ARS | Publication request: BIO-OIL FROM GUAYULE BAGASSE

Submitted to: Meeting Abstract
Publication Type: Abstract
Publication Acceptance Date: July 16, 2008
Publication Date: September 7, 2008
Citation: Mcmahan, C.M., Mullen, C.A., Boateng, A.A., Goldberg, N.M., Hicks, K.B., Cornish, K., Whalen, M.C. 2008. Bio-oil from guayule bagasse. Association for the Advancement of Industrial Crops 2008 Annual Meeting, September 7-11, College Station, TX.

Interpretive Summary: Guayule (Parthenium argentatum), a woody desert shrub indigenous to the southwestern USA, produces high molecular weight cis-1,4-polyisoprene, and has entered the commercial arena as an alternative material for the manufacture of medical devices safe for people suffering from Type I IgE-mediated Hevea latex allergies. Cultivation of guayule for latex production provides the favorable economics to support commercialization; however, use of crop residues to produce bio-energy could have a major impact on sustainability of this new industrial crop. Latex extraction leaves ~90% of the crop biomass as a finely-divided, free flowing feedstock suitable for conversion to biofuels. Our collaborative research is exploring several avenues to bio-energy, including biochemical and thermochemical conversion. Thermochemical conversion produces bioenergy while consuming the entire plant, significantly improving the value proposition for profitable and sustainable growth of domestic rubber in the USA.

Technical Abstract: Guayule, Parthenium argentatum, has recently been commercialized as a domestic source of rubber, primarily sold as latex for circum-allergenic medical applications. Latex extraction leaves ~90% of the crop biomass as a finely-divided, free flowing feedstock suitable for conversion to biofuels. Fast pyrolysis can convert lignocellulosic biomass into pyrolysis liquids (bio-oils) that can be used as boiler fuel or converted into liquid transportation fuels. Guayule bagasse and whole shrub material was successfully converted into bio-oil, charcoal, and non-condensable gases by fast pyrolysis at ~ 500°C in a bench-scale fluidized bed reactor. Over a sand medium, bio-oil was produced in the 60% yield range. Bio-oils from guayule pyrolysis had energy content higher than that of typical fast pyrolysis oil, about 30 MJ/kg, 75% the value of heavy fuel oil. Compositional analysis of feedstocks and of the bio-oil suggest guayule is a very attractive feedstock for fast pyrolysis and subsequent conversion processes. Thermochemical conversion produces bioenergy while consuming the entire plant, significantly improving the value proposition for profitable and sustainable growth of domestic rubber in the USA.