Carbon thermodynamic analysis

Thus, the electrode processes occurring in zinc-carbon batteries with salt electrolytes are complicated, and their thermodynamic analysis is difficult. In a rough approximation disregarding secondary processes, the current-producing reaction can be described as... 

Effect of Noble Metal Addition to Ni-Based Catalysts. Unmodified Ni-based catalysts tend to deactivate rapidly due to both carbon deposition and sintering. As suggested by the thermodynamic analysis above, carbon formation can be significantly limited by the addition of steam, which can react with carbon by the reverse of reaction (8). Figure 12 shows typical results for such a catalyst, which contained 5.4 mg carbon per gram of catalyst after 54 h on stream. 

Acetic acid, CH3COOH(l), could be produced from (a) the reaction of methanol with carbon monoxide (b) the oxidation of ethanol (c) the reaction of carbon dioxide with methane. Write balanced equations for each process. Carry out a thermodynamic analysis of the three possibilities and decide which you would expect to be the easiest to accomplish. 

Based on these observations, the decision was taken to use the thermodynamic properties of graphite in the thermodynamic analysis in C02 reforming, because this reaction has applicable conversions only at temperatures above 973 K. At this point, the difference in free energy between graphite and carbon on catalysts becomes so small that it has a negligible effect on the thermodynamic analysis. 

Thermodynamic Analysis of Carbon Formation in C02 Reforming of Methane... 

In Section I we introduce the gas-polymer-matrix model for gas sorption and transport in polymers (10, LI), which is based on the experimental evidence that even permanent gases interact with the polymeric chains, resulting in changes in the solubility and diffusion coefficients. Just as the dynamic properties of the matrix depend on gas-polymer-matrix composition, the matrix model predicts that the solubility and diffusion coefficients depend on gas concentration in the polymer. We present a mathematical description of the sorption and transport of gases in polymers (10, 11) that is based on the thermodynamic analysis of solubility (12), on the statistical mechanical model of diffusion (13), and on the theory of corresponding states (14). In Section II we use the matrix model to analyze the sorption, permeability and time-lag data for carbon dioxide in polycarbonate, and compare this analysis with the dual-mode model analysis (15). In Section III we comment on the physical implication of the gas-polymer-matrix model. 

The similar thermodynamic analysis along with the modem experimen tal data argue for the possibility of fluidization of small metal nanoparticles due to the formation of the oversaturated carbon solution not only during the graphitization of amorphous carbon or CO disproportionation but also during pyrolysis of low hydrocarbons by stepwise reaction... 

In the analysis of the deposition of iron sediments it has already been mentioned that quite likely both iron silicates and carbonates and amorphous iron hydroxide were formed, which could convert to other forms both during the formation of the sediment and in subsequent diagenesis. Reduction of hydroxide could have been controlled by external (atmospheric) or internal (organic matter, free carbon in the sediment) oxidation-reduction buffer systems. All these variants need additional consideration in the thermodynamic analysis of diagenetic processes. 

The energy consumption figures discussed so far represent a thermodynamic analysis based on the first law of thermodynamics. The combination of the first and second laws of thermodynamics leads to the concept of ideal work, also called exergy. This concept can also be used to evaluate the efficiency of ammonia plants. Excellent studies using this approach are presented in [1061], [1062], Table 39 [1061] compares the two methods. The analysis in Table 39 was based on pure methane, cooling water at 30 °C (both with required pressure at battery limits), steam/carbon ratio 2.5, synthesis at 140 bar in an indirectly cooled radial converter. 

Thermodynamic analysis indicates that such reactions are on the whole unfavorable. Furthermore, the complexity and uncertainty of the mechanism by which such reactions may occur makes the choice of proper catalysts largely an empirical selection. However, it must not be overlooked that such reactions as the Kolbe-Schmitt synthesis of salicylic acid from dry sodium phenoxide and carbon dioxide represent processes, the success of which might point the direction to the solution of the problems attending the realization of the type reactions mentioned above. 

Thermodynamic Analysis of Fermenters and Other Bioreactors 889 With this notation, we have for the steady-state carbon balance... 

Carbides, Silicides, and Germanides. The standard heat of formation and the dissociation energy of TiCjCg) have been determined as — 730 9 and 160 + 8 kJ mol , respectively, using the mass spectrometric Knudsen effusion technique. The standard heat and entropy of formation of TijSijis) have been reported as — 580 kJ moP and 272 e.u., respectively. A thermodynamic analysis of the co-reduction of TiOj with Si02 by carbon at elevated temperatures has shown that the formation of TiSi is more probable than TiSij. Phase equilibria in the Ti-Nb-Ge ternary system have been investigated. ... 

A thermodynamic analysis of the co-reduction of Zr02 and Si02 by carbon at 1500— 3000 K has suggested that the formation of ZrSi is more probable than that of ZrSi2- ... 

The regions of stability derived from the thermodynamic analysis are shown in Figure 1.9 below a cyclic voltammogram obtained using a vitreous carbon... 

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