Abstract
Catalytic pyrolysis of Kraft lignin and Scots pine wood
over three different catalysts HZSM-5, Y-zeolite and Pd/C
was studied. All experiments, with and without a
catalyst, were carried out in small scale, using
analytical pyrolysis gas chromatography mass spectrometry
(Py-GC-MS) at 600 °C. The catalytic pyrolysis result
showed that the Kraft lignin was less altered over the
tested catalysts in comparison to Scots pine wood
(lignin). Over the acidic zeolite catalysts, aromatic
hydrocarbons with one to three aromatic rings were formed
from both samples, together with deoxygenated phenolic
structures. Conversion of Scots pine wood-aromatic
hydrocarbons was higher with both zeolites in comparison
to Kraft lignin, especially when HZSM-5 was used.
Y-zeolite changed the product distribution of Kraft
lignin more than HZSM-5. With Y-zeolite, the proportion
of benzenediols and p-hydroxypehnyl structures was
increased, indicating demethylation and demethoxylation
of lignin guaiacyl units. With Pd/C catalyst,
deoxygenation of lignin guaiacyl units took place from
both Scots pine wood and Kraft lignin. At high
temperature pyrolysis with Pd/C, hydrogenation of double
bonds was avoided. Conversion of Scots pine wood
lignin-guaiacyl-type lignin derivatives with no
oxygen-containing side chain structures was higher in
comparison to Kraft lignin. Verification of the results
with principal component analysis (PCA) revealed that
catalytic pyrolysis treatments clearly differ from the
non-catalytic treatment of Scots pine wood. In the case
of Kraft lignin, only pyrolysis with Y-zeolite clearly
changed the product distribution in comparison to
non-catalytic pyrolysis. Based on the results, analytical
Py-GC-MS proved to be a promising method for testing the
behaviour of different catalysts.
Original language | English |
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Pages (from-to) | 186-192 |
Journal | Journal of Analytical and Applied Pyrolysis |
Volume | 113 |
DOIs | |
Publication status | Published - 2015 |
MoE publication type | A1 Journal article-refereed |
Keywords
- catalytic pyrolysis
- Py-GC-MS
- lignin
- HZSM-5
- Y-zeolite
- Pd/C