Abstract

A very efficient separation of lipids from wet sewage scum was optimised and positively tested on samples taken from several wastewater treatment plants (WWTPs). By simply heating sewage scum at 353 K and centrifuging the heated mass at 4000 rpm per 1 min, a recoverability of 93-99% of total oils was always obtained. This procedure resulted to be effective on samples with very different starting water contents. In all cases, extracted lipids have a very similar composition in terms of free fatty acids (FFAs), calcium soaps (32-40%wt) and glycerides (mono-, di- and tri-glycerides were practically absents), as well as fatty acid profiles. Once separated, lipids were converted into biodiesel through a direct esterification process carried out by adopting three sequential batch reactors, in which methanol and catalysts were charged in counter current. In this way, the complete conversion (>99%) of starting FFAs into FAMEs was perfectly matched with using the minimum amount of reactants under very mild conditions (345 K, 2 h). The overall convenience of the process was completed by the anaerobic digestion of fibrous residues obtained from centrifugation of starting sewage scum: the final biogas resulted largely enough to sustain the heat of process. (C) 2015 Elsevier Ltd. All rights reserved.

Autore Pugliese

• Pastore Carlo , Mascolo Giuseppe

Tutti gli autori

• di Bitonto L.; Lopez A.; Mascolo G.; Mininni G.; Pastore C.

Titolo volume/Rivista

Renewable energy

Anno di pubblicazione

2016

ISSN

0960-1481

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

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Settori ERC

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Codici ASJC

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