Effects of high-pressure homogenization on physicochemical properties and storage stability of switchgrass bio-oil

A high-pressure homogenization (HPH) technique was used to improve the physicochemical properties and storage stability of switchgrass bio-oil. The viscosity, ethanol-insoluble fraction, and mass average molecular weight (Mw) of the bio-oil decreased significantly, and particle size became smaller after HPH processing; however, no significant changes were detected in heating value, water content, density, pH value, or ash content. The bio-oil's chemical composition changed after HPH: amounts of some compounds (furfural, levoglucosan, diethoxymethyl acetate, and lignin-derived compounds) increased, while others (acetic acid and 1,2-ethanediol) decreased. The homogenization processing remarkably improved switchgrass bio-oil stability: the viscosity of bio-oil homogenized at 100 MPa increased by only 13.9% after storage at 40 °C for 60 days, whereas that of unhomogenized oil increased 56% after the same storage period. The operating cost was very modest at only $0.0102/L for bio-oil HPH processing at 100 MPa.

[1]  S. Silvestri,et al.  Degradation of tragacanth by high shear and turbulent forces during microfluidization , 1991 .

[2]  A. Bridgwater,et al.  Overview of Applications of Biomass Fast Pyrolysis Oil , 2004 .

[3]  J. Ulrich,et al.  High‐Pressure Homogenization as a Process for Emulsion Formation , 2004 .

[4]  A. Chaala,et al.  Bio-oils obtained by vacuum pyrolysis of softwood bark as a liquid fuel for gas turbines. Part I: Properties of bio-oil and its blends with methanol and a pyrolytic aqueous phase , 2000 .

[5]  C. Michiels,et al.  High-Pressure Homogenization as a Non-Thermal Technique for the Inactivation of Microorganisms , 2006, Critical reviews in microbiology.

[6]  Ed Hogan,et al.  Emulsification of pyrolysis derived bio-oil in diesel fuel , 2003 .

[7]  M. Corredig,et al.  Changes in the molecular weight distribution of three commercial pectins after valve homogenization , 2001 .

[8]  T. Bastow,et al.  Investigations into the control of odour and viscosity of biomass oil derived from pyrolysis of sewage sludge , 2005 .

[9]  D. Radlein,et al.  The composition of oils obtained by the fast pyrolysis of different woods , 1987 .

[10]  D. Knorr,et al.  Applications of high-pressure homogenization for food preservation : high-pressure homogenization can be used alone or combined with lytic enzyme or chitosan to reduce the microbial population and heat treatment damage in foods , 1990 .

[11]  D. Mohan,et al.  Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review , 2006 .

[12]  A. Demirbas,et al.  Biomass resource facilities and biomass conversion processing for fuels and chemicals , 2001 .

[13]  P. Paquin,et al.  Effects of microfluidization on the functional properties of xanthan gum , 1998 .

[14]  Rainer H. Müller,et al.  Nanosuspensions for the formulation of poorly soluble drugs: I. Preparation by a size-reduction technique , 1998 .

[15]  D. G. Black,et al.  Inactivation of Escherichia coli K-12 exposed to pressures in excess of 300 MPa in a high-pressure homogenizer. , 2007, Journal of food protection.

[16]  Anton P. J. Middelberg,et al.  Numerical and experimental study of a homogenizer impinging jet , 1997 .

[17]  P. Paquin Technological properties of high pressure homogenizers: the effect of fat globules, milk proteins, and polysaccharides , 1999 .

[18]  D. Meier,et al.  Norms and Standards for Pyrolysis Liquids. End-User Requirements and Specifications , 2005 .

[19]  Z. Qi,et al.  Review of biomass pyrolysis oil properties and upgrading research , 2007 .

[20]  A. Desrumaux,et al.  Formation of sunflower oil emulsions stabilized by whey proteins with high-pressure homogenization (up to 350 MPa): effect of pressure on emulsion characteristics , 2002 .

[21]  J. Floury,et al.  Degradation of methylcellulose during ultra-high pressure homogenisation , 2002 .