Process parameter estimation of supercritical carbon dioxide extraction of lipids fromspent coffee grounds

Lipids are a promising raw material for potential cheap and high-quality biodiesel production. The process parameters of lipid extraction from spent coffee grounds using supercritical carbon dioxide were estimated in this study. Two partial differential equations describing the solute transportation in the bed interstices and solid pores as well as an ordinary differential equation explaining the solute rate in the solid matrix were used to estimate the accumulation yield. The calculated yieldswerefittedtothe experimental ones to obtain the values of the process parameters through optimization. An increase in pressure at a certain temperature causes the desorption coefficient to rise. The calculated value of the diffusion coefficientof lipid in supercritical CO2 is 1 × 10−10 m2/s to 1.3 × 10−10 m2/s.