Impact of potassium and phosphorus in biomass on the properties of fast Pyrolysis bio-oil


This study investigates fast pyrolysis bio-oils produced from alkali-metal-impregnated biomass (beech wood). The impregnation aim is to study the catalytic cracking of the pyrolysis vapors as a result of potassium or phosphorus. It is recognized that potassium and phosphorus in biomass can have a major impact on the thermal conversion processes. When biomass is pyrolyzed in the presence of alkali metal cations, catalytic cracking of the pyrolysis liquids occurs in the vapor phase, reducing the organic liquids produced and increasing yields of water, char, and gas, resulting in a bio-oil that has a lower calorific value and an increased chance of phase separation. Beech wood was impregnated with potassium or phosphorus (K impregnation and P impregnation, respectively) in the range of 0.10-2.00 wt %. Analytical pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) was used to examine the pyrolysis products during thermal degradation, and thermogravimetric analysis (TGA) was used to examine the distribution of char and volatiles. Both potassium and phosphorus are seen to catalyze the pyrolytic decomposition of biomass and modify the yields of products. 3-Furaldehyde and levoglucosenone become more dominant products upon P impregnation, pointing to rearrangement and dehydration routes during the pyrolysis process. Potassium has a significant influence on cellulose and hemicellulose decomposition, not just on the formation of levoglucosan but also other species, such as 2(5H)-furanone or hydroxymethyl-cyclopentene derivatives. Fast pyrolysis processing has also been undertaken using a laboratory-scale continuously fed bubbling fluidized-bed reactor with a nominal capacity of 1 kg h-1 at the reaction temperature of 525 °C. An increase in the viscosity of the bio-oil during the stability assessment tests was observed with an increasing percentage of impregnation for both additives. This is because bio-oil undergoes polymerization while placed in storage as a result of the inorganic content. The majority of inorganics are concentrated in the char, but small amounts are entrained in the pyrolysis vapors and, therefore, end up in the bio-oil.

Publication DOI:
Dataset DOI:
Divisions: College of Engineering & Physical Sciences
College of Engineering & Physical Sciences > School of Infrastructure and Sustainable Engineering > Chemical Engineering & Applied Chemistry
College of Engineering & Physical Sciences > Energy and Bioproducts Research Institute (EBRI)
Additional Information: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Energy & Fuel, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see Funding: EPSRC (EP/E039995/1). Research data:
Uncontrolled Keywords: Chemical Engineering(all),Fuel Technology,Energy Engineering and Power Technology
Publication ISSN: 1520-5029
Last Modified: 13 May 2024 07:15
Date Deposited: 15 Nov 2016 09:05
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2016-10-20
Published Online Date: 2016-07-07
Accepted Date: 2016-07-04
Submitted Date: 2016-05-01
Authors: Banks, Scott W. (ORCID Profile 0000-0002-4291-2572)
Nowakowski, Daniel J. (ORCID Profile 0000-0001-8056-5316)
Bridgwater, Anthony V. (ORCID Profile 0000-0001-7362-6205)



Version: Accepted Version

| Preview

Export / Share Citation


Additional statistics for this record