Objective. Coal has been the important primary energy in China. Coal-fired power generation stays on the significant position due to the rich coal resources. The coal flow depends on the railways and coastal shipping because energy producing and consuming regions are geographically distinct. Thus, it is necessary to reduce CO₂ emission not only in generating electricity but also in coal transportation. This study is aimed to estimate CO₂ emission reduction potential in coal transportation in China. Directions of coal transportation were evaluated using a geographic information system (GIS). In this study, a liner programming (LP) analysis model is used for the optimization of coal transportation for minimizing its CO₂ emission and costs. We have also evaluated in the case of ultra super critical power plant (USC) as advanced thermal power generation technology.
Results and Discussion. From the result of current flow, the coal transportation from the north of the inland which is a coal production region to the east of the coastal place that is a coal consuming area is supposed to be a mainstream. On the other hand, the south area that coal production is poor has a big consumption in Guangdong. Therefore, the coal has been carried from all areas except the northeast to the south area by coast transportation. South-eastern coastal regions such as Zhejiang and Guangdong have high dependency on the coastal transportation show twice higher CO₂ emission in coal transportation than other regions. In the case of the optimization with the restriction on coastal transportation to reduce CO₂ emission, the amount of emissions in coal transportation becomes smaller and gets to be minimum amount of 12.3 Mt-CO₂ under the CO₂ emission minimization analysis. Moreover, replacing USC for existing conventional thermal power plants makes the CO₂ emission reductions in transportation much smaller amount, 8.1 Mt-CO₂, because of not just shortening transportation distance and shift in transportation but decreasing amount of transportation due to less coal consumption of USC.
Conclusions. From the results obtained by minimizing CO₂ emission in transportation, the amount of CO₂ emission reductions is 6.0 Mt-CO₂ from the current coal transportation. The amount of CO₂ emission reductions in transportation is estimated to be higher, 10.2 Mt-CO₂, in case that USC is replaced for existing conventional thermal power plant with less coal consumption.

抄録全体を表示

This paper presents a method for network reliability improvement of the road network of Mianyang City after the 2008 Sichuan earthquake in China. In order to improve the network reliability of Mianyang traffic system, the damage of the traffic system in this earthquake and the problem on the traffic system is stated firstly. Secondly, the present condition of disaster prevention planning in China is introduced. Since it is very difficult to obtain the exact values for the set ofthe link reliability of Mianyang road network after this earthquake, an assumption for calculating link reliability is proposed. Based on this set of link reliability, road network reliability is improved using the Importance Analysis. At the sametime, cost-benefit analysis is calculated with two cost-reliability functions.

抄録全体を表示