【作者】 李建彤；

【导师】 吕效平；

【作者基本信息】 南京工业大学 ， 化学工程， 2004， 硕士

【摘要】 (微)乳化柴油是一种节能、环保燃料。在能源紧缺、环保问题日益严重的今天,开发(微)乳柴油越来越受到科研工作者的重视。微乳化柴油燃烧时由于乳液内部的微小水珠的“微爆”效应,使油雾化成更细小的油滴,增加油滴与空气接触的比表面积,减少了物理上的不完全燃烧和排烟损失,降低氮氧化物的排放,提高了燃烧效率,从而可以达到节能效果,并降低污染物的排放。超声乳化主要是利用超声的空化效应。超声用于乳化不仅可以降低乳化剂的用量,同时可以改善乳液的性质,如减小乳液的粘度及乳液中水滴粒径等。本文研究了超声柴油微乳化,用HLB值筛选法选择复配乳化剂。通过分光光度计对乳液的浊度和室温下乳液的乳化稳定性进行了考察,并结合乳液的粘度变化,筛选出适合0#柴油乳化的乳化剂及其工艺条件。超声柴油微乳化的影响因素较多,不仅受超声的声强、作用时间的影响,而且乳化剂用量、掺水量等对乳液性质都有影响。通过参阅了大量文献,同时也在实验中发现有机极性物的添加对乳液的性质影响较大,可以提高乳液稳定性和降低乳液粘度,本研究通过各种醇的对比实验并结合经济等因素选择乙醇作为有机极性物。作者对所选乳化剂进行0#柴油微乳化的正交实验,通过分析发现各因素对乳液稳定性的影响顺序为声强>乳化剂用量>乙醇用量>掺水量>超声作用时间>稳定剂用量。并优选出柴油处理量为200ml时超声柴油微乳化的最佳工艺参数为:乳化剂用量为2.5wt%,电流为3A(即声强为0.148 W/cm2),稳定剂用量为0.158wt%,超声作用时间为15min,乙醇用量为5%(V),掺水量为10%(V)。本实验制备的柴油乳液的稳定时间为300min以上,色泽为透明半透明状。且制备的柴油乳液放置8个月以上不分层。更多还原

【Abstract】 Micro-emulsified diesel oil is a fuel with merit of energy saving and environmental protection. Intensive attention, for academic and industrial purpose, has been paid to micro-emulsified diesel oil during the last decades, since the energy and environment concerning problems became more and more essential for development of the society and people’s living. As a result of the micro-explosion of water droplets in the emulsion, emulsified diesel could be atomized when the burnt in the internal combustion engine. And it makes the contact area increased between the oil droplets and atmosphere, and reduces incomplete combustion and fume discharge. Incomplete combustion and discharge of the fume herein were most pollution and energy waste correlative. So the application of the emulsified diesel oil could realize the purpose of energy saving and environmental protection.Ultrasonic assisted emulsification, utilizing the cavitation effect, could be used as a helpful and effective method to prepare emulsion. Which can reduce emulsifier dosage and change the properties of emulsion, such as emulsion viscosity and diameter reducing of globule of emulsion.Emulsification of diesel oil by ultrasound was studied in this paper. According to knowledge of surfactants, the emulsifiers were selected by the rule of Hydrophile-Lipophile-Balance. To verify the result and effect of emulsification or emulsifier, the spectrophotometer was employed to characterize the turbidity of emulsion. The stability and viscosity of the emulsion at room temperature were simultaneously investigated to ascertain the appropriate emulsifier and technological conditions for emulsification of 0# diesel oil. There are many factors to affect diesel oil emulsification with ultrasound. There are many factors, such as ultrasound intensity and treatment time, able to affect diesel oil emulsification under ultrasound. Emulsifier dosage and water-oil ratio were both essential to the properties of emulsion. According to many literatures, some organic polar compounds could improve stability of diesel-water emulsion, decrease the viscosity of the emulsion and ameliorate the combustion performance of emulsified diesel oil. Ethanol was selected through many experiments, also with economic factors concerned. Some parameters of ultrasonic emulsification technology, that suit the diesel oil and water system, are found through orthogonal test. And the order of parameters affecting stabilization time <WP=5>is ultrasound intensity > emulsifier dosage > alcohol dosage > water dosage > ultrasonic treatment time > stabilizing agent dosage. The optimum emulsifying conditions for the system are: ultrasound intensity 0.148 W/cm2, emulsifiers dosage 2.5wt%, stabilizing agent dosage 0.158wt%, treatment time of ultrasound 15 min, ethanol dosage 5%(V), water-oil ratio 10%(V). The stable time is above 300min and the aspect of the emulsion is transparence or translucence of emulsion in this conditions. The delamination time of emulsion prepared in this condition was above 8 months.更多还原