The aim of this project was to explore the potential of the torrefaction treatment for upgrading sewage sludge into valuable product. An ancillary investigation on the cold fluidization and the behavior of sewage sludge was analyzed. The effects of the main torrefaction variables, temperature and residence time, on the performance parameters such as fixed carbon, calorific value; molar ratios, ultimate and proximate analysis, chemical exergy etc. were investigated for torrefied sewage sludge. Results for both the reactors showed that the thermochemical transformations that sewage sludge underwent, as a results of the release of volatile matter due to thermal decomposition of its organic constituents, resulted in significant improvement of their chemical and physical properties. Results obtained from this study showed that despite the leverage that fluidized bed offers (heat and mass transfer) fixed bed configuration was more pronounced for torrefaction of sewage sludge. However, a decisive conclusion cannot be made at this stage as more detail study would be required to draw a definitive conclusion over the preference of reactor for torrefaction.

현재 국내 도시 생활쓰레기 및 산업쓰레기의 처리 시, 매립지 부족과 침출수 등으로 인한 2차 오염문제로 매립처리 방법은 우리나라에서는 적절치 않다. 하지만 쓰레기의 소각처리의 경우, 소각으로 인한 열작감량이 매우 크고 폐에너지 회수의 장점도 있기에 국내 쓰레기의 처리는 소각에 많이 의존하고 있다. 또한 국내 대체에너지의 목표치가 높아지는 상황에서 폐기물의 대체 에너지가 큰 역할을 해 주어야 한다. 폐기물 고형연료를 연소하는 과정 중에는 여러 문제점이 있는데, 설비의 고온 부식의 영향 및 연소로 내 국부적인 가열로 인한 설비의 파손, 연소로 내 불규칙적 유동현상으로 인한 연소 장애 등이 있다. 따라서 앞에서 말한 문제점들을 보안하며 보일러의 안정적인 운전 및 열효율 향상을 위해서는 기본적으로 연소로 내 유동현상을 정확히 예측할 수 있어야 한다. 이를 위해 우리는 상용화 되고 있는 50ton/day 이상 Stoker 보일러 현장 운전조건을 대입, Ansys CFD Fluent.18을 사용하여 시뮬레이션을 진행하였다. 연소로 내 열의 유동해석, 배출가스의 흐름 등을 예측하여 연소장애의 원인을 찾아보고 이에 맞는 대안을 찾기 위한 연구를 하였다.

Background : While the anti-inflammatory effects of 20 (S)-ginsenoside Rg3 (Rg3) have been studied, it remains unclear how Rg3 regulates lipid metabolism in inflammatory macrophages. Thus, in this study, we characterized some eicosanoids related to the anti-inflammatory effects of 20 (S)-ginsenoside Rg3 in murine macrophages. Methods and Results : UPLC-MS/MS was used to profile various eicosanoids from RAW264.7 cells treated with lipopolysaccharide (LPS) and Rg3. The profiling data were statistically analyzed by principal component analysis, hierarchical clustering analysis and analysis of variance. The anti-inflammatory effect of Rg3 was validated by assessing the levels of nitric oxide, tumor necrosis factor-α, and interleukin-6 in the activated macrophages treated with Rg3. A total of 69 eicosanoids were analyzed in RAW264.7 cells. Principal component and hierarchical cluster analyses differentiated control cells from cells treated with LPS, Rg3, or LPS + Rg3 for 12 or 24 h. Furthermore, some differentially regulated compounds were found between macrophages treated with LPS for 24 h and those treated with LPS + Rg3 for 24 h. Conclusion : Rg3 alters eicosanoid metabolism in activated macrophages treated with LPS. Furthermore, we identified several eicosanoids correlated with the anti-inflammatory activity of Rg3.