【Paper】
The Effect of Garbage Separation Treatment on Municipal Waste Management
Kiyotaka Tahara*, Atsushi Inaba*, Yu Sakane** and Toshinori Kojima**
* National Institute of Advanced Industrial Science and Technology
（AIST）Research center for Life Cycle Assessment
** Department of Applied Chemistry, Seikei University
† Correspondence should be addressed to Kiyotaka Tahara:
National Institute of Advanced Industrial Science and Technology（AIST）Research center for Life Cycle Assessment
（16-1 Onogawa Tsukuba Ibaraki, 305-8569 Japan）

Abstract
Due to the fact that organic garbage with high water content decreases the low heating value of municipal waste, it is thought that this waste should be composted and/or fermented to produce methane after being separated out from other types of municipal waste. Remaining wastes should be incinerated to generate electricity in order to utilize their high heating value. In this study, CO2 emissions from the process of garbage treatment in the proposed system were first calculated. Next, CO2 emissions from the present municipal waste incineration system（with power generation and ash treatment）were compared with CO2 emissions from the proposed system. The effect of fertilizer production on the reduction of CO2 emissions was taken into consideration. The results showed that for most of the proposed system, the CO2 emissions that increased through energy consumption in the garbage treatment process were mostly compensated for with the reduction of CO2 emissions in the power generation using other municipal wastes and the fertilizer production process. By comparison to the present incineration system for municipal waste, the garbage separation strategy is thought to hold an advantage. However, in the case of the composting system distributed on a small scale, CO2 emissions increased with the use of urban gas because the first fermentation could not be compensated for with the above advantages.

Key words: CO2 emission, garbage, municipal waste, LCA