氢、碳氢燃料对向扩散火焰

对氢、正烷烃碳氢燃料与氧的对向扩散火焰,其中正烷烃包含了在工业用燃料中广泛应用的C_nH_2n+2正烷烃CH₄～C1₆H₃₄,对这些燃料的火焰结构进行了分析和比较,系统地分析了压力和拉伸率对火焰行为和热释放率等的影响,其中包含了2115个组分8157个可逆反应．研究结果表明,所有燃料的火焰厚度和热释放率与压力和拉伸率的乘积的平方根成线性关系．在相同工况下,氢的火焰厚度总是大于所有的碳氢燃料,而CH₄～C1₆H₃₄所有的碳氢燃料在相同工况下总是具有几乎相同的燃烧温度分布、燃烧产物分布、火焰厚度和热释放率,该结果表明由这些碳氢燃料组成的混合燃料具有同样的火焰特性.     

采用核磁共振信息的FACE汽油替代燃料机理构建

提出了一种基于核磁共振分析所得的官能基团信息来构建替代燃料模型的新方法。根据核磁共振的光谱信息,定义了五种基本官能基团:烷烃CH_3基团、烷烃CH_2基团、环烷烃CH-CH_2基团、烯烃CH-CH_2基团和芳香烃C-CH基团,并通过匹配实际燃料的这些官能基团来构建FACE汽油替代燃料。选取正丁烷、正庚烷、异辛烷、甲苯、2,5二甲基己烷、甲基环己烷和1-己烯作为备选基础燃料,根据FACE F、FACE G、FACE I和FACE J四种目标燃料的官能基团信息选取合适的替代燃料组分,进而构建相应的替代燃料模型。将所获得的替代燃料机理用于模拟不同初始条件下激波管内的燃料氧化燃烧,模拟结果与实验数据的对比表明,所构建的替代燃料机理能较好地预测FACE汽油在不同温度、压力和当量比条件下的着火特性。     

瞬态发射光谱法研究正十二烷燃烧反应特性

采用加热激波管和增强型CCD瞬态光谱测量系统,在波长范围200~900nm,点火压力4.0atm,点火温度(1 200~1 300)K,当量比0.5、1.0和2.0的条件下,实时测得了正十二烷/空气和正十二烷/氧气/氩气燃烧过程的瞬态发射光谱.结果表明:燃烧过程在此波段内的主要发射光谱带归属于反应中间产物OH、CH和C2自由基;在不同当量比条件下,燃烧过程中OH(306.4nm)/CH(431.4nm)/C2(516.4nm)的光谱强度显著不同,贫油情形有利于OH自由基生成,富油情形有利于C2自由基生成;浴气的不同会导致燃料燃烧温度的不同,从而引起燃料燃烧发射光谱的不同.所测燃烧反应自由基的时间分辩光谱直观反映出正十二烷燃烧过程中重要中间产物OH、CH和C2的变化情况.研究结果有助于认识正十二烷燃烧反应特性和验证其燃烧反应机理.     

环烷烃及烷烃的折光指数与结构的关系研究

以分子拓扑学点价和自相关函数研究为基础,设计开发出一种新的以点价计算为基础的结构信息自相关拓扑指数tX.基于多元线性回归技术建立了对环烷烃及其烷烃的折光指数作出估算的定量结构性质关系.点价被定义为βi,由βi建构结构信息自相关拓扑指数tX.得到了它们与64种环烷烃的折光指数(nD)的二元回归方程和与27种烷烃的折光指数的二元回归方程.对环烷烃和烷烃折光指数的计算结果表明,计算值与实验值的一致性令人满意,平均误差为0. 25% .利用建立的模型,对另外5种烷烃的折光指数进行了预测.     

煤基化学链燃烧过程中硫的演变

在双阶段流化床反应器内,基于溶胶凝胶法制备的Fe2O3/Al2O3氧载体研究了褐煤化学链燃烧过程中燃料硫的迁移路径及分布特性,并讨论了温度、过氧系数对燃料硫释放分布的影响.结果表明:所有工况下,氧载体均未出现被硫化的现象;在热解气化学链燃烧阶段,气相含硫物质以SO2和H2S为主,煤焦气化气化学链燃烧阶段绝大部分为SO2气体,部分来源于煤焦中CaSO4的分解。另外,部分燃料硫被碱金属固定于煤灰中。同时,提高温度和过氧系数都能导致SO2/H2S值和SO2释放量增大。     

一种新型生物柴油替代燃料模型

为了分析实际生物柴油的燃烧特性,综合考虑了燃料的分子量、碳氢比、化学键能和十六烷值等特性,基于丁酸甲酯、醋酸乙酯、癸酸甲酯与正十二烷四种燃料,采用配平原子个数和十六烷值的方法构建了反映生物柴油基本燃烧特性的一种新的替代燃料模型。通过不同工况下模拟结果与实验数据的比较,对该方法的合理性进行了验证,结果表明该替代燃料模型能较好地预测生物柴油在不同压力、温度和当量比下的氧化过程。该机理构成方法为替代燃料机理的构建提供了新的思路。     

