气相色谱法测定车用汽油中含氧化合物和苯胺类化合物

利用中心切割技术和双毛细管色谱柱系统,采用两次进样的方式,建立了气相色谱测定车用汽油中含氧化合物和苯胺类化合物的分析方法。第一次进样分析,组分首先进入非极性DB-1色谱柱(30 m×0.32 mm×1.0μm),按沸点由低到高的顺序分离,通过电磁阀切换将沸点小于2-己酮的组分切割至强极性GS-OxyPLOT色谱柱(10 m×0.53 mm×10μm)或CP-Lowox色谱柱(10 m×0.53 mm×10μm),其余重烃组分通过阻尼柱进入FID检测器。在GS-OxyPLOT或CP-Lowox色谱柱上,烃类组分与含氧化合物分离并进入检测器检测,消除了大量的烃类组分对含氧化合物测定的影响。第二次进样分析,设定电磁阀切换时间为间-甲基苯胺从非极性色谱柱流出的时间,苯胺类化合物在GS-OxyPLOT或CP-Lowox色谱柱上与烃类和含氧化合物分离并进入检测器检测。以乙二醇二甲基醚为内标化合物进行内标法定量。实现了在一套系统上同时测定车用汽油中添加的甲基叔丁基醚(MTBE)、甲醇、甲缩醛、乙酸仲丁酯、乙酸乙酯、苯胺、邻/间/对-甲基苯胺和N-甲基苯胺的含量,各组分的检测范围为0.01%~10%(质量分数),回收率为86.0%~102.6%。该法可以为车用汽油的质量控制提供有效的检测手段。     

全二维气相色谱-飞行时间质谱对催化裂化汽油的定性与定量分析

采用全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)对催化裂化汽油全馏分进行了定性与定量分析,建立了相应的分析方法.结果表明,汽油族组成中的烷烃、烯烃、环烷烃、芳烃在全二维点阵谱图中呈分区域、带状的分布特点.GC×GC-TOF MS根据催化裂化汽油组分内分子的沸点及极性差异对其进行两个维度分离,极大地避免了普通色谱法分析过程中沸点相似化合物共流的弊端,实现催化裂化汽油组分的精确分离和准确定性分析.通过引入响应因子,修正了不同性质的烃类在电离源上电离效率的差异,使得TOF对催化裂化汽油族组成的定量结果与普通气相色谱法的定量结果的相关性较好,且应用GC×GC-TOF MS方法获得了催化裂化汽油更为精确的族组成信息.GC×GC-TOF MS为催化裂化汽油精确表征提供了一种有效方法.     

中国催化重整技术进展

催化重整是将石脑油转化为高辛烷值汽油、芳烃,并副产大量氢气的过程,催化重整技术的进步关系到石油炼制与石油化工行业技术的战略安全与竞争力,因此受到极大重视.本文从催化材料、催化反应活性中心及反应机理、催化重整工艺、催化重整反应和再生动力学、关键设备、工程控制技术等方面阐述了我国在理论研究、工业开发及工业应用方面取得的技术进步和成果,对未来的技术进步途径进行了分析与展望.     

Dispersed Structure of Ethanol‐Gasoline Fuel According to Dynamic Light Scattering Method

The dispersed structures of mixtures of five different gasolines with anhydrous ethanol were investigated by the dynamic light scattering (DLS) method. The aim of the work was to find whether these blends are colloid systems. Influence of different parameters was investigated to verify the results of this research. Ethanol‐gasoline blends were found to be colloid systems with the drop size of 20–150 nm.     

晶化时间对ZSM-5/MCM-48复合分子筛结构及MTG反应性能的影响

采用两步晶化法制备ZSM-5/MCM-48微介孔复合分子筛,通过调变前驱体溶胶的晶化时间获得不同结构的ZSM-5/MCM-48基分子筛催化剂。采用XRD、N₂-吸附、SEM、TEM、FT-IR和Py-FTIR等手段进行表征,结果表明,前驱体溶胶的晶化时间对ZSM-5/MCM-48复合分子筛的结构和表面酸性产生重要的影响,而特定结构的复合分子筛基催化剂可以显著改变甲醇制汽油（MTG）反应的产物分布,与ZSM-5基催化剂相比显著降低了油品中芳烃和均四甲苯的含量。阐明了其催化作用机制是由于介孔结构的MCM-48对微孔结构的ZSM-5界面或表面的修饰作用。     

