ADSORPTION OF ASPHALT FUNCTIONALITIES AND OXIDIZED ASPHALTS ON AGGREGATE SURFACES

ABSTRACT

The adsorption of asphalt functionalities and asphalt oxidized to different degrees on real and model aggregates has been investigated. The functionalities used were: nitrogen-base, phenolic, carboxylic acid, ester, ketone, sulfoxide, and polynuclear aromatic. Adsorption isotherms of these functionalities on porous silica showed different affinity rankings dependent upon concentration. The competitive affinity ranking of the asphalt functionalities on dried silica was obtained as phenylsulfoxide > qulnoline > phenol > benzoic acid > benzophenone > benzylbenzoate > pyrene. The sensitivity to moist silica surface of the four most strongly adsorbed compounds was: qulnoline > benzoic acid > phenol > phenylsulfoxide.

Asphalts oxidized to different degrees were adsorbed on different aggregates. On silica and alumina, the oxidized asphalts with viscosities of 32,000 and 126,000 poise were adsorbed less than AC-20. On limestone and sandstone, the adsorption of AC-20 and oxidized asphalts was concentration dependent; asphaltene adsorption followed the same trends. These adsorptions followed the Langrauir isotherm with monolayer coverage decreasing with increased oxidation.

functionalities such as ketones produced during oxidation are not as strong adsorbers as other functionalities; thus, changes in chemical composition during oxidation may result in substantial changes in asphalt adsorptive behavior. As oxidation increased in the different asphalts, the monolayer coverages of the asphalts decreased. Aggregate sensitivity to oxidation ranked in the order of silica > alumina > sandstone > limestone. Thus, the adsorptive behavior of an asphalt is a function of both the degree of oxidation and the aggregate onto which it is adsorbing.     

MULTT-COMPONENT ADSORPTION OF ASPHALT FUNCTIONALITIES ON SILICA

ABSTRACT

Single- and multi-component adsorption of compounds representing highly polar functional groups in asphalt onto SI-1000 silica has been performed at 25?°C using cyclohexane as a solvent. The asphalt functionalities used are benzoic acid (strong acid), 1-naphthol (weak acid), phenanthridine (strong base), and phenyisulfoxide (weak base). The bi-, tri-, and quadh-component adsorption behaviors demonstrated that the competitive adsorptive affinities of the asphalt functionalities for the silica are ranked as 1-naphthol < benzoic acid » phenanthridine < phenyisulfoxide. The prediction of multi-component adsorption equilibria has been made by applying the Langmuir Competitive Model (LCM) and the Ideal Adsorbed Solution Theory (LAST) to single-component adsorption data. Both the LCM and the LAST provided a good prediction for benzoic acid/1-naphthol and phenanthridine/phenyisulfoxide combinations. In the cases that involved acid-base combinations, however, both the LCM and the LAST yielded predictions that deviated from actual behavior. This deviation was most likely caused by the nonideal behavior of strong adsorbate-adsorbate interaction in the adsorbed phase     

AN INVESTIGATION OF THE EFFECT OF ANTISTRIPPINGAGENTS ON SILICA ADSORPTION OF ASPHALT FUNCTIONALITIES

ABSTRACT

The effect of precoating antistripping (AS) agents onto silica on the adsorption behavior of model asphalt functionalities has been examined. Two commercially available polyamine AS agents were used. Their adsorption onto silica showed a strong surface interaction. One of the AS agents followed the Langmuir adsorption model; the other did not. After removing the weakly adsorbed AS fraction by washing with dichloromethane, seven asphalt functionalities In cyclohexane solution were adsorbed onto the precoated silica. The functionalities used represented those present in asphalt and were carboxylic acids, phenolics, nitrogen bases, sulfoxides, ketones, esters, and polynuclear aromatics. The adsorption of benzoic acid and phenol was increased by precoating with AS agents, whereas the other functionalities showed large decreases in their adsorption due to the precoated AS agents. The enhanced adsorption shown by benzoic acid and phenol is likely due to an acid-base interaction between the basic AS agents and the acidic model compounds.     

AN INVESTIGATION OF THE EFFECT OF ANTISTRIPPINGAGENTS ON SILICA ADSORPTION OF ASPHALT FUNCTIONALITIES

The effect of precoating antistripping (AS) agents onto silica on the adsorption behavior of model asphalt functionalities has been examined. Two commercially available polyamine AS agents were used. Their adsorption onto silica showed a strong surface interaction. One of the AS agents followed the Langmuir adsorption model; the other did not. After removing the weakly adsorbed AS fraction by washing with dichloromethane, seven asphalt functionalities In cyclohexane solution were adsorbed onto the precoated silica. The functionalities used represented those present in asphalt and were carboxylic acids, phenolics, nitrogen bases, sulfoxides, ketones, esters, and polynuclear aromatics. The adsorption of benzoic acid and phenol was increased by precoating with AS agents, whereas the other functionalities showed large decreases in their adsorption due to the precoated AS agents. The enhanced adsorption shown by benzoic acid and phenol is likely due to an acid-base interaction between the basic AS agents and the acidic model compounds.     

