Separation of hydrocarbons from activated carbon as a porous substance in a glycol regeneration process using supercritical carbon dioxide

Activated carbons are used in industrial applications; their cost is a major barrier to their more widespread application. Regeneration of activated carbons is indispensable to minimize operational costs and product wastage. Supercritical carbon dioxide (SC-CO(2)) as green technology was used to regenerate activated carbons. In this work, response surface methodology was employed to optimize the supercritical regeneration process and to evaluate the effect of the operational parameters including pressure (100–300 bar), temperature (313–333 K), flow rate (2–6 g/min), and dynamic time (30–150 min) on the regeneration yield. The maximum regeneration yield (93.71%) was achieved at 285 bar, 333 K, 4 g/min, and 147 min. Mathematical modeling was done using two one-parameter kinetics models, which agree well with the experimental data. The fitting parameter of the model was obtained by using a differential evolution algorithm. The chemical composition of the substances extracted from the activated carbon was identified by gas chromatography. The results showed that the regeneration of activated carbon by SC-CO(2) can be an alternative method to conventional methods.