改性Y型分子筛对FCC汽油脱硫性能的研究

采用液相离子交换法制备了Cu(I)Y、NiY、CeY分子筛,利用XRD、ICP/MS、N₂吸附脱附等技术对其物化性质进行了表征,使用固定床技术和色谱-硫化学发光检测(SCD)偶联技术系统考查了改性Y分子筛对FCC汽油的选择性吸附脱硫性能,着重探讨了FCC汽油选择性吸附脱硫过程中硫化物的脱除规律。结果表明,不同金属阳离子改性的Y分子筛对FCC汽油中不同硫化物选择性有所不同,对CeY分子筛:2-甲基-5-乙基噻吩<噻吩3硫醇< C₂噻吩<2或3-甲基噻吩<苯并噻吩<3,4-二甲基噻吩≈2,3,4-三甲基噻吩<四氢噻吩,而NiY与Cu(I)Y选择性相同:C₃硫醇<2-甲基-5-乙基噻吩2噻吩<2或3-甲基噻吩<噻吩<苯并噻吩<3,4-二甲基噻吩≈2,3,4-三甲基噻吩<四氢噻吩,改性Y分子筛对噻吩及小分子烷基取代噻吩类硫化物的选择性较差。     

Naphthalene and benzene levels in microenvironments associated with potential exposure: new and old apartments with moth repellents,and cabins of passenger cars

A lesser degree of information is available with respect to microenvironments associated with potential exposure to naphthalene, in comparison with other volatile organic compounds. The current study investigated the levels of benzene as well as naphthalene, both in the indoor and outdoor air of apartments and in the cabins of passenger cars. Two groups of 20 apartment buildings (20 new and 20 old) were chosen on the basis of the selection criteria (apartment location and size). In addition, 10 actual commuters were recruited for this study. The equal number of drivers was recruited for the study for comparison of two types of fuels for vehicles (five drivers of gasoline-fuelled and five drivers of diesel-fuelled passenger cars). Indoor naphthalene concentrations were similar between old and new apartments, while the benzene concentrations in new apartments were significantly higher than those of old apartments. The naphthalene concentrations in bedrooms, where wardrobes with moth repellent (MRs) were placed, were significantly higher than those for living rooms where no MRs were present. In turn, these indoor concentrations were significantly higher than outdoor levels. It is noteworthy that the mean and median values of naphthalene measured in the bedrooms exceeded the USEPA RfC (inhalation reference concentration) of 3?µg?m^?3, and the living room values were close to the RfC, while the residential benzene levels exceeded the European benzene limit of 5?µg?m^?3. In contrast, the maximum outdoor levels were well below that of the RfC. The use of passenger cars appeared to be a significant daily activity for both naphthalene and benzene exposure. The naphthalene-to-benzene ratios varied with the type of microenvironments. Both the indoor naphthalene and benzene concentrations in the present study were much higher than those of other studies.     

通过Hβ分子筛上的烯烃水合反应提高FCC汽油品质

 以Hβ分子筛为催化剂,通过烯烃水合反应可以降低FCC轻汽油(≤80 ℃)中烯烃含量并提高含氧化合物含量,从而提高汽油的品质. 在V(H2O)/V(oil)=0.6,WHSV=1 h-1,p=5.0 MPa,θ=140 ℃和t=10 h的条件下,FCC轻汽油中烯烃的转化率为16.7%,产物中含氧化合物的含量为9.5%.     

FCC汽油中含硫化合物在Ce交换的Y型分子筛上的吸附

 研究了NaY分子筛在与硝酸铈溶液进行液相离子交换前后对含有大量芳烃和烯烃的FCC汽油的吸附脱硫. 结果表明,在室温和常压下,以离子交换方式将Ce3+引入到Y分子筛中后,分子筛吸附剂对FCC汽油的脱硫选择性明显提高,并且脱硫选择性随分子筛中Ce3+含量的增多而提高. 噻吩吸附的红外光谱表明,在Ce3+改性后的分子筛吸附剂上存在着噻吩分子直接以硫原子与吸附剂相互作用的吸附模式,这种不同于π络合的吸附方式可能不易受FCC汽油中竞争分子的影响,因此分子筛表现出较高的吸附脱硫选择性.     

基于缸内直喷的汽油HCCI燃烧特性的研究

实现汽油机的均质混合气压燃(HCCI)的难点是精确地控制着火时刻、燃烧速率以及扩展高负荷运行范围.在缸内直喷汽油机(GDI)上试验研究了分层混合气和辅助火花点火对HCCI燃烧特性的影响,考察了对不同运行工况时的适应性.开展了负阀重叠与缸内多段喷油相结合控制HCCI着火稳定性的研究,考察了不同喷油控制策略对HCCI燃烧的影响,确定了HCCI运行工况范围.