枝孢霉菌对喷气燃料性质的影响及降解烷烃机理

以菌丝干重为指标,采用正交实验设计考察喷气燃料中特征真菌枝孢霉菌(A. resinae)的生长繁殖条件,及其生长过程中对喷气燃料总酸值、银片腐蚀等性能的影响;以喷气燃料替代物正十二烷构建枝孢霉菌生长体系,通过气相色谱、气-质联用仪考察枝孢霉菌生长规律,及正十二烷的降解率和降解中间产物,探讨正十二烷的降解机理,以考察枝孢霉菌影响喷气燃料性能的原因。结果表明：枝孢霉菌最佳生长繁殖条件为温度25 ℃、初始pH值8.0、钠元素质量浓度200.0 mg/L;枝孢霉菌能显著升高喷气燃料的总酸值,降低其表面张力,但对喷气燃料银片腐蚀实验结果和水反应实验结果没有明显影响;枝孢霉菌通过单末端氧化途径降解正十二烷,依次将其氧化为2-十二碳烯、2-十二碳烯-1-醇和2-十二碳烯酸。     

特征真菌对喷气燃料性质的影响

为探索喷气燃料中微生物污染对喷气燃料性质的影响,构建了以喷气燃料为唯一碳源的混合特征真菌培养体系,系统研究了喷气燃料特征真菌对喷气燃料外观、总酸值、银片腐蚀、水反应试验以及表面张力等指标的影响,结合三磷酸腺苷(ATP)生物荧光检测法,考察了微生物污染总量与喷气燃料质量指标之间的关系。结果表明：特征真菌在生长繁殖过程中会产生酸性物质和表面活性物质,使喷气燃料酸值上升、表面张力下降,引起喷气燃料外观不符合标准要求,在试验周期内对喷气燃料水反应试验、银片腐蚀等指标无显著影响;当喷气燃料中ATP含量大于5 500 RLU/L时,喷气燃料总酸值超标,导致质量不合格。     

油-水体系中枝孢霉菌对A3钢腐蚀行为的影响

采用开路电位法、动电位扫描法和表面分析法研究了油-水体系中枝孢霉菌对A3钢电化学行为的影响。结果表明，当枝孢霉菌活性较大时，其代谢产物改变了溶液的组成，A3钢开路电位负移，腐蚀速率加大，促进了A3钢的腐蚀；当枝孢霉菌活性较小时，A3钢的腐蚀也减缓。在枝孢霉菌菌液中浸泡的挂片上附有生物膜。在油一水体系中枝孢霉菌易于在水相中生长，在油一水两相界面处菌体浓度最大，对挂片的腐蚀最为严重。随浸泡时间的增加，挂片腐蚀加重。     

霉菌对喷气燃料的耐受性及其对喷气燃料质量的影响

在实验室对进入喷气燃料中的霉菌能否生长及其菌体、孢子和它们的代谢产物对喷气燃料质量的影响进行了试验研究,结果表明霉菌的孢子对喷气燃料有较强的耐受力;污染霉菌在喷气燃料内未出现大量繁殖,对喷气燃料的主要理化指标没有影响。但在喷气燃料储存期间,采取适当措施防止微生物污染是必要的。     

电位滴定法测定喷气燃料总酸值

 研究了用电位滴定法测定喷气燃料总酸值的方法。采用T50电位滴定仪对滴定剂的添加方式和终点的确定方式进行了研究,分析了非水测量电极和二氧化碳对测定结果的影响,确定了喷气燃料总酸值的最佳测定条件。电位滴定法测定结果的准确度满足指示剂法的再现性要求,多次测定结果的重复性满足格鲁布斯法检验要求。电位滴定法适用于喷气燃料总酸值的测定,尤其对低含量或有颜色的样品,终点判断干扰小,相对于指示剂法测定结果准确度高。     

硫酸盐还原菌对喷气燃料银片腐蚀机理研究

选取脱硫弧菌(Desulfotomaculumruminis)和脱硫肠状菌(Desulfovibriofructosivorans)两种硫酸盐还原菌（SRB）为对象,通过构建SRB和喷气燃料储存体系,考察其对银片腐蚀性能的影响,结合扫描电子显微镜/EDS能谱、X射线光电子能谱分析腐蚀后银片的形貌和官能团情况,分析了SRB对银片的腐蚀机理。结果表明：2种SRB均能导致喷气燃料出现银片腐蚀,SRB数量越多,银片腐蚀情况越严重;SRB集中于水相附着于银片表面发生腐蚀过程,H2S由水相扩散至油相导致油相银片发生腐蚀;银片在油相中的腐蚀产物以Ag2S相对较多,在水相中腐蚀产物以FeS2及FeS相对较多。     

