Gen eralized modified SAFT-B ACK mo del for lo ng chain hydrocarbons

The th ermodynamic properties of n-alkanes and their mixtures are important for practical interest, since they are involved in a number of refinery processes. More recently, a model based o n Statistical Associating Fluid Theory (SAFT), called modified SAFT-BACK EOS, has been strongly tested to describe the phase equilibria as well as second thermodynamics derivative properties for C۱- C۱۰ chain alkanes and their binary mixtures was developed by Maghari et al. [۱-۳]. This model EOS be able to describe the thermodynamic properties of chain fluids in whole of region, including near critical region.In this work, we generalized the modified SAFT-BACK EOS for longer chain fluids and obtained both first and second derivative properties of C۱۱ to C۲۰ chain alkanes.According to the modified SAFT-BACK EOS, the residual Helmholtz free energy for a fluid is written as a sum of the separate contribution to the energy(...)in which the hcb and dispersion contributions to the segment Helmholtz free energies are as follows:(...)

کلیدواژه ها:

modified SAFT-BACK ، Equation of state ، P VT properties ، second order derivative properties ، chain molecules