The results of the
preliminary methodology used in this work are presented in Table 1 and further discussed.
The calculated total annual energy yield for the three conversion processes
considered was 63.648 kWh/year of thermal energy, 50.971 Nm3/year
of syngas and 7.843,773 Nm3/year of biogas. Direct combustion and
gasification of pig manure would account for about 13% of thermal energy needs
of the farm, with the added benefit of electricity production for the case of
gasification (6% of total demand). Anaerobic digestion has the highest
potential and constitutes the best option for on farm energy production.
The calculated potentials clearly demonstrate that energy production from pig manure can have a significant impact on the energy budget at a farm level in Portugal.