequent formation of fossil fuels from the biomass, however, takes... 

Besides chemical catalytic reduction of carbon dioxide with hydrogen, which is already possible in the laboratory, we are exploring a new approach to recycling carbon dioxide into methyl alcohol or related oxygenates via aqueous eleetrocatalytic reduction using what can be called a regenerative fuel cell system. The direct methanol fuel cell... 

ESCA studies were also performed on the partially deactivated recycled carbon supported 5%Pd-0.3%Sn catalyst presented in Table 15.3. The sulfur detection limit for this study was -0.5%. Therefore these data implied that there was no obvious Pd-S formation on the used catalyst, but a large amount of nitrogen was present as shown in Table 15.5. We assign this as a possible Pd-CN species. These data suggested that the presence of HCN rather than H2S might be the predominant factor for the deactivation of the catalyst. 

Ethylene oxide is produced by adding ethylene, oxygen, a methane diluent, and recycled carbon dioxide to a continuous reactor. Gaseous compositions are controlled carefully to keep the concentrations outside the explosion limits. 

The tricaldum phosphate in phosphate rock, mixed with coke and silica, is thermally reduced to yield P2 vapor. The phosphorus vapors condense to a liquid and the carbon monoxide produced is returned for burning in the furnace. The process requires much heat and, in addition to the heat provided by the combustion of the coke and the heating value of the recycled carbon monoxide, an electric arc also is used. The reaction takes place in very large furnaces at a temperature of 1,300-1,500°C and at atmospheric pressure. A 70-MW furnace will produce 44,000 short tons (39,600 metric tons) of P4 per year, equivalent to 100.000 tons (90,000 metric tons) of P2O5 (if converted to acid). Although there are numerous intermediate and side reactions, the overall reaction is Caj(P04)2 + 5C +... 

A new energy system in which carbon is reused cyclically was discussed. A carbon recycle system has already existed in nature as a natural carbon neutral system. In this paper, a concept of an Active Carbon Neutral Energy System (ACRES) was proposed against the natural system. C02 is regenerated artificially into hydrocarbons consuming a primary energy source with no C02 emission, and re-used cyclically in ACRES. ACRES recycles carbon, and transform energy without C02 emission. Because ACRES was expected to solve the above carbon problems, the feasibility of ACRES was discussed thermodynamically. 

If, after several manual trials, the calculations appear to be converging, it is reasonable to switch from manual to automatic iteration. It is strongly recommended that the calculations always be checked by a simple hand calculation. In this example, for instance, the user may add the feed and recycle carbon monoxide flow rates, multiply the sum by the conversion, and compare the result with the tabulated value for the methanol product rate c8. 

Separator. In general, the lowest separator operating pressure and resulting operating temperature will produce the cleanest recycled carbon dioxide. Contamination carry over from the separator is a function of the contaminant vapor pressure and the separator design. Some of the contaminant that is removed from carbon dioxide in the separator will fractionate as a function its vapor pressure at... 

Inagaki, M., Kawahara, A., and Konno, H. (2002). Sorption and recovery of heavy oils using carbonized fir fibers and recycle. Carbon, 40, 105-11. 

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