Biomass gasification is being considered as a possible technology for converting 60 million acres of Texas brush into biofuel, according to Dr Jim Ansley, Texas AgriLife Research rangeland ecologist in the US. Source: North Texas eNews
A study using an adiabatic bed gasifier to convert mesquite and redberry juniper species found in the Southern Great Plains into usable bioenergy gases was conducted at Texas A&M University in College Station.
The study found some of the basic thermal properties of these solid fuels, including chemical composition and heat values, and various heating factors affected syngas yields.
Syngas is a mixture of carbon monoxide, ethane and hydrogen that can be used as a substitute for natural gas. A solid by-product of the conversion process, tar, may also be used for fuel or other chemical products.
With limitations for growing bioenergy crops on land normally used for growing food, Ansley is looking to the vast supply of unwanted woody plants on rangelands as a possible energy source.
Mesquite and juniper can achieve standing biomass of 20 dry tons per acre. Moisture content of these species is much lower than other woody feedstocks and this contributes to greater heating value and lower costs for drying the feedstock.
The trees used in the study were multi-trunked, 10-12 feet tall with diameters ranging from 2-8 inches. Tree ring counts indicated that above ground portions of these trees were 15-35 years old.
Wood chips of different sizes were combusted within a steel column that produced a range of temperatures from 400-2000 degrees. This caused various stages of wood decomposition and syngas yield.
