Supercritical CO2 oilseed extraction in multi-vessel plants. 1. Minimization of operational cost

Tunable solvents: Shades of green

“…The benefits of this approach will be diminished if the number of solvent reuses is limited by solvent decomposition or a build-up of impurities. Even if no technological issues arise industry must still be persuaded to make the initial high investment [89,90], for long term energy savings [91,92].…”

Supercritical CO2 oilseed extraction in multi-vessel plants. 2. Effect of number and geometry of extractors on production cost

“…Variables and parameter C B annual cost of the extraction batches (USD/year) C I cost of the installed SFE plant C L annual cost of labor (=424,000 USD/year) C PC production cost (total) per recovered oil (USD/kg oil) C SC annual cost of the solvent cycle (USD/year) C SD annual cost of lost CO 2 , dissolved in oil (USD/year) C T total annual cost in a SFE plant (USD/year) d p diameter of the diameter (m) D diameter of the extraction vessel (m) E total amount of vegetable oil produced in a SFE plant in a year (kg oil or ton oil) I cost a SFE plant (USD) I r cost of a reference SFE plant having n r extraction vessels of V r liters capacity each, and a mass flow rate of CO 2 of Q r (USD) L height of the extraction vessel L/D aspect ratio m scaling factor for SFE extraction plants (=0.48) m scaling factor for SFE extraction plants reported by Perrut [2] (=0.24) m 1 scaling factor for the solvent cycle in a SFE plant; parameter in Eq. (7) m 2 scaling factor for the extraction vessels in a SFE plant; parameter in Eq.…”

“…The decision to apply supercritical fluid (SF) extraction [1] to commercially recover high-value compounds from selected biological substrates demands accurate cost estimates. In a companion paper, del Valle et al [1] demonstrate the usefulness of mathematical simulation for the optimization of extraction time in the supercritical (sc) carbon dioxide (CO 2 ) extraction of vegetable oil from prepressed oilseed in a 1-m 3 vessel of an industrial multi-vessel SFE plant operating at 40 • C and 30 MPa.…”

“…In a companion paper, del Valle et al [1] demonstrate the usefulness of mathematical simulation for the optimization of extraction time in the supercritical (sc) carbon dioxide (CO 2 ) extraction of vegetable oil from prepressed oilseed in a 1-m 3 vessel of an industrial multi-vessel SFE plant operating at 40 • C and 30 MPa. The authors used a fully predictive shrinking-core mass transfer model to minimize the operational cost as a function of particle diameter (0.5 ≤ d p ≤ 4 mm), superficial CO 2 velocity (2.76 ≤ U ≤ 11.0 mm/s), and number (n) of extraction vessels (2, 3, or 4).…”

“…The authors used a fully predictive shrinking-core mass transfer model to minimize the operational cost as a function of particle diameter (0.5 ≤ d p ≤ 4 mm), superficial CO 2 velocity (2.76 ≤ U ≤ 11.0 mm/s), and number (n) of extraction vessels (2, 3, or 4). They observed that the operational cost diminishes as particle diameter decreases, and as the number of extraction vessels increases [1]. However, because of a sharp transition wave that develops when extracting small (≤1 mm) particles that separates fully extracted (downstream) from virtually unextracted (upstream) substrate within extraction vessels, del Valle et al [1] suggested using two-vessel industrial SFE plants for small particles, and three-or four-vessel plants for medium-to-large (≥2 mm) http …”