石料的碱值对沥青混合料水稳定性的影响

沥青与石料的粘附性好坏直接影响着沥青混合料的耐久性。如果石料选择不当且不掺外加剂，这就很难得到稳定的沥青混合料。本文探讨了不同性质的石料对沥青混合料水稳定性的影响，提出了满足沥青混合料水稳定性指标的石料碱值大小。     

ADSORPTION OF ASPHALTS AND THEIR SIZE EXCLUSION CHROMATOGRAPHY FRACTIONS ON AGGREGATE SURFACES

The adsorption behavior of two asphalts and their size exclusion chromatography (SEC) fractions from toluene solution onto aggregate was investigated. The effect of the differences in chemistry and molecular size of the asphalt samples on their adsorption behavior on silica, granite and greywacke was determined. The adsorption of asphalts and SEC fractions on SI-1000 silica was well-represented by the Toth model, while the Radke-Prausnitz model better described their adsorption behavior on both granite and greywacke. Combining the adsorption models with the Gibbs adsorption equation of state gave the spreading pressure of each adsorbate species adsorbed on the aggregate surfaces. The spreading pressure predicted the competitive adsorptive edge of the asphalt fractions. The SEC I fractions, containing molecules of larger molecular size and higher heteroatom contents, showed higher spreading pressures than the SEC II fractions, which contained molecules of smaller molecular size and fewer heteroatoms. The asphalts yielded intermediate spreading pressures for SI-1000 silica and granite, but they gave the highest spreading pressure values for greywacke.     

FLOW MICROCALORIMETRY AND SALI STUDIES OF THE ASPHALT/AGGREGATE INTERFACE

ABSTRACT

Sorption flow microcalorimetry methods were developed for measuring the amounts and heats of adsorption and desorption at the asphalt-aggregate interface. Model studies of the amounts and heats of phenylsulfoxide sorption on SHRP aggregates RH-greywacke and RC-McAdams limestone indicated strong and irreversible bonding of a large fraction of adsorbed phenylsulfoxide that resisted displacement by cyclohexane and water. In addition, the microcalorimetry results indicated that intermolccular interactions between adsorbed phenylsulfoxide molecules were very strong at submonolayer coverages. This suggests that phenylsulfoxide adsorbs with the sulfoxide directly attached and oriented perpendicular to the surface with strong face-to-face interactions of the phenyl groups. Similar experiments conducted on the sorption of SHRP asphalts AAD-1 and AAM-1 from solution on the RC and RH aggregates indicated significant differences in the sorption of these four asphalt-aggregate pairs. Similar to phenylsulfoxide, a large fraction of both asphalts adsorbed irreversibly with respect to cyclohexane and water-saturated cylohexane desorption. Surface analysis by laser ionization (SALI) was used to measure surface compositions of the aggregates and to monitor temperature programmed desorption (TPD) of adsorbed phenylsulfoxide. SALI analysis indicated that a significant fraction of die RC aggregate is covered with an aluminosilicate layer although bulk analysis indicates that this aggregate is predominantly limestone. TPD studies confirmed the microcalorimetry results that a large fraction of phenylsulfoxide irreversibly binds to silicate and aggregate surfaces and moreover that this irreversible binding leads to deoxygenation of the sulfoxide to sulfide at relatively low temperatures     

微生物对沥青集料间粘附作用的影响

沥青混合料的剥离是沥青路面几种常见破坏现象之一。通常认为沥青混合料水稳性主要依靠沥青与集料间的粘附程度，它同沥青集料间的物理化学作用密切相关。本文分析了微生物对沥青集料粘附作用的影响，这对改善沥青路面水稳性有重大意义。     

对我国石油资源评价的回顾与展望

对我国石油地质理论和油气资源评价的发展,近几年来曾有过一些总结和论述。本文试图从勘探实践的发展过程出发,作一些讨论。从二十世纪初期开始,八十多年来,随着地质学和石油地质学的发展、钻采技术的提高以及基础科学向石油地质学的渗透,对我国石油资源的认识、评价、预测不断深化。     

国产重交通道路沥青与进口沥青竞争现状及对策

详细介绍了国产重交通道路沥青的产量、营销现状及进口沥青的现状，并对它们进行了对比分析，指出了国产重交沥青存在的差距，并提出了合理的建议。     

沥青的酸值对沥青混合料水稳定性的影响

沥青与石料的粘附性好坏直接影响沥青混合料的耐久性。如果沥青选择不当且不掺外加剂，就很难得到稳定的沥青混合料。为此，探讨了不同性质的沥青对混合料水稳定性的影响，并提出了满足沥青混合料水稳定性指标的沥青酸值范围。酸性石料组成的混合料，必须对沥青进行改性处理后才能满足水稳定性要求。中性石料组成的混合料，当沥青酸值＞３．２ｍｇＫＯＨ／ｇ时，能满足抗水害要求；当沥青酸值＞３．５ｍｇＫＯＨ／ｇ时，混合料间接抗     

