System efficiency and economical analysis of system for producing energy material from wooden biomass (december 2006)

The ability of wooden biomass energy conversion system to produce energy material has been analyzed on the basis of the material and energy balances. In this study, as a first step towards analyzing the production of automobile fuels, we analyzed a zero-emission type biomass energy conversion system that produces methanol and methyl formate by biomass steam-reforming with a CO/H2 ratio of ˜1/(1.1˜1.6). This system also produces ethanol, lactic acid, and propanediol from cellulose and it supplies electric power and steam to satisfy the internal requirements of the system (wood throughput capacity: 420 ton/day). Payback periods were calculated from the raw material costs of wooden biomass and the major equipment cost of the energy plant; it was found that the payback period was within 9 years. Economic analysis using IRR indicated that sawmill residue and building waste wood, which cost less than $100/ton, were feasible in the proposed system. Furthermore, the subsidy of 1/3 of the fixed cost improved IRR approximately 10 %. The effect of the feedstock composition on economics was small.