长距离管输对3号喷气燃料导电性能和清洁性能的影响

分析了长距离管输后3号喷气燃料电导率严重衰减的原因和补加抗静电剂后对3号喷气燃料电导率和水反应指标的影响。对比了成品油长距离管输和喷气燃料馏分长距离管输对3号喷气燃料电导率和水反应指标的影响，并对比了两种管输方式的优缺点，提出对3号喷气燃料的管输建议。3号喷气燃料的长距离管输，优先采用喷气燃料馏分油管输在末端加注抗静电剂的方式；需兼顾汽运时，宜采用成品油管输并在末端根据电导率衰减情况，最小量补加抗静电剂的方式，以获得较高的成功率和较好的经济效益。     

长距离管输对3号喷气燃料导电性能和清洁性能的影响

分析了长距离管输后3号喷气燃料电导率严重衰减的原因和补加抗静电剂后对3号喷气燃料电导率和水反应指标的影响。对比了成品油长距离管输和喷气燃料馏分长距离管输对3号喷气燃料电导率和水反应指标的影响，并对比了两种管输方式的优缺点，提出对3号喷气燃料的管输建议。3号喷气燃料的长距离管输，优先采用喷气燃料馏分油管输在末端加注抗静电剂的方式；需兼顾汽运时，宜采用成品油管输并在末端根据电导率衰减情况，最小量补加抗静电剂的方式，以获得较高的成功率和较好的经济效益。     

原油减压渣油馏分的油-水界面性质Ⅲ.伊朗轻质减渣馏分油-水界面粘度

采用剪切界面粘度仪考察了伊朗轻质减压渣油超临界分离馏分的油-水界面粘度。结果表明，随着馏分的增重，油-水界面粘度增大。随着剪切速率的增大，界面膜结构被破坏，油-水界面粘度减小。油相中馏分质量分数以及水相中盐的增加，使得馏分的油-水界面吸附量增大，油-水界面粘度增大；油相中芳烃含量以及水相pH值的增大，改变了馏分在油-水界面的吸附状态，油水界面粘度减小。     

表面张力预测小桐子生物柴油氧化程度的应用与分析

采用Rancimat法在110 ℃下对小桐子生物柴油进行不同时间的加速氧化降解，利用GC-MS技术、酸值滴定等手段研究了用表面张力检测燃料氧化程度的适用性。通过对实验数据分析表明:小桐子生物柴油经加速氧化后生成醛、酮、相对分子质量较高的含氧化合物及可溶性聚合物;其表面张力、酸值以及密度在氧化14 h后分别增加了9.1%、551%和3.8%；经相关性分析得到氧化后小桐子生物柴油表面张力与酸值的相关系数为0.99。基于此提出了4种利用表面张力预测小桐子生物柴油氧化程度的模型，并采用留一交叉验证法进行了检验分析，通过比较均方根误差（RMESP）值、相关系数R值，最终确定对数模型精确度以及相关性较高，其RMESP值以及相关系数R值分别为0.0937、0.9879，并且酸值预测值与实际值的误差为2.95%，说明通过表面张力可以预测小桐子生物柴油的氧化程度。     

储罐罐底水含酸及对喷气燃料性能的影响

对喷气燃料储罐罐底含酸的原因及危害进行了研究,指出氧化硫硫杆菌生长繁殖产生的硫酸导致罐底水pH降低,硫酸与罐底水中的硫化物反应生成硫化氢导致喷气燃料银片腐蚀不合格。     

SURFACE ACTIVE PROPERTIES OF CLAY TREATED JET FUELS

The effect of water contamination in jet fuels on the adsorbent capacity of Attapulgite clay to adsorb and retain N compounds was studied. The effluent jet fuel showed the presence of N molecules indicating that the clay, contaminated with water, does not retain N compounds. The GC/MS analysis of spent clay indicated that only quinolines were adsorbed and retained on the clay. The interfacial tension (IFT) values measured at the jet fuel/water interface were found to increase with a decrease in basic N content of clay treated jet fuels. Quinolines and pyridines present in jet fuel are surface active and adsorb on the Attapulgite clay, however, in the presence of water some N molecules adsorb at the jet fuel/water interface. Since pyridines were not found on the spent clay, the results indicate that the pyridines adsorb at the jet fuel/water interface. The tendency of pyridines to adsorb at the jet fuel/water interface will lead to their poor retention on the clay. The presence of N compounds and water contamination in jet fuel might lead to inefficient operation of clay treaters. The jet fuels having the IFT value below 40 mN/m were found to contain basic N molecules and have poor stability. The clay treated jet fuels having the IFT values in the range of 42.6–46.2 mN/m were found to have a good stability. The use of IFT measurements at the jet fuel/water interface provides an opportunity to better monitor the efficiency of clay treatment and the quality of jet fuels.     

