In planning biomass-based power generation, planners should take into account the different stakeholders along the biomass supply chains, i.e. biomass resources suppliers, transportation, conversion and electricity suppliers etc. The different participants have different concerns and priorities about environmental, social and economical sides of establishing the biomass energy systems, e.g. electricity production from forestry residues. To help the planners fulfill such concerns a study that addresses the different possible scenarios of biomass supply chains and estimating their impacts is needed. Up to our best knowledge, no study has been reported that takes into consideration the different factors affecting the planning process of biomass supply chain systems for the Japanese case. In this context, our study has been developed as a first step toward integrating the planning parameters and their estimation in a single entity. In this paper, we propose a novel framework for estimating cost, CO2 emissions and labors of possible forestry residues supply-chains scenarios. We call our new framework a Cost-Emission-Labor Model (CELM). The proposed CELM approach provides the biomass planners as well as stakeholders with an integrated simulation tool helping them in their decision-making process. A sensitivity analysis was made, based on a given case study, for the proposed CELM. It is found sensitive to efficiency and capacity of the conversion plant when calculating the cost. While for emission calculations, the CELM is also influenced much by conversion plant efficiency, bulk density and CH4 emissions from storage.
Reduction of CO2 emission is one of the most important tasks for the construction industries in many countries, since they cover high ratio in the total emission. On the other hand, reduction of waste emission is another important task for the construction industries in highly populated countries, such as Japan, because of the depletion of landfill sites. Among the whole construction industries, concrete is the most widely and long-term used material. Some of the researchers has qualitatively pointed out that the amount of demolished concrete, especially those used in 1970s, is expected to cause a severe damage on the depletion of landfill sites. To solve the problem, there have been many technical and social proposals. In this paper, to find an optimal material balance and social circumstances for the proposal, we have firstly developed a resource-flow simulation system using the concept of Multi-Agent-System. Secondly, using the system, comparative case studies have been made to examine two typical and prospective proposals; high quality recycled aggregate, and enlargement of building lifetime. The studies have shown that even in the idealistic situation where recycled aggregate is aggressively used despite of its high price, the predicted amount of demolished concrete is overwhelming. The studies have also shown that in the idealistic situation where building lifetime is unrealistically long, the amount of demolished concrete can be reduce on some level.
Yokohama City started to collect and recycle waste plastic containers and packaging from all households (about 1.5 million households) in April 2005. At present, the collected waste plastics are chemically recycled into reducing agents for blast furnace and ammonia, although they had been burned together with other household wastes in the past. The present study evaluates environmental impacts of recycling the waste plastics instead of incineration in Yokohama City. This study found that waste plastics recycling greatly decreases the overall emissions of carbon dioxide (CO2) and solid waste as compared with the incineration case. While the recycling increases emissions from additional recycling-related processes, it decreases the emissions from the normal processes of coke and ammonia production. The former increase is almost the same as, or a little more than, the latter decrease. However, since the emissions from incineration factories of the city in the recycling case are much less than those in the incineration case, the recycling can reduce the overall CO2 and solid waste emissions considerably. In contrast, the overall emissions of sulfur oxides and nitrogen oxides in the recycling case were evaluated to be higher than those in the incineration case. The city has superior waste incineration factories, from which the emissions caused by incineration of waste plastics are extremely low. Thus, even if the waste plastics are recycled instead of incineration, the emissions from their incineration factories change only little. On the other hand, the emissions from recycling and power generation processes increase in the recycling case. As a result, the recycling does not reduce the overall emissions of sulfur oxides and nitrogen oxides.
In most case of materials inventory studies, mining activities are excluded from their system boundaries because of the difficulty in data acquisition from foreign mine sites especially for Japan. We have developed a database to estimate CO2 emission level on the mining and mineral processing process from fundamental information of the concerned mine by rearranging CES (Cost Estimating System, USBM). This database called MLED (Mining LCI Estimating Database) provides standard CO2 emission level for each production style on mining activities. In this study, CO2 emission level of copper mines from which Japanese smelters import ore concentrates into Japan are estimated by using the MLED. Eleven copper mines selected from availability of mine site data cover 84% of total imported concentrates. Adding inventories of sea transportation and smelting processes to mine development process, total CO2 emission level for copper ingot produced in Japan are calculated. As a result, weighted average of CO2 emission is estimated at 2.38 kg-CO2/kg-Cu. Emission share of mining and mineral processing processes for each mine is indicated around 50~70%, which implies the importance of mining activities for inventory of upper stream products.
This study attempts to examine the possible merits of introducing a new LRT (Light Rail Transit) system by specifically comparing the environmental impacts throughout its whole life cycle to those of BRT (Bus Rapid Transit). Emissions of carbon dioxide, sulfur oxides and nitrogen oxides are respectively estimated and integrated to monetary index using LIME. Six alternative scenarios were determined considering the ripple effects on traffic volume and travel speed of passenger car on the road. The results demonstrate that life cycle environmental load of LRT is lower than that of BRT. Besides, the reduction in passenger car trip demand is important in the cases of both changing an existing bus system to either BRT or LRT, and also an existing classical tramline to LRT.