可变偏心因子及对饱和蒸汽压计算的应用

一、前言 纯组分的饱和蒸汽压可用状态方程计算得到。当在使用状态方程方法计算相平衡及以热力学上一致性确定饱和态p-u-T关系时,这是十分有用的。本文从对比态原理讨论,认为偏心因子值是可变的。然后使用具有可变ω值的通用对比态方程计算正烷烃类饱和蒸汽压,得到了十分满意的精度。     

添加种子的煤燃烧产物的组分、热力和电物理性质

以煤为燃料的磁流体发电正引起各国磁流体发电研究工作者的极大兴趣,因此计算添加钾盐种子的煤燃烧产物的化学平衡组成、热力和电物理性质已成为重要的课题. 本工作有以下几个特点: 1.目前磁流体发电有多种燃煤方式,本文考虑了可能采用的两种主要燃煤方法:一级燃烧不排煤渣,种子与燃料同时输入;煤先与部分氧化剂进行燃烧,排渣以后再输入其     

烷烃/正庚烷和醇/正庚烷二元燃料低温着火特性的模拟研究

二元燃料燃烧技术作为一种应用替代能源的技术已经被广泛应用,为了深入地理解天然气、液化石油气和醇类等被引燃燃料对柴油低温着火的推迟影响,本文对二元燃料低温着火过程进行了模拟研究。结果表明,在初始温度小于1000 K时,被引燃燃料推迟正庚烷着火的能力由高到低的顺序为:乙烷丙烷正丁烷正戊烷正己烷,从正戊烷开始,被引燃燃料对正庚烷着火的抑制作用开始消失。甲醇和乙醇几乎没有低温反应活性,它们将活泼的OH转化为了稳定的H_2O_2;醛类和烯醇的生成反应是醇类燃料推迟正庚烷着火能力强于对应烷烃燃料的原因。     

自贡地区恐龙骨骼化石及围岩特征的研究

自贡地区恐龙化石埋藏丰富、分布广泛、保存完整,具有重要的科学价值、社会价值和经济价值。用X荧光衍射研究自贡恐龙骨骼化石及围岩元素组成,XRD结合红外光谱仪分析确定化石的矿物组成,化石切片和显微观察了解骨骼内部构造和填充物质。恐龙骨骼化石及围岩中的含钙量均较高(5%),但化石含钙量达到30%以上;化石中的含硅量较低(0.24%—1.45%),围岩中的含硅量较高(14%);化石中的含磷量为围岩的46倍以上。化石的主要化学成分是碳氟磷灰石,其次是碳酸钙;围岩的主要成分是二氧化硅。实验结果可为恐龙化石的鉴别及保护材料的研制提供理论依据。     

高光谱成像砖红壤中石油烃含量的可视化研究

高光谱成像具有快速无损和图谱合一的特点,每个波段都会呈现一幅图像,每个像素点都显示一条光谱曲线,不仅可以获取样本的光谱信息,还可以表征物体的空间信息,目前在诸多领域展现出极大的应用价值。采用高光谱成像实现土壤中石油烃含量分布的可视化。制备不同石油烃含量的砖红壤样本,分为建模样本和预测样本。采集高光谱图像,为避免图像背景的干扰,采用掩膜的方法进行背景剔除。之后提取建模样本中感兴趣区域的平均光谱,采用连续投影算法筛选特征变量,基于提取的特征变量,一方面建立MLR预测模型,另一方面从预测样本中提取特征波段的高光谱图像。最后,将特征图像上像素点的数据代入模型,得到石油烃的含量分布情况。通过图像处理的方法,不同的含量赋予不同的颜色,实现砖红壤中石油烃含量分布的可视化。研究结果表明,采用高光谱成像与图像处理方法能够初步实现砖红壤中石油烃含量分布的可视化,为以后大范围地识别和反演土壤中石油烃含量提供了基础。     

Temperature distribution above a heated surface in a CVD reactor with hydrocarbon-containing gaseous mixtures

Pyrolysis of C₂H₂ and CH₄ gases near a heated surface was investigated using coherent anti-Stokes Raman spectroscopy (CARS). Gas temperature and hydrocarbon density spatial profiles above the surface of deposition were measured. Although the measured hydrocarbon density distribution above the surface showed a gradual decrease upon approaching the surface, the observed temperature distribution revealed the presence of a temperature maximum at distances of 300-600 7m from the surface. The appearance of this maximum is explained by the release of condensation energy in the region where intensive homogeneous nucleation of carbon clusters takes place.     