SURFACE ACTIVE PROPERTIES OF CLAY TREATED JET FUELS

The effect of water contamination in jet fuels on the adsorbent capacity of Attapulgite clay to adsorb and retain N compounds was studied. The effluent jet fuel showed the presence of N molecules indicating that the clay, contaminated with water, does not retain N compounds. The GC/MS analysis of spent clay indicated that only quinolines were adsorbed and retained on the clay. The interfacial tension (IFT) values measured at the jet fuel/water interface were found to increase with a decrease in basic N content of clay treated jet fuels. Quinolines and pyridines present in jet fuel are surface active and adsorb on the Attapulgite clay, however, in the presence of water some N molecules adsorb at the jet fuel/water interface. Since pyridines were not found on the spent clay, the results indicate that the pyridines adsorb at the jet fuel/water interface. The tendency of pyridines to adsorb at the jet fuel/water interface will lead to their poor retention on the clay. The presence of N compounds and water contamination in jet fuel might lead to inefficient operation of clay treaters. The jet fuels having the IFT value below 40 mN/m were found to contain basic N molecules and have poor stability. The clay treated jet fuels having the IFT values in the range of 42.6-46.2 mN/m were found to have a good stability. The use of IFT measurements at the jet fuel/water interface provides an opportunity to better monitor the efficiency of clay treatment and the quality of jet fuels.     

EFFECT OF CLAYS AND ADSORBENTS ON THE NITROGEN CONTENT AND THE STABILITY OF JET FUELS

The effect of composition, surface area and pH of different clays and alumina adsorbents on the stability of jet fuel was studied. The stability of jet fuel was tested following the ASTMD 3241 procedure. Under the batch adsorption conditions, clays and adsorbents were not effective in adsorbing polar molecules and improving the stability of jet fuels. Under the column adsorption conditions, the effectiveness of clays and adsorbents in improving the stability of jet fuel was found to vary. Clays having a high surface area and an acidic pH were found to be more effective in adsorbing polar molecules and improving the stability of jet fuel. High surface area alumina adsorbents were found effective in adsorbing basic nitrogen molecules and improving the stability of jet fuel despite having a basic pH. The basic type nitrogen compounds, pyridines and quinolines, were found to affect the stability of jet fuel. The initial effluent jet fuel passed through fresh clays was found to have no N compounds and a good stability. However, the analysis of effluent jet fuel showed a gradual increase in N content reaching the level of N content in untreated jet fuel. The effluent jet fuel reaching 9–10 ppm of N content failed the stability test indicating that clays need to adsorb and retain N compounds. The adsorbent capacity of different clays was studied but no significant difference in retaining N molecules was observed.     

EFFECT OF CLAYS AND ADSORBENTS ON THE NITROGEN CONTENT AND THE STABILITY OF JET FUELS

The effect of composition, surface area and pH of different clays and alumina adsorbents on the stability of jet fuel was studied. The stability of jet fuel was tested following the ASTMD 3241 procedure. Under the batch adsorption conditions, clays and adsorbents were not effective in adsorbing polar molecules and improving the stability of jet fuels. Under the column adsorption conditions, the effectiveness of clays and adsorbents in improving the stability of jet fuel was found to vary. Clays having a high surface area and an acidic pH were found to be more effective in adsorbing polar molecules and improving the stability of jet fuel. High surface area alumina adsorbents were found effective in adsorbing basic nitrogen molecules and improving the stability of jet fuel despite having a basic pH. The basic type nitrogen compounds, pyridines and quinolines, were found to affect the stability of jet fuel. The initial effluent jet fuel passed through fresh clays was found to have no N compounds and a good stability. However, the analysis of effluent jet fuel showed a gradual increase in N content reaching the level of N content in untreated jet fuel. The effluent jet fuel reaching 9-10 ppm of N content failed the stability test indicating that clays need to adsorb and retain N compounds. The adsorbent capacity of different clays was studied but no significant difference in retaining N molecules was observed.     

温度对航空煤油中微生物生长繁殖的影响

微生物的危害已经是国际航空界普遍关注的问题。环境因素（包括温度、pH值、含氧率、含水率和营养物质等）会影响微生物的生命活动,进而对航空油料产生影响,对油储存甚至航空运输产生影响。由于飞机要经常往返于空中和地面,其温度变化剧烈,而其他影响因素则相对稳定,因此有必要研究温度对航空煤油中微生物生命活动的影响。     

活性硫化物银片腐蚀性能的研究

为提高喷气燃料的质量，在实验室研究了喷气燃料中不同硫化物对银片腐蚀的性能，结果表明，活性硫化物会导致银片腐蚀，其主要因素是元素硫。硫醇和二硫化物在无元素硫的情况下不腐蚀银片，与元素硫共存时加重腐蚀程度并出现颜色多样性；高浓硫化氢腐蚀银片，颜色主要为紫、红或黄色，金属锈、酸根、洗衣粉等杂质不足以使银片腐蚀超过1级，酸碱度（PH5－9）变化不影响硫化物银物腐蚀级别，非标准汽油含一定量的H2S、S，混入喷气燃料将导致银片腐蚀。