International Journal of Thermofluids (May 2024)

Axisymmetric flow model of cannabis oil extraction of supercritical fluid extraction CO2 process

  • Thanachai Obchoei,
  • Wiroj Limtrakarn

Journal volume & issue
Vol. 22
p. 100682

Abstract

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Supercritical fluid extraction using CO2 is a widely recognized method for purifying oil extracts. Understanding the extraction process is important for improving yields. While most research has focused on one-dimensional simulations, there is a need for three-dimensional models that better simulate real extraction behavior. This paper focuses on a two-dimensional axisymmetric model to study the complexities of three-dimensional extraction processes. The proposed mathematical and axisymmetric model describes the extraction of cannabis using a supercritical fluid extraction (SFE) CO2 process. The COMSOL program was used to solve 2D axisymmetric and laminar flow dynamics within the extractor. The velocity was derived from the axisymmetric Navier-Stokes equation was used in the mathematical model. A 2D mathematical and axisymmetric model was developed based on 1D Reverchon models, and it was validated using experimental data. The experimental data were used to determine one unknown parameter. The total mass transfer coefficient (K) was determined from the experimental results and integrated into computational model. Creating a computational model, meshing, and conducting a 2D axisymmetric simulation analysis of Cannabis sativa L. oil extraction. The proposed curve was computed using a numerical method and was adjusted iteratively to converge with the experimental data, verified by minimizing the Root Mean Square (RMS) error. The experimental data yielded a total mass transfer coefficient (K) of 1.0194 x 10-8 m/s, which was then used in the 2D axisymmetric simulation. The results of the axisymmetric simulation show the concentration distribution within the extractor. The predictions of the proposed numerical 2D solutions closely aligned with the experimental data. The concentration of oil in the axisymmetric results is in accordance with the velocity. The model used in the supercritical fluid extraction process is ideal for purifying extractions, especially for medical and pharmaceutical purposes. This model can be further developed into more complex process and new design extractor for achieving high performance extraction. The scientific community can benefit from the model that combines the Navier-Stoke equation and extraction equation. It can be used to improve extraction simulations for other extraction methods or supercritical fluid in different fields.

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