How should we alter consumption towards more sustainable consumption patterns if we do not know the effects of such alterations? Our attempt was to develop an indicator to evaluate sustainable consumption activities. Combining an empirical panel analysis of the Japanese Panel Survey of Consumers (JPSC) data, on shifts in consumption patterns, and calculations of consumption-based lifecycle CO2 emissions, allowed for the estimating of correlations between new life events and shifts in consumption patterns, and hence the subsequent CO2 emissions from a household. Due to a lack of variables in the data used, nine life events, instead of sustainable consumption activities, were chosen to analyze the impacts to consumption patterns. Unlike cross-sectional data, the use of individual panel data was particularly useful to observe clear differences of mean values in consumption patterns between groups classified according to detailed attributes. Increasing numbers of adult family members and increasing household income were found to be possible major factors that induce CO2 emissions through household living expenditure. Altering physical places of living was a factor that induces CO2 emissions through changes to possession of durable consumer goods. The life events that we chose for analysis are unavoidable by consumers as they are important parts of human’s lives. Therefore, our evaluation tool is not to suggest which life events should be avoided due to high CO2 emissions, but rather provides decision-makers with the factors that must be considered in the process of promoting new environmental activities that have the potential of leading to sustainable consumption.
Although the matrix method in LCA has been proposed for many years, there are still some unsolved problems, which result in that matrix method is rarely used in the practical LCA case studies. The conventional approach of the matrix method is somewhat complicated, and it is inconvenient to use, especially to the LCA practitioners with few LCA experience and knowledge. In this paper, a new practical approach for matrix composition in LCI is proposed, and the algorithm of the matrix method is generalized. In the improved matrix method, the necessary matrices can be composed easily by specifying some process data. Moreover, by the improved matrix method, the operations from LCI analysis to sensitivity and uncertainty analysis are connected to facilitate the LCA analysis. After that, in this paper, a general-purpose LCA system, which adopts the generalized matrix method in LCI and is established on worksheet, is introduced. In this system, the necessary matrices are composed automatically, and the operations are fully based on matrix algebra. Finally, using an example of LCA case study, the practicability of the improved matrix method and the LCA system is examined.
Data for LCI analysis associated with seaborne transportation are very limited although a great quantity of natural and energy resources are imported and various kinds of manufactured products are exported by oceangoing cargo-ships in Japan. Therefore based on logbooks of typical oceangoing cargo-ships, fuel oil consumptions and gaseous exhaust emissions per unit transportation were studied. The studied ships comprise of eight ships, which are categorized in five types of ships, namely, two oil tankers, two bulk carriers, two container ships with different sizes, a pure car carrier and an LNG carrier. Averaged fuel oil consumptions per unit transportation were compared and evaluated with the ones derived from nominal data. Averaged data of navigation were provided such as distances, service speeds, cargo loading factors, and averaged load factors of main engines, diesel generators and auxiliary boilers. The gaseous exhaust emissions per unit transportation derived from the averaged fuel oil consumption include carbon dioxide, sulfur oxides and nitride oxides.
With becoming widespread of Information Technology (IT), increase of resource and energy consumption has been anxious which caused by manufacturing or using Personal Computer (PC), Server and so on. Then, SI-LCA (System Integration -LCA) which is an environmental-impact-assessment technique and a program was developed for the purpose of evaluating quantitatively the environmental load of a SI product which is a kind of IT. In this definition, SI product is Information Products and Services. In this technique, the both a hardware product and a software product, which constitute a SI product are objects for evaluation. And so, a life cycle of a SI product was defined newly, which has a total of ten stages, as a system boundary. For instance, a “design / development” of a software product was added to the general life cycle of a hardware product. Furthermore, a method about calculation of CO2 emissions for a software product was developed. In this method, that is computed from CO2 emissions exhausted from office and the ratio of design / development expense for a SI product to the total sales. This technique was applied to the electronic forms system with the data management by the server, and reference / search function by PC which was introduced into the supermarket. As a result of comparing with the management by the conventional printed matter, about 82% of CO2 emissions reduction effect was achieved.
The study examined the volume of Life Cycle CO2 emission from Japanese, Western and Chinese dishes that are daily consumed by the Japanese, especially it compared the volume of CO2 emission depending upon a different cooking process. The results of the analysis revealed as follows. 1. CO2 emission is greatly influenced by the purchase of in-season product and the use of food ingredients produced in nearby prefecture. 2. It is clear that the size of cooking pot, adjustment of cooking temperature, whether or not to use a pot cover while cooking could affect on the reduction of CO2 emission. It is necessary to devise suitable cooking process for CO2 emission reduction because CO2 emission could be increased depending on certain cooking process such as boiled or steamed. The volume of CO2 discharged from cooking by one household is limited; however it becomes larger when taking the total number of Japanese households into account. (49,530,000 according to 2005 census) It is evident that every household should concern on CO2 emission from cooking since it could reduce the environmental burdens.