(147b) Reactant Conversion and Product Speciation of Carbohydrate Model-Compound Pyrolysis Using a Novel Flow Reactor
AIChE Annual Meeting
2013
2013 AIChE Annual Meeting
2013 International Congress on Energy (ICE)
Thermochemical Conversion of Biomass II
Monday, November 4, 2013 - 1:20pm to 1:45pm
Reactant Conversion and Product Speciation of Carbohydrate Model-Compound Pyrolysis Using a Novel Flow Reactor
Patrick J. Fahey, Vikram Seshadri, Xinglian Geng, and Phillip R. Westmoreland*
North Carolina State University, Raleigh, NC 27695
The model compounds 1,2-propanediol, 1,3-propanediol, 1,2,3-propanetriol, hydroxypropanone, and acetaldehyde diethyl acetal were pyrolyzed neat and as methanol solutions in a pulse-injected tube-furnace reactor. Reaction products were analyzed directly by comprehensive, two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS). For example, pyrolysis of 1,3-propanediol at 500°C produced 90 identified peaks.
We experimented with molecules smaller than glucose to understand better the pyrolysis reaction networks of glucose-based carbohydrates. Cellulose has a complicated pyrolysis reaction network that researchers have tried to understand through experimenting with monosaccharide, disaccharide, and small-oligosaccharide pyrolyses.1,2 Here, using molecules smaller than glucose provided two benefits not possible with using entire monomers or dimers. First, smaller molecules isolate specific sequences of functional groups, which reduces the number of possible side reactions and products. Thus, smaller molecules simplified the chemical analysis of the reaction-product mixture and the construction of reaction pathways.3 Second, smaller molecules allow computational-quantum-chemistry simulations to execute faster with the same level of theory. Thus, smaller molecules allow deeper analyses of the specific reaction mechanisms in their hypothesized pyrolysis reaction networks.4
References
- Pushkaraj R. Patwardhhan, Justinus A. Satrio, Robert C. Brown, Brent H. Shanks, “Product distribution from fast pyrolysis of glucose-based carbohydrates,” Journal of Analytical and Applied Pyrolysis, 86 (2009) 323-330.
- Edward B. Sanders, Alan I. Goldsmith, Jeffrey I. Seeman, “A model that distinguishes the pyrolysis of D-glucose, D-fructose, and sucrose from that of cellulose. Application to the understanding of cigarette smoke formation,” Journal of Analytical and Applied Pyrolysis 66 (2003) 29-50.
- John B. Paine III, Yezdi B. Pithawalla, John D. Naworal, Charles E. Thomas Jr. “Carbohydrate pyrolysis mechanisms from isotopic labeling Part 1. The pyrolysis of glycerin: Discovery of competing fragmentation mechanisms affording acetaldehyde and formaldehyde and the implications for carbohydrate pyrolysis,” Journal of Analytical and Applied Pyrolysis 80 (2007) 297-311.
- Vikram Seshadri and Phillip R. Westmoreland, “Concerted reactions and mechanism of glucose pyrolysis and implications for cellulose kinetics,” Journal of Physical Chemistry A, 116 (2012) 11997-12013.
Contact Information
Patrick J. Fahey
Department of Chemical & Biomolecular Engineering
North Carolina State University
Box 7905
Raleigh, NC 27695-7905
Vikram Seshadri
Department of Chemical & Biomolecular Engineering
North Carolina State University
Box 7905
Raleigh, NC 27695-7905
Xinglian Geng
Department of Chemical & Biomolecular Engineering
North Carolina State University
Box 7905
Raleigh, NC 27695-7905
Phillip R. Westmoreland*
Professor, Department of Chemical & Biomolecular Engineering
Executive Director, Institute for Computational Science and Engineering
North Carolina State University
Box 7905
Raleigh, NC 27695-7905
*To whom correspondence should be addressed.