Delumping method

Verification of the Delumping Method Caussian-Legendre Quadrature... 

To verify that the delumping method of Gauss-Legendre quadrature with 20 pseudocomponents based on boling-point ranges is sufficient for column models, we perform another sensitivity test as a conhast, which uses the even cut-point range method to cut reactor model effluent into 46 pseudocomponents based... 

Figures 6.45 to 6.48 illustrate the specific gravity predictions of liquid products, which are calculated by Aspen HYSYS. The accurate predictions not only reflect the accuracy of the model to predict specific gravity of the liquid product, but also demonstrate that the delumping method described in Section 6.4.5 is able to carry over density distribution to pseudocomponents based on boiling-point ranges.

Our delumping method gives a continuous response to changes in fractionator specification such as distillate rate. 

Even though, as presented above, certain characteristic relationships have been developed for many agglomeration methods, scale-up is a serious problem. Furthermore, aging has very often a marked effect on the results, because binding mechanisms rely on chemical and physical interactions at the surfaces of particles to be agglomerated and, if applicable, with the binder component(s). Therefore, a representative material which is several days or weeks old and may have to be reheated, re wetted, dried, or delumped to bring it back to a comparable condition as found in the real plant environment may yield completely different results than those found later in-line. This means that not only tests must be carried out with representative samples of raw materials and, if applicable, binders but pilot plant evaluations on site and/or in-line should also be considered if the risk of a new application is to be minimized. 

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. 

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. 

Haynes and Matthews [38] apply the Gauss-Legendre quadrature to predict the vapor-liquid equilibrium (VLE) of thydrocarbon mixture derived from a continuous equation-of-state developed by Cotterman et al. [39]. Later, Mani et al. [40] extend the work of Haynes and Matthews [38] to partition the cut-point ranges of the TBP curve of a petroleum fraction to define pseudocomponents based on boiling-point ranges, and the predicted VLE satisfactorily matches the experimental data. Hence, we extend the method represented by Mani et al. [40] to delump the reactor model effluent into pseudocomponents. 

In this work, we develop a method with six steps to delump the reactor model effluent into pseudocomponents by the Gauss-Legendre quadrature. 

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