An integrated biorefinery concept for olive mill waste management : Supercritical CO2 extraction and energy recovery
Articolo
Data di Pubblicazione:
2015
Citazione:
An integrated biorefinery concept for olive mill waste management : Supercritical CO2 extraction and energy recovery / A. Schievano, F. Adani, L. Buessing, A. Botto, E.N. Casoliba, M. Rossoni, J.L. Goldfarb. - In: GREEN CHEMISTRY. - ISSN 1463-9262. - 17:5(2015 May), pp. 2874-2887. [10.1039/c5gc00076a]
Abstract:
Commercial production of olive oil generates four times the amount of waste as it does oil, along with a
number of environmental issues. We propose an integrated biorefinery concept for the management of
pomace, i.e. solid Olive Mill Waste (OMW), that utilizes supercritical carbon dioxide (SCO2), coupled with a
polar co-solvent (Ethanol), for extracting value-added polyphenols and mono/poly-unsaturated fatty
acids (MUFA/PUFA), followed by thermochemical (oxidation or pyrolysis) recovery of energy, biofuels and
materials. The SCO2 + EtOH extraction recovered 77.6 g of freeze-dried extract per kg of raw OMW, with
relatively high concentrations in polyphenols (10.9 g kg−1 of which 60.1% of di-hydroxytyrosol), PUFA
(20 g kg−1), MUFA (601 g kg−1) and other valuable compounds, such as squalene (10 g kg−1). All these substances
are of extreme interest in pharmaceutical and nutraceutical market, for their antioxidant, anticancer,
functional, anti-bacterial and nutritional properties. The SCO2 + EtOH flux acted as physical/
chemical carrier for over 85% of humidity, leaving the exhaust OMW almost dry, with evident advantages
for downstream. Using nonisothermal thermogravimetric analysis, the apparent activation energies
required to pyrolyze OMW to produce fuel and biochar ranged from 20 to 140 kJ mol−1 depending on
heating ramp rate and temperature regime. BET analysis of unactivated biochars show increased (+25%)
mesopore surface areas after SCO2 extractions (up to 500 m2 g−1). A more in-depth view on the proposed
biorefinery is needed, to consider the overall energy balance, as well as possible market values of the
obtained extract, and evaluate the real feasibility of the proposed concept.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
environmental chemistry; pollution
Elenco autori:
A. Schievano, F. Adani, L. Buessing, A. Botto, E.N. Casoliba, M. Rossoni, J.L. Goldfarb
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