Biomass gasification is a well-developed
technology with the potential to convert agricultural residues to value-added products. The
availability of on-farm gasifiers that can handle low-density agricultural
wastes such as soybean residue, an underutilized feedstock, is limited. Therefore, the goal of this research was to install and assess an allothermal,
externally heated, auger gasifier capable of converting agricultural wastes to
combustible gas for on-farm grain drying. The system was used to convert soybean residues
under different reactor temperature, i.e., 700°C, 750°C, 800°C, and
850°C. The results showed
that increasing the reactor temperature from 700°C to 850°C increased the
producer gas molar fractions of H2, CO, and CH4, from 1.1% to 1.5%, from 15.0% to 23.8%, and from 5.1% to 7.7%, respectively. The higher heating value of
the producer gas reached 6.3 MJ/m3 at reactor temperature of 850°C.
Specific gas yield increased from 0.32 to 0.58 m3/kgbiomass while char and particulate yield decreased from 41.7% to 33.6% by increasing the reactor temperature
from 700°C to 850°C. Maximum carbon
sequestration achieved, in the form of biochar-carbon, was 32% of the raw
feedstock carbon. Gasification of
collectable soybean residues from 1 acre would be sufficient to dry 1132 kg of
soybean seeds (the average yield from one acre)