The objective of the present study is to propose a method based on a life cycle approach for assessing direct and indirect employment effects induced by the implementation of a biomass project. The proposed method divides Japan into three regions, namely, the project spot (i.e. the region where a biomass project is actually done), the nearby region and the distant region, to estimate the increase/decrease in employment in the above three regions. A hybrid method that combines process and input-output analysis is used for estimating direct and indirect employment. As a result of applying the proposed method to a small-scale biogas project in Hokkaido, Japan, the increase in indirect employment outside the project spot was larger than the increase in direct employment in the project spot. Moreover, it was clarified that increased employment in the distant region (outside of Hokkaido) resulting from equipment maintenance/repair and fuel production can be moved to the nearby region (inside of Hokkaido) by using local businesses and a wide-range cooperation. The method proposed in the present study allows for an appropriate understanding of the employment effect of a project and a successful design and/or improvement of a project for the region and/or Japan.
Evaluation of global hydrogen demand in electricity, stationary and transportation sectors has been conducted under the assumption that CO2-free hydrogen is produced in seven regions by using a global and long-term intertemporal optimization model, GRAPE. CO2-free hydrogen was assumed to be transported to other regions. Applied CO2 constraint is 50% reduction for all regions and 80% reduction for developed regions in 2050 from the 1990 level. It has been found that under the severe CO2 constraint, approximately 800 Mtoe and 57 Mtoe of hydrogen is used in the world and in Japan in 2050, respectively. It has also been found that hydrogen demand in Japan is largely influenced by other zero emission technologies such as nuclear and CO2 capture and storage in the power sector.
The aeration rate is an important factor influencing the growth of microalgae. In this work, different aeration rates: 0.2, 0.4, 0.6, 0.8 and 1 volume per volume per minute (vvm) were applied to investigate the effect of aeration rate on Scenedesmus quadricauda (S. quadricauda) by using a column photobioreactor. The biomass concentration at early stationary phase and growth rate increased with the increasing of aeration rate, but the aeration rate above 0.6 vvm caused the decline in both growth rate and biomass concentration. The aeration rate did not have the effect on lipid content (around 17%), lipid yield has similar trend with biomass concentration. The optimum aeration rate for lipid yield was 0.6 vvm with 0.553 g L-1 of biomass concentration, 17.6 % of lipid content and 97.3 mg L-1 of lipid yield.