Biodiesel is a fuel derived from a renewable vegetable origin and is object of growing interest in recent years both as a pure fuel and as blending component to reduce exhaust pollutants of traditional diesel fuel. The conventional biodiesel production technology involves the use of alkaline catalysts and is therefore not compatible with large amounts of free fatty acids (FFAs) and moisture in the feedstock due to the formation of soaps that strongly affect the feasibility of glycerol separation by liquid–liquid splitting. A preliminary stage of acidity reduction is therefore necessary, for this process, if the starting material is characterized by a free acidity higher than 0.5% by weight often contained in cheaper feedstock which lowers the production costs. This can be pursued, for example, by means of an esterification reaction of the FFAs with methanol, catalyzed by ionic-exchange sulphonic acid resins. In the present work, the abovementioned reaction has been studied in different reactor configurations on a model mixture composed by artificially acidified soybean oil with oleic acid using an acid exchange resin as catalyst. Thiswork has been developed in two parts: (i) a kinetic study in batch conditions with the purpose of developing a suitable kinetic expression and determining the related parameters and (ii) a study of the FFAs esterification in a packed bed tubular reactor operated inside a circulation loop. The kinetic model that is developed on the basis of several batch runs is able to simulate also the behavior of dynamic tubular loop reactor, providing that the externalmasstransfer resistance is properly accountedfor. Themasstransfer coefficient is satisfactorily modeled using correlations available on literature.

Kinetics of free fatty acids esterification: batch and loop reactor modeling.

TESSER, RICCARDO;DI SERIO, MARTINO;SANTACESARIA, ELIO
2009

Abstract

Biodiesel is a fuel derived from a renewable vegetable origin and is object of growing interest in recent years both as a pure fuel and as blending component to reduce exhaust pollutants of traditional diesel fuel. The conventional biodiesel production technology involves the use of alkaline catalysts and is therefore not compatible with large amounts of free fatty acids (FFAs) and moisture in the feedstock due to the formation of soaps that strongly affect the feasibility of glycerol separation by liquid–liquid splitting. A preliminary stage of acidity reduction is therefore necessary, for this process, if the starting material is characterized by a free acidity higher than 0.5% by weight often contained in cheaper feedstock which lowers the production costs. This can be pursued, for example, by means of an esterification reaction of the FFAs with methanol, catalyzed by ionic-exchange sulphonic acid resins. In the present work, the abovementioned reaction has been studied in different reactor configurations on a model mixture composed by artificially acidified soybean oil with oleic acid using an acid exchange resin as catalyst. Thiswork has been developed in two parts: (i) a kinetic study in batch conditions with the purpose of developing a suitable kinetic expression and determining the related parameters and (ii) a study of the FFAs esterification in a packed bed tubular reactor operated inside a circulation loop. The kinetic model that is developed on the basis of several batch runs is able to simulate also the behavior of dynamic tubular loop reactor, providing that the externalmasstransfer resistance is properly accountedfor. Themasstransfer coefficient is satisfactorily modeled using correlations available on literature.
File in questo prodotto:
File Dimensione Formato  
096) Esterification batch and loop.pdf

non disponibili

Tipologia: Documento in Post-print
Licenza: Accesso privato/ristretto
Dimensione 584.06 kB
Formato Adobe PDF
584.06 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/362681
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 69
  • ???jsp.display-item.citation.isi??? 56
social impact