Variability in pyrolysis product yield from novel shrub willow genotypes

Authors: Serapiglia, Michelle; Mullen, Charles; SMART, LAWRENCE - Cornell University; Boateng, Akwasi

Submitted to: Global Change Biology Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2014
Publication Date: 12/4/2014
Publication URL: http://handle.nal.usda.gov/10113/60177
Citation: Serapiglia, M., Mullen, C.A., Smart, L.B., Boateng, A.A. 2014. Variability in pyrolysis product yield from novel shrub willow genotypes. Global Change Biology Bioenergy. 72:74-84.

Interpretive Summary: Fast pyrolysis, is a process that involves rapid heating to about 500 degrees C in the absence of oxygen. Fast pyrolysis is becoming an attractive conversion option for the production of biofuels, due to the potential for directly producing hydrocarbon fuels seamlessly compatible with petroleum products (drop-in fuels). Dedicated bioenergy crops, like perennial grasses and short-rotation woody crops, are excellent sources of biomass for conversion technologies like fast pyrolysis. In order to aid in the advancement of fast pyrolysis conversion and to identify appropriate feedstock crops, novel cultivars of shrub willow recently bred for high yield were evaluated for pyrolysis product yields. The main goal of this study was to understand how variations in biomass composition impact pyrolysis conversion efficiency and pyrolysis oil (bio-oil) quality. Our results demonstrate that variation in pyrolysis product yield can be related directly back to the compositional differences observed in the various genotypes of shrub willow biomass. Continued manipulation of the biomass composition through breeding will produce new cultivars ideal for bio-oil production, ultimately lowering the cost associated with producing and refining bio-oil. These results are important to both bioenergy crop breeders and those involved in biofuels synthesis via bio-oil production and refining.

Technical Abstract: Fast pyrolysis is becoming a more attractive conversion option for the production of biofuels, due to the potential for directly producing hydrocarbon fuels seamlessly compatible with petroleum products (drop-in fuels). Dedicated bioenergy crops, like perennial grasses and short-rotation woody crops, will be among the major sources of biomass for conversion technologies like fast pyrolysis. In order to aid in the advancement of fast pyrolysis conversion and to identify appropriate feedstock crops, novel genotypes of shrub willow recently bred for high yield were evaluated for pyrolysis product yield using pyrolysis-gas chromatography-mass spectroscopy (py-GC/MS). The main goal of this study was to understand how variations in biomass composition impact pyrolysis conversion efficiency and pyrolysis oil (bio-oil) quality. The results of the py-GC/MS analysis showed significant differences in products from both non-catalytic and catalytic pyrolysis carried out over zeolite catalyst (HZSM-5), which were correlated with differences in biomass composition. For non-catalytic conversion, the most significant relationships were between the syringyl:guaiacyl ratio in the biomass and monolignol products in the bio-oil. In addition, cellulose content was correlated with levoglucosan yields in the bio-oil. The production of phenols, guaiacols, and syringols were largely independent of total lignin content, but were strongly related to the syringyl:guaiacyl ratio. Catalytic pyrolysis of willow genotypes with low ash content and high cellulose content produced more liquid bio-oil products and higher levels of deoxygenated aromatics. These results demonstrate that it is possible to breed for improvements in biomass compositional traits that can ultimately lead to improvements in bio-oil quality and production yield.