(242c) CFD Applied to SHALE OIL Pyrolisys
The use of oil is intensive in the architecture of the world energy matrix. Consumption has only increased in the last decades, which has been causing the search for alternative routes of generation. Discovery of shale oil/gas and its recent commercial exploitation at industrial scale may, in a few years, change the current axis of unilateral dependence on it. However, much remains to be done about the technology behind the obtaining process, since such substance is confined in rocks. The shale pyrolysis has been investigated numerically under non-isothermal conditions. This reactive flow process, dominated by diffusion mechanism and chemical kinetics, in a porous moving bed uses a vertical cylindrical geometry with gas internal distributor and fluid injections. The main idea was to reproduce the regions, respectively from the top to the base, formed along the reactor. The shale drying takes place in the inlet zone, due to the thermal exchange that occurs because of the local fluid temperature, once the material enters the reactor at room temperature. Chemical reactions happen shortly after drying zone; kerogen decomposition and consumption generating bitumen, which is broken in products and residues (pyrite and coke). A three dimensional, turbulent and multiphase mathematical modeling and numerical simulation (CFD) of the shale thermal degradation were presented. Mass, heat and momentum balances were formulated following the Eulerian approach. All chemical species were subject to consumption and formation reactions of the process on space and time domain, under first-order kinetic. Empirical correlations guarantee the closure of the model and its numerical solution. The obtained results are evaluated and compared with the literature. An understanding of all these chemical reactions and their rates, as well as process regions can help in design and security minimizing costs, including those associated with meeting environmental regulations.