Objective. The objective of this research is to perform potential evaluations of the biomass energy of all municipalities from Japan by using the same methodology. After comparing with other renewable energy, it aims to grasp the use of aptitude, according to geographic division. The calculation of the annual amount of potential evaluations was considered as the year 2010 or the most recent year, and it was calculated to be 1,711 municipalities as of 2010. Results and Conclusions. Out of all the renewable energy, heat usage of the biomass of an agricultural production system has the 2nd largest amount of potential and the biomass of a forest-product system has the 4th largest amount of potential, which is greater than sunlight. Also, if the field of cost is disregarded, it is required to promote exploitation of energy of the biomass in a country’s policy when controlling fossil fuel and nuclear power plants. Moreover, if assumed that the introductory cost is proportional to the amount of potential per area, the local government should promote more introductions and a flat-ground agricultural area in the municipalities belonging to 6th area, which is Okinawa Prefecture. However, since the forest area has a high potential in large cities and in municipalities of Tokyo, it should promote policies even in metropolis areas.
The objective of this commentary is to review the researches and/or methodologies for the estimation of biomass utilization at rural area. The purpose of the estimation is divided to the business of one stakeholder, the businesses of several stakeholders, the finding resource/conversion and consensus forming, the energy-economic model, and the ripple effect using Input/Output tables. Recently, the estimation of the effect for the policy purpose in Biomass Nippon Strategy is required. The estimation methodology should be developed for the several policy items.
Appropriate and effective use of waste biomass is anticipated because it is estimated that waste biomass accounts for a maximum ratio in biomass of Japan. Three salient issues related to the LCA of waste biomass use are presented herein: system boundary, uncertainty, and impact assessment. First, renewable resource collection and waste landfills are specifically addressed as issues in related to the boundary separating technological and nature systems. Forests and forestry should be included in evaluation of waste wood recycling; and attention must be devoted to the period of environmental impact when evaluating waste landfills. Regarding the boundary surrounding waste biomass use systems, selection of processes that would be replaced by the use of waste biomass is important. As an issue related to boundaries when comparing various recycling systems, some methods of system expansion to establish the same functional units are presented. Classification of recycling by association with existing industries is also presented in conjunction with system boundaries. Second, in conjunction with uncertainty, factors of uncertainty generally related with LCA, their specific examples, and coping methods for those factors are explained. As uncertainty factors in the LCA of the waste biomass use, we present the maturity of recycling technologies, variation of the amount of energy and waste composition, and preparation of databases for venous industries. As coping methods applied to those factors, acquisition of more data, adequate classification of technologies, presentation of the range of results, and clarification of uncertainty factors through discussion among the donors and recipients of LCA information are suggested. Furthermore, regarding impact assessment, we introduce existing methodologies and research and development trends and describe that impact categories at the midpoint and endpoint are applied in Japan and Europe, respectively, in LCA of waste management. As impacts related to waste biomass use, regional water pollution by discharge to the natural environment and inappropriate application of fertilizer to farmland, NIMBY problems related to facility location, and changes in bio-diversity by agriculture and forestry are considered. Finally, we describe the conduct of activities parallel to LCA and use of LCA results for planning waste biomass use.
Human beings have dramatically converted forest land to agricultural field in the past three century. Currently, technological innovation to produce biofuel from plant is wondered as a new land use pressure. This paper reviewed several studies which evaluated biomass production including the impact of land use change. Life cycle greenhouse gas emission by biomass production has been studied by considering direct and indirect land use change. In addition, land use change avoidance scenario and comparing with afforestation also has been discussed. Currently, climate regulation services of biomass production were arisen to discuss in some studies. Further study is needed to evaluate the several aspects of ecosystem services about land use change by biomass production.
Conservation of biodiversity is a major global issue. We are highly dependent on ecosystem services which are sustained by biodiversity. The objective of this review is to examine potential effects of biomass production to soil ecosystems. Terrestrial primary production is supported by the activities of soil organisms. Not only soil microorganisms, but also soil animals are important key players on promoting nutrient cycling in soil. Irrespective to crop species, soil disturbance, especially tillage is the main driver of soil organisms. Earthworms are important organism because they numerically dominate in biomass in temperate and tropical grasslands and forests where agricultural biomass production will be expected. Conservation of soil biodiversity is essential for sustainable production of biomass. Adoption of perennial crops (e.g. Miscanthus x giganteus, willows) is better option to maintain soil biodiversity compared to annual crops, because less frequent cultivation and low input of nutrients are possible as land management in the perennial crops.
It is generally acknowledged that biomass energy can make a significant contribution to environmental improvement, energy supply diversity from fossil fuels and socio-economic development goals, both in the developing and developed world. On the other hand, there is also a widespread recognition that biomass energy must be produced and used in a sustainable way, considering all the positive and negative effects from environmental, economic and social pillars of sustainability. This article overviews the state-of-the-art worldwide trend related to biomass energy sustainability.
