The kinetics analysis aimed at specifing the attributes of an optimal chain-transfer solvent for coal liquefaction was extended to include the reality of the distributions of functional groups and bonds in coal. In particular, the possibility that the desirable enhancement predicted for the liquefaction rate was an artifact of the two-lump coal-solvent model, with the coal being characterized as a single pseudo species, was tested. Thus, Gaussian-distributed coal and solvent bond strengths were considered to assess the importance of the off-optimal interactions that could be anticipated in a multicomponent mixture. The results show that significant enhancement can be maintained in the mixture. Indeed, in several instances, the distribution of coal bond strengths improved the obtained enhancement.

Mechanism-derived rate laws for kinetically coupled Rice-Herzfeld pyrolysis were used to deduce the form of semiempirical rate laws (SERLs) that nevertheless represent the mechanistic chemistry. These SERLs strike a balance between the CPU demands of mechanistic models and the lack of chemical,significance of purely empirical models. The mechanism-derived pyrolysis rate laws were phrased in terms of a pure component, initiation, propagation, and termination groups, akin to the kinetic term, the driving force, the adsorption group, and exponent of Langmuir-Hinshelwood-Hougen-Watson models. Taylor series expansions of the pyrolysis groups provided polynomial representations of each, which combined to form the SERL. Convergence of the Taylor series expansions further provides a relationship between the elementary step kinetic parameters of the mechanism and the parameters of the SERL. The coupled pyrolyses of (1) dibenzyl ether and phenethyl phenyl ether; (2) pentadecylbenzene (PDB); and (3) PDB and tridecylcyclohexane were well represented by SERLs.