The distributions of the adsorption energies (AED) of two enantiomers on a chiral stationary phase were measured, and the results are discussed. The enantiomers studied are two beta-blockers, alprenolol and propranolol. The chiral phase is made of the protein Cel7A immobilized on porous silica. The determination of these AEDs was carried out using the expectation-maximization method, a numerical method that uses directly the raw experimental isotherm data and inverts this set of data into an AED, using in the process the Langmuir equation as the local isotherm. The distributions obtained were found to be bimodal and consistent with observations previously made on the isotherms and reported. The AEDs of two enantiomers have the same low-energy mode (same mean energy, mode profile, and mode area). Their high-energy modes are different. Depending on the eluent pH, the mode for the (S)-enantiomer has a larger mean energy or a larger area than the one for the (R)-enantiomer. The experimental data fit very well to the bi-Langmuir isotherm model. At low mobile phase pH, the difference between the retention of the two enantiomers is due to the difference of their saturation capacities at the enantioselective (or high-energy) sites. By contrast, at high pH, their separation is governed by the difference in their adsorption energies. This work illustrates how the consideration of the AEDs of two enantiomers may be informative on the validity of the method of determination of these distributions and on the properties of the surface.