RK-, SRK-, & SRK-PR-TYPE EQUATION OF STATE FOR HYDROCARBONS, BASED ON SIMPLE MOLECULAR PROPERTIES...

Fitting their critical pressure and temperature as a function of molecular weight and carbon atomic fraction was done using a database of 429 distinct hydrocarbons. Two curve-fitted equations were used to substitute the critical parameters 4511.png found in the Redlich-Kwong, Soave-Redlich-Kwong, and Redlich-Kwong-Peng-Robinson equations of state (EoS). The aforementioned original equations were compared to their counterparts in terms of predicting the molar volume of both liquid and vapour for a specific hydrocarbon at a given pressure and temperature. It was discovered that using either an empirical or a reference datum for the estimated molar volume, the substituted equation accurately predicted the volumetric parameters as well as the original equation. The upgrade will make it easier to calculate liquid and vapour volumetric parameters with reasonable accuracy. In general, all models, both the original and substituted/modified equations, were shown to predict well and with good precision (i.e., a percent relative error (PRE) of less than 10%). The projected values were practically identical. Furthermore, none of the models, neither the original nor its counterpart equation, could accurately forecast if the hydrocarbon molecular size was greater than C7 (i.e., PRE 10%). The best three models that predicted with a good accuracy (i.e., PRE 10%) for a hydrocarbon molecular size less than C7, on the other hand, were SRK-type, RK-type, and SRK. Finally, all models failed to forecast the critical molar volume (; i.e., PRE values > 10%) at the critical condition (i.e., Tr=1.0 and Pr=1.0).

Please see the link :- https://www.ikprress.org/index.php/JACSI/article/view/2808