On account of the atmospheric greenhouse effect, environmental pollution and rapid shortage of fossil fuels encountered currently, the interest in developing renewable energy has received a considerable deal of attention for years. To date, renewable energies which are being developed include solar, wind, geothermal, hydroelectric, marine and biomass energies. Among these renewable energies, biomass energy or bioenergy is the largest and the most important one in that it has been employed worldwide, including in underdeveloped, developing and developed countries.