Characterization, pyrolysis oils

HPSEC may be used to characterize pyrolysis oils obtained from different sources, and comparisons may be drawn regarding their... 

HPSEC has been shown to be a useful method of characterizing pyrolysis oils because it examines the whole of the oil. When... 

The objective of this work is to synthesize and characterize zeolite-bentonite hybrid catalysts and perform test reactions in the pyrolysis of woody biomass in a dual-fluidized bed reactor. The aim is to produce catalytic materials which have good mechanical strength and are still able to de-oxygenate the pyrolysis oil. 

Elder, T. J. The Characterization and Potential Utilization of Phenolic Compounds Found in Pyrolysis Oil. Ph.D. Dissertation, Texas A M University, 1979. 

The quality of the product is of primary importance in developing a recycling technology converting plastics into fuels by pyrolysis. Today the characterization of a liquid fuel from any sources is obviously based on the qualification methods and standards of fuels from mineral oil. The properties of the pyrolysis-derived fuels from plastics are expected to be similar to conventional fuels (energy content, viscosity, density, octane and cetane number, flash-point, etc.). However, in addition to the familiar ranking values it is necessary to know more about the chemical composition of the plastic pyrolysis oil, because of the peculiarities as follows ... 

While all pyrolysis oil production reactor systems produce similar materials, each reactor produces a unique compound slate. The first decision, especially for a potential chemical or fuel producer, rather than a reactor developer, is to determine what products to make and which reactor system to use. The operating parameters of any reactor system designed to produce pyrolysis oil, especially temperature, can be altered to change the pyrolysis oil product composition and yield. Different feedstocks will produce different pyrolysis oil compositions and by-products, e.g. amorphous silica from rice hulls or rice straw, fatty acids from pine. Finally, feedstock pretreatment and/or catalysis, or reactor-bed catalysis can be used to improve specific product yields (7). Reactor system developers need to examine what they can produce and make this information available to chemical manufacturers and suppliers/owners of biomass feedstocks. This assumes that analysis of die entire liquid product from thermal conversion can be made, including quantitative analysis for any compounds that are being considered for recoveiy. Physical characterization - pH, viscosity, solids content, etc.is also needed. However, what can be produced is of no value, if it cannot be recovered or used economically. This involves examining the trade-offs between yield and current commercial value, recovery costs, and potential commercial value,... 

Scholze B. Meier D. (2000) Characterization of the water-insoluble fraction from pyrolysis oil (pyrolytic lignin), Part I. Py- GC/MS, FTIR, and functional groups, J. Anal. Appl. Pyrolysis, in press. 

The crude black, viscous pyrolysis oil product requires an upgrading step to make it suitable as a refinery feedstock. This is accomplished by high-pressure hydrogenation in a manner very similar to the upgrading step used for the coking products in tar sands processing. The influence of overall process conditions on the polycyclic aromatic compounds found in the product has been examined [62], and the supercritical water extract of the pyrolytic product has been characterized [63]. 

Characterization Tools for Pyrolysis Oils. It wasn t too many years ago that the only tools available to the scientist interested in pyrolysis oil composition were gas chromatography and thermogravi-metric analysis. The complexity of the pyrolysis oils demands high performance equipment, and a list of such equipment mentioned during the symposium would include proton and carbon nuclear magnetic resonance spectroscopy, free-jet molecular beam/mass spectrometry (16.25), diffuse reflectEuice Fourier transform infrared spectrometry ( ), photoelectron spectroscopy ( ), as well as procedures such as computerized multivariate analysis methods (32) - truly a display of the some of the most sophisticated analytical tools known to man, and a reflection of the difficulty of the oil composition problem. 

Hoesterey, B.L. Windig, W. Meuzelaar, H.L.C. Eyring, E.M. Grant, D.M. Pugmire, R.J. "An integrated spectroscopic approach to the chemical characterization of pyrolysis oils," In This Volume. 

Johnson, D.K. Chum, H.L. "Some aspects of pyrolysis oils characterization by high performance size exclusion chromatography (HPSEC)." In This Volume. 

Laboratory (4) and Process Development Unit (5,6) studies originally conducted at the Universite de Sherbrooke, and now conducted jointly with the private industry at Universite Laval, province of Quebec, have led to the conclusion that thermal decomposition under reduced pressure is an attractive approach for the conversion of biomass into chemicals and fuels products. The process uses a multiple-hearth furnace for wood pyrolysis. This approach is characterized by a low pressure and a short residence time of the vapor products in the rciactor. When compared with conventional, atmospheric pressure carbonization, vacuum pyrolysis has the potential to significantly enhance the yields of organic liquid products with respect to solid and gaseous products. The pyrolysis oils (biooils) obtained from this process can be deoxygenated into transportation fuels upon further upgrading (7). Specialty as well as commodity (Pakdel, H. Roy, C. Biomass, in press) chemicals can also be extracted from the pyrolysis oil product. 

Some Aspects of Pyrolysis Oils Characterization by High-Performance Size Exclusion Chromatography... 

Nicolaides, G. M. The Chemical Characterization of Pyrolysis Oils, MASc Thesis, Dept, of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada, 1984. 

An Integrated Spectroscopic Approach to the Chemical Characterization of Pyrolysis Oils... 

Chemical Characterization of Wood Pyrolysis Oils Obtained in a Vacuum-Pyrolysis Multiple-Hearth Reactor... 

Pyrolysis oil, water, char and gas are the wood pyrolysis products. Depending on the liquefaction process, pyrolysis oils composition change significantly. Lack of a standard pyrolysis oil characterization technique has initiated us at the first stage to develop a... 

Characterization of the low molecular weight carboxylic acids was successfully achieved following benzylation technique developed in our laboratory (Pakdel, H. Roy, C. Biomass, in press). Formic and acetic acids as decomposition products of cellulose and hemicellulose were the major constituents of pyrolysis oils (15). 

Even though they are only present in relatively low concentration, the compounds such as methyl cyclopentene-ol-one, 3-hydroxy-2-methyl-4 pyrone, isoeugnol, for example, can serve to characterize various oils and monitor the pyrolysis liquefaction procedure. They can also be separated and extracted as fine chemi cals. 

We thank the sponsoring divisions and all contributors to this volume and hope that their results will foster both interest in, and support of, continuing work on the fascinating chemistry and engineering of biomass pyrolysis, oil characterization, and upgrading for many uses. 

The pyrolysis oil, PO, is characterized as a conventional full-range hydrocarbon liquid, the nature of which is somewhat different than those normally encountered in a refinery. While it is similar to streams in a catalytic cracking unit in that it is rich in olefins, diolefins and aromatics, it is much more highly cracked. Thus, the heavier portion which boils above approximately 425 degrees F is rich in polynuclear aromatics such as naphthalene and similar materials. In some cases, a solid phase may develop upon cooling the heavier portions. The process designer must consider such... 

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