So far, the biomass Life Cycle Assessment (LCA) analyses, in which the pre-processing process of chipping, transportation and drying of biomass materials are included, and in which the energy conversion process of a production energy of electricity and/or heat through an integrated gasification combined cycle (IGCC) power system or a co-generation system (CGS) is included, were analysed (Dowaki et al. 2002, Dowaki et al. 2003).

In this section, we describe on the BT-CGS and the production system of Bio-H2. At the beginning, in this section, we defined the system boundary of the biomass LCA. A target is to estimate a life cycle inventory (CO2 emissions and/or energy intensities) of the entire system with a biomass gasification system and/or a purification one. That is, we refer to the environmentally friendly system, such as the biomass energy system, considering CO2 emissions and/or energy intensities from the entire system based on LCA methodology.

In the case of BT-CGS or Bio-H2, due to the shortage of reaction heat in the furnace or the larger auxiliary power output of PSA, the specific CO2 emission might be affected. That is, the process design and the energy analysis on basis of the process simulation would be extremely significant.