Oil shale reactor: process analysis and design by CFD

• Published in: Chemical engineering research & design 2019-12, Vol.152, p.180-192
• Main Authors: Stahnke, C., Silva, M.K., Rosa, L.M., Noriler, D., Martignoni, W.P., Bastos, J.C.S.C, Meier, H.F.
• Format: Article
• Language: English
• Subjects: Chemical reactions; Computational fluid dynamics; Design analysis; Energy consumption; Fluid dynamics; Heat transfer; Mass transfer; Mathematical models; Moving beds; Multiphase and reactive flows; Multiphase flow; Oil shale; Oil shale reactor; Organic chemistry; Organic matter; Parameter sensitivity; Porous media; Porous moving bed; Process analysis; Pyrolysis; Reaction mechanisms; Reactors; Response surface methodology; Scaling-Up effects; Sensitivity analysis; Shale pyrolysis; Three dimensional models; Turbulent flow; Viability
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2019.09.043

[Display omitted] •Oil shale reactor was modeled by using a reactive moving bed approach.•Three models for the interphase thermal exchange were evaluated.•Drying, heating, reaction and cooling zones were identified.•Hot gas injection temperature and flow rate have the greatest effect on the process.•Scale effects were observed for pilot and industrial-scale reactors. The oil shale pyrolysis process using a moving bed reactor was investigated with a three-dimensional mathematical model considering turbulent and multiphase flow in a porous moving bed, under non-isothermal and reactive conditions. Mass, heat and momentum balances involving chemical reactions of interest were formulated following a Eulerian approach to represent the process behavior. In the present approach, the shale bed was modeled as a porous medium and the advection due to its movement was implemented. Process analysis via CFD enabled the location of the drying, heating, reacting and cooling zones to be identified in the pilot-scale reactor. Moreover, it was possible to analyze in detail the conversion of organic matter to products, according to the reaction mechanism. The effects of heat and mass transfer inside the reactor were assessed through parametric sensitivity analysis, considering five parameters and five response values. The results were analyzed using the response surface method, which established the influence of each variable. The best values obtained for the thermal-energy consumption and the mechanical-energy consumption were 126.16 and 12.39kJ/kg, respectively. Considering the best operational conditions, scaling-up effects were also evaluated to shed light on the technical viability as well to carry out the design and analysis of the process.