Characterization of carbonate rocks through X-ray microfluorescence and X-ray computed microtomography

Carbonate rocks play an important role in petroleum geology by acting as reservoir rocks, generators, and even hydrocarbon sealants, accounting for about half of the oil and gas reserves known in the world. The study of these carbonate rocks have become very important in the hydrocarbon exploration scene in Brazil because of they consist in analogous for reservoir rocks of the presalt interval. Thus, the objective of this research was to use X-ray microfluorescence (micro-XRF) and X-ray microtomography analysis, as complementary techniques, in order to characterize samples of carbonate rocks in respect to their structures, textures, mineralogy, and pores. The microtomographic analyses allowed the identification of the horizontal structures as parallel lamination, horizontal, and vertical fractures filled by calcite and biotic constituents (gastropods bioclasts). Different composition of minerals were also identified, as calcite, quartz, feldspars, iron sulfides, and oxides. The porosity (ranges <1 to17%), and the high-density elements could also be quantified, as well as their distribution in each sample. The micro-XRF analysis present a direct relationship with the distribution of minerals that compound carbonate rocks, highlighting some structures, as well as helping to identify trace and minor elements in the carbonates (Mn, Sr, and Mg).     

Distribution and dimerization of some μ-imidodiphosphates

The distribution of chelate-forming reagents on a basis of arylimidodiphosphate between different organic solvents and 0.1 mol L⁻¹ HNO₃ has been studied by liquid-liquid extraction of ⁴⁶Sc. The values of dimerization constants K₂ in selected solvents, particularly on the chlorine and chlorine-fluorine hydrocarbon basis as well as distribution constants K_D(HA) have been determined.     

CYCLCROP indirect 13C mapping for long-time and chemical-shift selective diffusion measurements in complex hydrocarbon systems

Cyclic cross-polarization from a proton magnetization to ¹³C and from there back to proton coherences permits the indirect, ¹³C chemical shift selective detection of hydrocarbon compounds in the proton NMR channel. This excitation technique can be combined with elements of one-, two- or three-dimensional magnetic resonance imaging permitting the measurement of time-resolved spatial distributions of hydrocarbon components. Beginning this sort of CYCLCROP mapping experiment with a non-equilibrium distribution of the constituents in the system allows one to study the time evolution of the concentrations of all components that can be identified by characteristic ¹³C resonance lines. As applications, studies of ingress, mixing, gel formation, transport and metabolism in living plants, long-time inter- and self-diffusion in complex hydrocarbon systems are suggested. As a test experiment, the diffusion of methanol in swollen polymethylmethacrylate was examined.     

Surface studies of radiation grafted sulfonic acid membranes: XPS and SEM analysis

PTFE-g-polystyrene sulfonic acid membranes prepared by radiation-induced graft copolymerization of styrene onto poly(tetrafluoroethylene) (PTFE) films followed by sulfonation reactions were investigated with respect to their morphology and surface chemical properties. The chemical composition of the membranes surfaces was monitored at various degrees of grafting using X-ray photoelectron spectroscopy (XPS). Considerable differences in the concentration of the chemical components of the surfaces were observed despite the predominance of all membranes surfaces by a hydrocarbon fraction originated from the incorporated sulfonated polystyrene grafts. The distribution of the sulfonated polystyrene grafts in membranes having various degrees of grafting was investigated by scanning electron microscopy (SEM). The membranes achieved a homogenous distribution at degrees of grafting of 24% and above. The results of this work suggest that the membranes have a chemically sensitive surfaces and this is most likely to have an impact on their interfacial properties and chemical stability.     

基于近红外漫反射光谱的烃源岩生烃潜量的确定

对比了近红外光谱和中红外光谱对烃源岩样品生烃潜量的定量分析能力.由于近红外光谱受样品的颗粒度、密度、表面粗糙度等造成的光散射的影响更大,使得其漫反射光谱数据的信噪比很低,背景干扰很大,很难直接应用于定量分析.因此需要一种有效的方法对近红外漫反射数据进行预处理来消除散射的影响.本文对比了正交信号校正算法(OSC)及其两种...     

NMR investigation of hydrophobe molecule solubility in a DBS micelle solution

The distribution of hydrophobe molecules in the volume of a micelle of sodium dodecylbenzene sulfonate was examined by high resolution NMR spectra. The supposition of an arrangement of the hydrocarbon chains in the micelle volume of a large density in the center and small density in the periphery was confirmed.     

C-14 tracer studies on zeolite catalysis

To elucidate the mechanism of hydrocarbon conversion on zeolite catalysts, small amount of ¹⁴C-labelled substances were added to the regular feed. Catalytic studies on isomerization of m-xylene and n-butene were carried out in a fixed-bed microreactor and the ¹⁴C distribution was determined by Radio-GC and Radio-HPLC.     

冷凝法油气回收技术与应用

油品在储运和销售过程中部分轻烃组分挥发进入大气,造成资源浪费和环境危害.油气回收既可实现油气污染治理又能产生可观的经济效益.结合中国油气储运和销售环节的现状以及相关技术的发展,对几种油气回收的方法进行了对比分析,认为采用多元工质复叠(或自复叠)制冷技术的冷凝法具有较好的经济性和可靠性.介绍了自主研发的冷凝式油气回收设备...