Due to limitations of land area for growing biomass for large biofuel
conversion facilities in the upper Midwest and the high cost of
feedstock transportation in regions that have lower biomass
density, it would be beneficial to develop a small scale, less
expensive, and localized conversion facilities that require less
feedstock and have lower feedstock transportation costs. Woody
species (brush) growing on semi-arid non-cultivated lands (rangelands),
such as mesquite (Prosopis glandulosa) and juniper
(Juniperus spp.), may have potential as bioenergy feedstock. These
species occur on over 20 million ha in Texas alone and can achieve
standing biomass of 50 dry metric tons ha1 [4]. They are perceived
as noxious plants that are detrimental to rangeland ecosystems and
their removal and use as a bioenergy feedstock would result in
improvements in ecosystem quality as well as services from these
lands such as increased income from livestock grazing [5]. These
species may be ideal candidates to produce syngas and bio-oil in
small scale gasification units that can be located near the fuel
source to reduce feedstock transport costs.