Rashedul Hasan Khondakar, Kalam Md Abdul, Masjuki Haji Hassan, Teoh Yew Heng, How Heoy Geok, Monirul Islam Mohammad, Imdadul Hassan Kazi
Centre for Energy Sciences, Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.
School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal, 14300, Penang, Malaysia.
Environ Sci Pollut Res Int. 2017 Apr;24(10):9305-9313. doi: 10.1007/s11356-017-8573-9. Epub 2017 Feb 23.
The study represents a comprehensive analysis of engine exhaust emission variation from a compression ignition (CI) diesel engine fueled with diesel-biodiesel blends. Biodiesel used in this investigation was produced through transesterification procedure from Moringa oleifera oil. A single cylinder, four-stroke, water-cooled, naturally aspirated diesel engine was used for this purpose. The pollutants from the exhaust of the engine that are monitored in this study are nitrogen oxide (NO), carbon monoxide (CO), hydrocarbon (HC), and smoke opacity. Engine combustion and performance parameters are also measured together with exhaust emission data. Some researchers have reported that the reason for higher NO emission of biodiesel is higher prompt NO formation. The use of antioxidant-treated biodiesel in a diesel engine is a promising approach because antioxidants reduce the formation of free radicals, which are responsible for the formation of prompt NO during combustion. Two different antioxidant additives namely 2,6-di-tert-butyl-4-methylphenol (BHT) and 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (MBEBP) were individually dissolved at a concentration of 1% by volume in MB30 (30% moringa biodiesel with 70% diesel) fuel blend to investigate and compare NO as well as other emissions. The result shows that both antioxidants reduced NO emission significantly; however, HC, CO, and smoke were found slightly higher compared to pure biodiesel blends, but not more than the baseline fuel diesel. The result also shows that both antioxidants were quite effective in reducing peak heat release rate (HRR) and brake-specific fuel consumption (BSFC) as well as improving brake thermal efficiency (BTE) and oxidation stability. Based on this study, antioxidant-treated M. oleifera biodiesel blend (MB30) can be used as a very promising alternative source of fuel in diesel engine without any modifications.
该研究对一台使用柴油 - 生物柴油混合燃料的压燃式（CI）柴油发动机的尾气排放变化进行了全面分析。本研究中使用的生物柴油是通过辣木油的酯交换工艺生产的。为此使用了一台单缸、四冲程、水冷、自然吸气的柴油发动机。本研究监测的发动机尾气污染物有氮氧化物（NO）、一氧化碳（CO）、碳氢化合物（HC）和烟度。同时还测量了发动机燃烧和性能参数以及尾气排放数据。一些研究人员报告说，生物柴油中NO排放较高的原因是快速型NO生成量较高。在柴油发动机中使用经抗氧化剂处理的生物柴油是一种很有前景的方法，因为抗氧化剂可减少自由基的形成，而自由基是燃烧过程中快速型NO形成的原因。将两种不同的抗氧化剂添加剂，即2,6 - 二叔丁基 - 4 - 甲基苯酚（BHT）和2,2'-亚甲基双（4 - 甲基 - 6 - 叔丁基苯酚）（MBEBP），分别按体积浓度1%溶解在MB30（30%辣木生物柴油与70%柴油的混合燃料）中，以研究和比较NO以及其他排放物。结果表明，两种抗氧化剂均能显著降低NO排放；然而，与纯生物柴油混合燃料相比，HC、CO和烟度略有升高，但不超过基准燃料柴油。结果还表明，两种抗氧化剂在降低峰值热释放率（HRR）和制动比油耗（BSFC）以及提高制动热效率（BTE）和氧化稳定性方面都相当有效。基于这项研究，经抗氧化剂处理的辣木生物柴油混合燃料（MB30）无需任何改装即可作为柴油发动机中非常有前景的替代燃料来源。
