汽油芳构化降烯烃ZSM-5型催化剂的研究

通过催化剂表征和小型固定床反应发现，减小沸石晶粒度和提高沸石表面L酸B酸比值，或者适当采用高氢油比，可以提高ZSM-5沸石在汽油芳构化降烯烃反应中的活性稳定性．而适当提高反应温度及减小汽油进料空速则可以提高汽油中烯烃的芳构化程度．连续300h的小试运转表明，FCC和DCC汽油中的烯烃在一种晶粒度为20～50纳米的改性纳米ZSM-5沸石上可有效地转化为芳烃，降烯烃幅度达20个体积百分点以上，改质后汽油的辛烷值、组成和沸程等指标均满足新国标要求．     

"大组讨论、小组实验"化工专业实验的新思路——以甲醇制汽油实验为例

甲醇制汽油工艺参数比较多、实验时固定床反应器中催化剂的装载和反应后的冷却过程时间比较长,在化工综合实验有限的学时内,一组学生不可能将所有的实验参数摸索清楚。针对这种情况,设计了学生“大组集体讨论+小组实验+结果汇总”的实验模式。在保证学生掌握实验基本操作的基础上,得到整个工艺的完整数据,通过对数据的处理和分析,得到一个综合性较强的实验报告。通过实践,该实验模式激发了学生的实验兴趣,提升了实验效率,取得了良好的教学效果。     

Ethanoled gasoline bubble pressure determination: Experimental and Monte Carlo modeling

In this work, we present some experimental and modeling studies of ethanoled gasoline bubble pressures (ethanol + gasoline blends) at various temperatures and ethanol contents. Modelings are carried out using Monte Carlo simulations in a specific bubble-point pseudo ensemble and using the AUA4 force field. This method is first validated on the prediction of binary mixture bubble pressures (ethanol + n-hexane, ethanol + propylene, ethanol + toluene, ethanol + isooctane). It is shown that a good accuracy is reached without introducing empirical binary interaction parameter, demonstrating the predictivity of the approach. Then, simulations of ethanoled gasolines have been performed. The molecular representation of the gasoline is obtained using a lumping scheme from the detailed composition of a commercial gasoline. Simulation results are compared to experimental bubble pressures measured in this work on this commercial gasoline in which various proportions of ethanol have been added. From a qualitative point of view, the azeotropic behavior of such fuels is observed both experimentally and by simulations. From a quantitative point of view, an average deviation of 15% between experimental and simulation data is found. Such results show that Monte Carlo simulation using an accurate force field is an efficient method to predict phase equilibrium of complex mixtures such as oxygenated gasolines. This methodology can thus be seen as an efficient tool that can be used by engineers for fuel formulation or for equation of state or process model calibration.     

中国燃油大气铅排放量估算

依据不同时期车用汽油铅含量国家标准及汽油消费量数据,估算了我国1980—2006年的全国燃油大气铅排放量及2001—2005年分地区燃油大气铅排放量。结果表明,27年间我国因汽油燃烧共计向大气排放了约20万t铅。汽油无铅化后,燃油大气铅年排放量比从前降低了98%。     

磷钨酸季铵盐催化氧化汽油深度脱硫

以十六烷基三甲基溴化铵和磷钨酸为原料制备了磷钨酸季铵盐催化剂,并对催化剂进行了红外光谱和SEM表征。研究了磷钨酸季铵盐为催化剂,双氧水为氧化剂,催化氧化法生产低硫汽油技术。考察了萃取剂以及氧化条件和萃取条件对脱硫效果的影响。结果表明,在汽油10 mL,双氧水0.01 mL,催化剂0.0016 g,氧化温度30℃,氧化时间60 m in的条件下,采用复合溶剂LJ-1进行萃取,萃取温度20℃,静置时间15 m in,剂油比为1时,直溜汽油中的硫含量由179.3 mg/L降至10.8 mg/L,脱硫率达94.0%。氧化萃取时的脱硫率比未经氧化直接萃取时的脱硫率高45.6%,氧化脱硫效果显著。     

