Studies on catalysis by molten metals. 14. Catalytic cracking of asphalts at low temperature

The catalytic effects of liquid metals for low-temperature (336 °C) asphalt-cracking have been examined using a semi-batch reactor. All the liquid metals examined (Bi, Cd, Ga, In, Pb and Sn) effectively catalysed the reduction of molecular weight with minimal gasification (<1 wt%). Gasification had a positive correlation with the reduction in molecular weight in the processed asphalts. The catalytic activities of liquid metals tor these two reactions were proportional to a parameter which represents the interaction between the atoms of the catalyst metal and the radicals formed in the course of the reaction. Mass flow among four fractions (saturates, aromatics, resins and asphaltenes) had two independent paths: conversion of resins to saturates and of aromatics to asphaltenes. The former path dominated when catalytic dehydrogenation activity was relatively low, whereas the latter dominated when the catalytic activity was high.     

A KINETIC STUDY OF THE SULPHURIZATION OF RESIDUAL ASPHALTS

The kinetics of the sulphurization reaction of residual asphalts were investigated at temperatures of 220^°-250^°C and reaction time of 1 hr. The apparent reaction order varied from 1.40-3.50 for the range of temperature studied. The maximum reaction order was obtained at 24O^°C which appeared to be the optimum reaction temperature. The apparent kinetic rate parameters estimated for the sulphurization reactions were activation energy of 99.5 kJ/mol and a frequency factor of 15.48 × 10⁸. The rate parameters show some good agreement with other work reported in the literature.     

催化油浆综合利用的技术措施

综述了催化油浆利用技术方面的研究进展,包括炼油装置掺炼,生产道路沥青、针状焦、炭黑,作为橡胶软化剂和填充油等,对催化油浆的综合利用前景进行了展望。     

Studies on Nigerian Crudes. II. Physical Characteristics and Rheological Properties of Residual Asphalts

The characteristics of some residual asphalts samples obtained from Nigerian medium and heavy crudes were studied using ASTM/IP standard tests. The residual asphalts were compared with industrial solid grade asphalts and cut back samples. Penetration and softening point tests performed on the treated samples showed that some of these samples fall within the range of road paving asphalts while sample having a low temperature susceptibility was found to be of better than the solid grade asphalt. The rheological behavior of an asphalt sample was investigated using a rotational viscometer. The sample showed a complex non-Newtonian character with structural breakdown as temperature is raised above its softening point. The study further confirmed the suitability of Nigerian medium crudes for the production of road paving asphalts.     

Effects of polymer modification on the fuel resistance of asphalt binders

Fuel resistance is an important characteristic of asphalt binders, especially when used in airport fields and filling stations. However, the relevant standards are presently lacking and the scientific literature on the development of suited formulations is sparse. In this paper, a simple procedure to assess the fuel resistance of asphalts (considered in a dynamic sense) is proposed. A number of polymer modified asphalts (PMAs), prepared from two bases and 4 or 6 wt% of several polymers, have been analyzed with this procedure and the relationships between fuel resistance and morphology of the PMAs, the chemical structure of the polymers and the composition of the asphalt bases have been investigated.     

Study on Composition and Structure of Liaoshu Asphalt

Abstract

In this article, the structure characteristics of Liaoshu paving asphalts have been studied by the methods of element analysis, SARA and E-D-M. At same time, the relation between composition and structure and using performance of Liaoshu paving asphalt were established. The experimental results show that carbon and hydrogen contents were more than 95%, the hydrogen/carbon atom ratio was about 1.5 in the Liaoshu paving asphalts. The content of saturates is between 20 and 25% in the Liaoshu paving asphalt, aromatics 35–40%, resin 25–30%, and asphaltene 8–10%. There are 45 carbon atoms in asphalt average molecule, which contain 16–17 aromatic carbon atoms. The number of total ring in asphalt average molecule is 5–6, the aromatic ring is 3–4, the naphthene ring is 1–2.     

连续式静态混合器沥青改质研究

对上海石油化工股份有限公司溶剂脱沥青ＤＯＡ进行连续式静态混合器改质，制备出合格的６０号甲和１００号甲道路沥青，并对此二种道路沥青进行马歇尔试验，表明二种道路沥青具有较好的路用性能，说明静态混合器连续式沥青改质是一种有效的沥青改质手段。     

Influence of Chemical Composition on the Physical Characteristics of Paving Asphalts

The simplest general compositional model considers asphalt to be made up of asphaltenes, heavy oils, and resins. In the present study the extent of similarity between the properties and composition of various types of asphalt obtained from different sources has been carefully explored. It shows how ductility, penetration, and softening point are related to the chemical nature of paving asphalts in the range 41-58 softening points. Asphalt properties are found to be a direct function of its chemical constituents. The relationship between softening point and asphaltene content was found to be linear while asphalts of the same softening point are easily distinguished by the content of the resins. Evaluation of the two asphalt indices—the asphaltene index (I_A) and the Gaestel index (I_C), reveals that they both vary linearly with the composition of asphaltenes and resins thus confirming their suitability in the characterization of asphalts. Comparison of the two indices shows that IC is more suitable in estimating the colloidal stability of different groups of asphalts. The observed correlations can be found useful in the areas of asphalt blending and rejuvenating through the appropriate selection of asphalt components.     

HON-DESTRUCTIVE EXTRACTION IECHANIS1 OF BITUMINOUS COALS USING K-IETBTL-2-PY1LR0LID0NE

ABSTRACT

A technique whereby substantial portions of bituminous coals are extracted, non-destructively using N-Methyl-2-Pyrrolidone under mild conditions (202° C and 1 atm pressure) was previously reported. Herein, a parametric study on the extraction step is presented and a possible mechanism on the extraction is proposed. The extent of extraction shows little dependence on the solvent-to-coal ratio, coal particle size and treatment time whereas coal type and treatment temperature significantly affect the extent of extraction. Extractions for 26 different coals are reported and the results show reasonable correlation with the ratio of the volatile matter to fixed carbon (VM/FC), i.e. the inverse of the fuel ratio of the coal.

A postulated mechanism of extraction is based on the assumption of the two-phase structure of coal. Electron Paramagnetic Resonance (EPR) studies of the raw coal, and unextracted and extracted species support the proposed mechanism and lend support to the two-phase model of coal structure. The ratio (VM/FC) seems to be a fundamental parameter which relates coal properties to the accessibility of extractable components in the coal matrix.     

Study on Composition and Structure of Liaoshu Asphalt

In this article, the structure characteristics of Liaoshu paving asphalts have been studied by the methods of element analysis, SARA and E-D-M. At same time, the relation between composition and structure and using performance of Liaoshu paving asphalt were established. The experimental results show that carbon and hydrogen contents were more than 95%, the hydrogen/carbon atom ratio was about 1.5 in the Liaoshu paving asphalts. The content of saturates is between 20 and 25% in the Liaoshu paving asphalt, aromatics 35 and 40%, resin 25 and 30%, and asphaltene 8 and 10%. There are 45 carbon atoms in the average asphalt molecule, which contain 16-17 aromatic carbon atoms. The number of total ring in the average asphalt molecule is 5-6, the aromatic ring is 3-4, and the naphthene ring is 1-2.