Numerical Integral in the Ideal Adsorbed Solution Theory

The ideal adsorbed solution (IAS) theory has an advantage that no restriction exists for the type of pure component isotherm. One can choose the isotherm that fits the experimental data best. However, the theory requires a lot of numerical calculation, including numerical integration. This study shows that IAS needs very accurate values of numerical integration when the D-R equation is used as a single component isotherm. The error of numerical integration should be set to be no larger than 10-7. Otherwise the error of numerical calculation will occur, which may increase prediction deviation.