环保型汽油清净剂的研制及性能测试

以聚异丁烯基丁二酰亚胺和脲基氨基甲酸酯化合物为复合清净分散剂、多羟基醚类化合物为协同增效剂，研制了环保型汽油清净剂，通过试验确定了各组分的配比。对汽油清净剂进行了性能测试，如模拟试验、铜片腐蚀性能测试和辛烷值测试等。该汽油清净剂对发动机燃油吸入系统有良好的清洗和保洁功能，达到了降低尾气排放和节省燃油的效果。     

Mechanism of reaction of n-butane with but-2-enes in the presence of LaCaX faujasites

The reactions of n-butane and an n-butane (80 mol.%)—isobutane (20 mol.%) mixture with but-2-enes in the presence of polycationic PdLaCaX faujasites were studied. Quantum-chemical calculation of the enthalpies of formation of alkanes C₄—C₈ and their cations showed that the reaction [Bnⁿ]⁺ [Buⁱ]⁺ is of crucial importance for the isomeric composition of the products of alkane alkylation. The general scheme of transformations of the hydrocarbons in the alkylation of n- and iso-paraffins was proposed based on the experimental data on the distribution of the C₈ isomers in the catalyzate at different temperatures and duration of the reaction.     

Problems of producing motor fuels from alternative raw materials

The mechanism and kinetics of reactions occurring in different processes of natural gas processing to motor fuels are considered. Among them are the syntheses of methanol, dimethyl ether, and gasoline from synthesis gas (syngas) and production of pure hydrogen from methanol. The general scheme of carbon-containing raw materials processing to produce motor fuels is considered using natural gas as example. The advantages of the direct synthesis of dimethyl ether (DME) from syngas (instead of methanol synthesis) over all processes producing motor fuels were shown. The synthesis of DME uses the syngas of almost any composition and, hence, the process scheme of carbon-containing feedstock syngas DME gasoline becomes universal and appropriate for processing various raw materials. Prospects of using methanol as an easily transportable source of pure hydrogen were considered. The steam reforming of methanol is a reaction inverse to its synthesis. The oxidation of residual CO in order to purify hydrogen is favored in the mode of catalyst surface ignition. Modern catalysts and methods for removal of CO traces can provide production of pure hydrogen by methanol processing with an efficiency appropriate, in principle, for using the corresponding devices aboard a vehicle.The materials of the report at the III International School Engineering Chemical Science for Advanced Technologies¹ and recent publication² were used in part.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2352–2363, November, 2004.     

FCC硫转移复合助剂的研究

以Mg-Al元素为基础,引入Fe、稀土等元素,制备了一系列FCC（流化催化裂化）液体硫转移复合助剂,负载于FCC平衡剂上,得待评价的催化剂。利用工业模拟装置考察了复合助剂降低FCC烟道气和FCC产品油总硫质量分数的效果。结果表明,同时加入稀土、Fe元素的复合助剂在烟道气和汽油中的降硫效果都较好,经热重仪分析发现,稀土,Fe元素的加入加强了复合助剂吸附氧并转化为结晶氧的能力,使SO2更易被氧化吸收,达到脱硫目的。此复合助剂在烟道气中最高脱硫率可达85.7%,FCC产品油的最高降硫量达到15.8%。通过酸性数据分析和产品油分布对比实验,发现加入少量复合助剂,对FCC催化剂活性和选择性均无不良影响。     

A Robust Thermal Modulator for Comprehensive Two-Dimensional Gas Chromatography

In comprehensive two-dimensional gas chromatography (GC×GC), two capillary columns are connected in series through an interface known as a “thermal modulator”. This device transforms effluent from the first capillary column into a series of sharp injection-like chemical pulses suitable for high-speed chromatography on the second column. Dramatic increases in the resolving power, sensitivity, and speed of the gas chromatograph result. This paper describes the development of a robust and reliable thermal modulator for GC×GC.