Reactions and Equations

Methanation of the clean desulfurized main gas (less than 1 ppm total sulfur) is accompHshed in the presence of a nickel catalyst at temperatures from 260—400°C and pressure range of 2—2.8 MPa (300—400 psi). Equations and reaction enthalpies are given in Table 4. 

Table 2.1. Molecularities, rate equations, and reaction orders of elementary steps.

Table 8.3. Algebraic forms of rate equations and reactions orders for catalytic cycle 8.60 with different macs (collective coefficients ka etc. are defined differently in the different equations).

If significant fractions of the catalyst material may be bound in the form of reaction intermediates, the rules for reaction orders in noncatalytic simple pathways no longer apply. However, if one of the cycle members—the free catalyst or an intermediate—is a macs (most abundant catalyst-containing species, containing practically all of the catalyst material), the rules for noncatalytic pathways can be adapted The rate equation and reaction orders for the cycle are the same as for an imaginary equivalent linear pathway that starts and ends with macs. A cycle member that contains only an insignificant fraction of catalyst material is a lacs (low-abundance catalyst containing species), and the denominator terms it contributes can be dropped. 

Refer to the "Chemical Equations and Reactions" chapter for a discussion of chemical reactions. 

Chemical Formulas, Chemical Equations, and Reaction Yields... 

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