Quantitative Insights into the Fast Pyrolysis of Extracted Cellulose, Hemicelluloses, and Lignin

• Published in: ChemSusChem Vol. 10; no. 16; pp. 3212 - 3224
• Main Authors: Carrier, Marion, Windt, Michael, Ziegler, Bernhard, Appelt, Jörn, Saake, Bodo, Meier, Dietrich, Bridgwater, Anthony
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 24.08.2017; ChemPubSoc Europe/Wiley; John Wiley and Sons Inc
• Subjects: Analytical chemistry; Biomass; Carbon - chemistry; Catalysis; Cellulose; Cellulose - chemistry; Cellulose - isolation & purification; Chemical Sciences; Degradation; Functional groups; Hot Temperature; isotopic labeling; Kinetics; Lignin; Lignin - chemistry; Lignin - isolation & purification; Lignocellulose; Mass spectrometry; Microreactors; NMR spectroscopy; polymers; Polysaccharides - chemistry; Polysaccharides - isolation & purification; Pyrolysis; reaction mechanisms; Selectivity; Spectroscopic analysis; Volatile compounds; reaction mechanisms; biomass; isotopic labeling; polymers; NMR spectroscopy
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201700984

The transformation of lignocellulosic biomass into bio‐based commodity chemicals is technically possible. Among thermochemical processes, fast pyrolysis, a relatively mature technology that has now reached a commercial level, produces a high yield of an organic‐rich liquid stream. Despite recent efforts to elucidate the degradation paths of biomass during pyrolysis, the selectivity and recovery rates of bio‐compounds remain low. In an attempt to clarify the general degradation scheme of biomass fast pyrolysis and provide a quantitative insight, the use of fast pyrolysis microreactors is combined with spectroscopic techniques (i.e., mass spectrometry and NMR spectroscopy) and mixtures of unlabeled and 13C‐enriched materials. The first stage of the work aimed to select the type of reactor to use to ensure control of the pyrolysis regime. A comparison of the chemical fragmentation patterns of “primary” fast pyrolysis volatiles detected by using GC‐MS between two small‐scale microreactors showed the inevitable occurrence of secondary reactions. In the second stage, liquid fractions that are also made of primary fast pyrolysis condensates were analyzed by using quantitative liquid‐state 13C NMR spectroscopy to provide a quantitative distribution of functional groups. The compilation of these results into a map that displays the distribution of functional groups according to the individual and main constituents of biomass (i.e., hemicelluloses, cellulose and lignin) confirmed the origin of individual chemicals within the fast pyrolysis liquids. Supergroup: The quantitative mapping of functional groups in fast pyrolysis bio‐oil is performed by combining to the use of fast pyrolysis microreactors with spectroscopic techniques and labeling experiments. The results provide a map that displays the distribution of functional groups according to the main constituents of biomass (i.e., hemicelluloses, cellulose and lignin).