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In Korea, municipal solid waste (MSW) treatment is conducted by converting wastes into energy resources using the mechanical biological treatment (MBT). The small size MSW to be separated from raw MSW by mechanical treatment (MT) is generally treated by biological treatment that consists of high composition of food residue and paper and so forth. In this research, the hydrothermal treatment was applied to treat the surrogate MT residue composed of paper and/or kimchi. It was shown that the hydrothermal treatment increased the calorific value of the surrogate MT residue due to increasing fixed carbon content and decreasing oxygen content and enhanced the dehydration and drying performances of kimchi. Comparing the results of paper and kimchi samples, the calorific value of the treated product from paper was increased more effectively due to its high content of cellulose. Furthermore, the change of the calorific value before and after the hydrothermal treatment of the mixture of paper and kimchi can be well predicted by this change of paper and kimchi only. The hydrothermal treatment can be expected to effectively convert high moisture MT residue into a uniform solid fuel. [ABSTRACT FROM AUTHOR]

Featured Application: This work investigates the economic effects of the same amount of production or investment in the individual heating system and the district heating system in South Korea using an input-out analysis. When South Korea develops a new city, the government has made a preliminary decision on one of two heating systems, an individual heating system (IHS) or a district heating system (DHS). However, it is still unclear which system is desirable in terms of maximizing the national economic effect. Thus, this article aims to derive quantitative information about the economic effects of the same amount of production or investment in the two systems through an input-output (IO) analysis using the recently published 2017 IO table. More specifically, the production-inducing effects, value-added creation effects, and wage-inducing effects are systematically analyzed focusing on the IHS and DHS sectors. The results show that one dollar of production or investment in IHS or DHS causes about 1.073 and 1.388 dollars of production, about 0.228 and 0.658 dollars of value-added, and about 0.051 and 0.108 dollars in wages, respectively, throughout the national economy. Overall, the economic effects of the DHS sector are greater than those of the IHS sector. That is, when the same amount of investment or production is made in the two sectors, DHS produces more economic effects than IHS. [ABSTRACT FROM AUTHOR]

In South Korea, heating degree-days (HDD) and cooling degree-days (CDD) have been widely used as climatic indicators for the assessment of the impact of climate change, but arbitrary or customary base temperatures have been used for calculation of HDD and CDD. The purpose of this study is to determine real base temperatures to accurately calculate HDD and CDD for South Korea, using monthly electric energy consumption and mean temperature data from 2001 to 2010. The results reveal that the regional electricity demand generally depends on air temperature in a V-shaped curve in urban settings but in an L-shaped curve in rural settings, indicating that the sensitivity of the electricity demand to the temperature change is affected by the size of cities. The South Korean regional base temperatures, defined by a piecewise linear regression method, range from 14.7° to 19.4°C. These results suggest that the assessment of climate change impacts on the energy sector in South Korea should be carried out on a regional scale. [ABSTRACT FROM AUTHOR]

Most apartment buildings in South Korea use internal insulation systems to reduce building energy demand. However, thermal bridges such as balcony slabs in apartment buildings still lead to significant heat loss in winter, because the internal insulation system is not continuous in the balcony slab structure, and floor heating systems are commonly used in residential buildings. Therefore, this study investigates two types of thermal break elements, namely thermal break (TB) and thermal break-fiber glass reinforced polymer (TB-GFRP), to improve the thermal resistance of a balcony thermal bridge. To understand the effects of balcony thermal bridges with and without thermal break elements, the linear thermal transmittances of different balcony thermal bridges were analyzed using Physibel simulations. Then, the heating demand of a model apartment under varying thermal bridge conditions was evaluated using TRNSYS simulations. To understand the effect of insulation systems on heat loss through a balcony thermal bridge, apartments with internal and external insulation systems were studied. Whether the apartment was heating was also considered in the thermal transmittance analysis. Thus, the linear thermal transmittance of the thermal bridges with thermal break elements was reduced by more than 60%, and the heating energy demands were reduced by more than 8%. [ABSTRACT FROM AUTHOR]