REACTION-ENGINEERING APPROACHES TO THE OXIDATIVE COUPLING OF METHANE TO C-2+ HYDROCARBONS

Various reaction engineering aspects of the oxidative coupling of methane (OCM) to C-2+ hydrocarbons are dealt with based on catalytic performance of PbO/Al2O3, NaOH/CaO, La,Os/CaO and Li2O/CaO. Among these catalysts La2O3/CaO seems to be most promising for large-scale OCM operation due to its catalytic and mechanical properties. When applying La2O3/CaO in a polytropic fixed-bed as well as in a fluidized-bed reactor C-2+ yields of nearly 16 % were achieved. Reactor operation with distributed feed of oxygen was examined as a means of improving C-2+ yield. While an increase of C-2+ yield was achieved for PbO/Al2O3 no such improvement was observed for La2O3/CaO. Models of fired-bed and fluidized-bed reactors were developed for scale-up purposes using reaction engineering kinetics. Simulations based on those models led to good qualitative agreement with lab-scale experimental data; however, further improvement of accuracy is necessary for their use as predictive models.