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Reductive Catalytic Fractionation of Flax Shive over Ru/C Catalysts
- Source :
- Catalysts, Volume 11, Issue 1, Catalysts, Vol 11, Iss 42, p 42 (2021)
- Publication Year :
- 2020
- Publisher :
- MDPI AG, 2020.
-
Abstract
- Flax shive is the main waste (up to 70 wt %) in the production of flax fiber. It represents the lignified parts of the flax stem mainly in the form of small straws. Complex processing of such wastes is a significant problem due to the heterogeneity of the chemical structure of lignin. This article presents the results of reductive catalytic fractionation (RCF) of flax shive in ethanol and isopropanol at elevated temperatures (225&ndash<br />250 &deg<br />C) in the presence of a bifunctional catalyst (Ru/C) and molecular hydrogen. This provides solvolytic depolymerization of lignin and hemicelluloses presented in flax shive. Catalytic hydrogenation effectively stabilizes the formed lignin intermediates and prevents repolymerization reactions producing the lignin fraction with a high degree of depolymerization. RCF of flax shive produces solid products with a high cellulose content and liquid products consisting mainly of monophenolic compounds. Furthermore, the effect of different characteristics (the ruthenium content, particle size, and support acidity) of the bifunctional catalysts containing ruthenium nanoparticles supported on mesoporous, graphite-like carbon material Sibunit&reg<br />4 on the yield and composition of the products of hydrogenation of flax shive in sub- and super-critical ethanol has been studied. Bifunctional catalysts Ru/C used in the RCF of flax shive increase its conversion from 44 to 56 wt % and the yield of monophenols from 1.1 to 10.2 wt % (based on the weight of lignin in the sample). Using the best Ru/C catalyst containing 3% of Ru on oxidized at 400 &deg<br />C carbon support, the high degree of delignification (up to 79.0%), cellulose yield (up to 67.2 wt %), and monophenols yield (up to 9.5 wt %) have been obtained.
- Subjects :
- chemistry.chemical_element
lcsh:Chemical technology
010402 general chemistry
01 natural sciences
Catalysis
lcsh:Chemistry
chemistry.chemical_compound
Lignin
lcsh:TP1-1185
Physical and Theoretical Chemistry
Cellulose
valorization
Bifunctional
biomass
010405 organic chemistry
Depolymerization
reductive catalytic fractionation
Ru/C catalysts
0104 chemical sciences
Bifunctional catalyst
Ruthenium
flax shive
lcsh:QD1-999
chemistry
Yield (chemistry)
Nuclear chemistry
Subjects
Details
- ISSN :
- 20734344
- Volume :
- 11
- Database :
- OpenAIRE
- Journal :
- Catalysts
- Accession number :
- edsair.doi.dedup.....6d4487e67c0209a750e07a3940058e05