Carbon monoxide, formation

Mechanism of carbon monoxide formation under the conditions of smelting reduction... 

The matrix photochemistry of 2v proved to be fairly complicated.108 The primary product of the photolysis of 2v is carbene lv, which was identified by ESR spectroscopy. Under the conditions of matrix isolation the carbene showed the expected reactivity towards molecular oxygen (formation of carbonyl oxide 7v) and carbon monoxide (formation of ketene lOv) (Scheme 22). In contrast to the oxocyclohexadienylidenes (la and derivatives) carbene lv slowly reacted with CO2 to give an a-lactone with the characteristic C=0 stretching vibration at 1896 cm-1. The latter reaction indicates that lv is — as expected — more nucleophilic than la. 

The operation of the smoking rooms needs to be addressed further. It is not clear that the misting process employed in the rooms and the associated carbon filters will remove the smoke generated from the contents removed from the TRBPs. If the smoke is not adequately managed, a visible plume will be emitted from this part of the facility. Because the oxygen supply is limited, carbon monoxide formation can be expected, but this appears to not have been addressed in the design. 

The rate of carbon monoxide formation to carbon dioxide in the case of the four reaction conditions is calculated from the slopes of the curves for the formation of carbon monoxide and carbon dioxide in Figure 5. The rate is approximately in inverse proportion to the reaction time. 

Reaction of Carbon Atoms with Alcohols and Ethers. The electro-philicity of atomic carbon and the exothermicity of carbon monoxide formation in its reactions facilitates attack on, and removal of oxygen by C atoms. Deoxygenation of ethers, alcohols, and carbonyl compounds has been reported. This process is generally a highly exothermic reaction, which is likely to generate products with excess energy. 

Toumay, Murphy, Damon and Van Dolah [41] examined the fumes produced by the detonation of ammonium nitrate-fuel mixtures. They came to the conclusion that carbon monoxide formation is within the allowed limits. However, the concentration of nitric oxide and nitrogen dioxide is much higher than in typical dynamite compositions. On the ground of these experiments they expressed the view that ammonium nitrate-fuel compositions should not be recommended for underground blasting. 

The experiments were carried out at residence times between 200 and 100 ms and total flow rates between 500 and 900 Ncm3 min-1 using five coated plates. A 15% decrease in conversion was found when the flow rate was increased from 500 to 800 Ncm3 min-1, leading to a 36% relative decrease in the hydrogen content of the product. This was attributed to the slow kinetics of the reverse water-gas shift reaction. Increasing the temperature from 200 to 275 °C increased the conversion from 37 to 65%. At temperatures exceeding 250 °C, carbon monoxide formation started [26]. 

We may also make use of the reaction of carbon monoxide formation, C(solid) + (1/2)... 

Figure 5. Quantum yields for carbon monoxide formation in ketones of type O...

K. (2002). Measurement of endogenous carbon monoxide formation in biological system. Antioxid. Redox Signal. 4 271-7. 

The quantum yield of carbon monoxide formation, (CO), at X = 2537 and 2288 A., and at room temperature in the range of COS pressures 100-700 torr, is 1.8 moles/einstein. 

Commentary on Studies of Cations in Zeolites Adsorption of Carbon Monoxide Formation of Ni Ions and Na/ Centres, J. A. Rabo, C. L. Angell, P. H. Kasai and V. Schomaker, Discuss. Faraday Soc, 1966, 41, 328-349. 

Studies of Cations in Zeolites Adsorption of Carbon Monoxide Formation of Ni ions and Na centres... 

J. M. Thomas comments on Studies of cations in zeolites adsorption of carbon monoxide formation of Ni ions and Na4 centres ... 

Rates were followed manometrically in a carbon coated reaction vessel added propene and isobutene had no effect on rates although nitric oxide accelerated the reaction a linear dependence of the carbon monoxide formation on the initial pressure was interpreted in terms of a unimolecular decomposition of the dimer. 

It seems likely that CO, anion radicals in low polar solvents tend to predominantly adsorb on the positively charged Cd " " sites, resulting in carbon monoxide formation. Since the thiol compounds should be bound to the surface Cd sites, the amount of the adsorbed CO, on Cd " " sites must decrease with increase of the degree of surface modification, and then formate production becomes predominant with increasing the surface coverage. 

To obtain complete combustion and to abate smoke and corrosive carbon monoxide formation, the unburned volatile (or pyrolysis) gases rising from the fuel bed must be mixed rapidly with ample oxygen. This mixing must be done relatively near the fuel bed with the assistance of high velocity secondary air jets. 

The effect of the YSZ coating on the ceria-based solid electrolyte was shown in Table 1. When the YSZ I SDC membrane was used as the solid electrolyte, selectivities to acrylaldehyde (Scho) carbon monoxide (Sco) and carbon dioxide (Scoa) based on converted propene was 13.4%, 25.6% and 61%, respectively. Here, it should be emphasized that the selectivity to acrylaldehyde increased with YSZ coating compared with that (Scho =8.5 %) obtedned by using SDC alone as a solid electrolyte. In addition, it was found that carbon monoxide formation was observed in the present study, although its formation was not detected in the case of SDC alone. The same phenomena were observed, when the Gd doped... 

Norrish Type I cleavage reactions dominate in the gas phase photochemistry of many acyclic aldehydes and ketones, whereas in the liquid phase this process is less common and alternative pathways (ii, iii, v) dominate. When no suitable C-H bonds are present to allow hydrogen abstraction reactions, however, this process will also constitute an important synthetic method for the cleavage of a-C-C bonds in solution. One important subsequent reaction of the resulting acyl and alkyl radicals is carbon monoxide formation and radical combination. Overall CO extrusion results which represents a versatile method for the formation of C-C single bonds from ketones. When cyclic substrates (cycloalkanones but not conjugated cycloalkenones which exhibit a different photochemistry) are used, ring... 

It is to be noted, however, that the reaction was decidedly luminous in certain temperature intervals above 270° G, and that up to 250° G, no carbon monoxide had formed and only small amounts of carbon dioxide notwithstanding that one mol of oxygen had been absorbed per mol of octane. The fact that carbon monoxide formation is suppressed by packing further suggests a chain type of reaction. Up to 250° C. the first step with fonnation of water is indicated. 

The most striking effect of lead tetraethyl in the reaction with n-octane is on the reaction producing carbon monoxide, reaction 2. Although oxidation starts at about the same temperature as without the antiknock, the consumption of oxygen rises with increases of temperature more slowly than can be accounted for by the suppression of carbon monoxide formation particularly at low and intermediate temperatures. This indicates that the primary oxidation of the hydrocarbon (reaction 1) to aldehyde is retarded and that complete oxidation requires a higher temperature than when lead tetraethyl is absent. The disturbance which normally occurred in the reaction zone at a low temperature, takes place at a more elevated temperature when lead tetraethyl is present. 

Conrad, R., and W. Seiler (1985b). Characteristics of abiological carbon monoxide formation from soil organic matter, humic acids and phenolic compounds. Environ. Sci. Technol. 19, 1165-1169. 

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