Results of the International Energy Agency Round Robin on Fast Pyrolysis Bio-oil Production

Abstract

An international round robin study of the production of fast pyrolysis bio-oil was undertaken. A total of 15 institutions in six countries contributed. Three biomass samples were distributed to the laboratories for processing in fast pyrolysis reactors. Samples of the bio-oil produced were transported to a central analytical laboratory for analysis. The round robin was focused on validating the pyrolysis community understanding of production of fast pyrolysis bio-oil by providing a common feedstock for bio-oil preparation. The round robin included: distribution of three feedstock samples, hybrid poplar, wheat straw, and a blend of lignocellulosic biomasses, from a common source to each participating laboratory, preparation of fast pyrolysis bio-oil in each laboratory with the three feedstocks provided, and return of the three bio-oil products (minimum of 500 mL) with operational description to a central analytical laboratory for bio-oil property determination. The analyses of interest were CHN, S, trace element analysis, water, ash, solids, pyrolytic lignin, density, viscosity, carboxylic acid number, and accelerated aging of bio-oil. In addition, an effort was made to compare the bio-oil components to the products of analytical pyrolysis through gas chromatography/mass spectrometry (GC/MS) analysis. The results showed that clear differences can occur in fast pyrolysis bio-oil properties by applying different process configurations and reactor designs in small scale. The comparison to the analytical pyrolysis method suggested that pyrolysis (Py)–GC/MS could serve as a rapid qualitative screening method for bio-oil composition when produced in small-scale fluid-bed reactors. Gel permeation chromatography was also applied to determine molecular weight information. Furthermore, hot vapor filtration generally resulted in the most favorable bio-oil product, with respect to water, solids, viscosity, and carboxylic acid number. These results can be helpful in understanding the variation in bio-oil production methods and their effects on bio-oil product composition.

Recent research progress on bio‐oil conversion into bio‐fuels and raw chemicals: a review

“…Molecular distillation enables separation of bio‐oil into several fractions, such as an organic fraction with high calorific value . Several studies predict the phase separation of bio‐oil, and there is also detailed work in which the bio‐oil composition is related with the production method . The high content of phenolic compounds in bio‐oil (particularly in the organic phase) makes it attractive for synthesizing phenol‐formaldehyde (PF) resins.…”

Accelerated aging of fast pyrolysis bio-oil: a new method based on carbonyl titration

“…Further, the times and temperatures used to age the oils are restricted by the phase separation problem if viscosity is used to track aging. The commonly used aging protocol heats samples at 80 C for 24 hours, 9,[11][12][13] however at these conditions many bio-oil samples will phase separate. The reactions that form the condensation products can have a widely varied effect on the viscosity of the sample as well.…”

Brisk Method for Fractionating and Separating Bio-Crude Oil

“…And new generation analytical techniques such as comprehensive two-dimensional GC have been employed to study even more detailed composition [4]. The International Energy Agency (IEA) has focused on applying improved analytical methods for BCO [5]. Almost all these analytical studies have dealt mostly with the volatile fractions of BCO leaving the non-volatile fractions as unidentified most of which are sugarderived products.…”