集料吸入沥青数量评价方法的研究

研究了集料吸入沥青数量评价方法，以便在沥青混合料配合比设计中得出正确的空隙率、骨贺间隙率和沥青饱和度，从而满足路面性能的要求，研究结果表明，采用实测沥青混合料在150℃，老化4h最大理论密度的方法可以决定集料吸入沥青数量的多少。     

THE PROPERTIES OF WATER LAYERS ON COAL SURFACES

ABSTRACT

The results of programmed thermodesorption investigations of water from coal surfaces are presented and correlated with the measurements of water adsorption and desorption from the gaseous phase at a temperature of 20^°C. From the data obtained, the activation energies of water molecules were calculated and possible structures of water adsorbed layers on the coal surfaces were suggested. On the basis of the DTA curve, the water adsorption heat on the coal surfaces 20^°C was calculated and presented in the form of dependence on water adsorption value from the gaseous phase.     

THE PROPERTIES OF WATER LAYERS ON COAL SURFACES

The results of programmed thermodesorption investigations of water from coal surfaces are presented and correlated with the measurements of water adsorption and desorption from the gaseous phase at a temperature of 20^°C. From the data obtained, the activation energies of water molecules were calculated and possible structures of water adsorbed layers on the coal surfaces were suggested. On the basis of the DTA curve, the water adsorption heat on the coal surfaces 20^°C was calculated and presented in the form of dependence on water adsorption value from the gaseous phase.     

陇东油区石油类物质在土壤中的吸附解吸行为研究

洒落在油区土壤中的原油在土壤中发生吸附解吸、迁移转化以及降解等一系列复杂的理化作用,而吸附解吸行为是制约原油在土壤中迁移入渗的关键步骤。通过静态吸附和解吸实验,研究了原油在以黄绵土为主的陇东油区土壤中的吸附解吸行为,考察了温度、pH、土壤盐度等因素对吸附量的影响,结果表明:黄绵土对石油类物质的等温吸附过程可以用Langmuir等温吸附模型描述,吸附动力学过程可以用二级动力学方程很好地描述。通过吸附解吸行为研究,得出石油类物质易被黄绵土吸附,但是由于吸附量较小,且吸附作用以物理单分子层吸附为主,易发生脱附迁移。     

石油磺酸盐/烷醇酰胺复配体系吸附损耗及色谱分离研究

以石油磺酸盐、烷醇酰胺形成的复配体系为研究对象,油砂为吸附介质,考察了吸附损耗和色谱分离。实验结果表明,在温度70℃、质量分数0.2%、溶液体积和油砂比例为3∶1(mL/g)的条件下,石油磺酸盐和烷醇酰胺的平衡吸附量分别为1.2mg/g和6.9mg/g;最大吸附量分别为7.0mg/g和10.3mg/g。石油磺酸盐和烷醇酰胺之间存在色谱分离现象,同时存在色谱重叠现象。以色谱分离度为评价指标,建立该体系的色谱分离模型,并以此为标准对石油磺酸盐和烷醇酰胺之间是否发生色谱分离和色谱分离程度进行了评价。     

江汉油气区发现过程之回顾与讨论

江汉盆地的油气,大都集中于沉积范围收缩的早第三纪晚期裂谷盐湖沉积系列中,由盐湖一侧发育的水下冲积扇砂体和组成旋卷构造体系的盐背斜共同控制而富集。这在国内外油区中是一种独特的类型。由于重视了区域地质研究,因而重点坳陷的确定和主要生油凹陷与目的层系的选择都很顺利。但因对岩相控油一度认识不足且缺乏相应勘探手段,在预测油田时曾走过一段弯路。     

石油羧酸盐的磁化降吸附研究

探讨了磁化前后，石油羧酸盐表面活性剂在高岭土表面静吸附规律的变化。实验发现，经磁化处理的石油羧酸盐表面活性剂，在高岭土表面的吸附速度变快，液固比变小，吸附等温线仍有最大值，但已大为下降，从而推断其吸附模式发生改变。     

石油羧酸盐在高岭土上静吸附规律的实验研究

本文在实验基础上研究了石油羧酸盐表面活性剂在高岭土上的静吸附量随时间、液固比、含盐量、活性剂浓度而变化的规律，观察到了吸附最大值，对全部实验结果作了理论解释。     

十六烷基三甲基溴化铵在钠、铝蒙脱土吸附研究

用静态法在pH2-12范围内研究了十六烷基三甲基溴化铵（HDTMAB）在钠和铝蒙脱土上的吸附反应,得到了吸附等温线。结果表明,HDTMAB在这两种蒙脱土上的吸附有离子交换和分子吸附两种机理;pH值增加时吸附量增加,Al^3 不易被交换,因而在铝蒙脱土上吸附量较钠蒙脱土上少。