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Amberlyst-15를 이용한 산가가 높은 유지로부터 바이오디젤의 생산
심연주(Yeon Ju Sim),김의용(Eui Yong Kim) 한국생물공학회 2010 KSBB Journal Vol.25 No.5
Biodiesel has attracted great attention as an alternative renewable energy source for the replacement of petroleumbased diesel fuel, yet its high production cost due to expensive oil feedstock remainsas the major economical obstacle. In this study, we investigated catalysts and reaction conditions for the acid catalyzed pre-conversion of free fatty acid (FFA) to fatty acid methyl ester (FAME) in cheap low-grade oils of high acid value. The NaOH base catalyzed reaction of vegetable oil of the initial acid value of 2 mg KOH/g led to a high FAME conversion above 95.4%, but the conversion abruptly decreased at higher initial acid values. This base catalyzed reaction was practically ineffective displaying the FAME conversion below 15% even at the initial acid value of 10 mg KOH/g by the severe saponification side reaction. Among the various catalysts studied for the pre-conversion of FFA to FAME, Amberlyst-15 was the most effective in reducing the acid value, and the optimum reaction condition identified was 65℃ with oil to methanol ratio of 1:3 and catalyst concentration of 15% (w/w). As the results, great enhancements in the overall biodiesel conversion were achievable via a consecutive reaction of the acid catalyzed FFA pre-conversion to FAME under the optimal condition obtained with Amberlyst-15 followed by the NaOH base catalyzed reaction, far above the extent which was obtainable by the single NaOH catalyzed reaction.
바이오디젤 생산을 위한 K2CO3/γ-Al2O3 고체염기촉매의 개발
심연주 ( Yeon Ju Sim ),김종훈 ( Jong Hoon Kim ),김의용 ( Eui Yong Kim ) 한국화학공학회 2016 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.54 No.1
The applications of heterogeneous catalyst have been relatively active area of research in the biodiesel process. These catalysts have the benefit of easy recovery and reusability of the catalyst. The objective of this study is to find out significant effect of calcination temperature on K2CO3/γ-Al2O3 catalytic activity in the biodiesel formation reaction. As a results, the temperature at which a catalyst was calcined had very important influence on the catalytic activity. The catalytic activity increased up to 600?, but it severely decreased above the temperature. The reduction of catalyst activity at high temperature would be due to the deduction of the active sites of Al-O-K and Al-O2-K.
폐(廢)알칼리의 재활용(再活用) 현황(現況) 및 관리(管理) 방안(方案)
심연주,김의용,Sim, Yeon-Ju,Kim, Eui-Yong 한국자원리싸이클링학회 2010 資源 리싸이클링 Vol.19 No.4
세계 각국은 폐기물의 발생과 이의 처리를 위해 많은 노력을 기울이고 있다. 폐기물 중 특히 폐알칼리는 부식성으로 인해 환경오염에 대한 위험성이 높기 때문에 효율적 관리를 통해 재활용되어야 하며, 이를 위해 재활용 생성물에 대한 품질기준에 따라 관리될 필요가 있다. 그러나 현재 품질관리가 필요한 대상물질에 대한 국내 자료가 전혀 없다. 따라서 본 연구에서는 최근 5년간의 자료 분석과 현장방문을 통해 체계적인 관리가 필요한 폐알칼리 재활용 대상물질을 선정하였다. 그 결과 재활용 대상 주요물질은 가성소다, 황산알루미늄, 폴리염화알루미늄인 것으로 나타났다. 장차 국가적 차원에서 이들 주요물질에 대한 적절한 관리체계가 구축될 필요가 있는 것으로 판단되며, 이를 통하여 폐기물의 자원화 뿐 아니라 우리 주변의 환경오염을 막는 긍정적인 효과가 있을 것으로 기대된다. Effort of reducing wastes and their recycling is increasing in worldwide. Especially, extreme care for alkali recycling is required because of its environmental pollution and its corrosive characteristics. In order to manage alkali wastes effectively, it is necessary to make quality standards for recycling products from the alkali wastes because there are no quality specifications yet. In this study, we selected several recycling candidates from the alkali wastes based on the analysis of the most recent data of the various industrial sites. As a result, the recycling candidates from the alkali wastes are sodium hydroxide, aluminum sulfate, poly aluminum chloride. It is believed that the proper management system for waste products is required in governmental point of view and it propagates positively for resolving various environmental issues.
홍연주(Yeon Ju Hong),김민성(Min Sung Kim),이경연(Kyung Yeon Lee),심창선(Chang Sun Sim) 대한소아신경학회 2010 대한소아신경학회지 Vol.18 No.2
Purpose : Childhood headache is different from adulthood headache and according to their age in clinical aspects. This study investigated the clinical differences of pri- mary headache according to ages of children and adolescents. Methods : A 300 children who did not show abnormalities on neurologic exami- nation or brain CT or MRI were classified into two groups according to their ages. Results : The percentage of those in the migraine group (24.2% vs. 35.9% in Groups 1 and 2 respectively) was higher in Group 2, but it was not statistically signi- ficant. In relation to the duration of headache, pain lasting for less than one hour accounted for 59.8% and 40% in Groups 1 and 2, respectively (P =0.001). In relation to the location headaches developed, the frontal region (40.2%) and temporal region (48.1%) were the most common in Groups 1 and 2, respectively (P<0.001). In rela- tion to the nature of the headaches, tightening sensation accounted for the highest percentage in both groups; however, pulsating sensation were more common in Group 2 than in Group 1 (16.2% vs. 8.3%, P =0.038). In relation to the severity of head- aches, severe to profound headaches accounted for 35.5% and 61.1% in Groups 1 and 2, respectively (P <0.001). In relation to laterality, unilateral headaches accounted for 12.4% and 26.7% in Groups 1 and 2, respectively (P =0.002). In relation to accom- panying symptoms, the incidence of photophobia was higher in Group 2 than in Group 1 (P =0.047). Conclusion : Age factors should be considered in the diagnosis of childhood head- aches. Also, we consider that there may be a need to establish diagnostic criteria specifically for childhood headaches separately from those for adulthood headaches.