Recently air pollution is becoming a global environment issue. Especially, the smoke from engines and boiler systems, which burn fossil fuels directly, is an extremely serious issue. For this reason, IMO is tightening regulations for the control of NOx and SOx. Therefore, in this study, the NOx reduction effect of emulsified oil mixed with 10% of water was tested after applying the emulsified oil to an industrial boiler burner using Bunker-C oil. The study showed that the exhaust gas oxygen concentration of emulsified oil was nearly 1.3% high and this was identified by the effect of dissolved oxygen contained in water. Also, based on the standard oxygen concentration(4%), the average and maximum NOx reduction rates were 28.53% and 30.23% respectively, which means the reduction efficiency was very high.
Recent approaches and opinions support that shipping companies must take precautionary measures against financial risks and design steadier steps for financial management. The key to developing, implementing, and managing a successful hedging strategy is to use effective forecasting systems and appropriate financial derivative products. The key objective of this study is to control risks from bunker cost fluctuations using financial derivative products. To do so, a time-series analysis is conducted using a dataset derived from a bunker index system. The artificial neural network method is used for time-series analysis with a mean absolute percentage error of 0.9182105. Next, progress predictions of bunker costs and hedging strategies are determined to use financial derivative products against their risks. Finally, this study concludes that forward agreements can serve as the perfect protection mechanism against bunker risks in tramp shipping.
본 연구에서는 균질기에 의해 혼합된 물과 벙커-A를 보일러로 연소하였을 때의 배기 배출물 특성에 대해 연구를 수행하였다. 그 결과로 균질기로 균질화 된 벙커-A의 경우, 순수 벙커-A에 비해 NOx 농도는 19 %, CO 농도는 54 % 감소를 나타냈다. 물-벙커A의 경우 물 혼합 비율이 증가할수록 NOx 농도분포가 낮아지는 것을 확인할 수 있었다. 특히, 20 %물-80 %벙커-A의 경우 순수한 벙커-A 보다 배기가스 내 NOx 농도가 45 %까지 감소하였다. 그러나 20 %물-80 %벙커-A의 경우, CO농도 분포는 불규칙한 변화를 나타냈다. 이것은 일정량 이상의 물 혼합은 보일러의 연소 성능 저하 원인이 될 수 있다는 것을 의미한다. 이 결과로부터 본 연구에서 보일러의 정상 연소를 위한벙커A유 내 물의 한계 혼합율은 15 % 인 것을 알 수 있었다. 연돌 부근에서 채취한 매연 부착양은 물의 혼합율이 증가할수록 감소하였다.
Oil dispersants using polyoxyethylene monooleate, polyoxyethylene oleylether, and poly(oxypropylene-oxyethylene)glycol block copolymer were prepared, and oil dispersant efficiency was measured using vertical shaking flask method to 4 kinds of Bunker B oil with different physical properties by appling the prepared dispersants. Although the dispersant efficiency was differed according to the differences of physical properties of Bunker B oil, the dispersant prepared using polyoxyethylene oleylether was the most effective to disperse the oil into water. The impurities like surfur contained in sample oil have to be removed by filteration to obtain the correct degree of absorption using UV spectrophotometer.
Microorganisms utilizing petroleum as substrate were screened from the seawater in Pusan coastal area. Among them, fifty strains utilized bunker-A oil as a sole carbon and energy source. Five of these fifty strains were selected to experiment this study. According to the taxonomic characteristics of its morphological, cultural and biochemical properties, the selected strains were named Pseudomonas sp. EL-12, Flavobacterium sp. EL-15, Acinetobacter sp. EL-18, Enterobacter sp. EL-27 and Micrococcus sp. EL-43, respectively. The optimal medium compositions and cultural conditions for assimilation of bunker-A oil by the selected strains were 1.5-2% bunker-A oil, 0.1% NH4NO3, 1-1.5% MgSO4·7H2O, 0.05-0.15% KCl, 0.1-0.15% CaCl2·2H2O, 2.5-3.5% NaCl, initial pH 8-9, temperature 30℃ and aeration, respectively. The utilization and degradation characteristics on the various hydrocarbons by the selected strains were showed that bunker oil, n-alkane and branched alkane compounds were highly activity than cyclic alkane and aromatic hydrocarbon compounds.