Title:
Two-Step Pyrolysis of Biomass to Enhance the Chemical Stability of Pyrolytic Liquids
Author(s):
Persson, H., Evangelopoulos, P., Svanberg, R., Yang, W.
Document(s):
Paper
Poster
Abstract:
Aging of pyrolytic liquid during storage changes its chemical and physical properties. The reason for aging is the chemical instability of the liquid, which is not at thermodynamic equilibrium when quenched after pyrolysis. Compounds active in these reactions mainly derivatives from hemicellulose (e.g. acids and carbonyls). In this work, a two-step pyrolysis concept was investigated to separate these compounds in a lower temperature treatment step upstream a conventional pyrolyzer. Different temperatures of the lower temperature treatment was investigated with constant conditions of the conventional treatment. The total liquid yield derived did not vary from pyrolysis in one step. Results show that the two-step pyrolysis process significantly reduces the concentration of organic acids and carbonyls in the liquid product from the second pyrolyzer, which instead are found in the liquid from the lower temperature treatment. Also, the concentration of sugar derivatives from the second step treatment is increased with the temperature of the first step. However, a complete separation of aging active compounds is not possible without sacrificing partial fractions of others (lignin derivatives were found in the low-temperature treatment). By varying the temperature of the first step one can control the concentrations and the liquid yield from each step.
Keywords:
biomass, pyrolysis, torrefaction, chemical composition, low temperature, softwood
Topic:
Biomass Conversion Technologies for Liquid and Gaseous Fuels, Chemicals and Materials
Subtopic:
Pyrolysis and other biomass liquefaction technologies
Event:
25th European Biomass Conference and Exhibition
Session:
3AV.3.38
Pages:
1186 - 1189
ISBN:
978-88-89407-17-2
Paper DOI:
10.5071/25thEUBCE2017-3AV.3.38
Price:
FREE
