Based on the above data, CO2 emissions of CGS (electricity and/or thermal energy) and Bio — H2 fuels are shown in Fig. 5.

According to Fig. 5, the entire CO2 emissions are 16.3-65.7 g-CO2/MJ of CGS and 39.6-95.3 g — CO2/MJ of Bio-H2, respectively. Especially, in the CGS case, the specific CO2 emissions of electricity are 5.9-23.9 g-CO2/MJ, and the reduction percentages in comparison to the conventional electricity in Japan are 80.6-95.2%. In the case of Bio-H2 case, the reduction percentages against the conventional H2 production (121.3 g-CO2/MJ, Natural gas origin) are 21.4-67.3%.

CO2 emissions at the material drying and at the auxiliary power of a purification process of PSA occupy a large portion of the entire CO2 emission. Especially, the influence due to the compression power of H2 purification would be significant. In the case of Bio-H2, the amount of 35.1% to 84.4 % of the total CO2 emissions would be emitted from the auxiliary power including the power for BT operation. Also, in the case of CGS, that of 16.5% to 66.6 % would be emitted from the auxiliary power origin, even if the PSA operation is not equipped.

The deviations of CO2 emissions (the maximum value — the minimum one) due to the uncertainties on the moisture content and the transportation distance would be within 49.5 g-CO2/MJ of CGS and 55.7 g-CO2/MJ of Bio-H2, respectively.

That is, the range of collection of biomass feedstock would be extremely significant from the viewpoint of CO2 emission reduction on basis of LCA methodology.