Modeling and Validation of Heat and Mass Transfer in Individual Coffee Beans during the Coffee Roasting Process Using Computational Fluid Dynamics (CFD)

FHHES Universities of Applied Sciences

Authors

  • Beatriz Alonso-Torres Centro de Investigaciones en Ingeniería y Ciencias Aplicadas, Universidad Autónoma del Estado de Morelos, Avenida Universidad No. 1001, col. Chamilpa 62209 Cuernavaca, Morelos, México
  • José Alfredo Hernández-Pérez Centro de Investigaciones en Ingeniería y Ciencias Aplicadas, Universidad Autónoma del Estado de Morelos, Avenida Universidad No. 1001, col. Chamilpa 62209 Cuernavaca, Morelos, México
  • Fernando Sierra-Espinoza Centro de Investigaciones en Ingeniería y Ciencias Aplicadas, Universidad Autónoma del Estado de Morelos, Avenida Universidad No. 1001, col. Chamilpa 62209 Cuernavaca, Morelos, México
  • Stefan Schenker Bühler AG, Gupfenstrasse 5, CH-9240 Uzwil, Switzerland
  • Chahan Yeretzian Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, CH-8820 Wädenswil, Switzerland. yere@zhaw.ch

DOI:

https://doi.org/10.2533/chimia.2013.291

Keywords:

Coffee roasting, Cfd, Heat and mass transfer, Modeling

Abstract

Heat and mass transfer in individual coffee beans during roasting were simulated using computational fluid dynamics (CFD). Numerical equations for heat and mass transfer inside the coffee bean were solved using the finite volume technique in the commercial CFD code Fluent ; the software was complemented with specific user-defined functions (UDFs). To experimentally validate the numerical model, a single coffee bean was placed in a cylindrical glass tube and roasted by a hot air flow, using the identical geometrical 3D configuration and hot air flow conditions as the ones used for numerical simulations. Temperature and humidity calculations obtained with the model were compared with experimental data. The model predicts the actual process quite accurately and represents a useful approach to monitor the coffee roasting process in real time. It provides valuable information on time-resolved process variables that are otherwise difficult to obtain experimentally, but critical to a better understanding of the coffee roasting process at the individual bean level. This includes variables such as time-resolved 3D profiles of bean temperature and moisture content, and temperature profiles of the roasting air in the vicinity of the coffee bean.

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Published

2013-04-24