Lumps delumping

While the 13 hydrocarbon lumps accurately represent the hydrocarbon conversion kinetics, they must be delumped for the deactivation kinetics. In addition, delumping is necessary to estimate many of the product properties and process conditions important to an effective reformer process model. These include H2 consumption, recycle gas H2 purity, and key reformate properties such as octane number and vapor pressure. The following three lump types had to be delumped the C5- kinetic lump into Cl to C5 light gas components, the paraffin kinetic lumps into isoparaffin and n-paraffin components, and the Cg+ kinetic lumps into Cg, C9, C10, and Cn components by molecular type. 

As an example of delumping, the kinetically predicted C5- lump is delumped by means of distribution correlations C5- is distributed into Ct, C2, C3, iso-C4, n-C4, iso-C5, and n-C5, as indicated in Table VIII. The... 

The paraffin isomer and Cg+ kinetic lumps are delumped in a more rigorous fashion than the C5-. Semikinetic delumping equations have been developed for both the Cg+ lumps and paraffin distribution (Table VIII). The paraffin distribution is constrained by known equilibrium. 

Nichita et al applied the pseudo-component method to the wax precipitation from hydrocarbon mixtures. To do so a general form of a two-parameter equation of state was used for vapour and liquid phases. The heavy components were assumed to precipitate in a single solid solution. Because lumping in pseudo-components often results in difficulties in solid-liquid equihbrium calculations the authors proposed a delumping procedure (mentioned in section 9.3.1). Lira-Galeana et al calculated wax precipitation in petroleum mixtures by assuming the wax consisted of several solid phases each described as a piue component or pseudo-component immiscible with other solid phases. 

The simplified fractionator includes a delumper model to convert the 21 kinetic lumps into >80 pure- and pseudo-components, which are then divided into user-specified boiling fractions. A non-linear distribution function generates ideal distillation curves with realistic fraction-to-fraction overlap. The fractionator can inter-convert distillation methods, so a user can calculate D-86, D-1160, D-2887, and/or TBP curves for gasoline and LCO. 

Delumper Converts lumped composition into set of pseudocomponents based on true boiling point (TBP) suitable for fractionation Carries chemical information about the kinetic lumps as an attribute of the pseudocomponent Additional delumping of light gas into C1-C4 components using known kinetics [43]... 

Figure 4.85 shows the key results of the calibration procedure. The Reactor group tuning parameters control the activity of each group of kinetic pathways and the light ends distribution. The delumping curves covert the kinetic lumps into fractionation lumps appropriate for a petroleum refining component slate. 

The final step in an integrated model is the delumping of kinetic lumps back to bulk properties and lumps suitable for fractionation models. Many authors do not consider this delumping process since they do not include a rigorous fractionation section. Typically, many studies report only properties such as RON and MON. If the kinetic lumping method used spans a significant range, then fractionation models can work directly with the kinetic lumps. Studies by Hou et al. [32] and H et al. [34] use the kinetic lumps directly. 

The final step in the integrated model before fractionation is the delumping of products and prediction of bulk properties. Since our lumping system is quite broad, we can just calculate key properties of the reformer effluent as combination of the individual projjerties of the lumps. 

Delumping the reactor model effluent is an essential step to integrate the reactor model with the fractionator model, because kinetic lumps used in the reactor model are based on the structure and carbon number and cannot represent accurate thermodynamic behavior of the fractionator model. Because boiling point (volatility) is the most important property for distillation operation, process modelers typically use pseudocomponents based on the true boiling point (TBP) curve to represent the feed oil to the HCR fractionators. We present five steps to develop pseudocomponents based on boiling-point ranges to represent the petroleum fraction [32, 34] ... 

We apply the Gauss-Legendre Quadrature to convert kinetic lumps into Pseudocomponents based on boiling-point ranges (delumping) for rigorous fractionator simulation. 

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