Biomass, which is a type of traditional fuel with the features of
availability and affordability, currently still ranks fourth as an
energy resource, providing approximately 14% of the world’s
energy demands [1]. In addition of the renewability of biomass
energy, it has its advantage of continuity over the intermittence of
solar energy and wind energy due to its relatively easy storage and
transportation. Biomass energy utilization can reduce human reliance
on fossil fuels. However, biomass’s low energy density and
scattered sources push up the cost of logistics (collection, transportation
and storage) and make the biomass suitable for on-site
use; biomass planting would occupy vast farmable lands which
could affect the supply and cost of food.