Objective. Life cycle assessment（LCA）and decision analysis were compared with each other, in order to clarify the effectiveness of decision support methodologies for establishing sustainable society based on biomass utilization. First, conjoint analysis applied to life cycle impact assessment（LCIA）and multi-attribute value theory（MAVT）in decision analysis were compared to distinguish the differences in weighting. Second, conjoint analysis in LCIA and the group decision support technique（decision conferencing）were compared to find the dissimilarities in approaches to multiple participant decision making. Results and Discussion. Six differences were identified between conjoint analysis in LCA and MAVT in decision analysis; they include preference models, existence of decision problems, owners of preferences, approaches to preferences, timing to derive preferences, and the distinction between individual and group decisions. In addition, six differences were revealed between conjoint analysis and decision conferencing; fundamental approaches, approaches to weighting, the method to collect/construct preferences, existence of decision support techniques, existence of facilitators, and the size of organizations. These results indicate that there are fundamental differences between the derivation of a single integrated indicator in LCA and decision support based on preference construction. Conclusions. Preference construction will play an important role in supporting decisions to establish sustainable society based on biomass utilization. Further studies are needed in this direction.
Objective. In hot spring areas, the water is generally heated by heavy oil boilers. However, substantial CO2 is emitted in the heating process, and the process is always affected strongly by oil prices. The Nagareyama Hot Spring, which is owned by the Hokkaido Railway Company, has recently introduced a waste oil boiler that is fueled by lubricating oil discarded by the railway company. Regarding a hotel with hot spring, used bath water is usually thrown away to the river and extra heat generated from a machine room is usually released to the outside. Given the current situations, we considered 2 possibilities: (1) using waste oil in place of heavy oil in Nagareyama Hot Spring, and (2) utilizing wasted bath water and released heat from the machine room for warming greenhouses in winter in Yubari Hot Spring. These modifications were designed to minimize the environmental burdens as represented by CO2 emissions and economic costs. The potential CO2 reduction was evaluated quantitatively by using a method of Life Cycle Assessment (LCA). Results and Discussion. CO2 emission was reduced by 94.1 t-CO2 annually by using waste oil in place of heavy oil at the Nagareyama Hot Spring. The replacement of a heavy oil boiler with a waste oil boiler also contributed to reduce the annual running cost by 141,000 yen. By utilizing the heat of the used bath water in the Yubari Hot Spring to improve asparagus production in the greenhouses in winter, it was estimated that the annual CO2 emission is reduced by 7.26 t-CO2. However, the running cost was predicted to be 939,000 yen higher than in the present system. Conclusions. The replacement of the heavy oil boiler with the waste oil boiler was expected to reduce both CO2 emissions and the running cost. In the case of the heat-use of old bath water, it was effective in terms of the reduction of CO2 emission. However, economic benefits were not expected because of the high price for installing a new equipment to transport the hot water into the greenhouses. Introduction of further carbon pricing such as a carbon tax and carbon credits is necessary to promote these alternative energy systems throughout local communities.
Objective. We have developed the “Methane Fermentation System with Hyper Thermal Solubilization (Methane Fermentation System – H.T.S)” that consists of an 80℃ solubilization tank and a 53℃ methane fermentation tank. Organic matter (sludge) is solubilized by a specific microorganism, Anoxybacillus beppuensis MU3, which produces thermophilic protease. We isolated this microorganism from Beppu hot spring located in the Kyushu Island of Japan. The system can produce 6,500 L/day biogas from 0.5 m3/day sewage sludge (65.7% digestibility in VSS equivalent). It generates approximately 2-fold higher biogas than the general single-tank methane fermentation system and seems more environmentally friendly, although it requires relatively more resources (e.g., pumps, electricity, and tubes) for its operations. This study, therefore, comparatively evaluated the environmental impacts of both these systems by LCA method. Results and Discussion. The Methane Fermentation System – H.T.S requires more propane gas than the single-tank methane fermentation system to maintain the temperature of the solubilization tank at 80℃; thus, the environmental impact of this system on fuel consumption increases. Therefore, the results of the Environmental Impact Assessment have shown that the Methane Fermentation System – H.T.S has a more significant impact on human health and social assets than the single-tank methane fermentation system. Similar results were obtained with regard to the single index. On the other hand, the Methane Fermentation System – H.T.S had a smaller impact on biodiversity, whereas both systems showed nearly the same degree of impact on primary production, as the impact on fuel consumption was lesser than that on biodiversity and primary production. Furthermore, it was observed that the reduced use of thermal energy generated by burning the biogas (methane gas) produced, for keeping the solubilization and fermentation tanks warm, could significantly reduce the consumption of propane gas and, consequently, the impact on human health, social assets and single index. Conclusion. From the above results, it can be concluded that although the Methane Fermentation System – H.T.S can generate more biogas than the single-tank methane fermentation system, efforts must be made to reduce the propane gas consumption in order to reduce the environmental impact of such biogas production.