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The water–gas shift reaction (WGSR) describes the reaction of carbon monoxide and water vapor to form carbon dioxide and hydrogen: CO + H 2 O ⇌ CO 2 + H 2. The water gas shift reaction was discovered by Italian physicist Felice Fontana in 1780. It was not until much later that the industrial value of this reaction was realized.
The first step in the WGS reaction is the high temperature shift which is carried out at temperatures between 320 °C and 450 °C. As mentioned before, the catalyst is a composition of iron-oxide, Fe 2 O 3 (90-95%), and chromium oxides Cr 2 O 3 (5-10%) which have an ideal activity and selectivity at these temperatures.
With an instantaneous temperature switch the initial fluid velocity is infinite, resulting in an initial infinite kinetic energy. In fact the liquid layer is often in motion, thus requiring advection or convection terms in the heat equation. The melt temperature may vary with size, curvature or speed of the interface.
Using the Eyring equation, there is a straightforward relationship between ΔG ‡, first-order rate constants, and reaction half-life at a given temperature. At 298 K, a reaction with ΔG ‡ = 23 kcal/mol has a rate constant of k ≈ 8.4 × 10 −5 s −1 and a half life of t 1/2 ≈ 2.3 hours, figures that are often rounded to k ~ 10 −4 s ...
The ideal temperature for a reaction under thermodynamic control is the lowest temperature at which equilibrium will be reached in a reasonable amount of time. [15] If needed, the selectivity can be increased by then slowly cooling the reaction mixture to shift the equilibrium further toward the most stable product.
When heat is removed and the temperature decreases, the reaction shifts to the left and the flask turns colorless due to an increase in N 2 O 4: again, according to Le Chatelier's principle. The effect of changing the temperature in the equilibrium can be made clear by 1) incorporating heat as either a reactant or a product, and 2) assuming ...
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In thermodynamics, a temperature–entropy (T–s) diagram is a thermodynamic diagram used to visualize changes to temperature (T ) and specific entropy (s) during a thermodynamic process or cycle as the graph of a curve. It is a useful and common tool, particularly because it helps to visualize the heat transfer during a process.