Fundamental Understandings of Fast-Hydropyrolysis to Reduce Bio-Oil Complexity

catalytic HDO reactor system Thermal treatments deconstruct biomass into an array of liquid and gaseous products along with residual char. However, bio-oil resulting from pyrolysis has an extremely high oxygen content (35 to 40% by weight), is unstable over time, and its energy content is barely half that of petroleum. Efforts to upgrade bio-oils by hydrodeoxygenation (HDO) catalysis are complicated by the presence of a very large number of unstable compounds. C3Bio uses a suite of hydropyrolysis and catalytic upgrading reactors coupled with in-house, cutting-edge mass-spectrometric analyses to develop a detailed understanding of how fast-hydropyrolysis and in situ HDO in the presence of appropriate catalyst(s) can lead to drop-in hydrocarbon fuels. On a systems engineering level, this maximizes carbon efficiency while minimizing the hydrogen inputs necessary for deoxygenation.

A partnership of chemical engineers and chemists led to the development of a lab-scale, high-pressure, continuous-flow, fast-hydropyrolysis and vapor-phase catalytic HDO reactor system (Provisional Patent Application 61/527051), new analytical methods (Amundson et al. 2012, Borton et al. 2013, Eismin et al 2012, Gao et al. 2012, Gqamana et al. 2012) and a novel tandem mass spectrometer (TWIN; International Patent Application PCT/US2012/056909) with exceptional versatility to improve the fundamental understanding of fast-pyrolysis.

It was generally believed that pyrolytic products such as levoglucosan arise via glycosidic bond cleavage, which have been proposed to react further to produce light oxygenates. Using carbon-13 labeling, we demonstrated that C1-C3 oxygenates are formed through alternative fragmentation pathways, such as decomposition of the reducing end of cellobiose. The kinetic barriers for these pathways have been calculated by quantum chemical methods and are comparable with barrier values reported in the literature (Degenstein et al. in review).

Mass spectraBy capturing the very first reaction products of fast-hydropyrolysis of biomass, we can reduce the complexity of bio-oils from thousands of molecular species to just a few, making the discovery and design of HDO catalysts feasible, and enabling a paradigm-shifting 100% deoxygenation to directly produce fuel molecules from cellulose (Venkatakrishnan et al. 2014).
Mass spectra showing that the primary fast pyrolysis products of cellotriosan (top) and cellulose (bottom) ionized by APCI with NH4OH are remarkably simple and similar. Same products are indicated with dotted lines.


Amundson LM, Gallardo VA, Vinueza NR, Owen BC, Reece JN, Habicht SC, Fu M, Shea MRC, Mossman AB, Kenttämaa HI (2012) Identification and counting of oxygen functionalities and alkyl groups of aromatic analytes in mixtures by positive-mode atmospheric pressure chemical ionization tandem mass spectrometry coupled with high-performance liquid chromatography. Energy Fuels 26:2975-2989.

Borton DJ, Amundson LM, Hurt MR, Dow A, Madden JT, Simpson GJ, Kenttämaa HI (2013) Development of a high-throughput laser-induced acoustic desorption probe and raster sampling for laser-induced acoustic desorption/atomospheric pressure chemical ionization. Anal. Chem. 85:5720-5726.

Degenstein JC, M Hurt, P Murria, M Easton,  L Yang, J Riedeman, JJ Nash, R Agrawal, WN Delgass, FH Ribeiro, HI Kenttämaa. Fast-pyrolysis of small dehydrated glucose oligomers yield the same primary product distribution as cellulose. Energy and Environmental Science (in review)

Eismin RJ, Fu M, Yem S, Widjaja F, Kenttӓmaa HI (2012) Identification of epoxide functionalities in protonated monofunctional analytes by using ion-molecule reactions and collision-activated dissociation in different ion trap tandem mass spectrometers. J. Am. Soc. Mass Spectrom. 23:12-22.

Gao J, Owen BC, Borton DJ, Jin Z, Kenttamaa HI (2012) HPLC/APCI mass spectrometry of saturated and unsaturated hydrocarbons by using hydrocarbon solvents as the APCI reagent and HPLC mobile phase. J. Am. Soc. Mass Spectrom. 23:816-822.

Gqamana PP, Duan P, Fu M, Gallardo V, Kenttamaa HI (2012) A novel chemical ionization reagent ion for organic analytes: The aquachloromanganese (II) cation [ClMn(H2O+]. Rapid Commun, Mass Spectrom. 26:940-942.

Venkatakrishnan VK, Degenstein JC, Smeltz AD, Delgass WN, Agrawal R, Ribeiro FH (2014) High pressure fast-pyrolysis, fast-hydropyrolysis and catalytic hydrodeoxygenation of cellulose: Production of liquid fuel from biomass. Green Chem. 16:792-802.

Provisional Patent Application 61/527,051. Ribeiro, F. H.; Agrawal, R.; Delglass, W. N. and Gawecki, P. Production of Molecules in the Fuel Range by Selective Tailoring of Biomass Fast Pyrolysis. (2011)

International Patent Application PCT/US2012/056909. Owen, B. C.; Kenttämaa, H. I. Differentially Pumped Dual Linear Quadrupole Ion Trap Mass Spectrometer (TWIN). (2012)