When considering a material for use as a catalyst or adsorbent, its pore structure is important, and can be determined by nitrogen gas adsorption. This thesis focuses on activated carbon materials prepared from petroleum coke, which are challenging to characterize due to the difficulties in modelling their disordered pore structures. The published models used to calculate the pore structure from experimental data have been reviewed and compared. From this review a procedure has been developed to select the most appropriate model for the material being studied, which is generally based on 2-Dimensional Non-Local Density Functional Theory, and applied to four carbon materials with varying pore structures. The results from this procedure show that pore structure properties can be calculated from a single model, and have been complemented with carbon dioxide adsorption, hysteresis scanning isotherms, and helium ion microscopy images but further work is recommended with the latter two methods.