【作者】 张秀兰；

【导师】 马洁；

【作者基本信息】 首都师范大学 ， 物理化学， 2008， 硕士

【摘要】 柴油是我国目前消费量最大的发动机燃料之一,但其中含氮有机化合物的存在对生产和环境造成许多危害,其影响油品的色度,降低油品的抗氧化安定性,进而影响其储存和使用性能,并在柴油的催化加工过程中造成催化剂中毒。含氮化合物具有致癌、致突变性,燃烧会产生NOX,形成酸雨,造成空气污染。传统的加氢脱氮工艺操作复杂,成本高,因此非加氢脱氮日益受到重视。本文以咔唑作为微生物脱氮的模式化合物进行微生物脱氮研究,同时探讨直流电场对脱氮菌株的生长速率和脱氮活性的影响。并在超声辅助的条件下用Ce4+氧化法对柴油进行同时脱硫脱氮的研究。本论文的主要研究内容概括如下:以咔唑为模型化合物,从燃油污染的土壤、污水中筛选出一株能够将咔唑降解为邻氨基苯甲酸的假单胞杆菌YSSH。以咔唑的脱除率为指标,用正交实验考察初始pH、速效碳源(葡萄糖)的浓度及速效氮源(氯化铵)的浓度等因素对该菌株生长和脱氮率的影响,确定该菌株最优的生长和脱氮条件为:氯化铵1.0 g/L,初始pH=7.0,葡萄糖3.0 g/L。将其应用于柴油体系,在油水比为1:9的条件下可使含氮量为100 ppm的柴油脱氮率达到63.9%。对所筛选的脱氮菌株施加不同强度的直流电场刺激,以细胞浓度和脱氮率为指标,研究外加电场对菌株生长速率和脱氮活性的影响。实验证明电流强度为10.0 mA时菌株的脱氮活性最高;电流强度升高至20.0 mA和40.0 mA时菌株的脱氮活性受到明显抑制。并将其应用于实际柴油体系,采用1:9的油水比,发现柴油脱氮率并未比不加电场时有所提高。在超声波辅助的条件下,使用Ce4 +同时氧化柴油中的硫氮化合物,并选用合适的溶剂DMF萃取除去氧化产物,可以将柴油中的硫含量从11000 ppm降低到6500 ppm,脱硫率达到40.9%;将柴油中的氮含量从100 ppm降低到44.6 ppm,脱氮率达到55.4%。由实验得到超声条件下的最佳脱氮条件为:反应温度为70℃,溶液的pH值为0.7,反应时间为50 min,油水比为1:9。更多还原

【Abstract】 Diesel oil is one of the engine fuels having largest consumption in China at present, but the nitrogen-containing organic compounds in diesel oil are harmful to production and environment. They have a big effect on the chroma of oil, reduce the anti-oxidation stability of oil. Therefore the storage and using performance are also influenced. Furthermore they inactivate refining catalyst in diesel oil catalyzed processing. And some nitrogen-containing organic compounds have mutagenic and toxic activities, their combustion leads to the formation of nitrogen oxides (NOX), which is one of the important air pollutants forming acid rain. The classical hydrodenitrogenation is costly and complicated. Therefore, non-hydrodenitrogenation technics are utilized. Carbazole was selected in this text as a model compound on biodenitrogenation study of diesel oil. The influence of direct current field on the strain growth rate and denitrogenation activities was discussed at the same time. Ultrasonically auxiliary oxidation by Ce4+ was used to desulfurize and denitrogenize the diesel oil simultaneously.The main contents of the thesis are as follows:A new strain able to convert carbazole into anthranilic acid was isolated from the sullage and soil samples polluted by fuel oil and was identified as pseudomonas aeruginos YSSH. Taking the denitrogenation rate of carbazole as an evaluating indicator, the orthogonal experiment was used to exam the effects of initial pH, rapidly available sources of carbon (glucose) and nitrogen (ammonium chloride) on growth and biodenitrogenation rate. The optimum conditions for the growth and biodenitrogenation were 1.0 g/L of ammonium chloride, the initial pH 7.0, and 3.0 g/L of glucose. When applied in the diesel oil system, it removed 63.9% of 100 ppm total nitrogen content in the diesel oil under the oil-water ratio of 1:9.Taking cell thickness and denitrogenation rate of carbazole as evaluating indicators, applied direct current field stimulation of different intensity to the isolated strain, and studied the influence of adscititious electric field on the strain growth rate and denitrogenation activities. The experiment proved that the strain denitrogenation activities was highest when the current intensity was 10.0 mA, but when the current intensity increased up to 20.0 mA and 40.0 mA, the strain denitrogenation activities was restrained obviously. Applied the results to the diesel oil system (the oil-water ratio is 1:9), the denitrogenation rate in diesel oil did not improve compared with the results of that without the electric field stimulation.Used the Ce4+ to oxidize the sulfur and nitrogen compounds in diesel oil simultaneously under ultrasonic auxiliary conditions, and removed the oxidation products by choosing a proper solvent DMF to extract them, it reduced the total sulfur content in diesel oil from 11000 ppm to 6500 ppm, achieving a desulfurization rate of 40.9%, and reduced the total nitrogen content in diesel oil from 100 ppm to 44.6 ppm, achieving a denitrogenation rate of 55.4% simultaneously. The best denitrogenation conditions obtained from the experiment was that the reaction temperature was 70℃, the solution pH value was 0.7, the reaction time was 50 min, and the oil-water ratio was 1:9.更多还原