摘要:

The problem concerning the determination of asphaltene molecular weight has been critically investigated. A size exclusion chromatography (SEC) analytical method has been developed using innovative calibration standards. The obtained results have been compared with those derived from vapor pressure osmometry (VPO). All the experimental data indicate that the number-average molecular weights (Mn) determined either by SEC or VPO are always different Nevertheless such discrepancies are less pronounced using the new calibration curve instead of either the conventional polystyrene standards or other polymers such as poly(ethylene glycol). Furthermore it has been observed that VPO measurements, considered to give the most reliable Mn values when performed in a highly dissociating solvent, at high temperature and low concentration, fails when strong interactions among single molecules are present.

ISSN:0884-3759    

DOI:10.1080/08843759508947735

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The sludge formed from crude oil (Bombay High crude oil) dump storage has been analysed by solvent extraction with a series of solvents of increasing polarity. The extract fractions so obtained have been analysed extensively. The nature of the sludge is compared with the similar sludges reported by other workers.

ISSN:0884-3759    

DOI:10.1080/08843759508947734

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Relation between swelling ratio of lignites and lignite and solvent characteristics was developed using a third level factorial design with three variables; percent carbon content, particle size of the lignite and electron donor number of the solvent. The results indicate that particle size of the lignite does not affect the swelling ratio. While swelling ratio of the lignites decreases slightly with increasing carbon content of the lignites electron donor number of the solvent has a noticeable effect on the swelling ratio.

ISSN:0884-3759    

DOI:10.1080/08843759508947736

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In the present work, coal co-processing with sugar cane bagasse oil was studied for the first time. Sugar cane bagasse was chosen due to its great offer, since it is a residue in the process of a large project named PROALCOOL aiming the producing ethanolfrom sugarcane. In addition, the liquefaction of sugar cane bagasse with monoethanolamine was already developed in our laboratory showing good results. Four coal samples were studied. The yields of the total conversion and the oil productions were obtained in order to evaluate the efficiency of the liquefaction process studied.

ISSN:0884-3759    

DOI:10.1080/08843759508947737

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In the present work, the chemical characterization of the oils obtained from liquefaction of different coals with sugar cane bagasse oil and also from the liquefaction of coal with monoethanolamine are presented. Characterization of the oil samples was done with the add of spectroscopic and chromatographic techniques, including UV-vis, FTIR, NMR, preparative liquid chromatography (PLC) and high resolution gas chromatography (HRGC).

ISSN:0884-3759    

DOI:10.1080/08843759508947738

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In this paper simulated distillation employing HRGC (high resolution gas chromatography) was used to evaluate the quality of the oils obtained from coal co-processing using sugar cane bagasse oil as the process solvent. Four coal samples were used, two of them corresponding to Brazilian coals, one to an American coal and one to a Polish coal. The results shows that the oil produced through co-processing with sugarcane bagasse oil presents characteristics of lighter oils than those obtained by direct liquefaction of coal with monoethanolamine as solvent.

ISSN:0884-3759    

DOI:10.1080/08843759508947739

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The oxidation and age-hardening propensities of eight widely varying petroleum asphalts used for paving were studied with and without hydrated lime, and with inert particulate matter in place of lime. The results show that oxidation of sulfides to sulfoxides and benzyl carbon to ketone is affected very little by the presence of lime. However, the addition of lime does inhibit age-hardening in asphalt whereas the inert particulate matter in the same amount and particle size has little effect other than the filler effect exhibited by the lime and the inert particulate.

ISSN:0884-3759    

DOI:10.1080/08843759508947740

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The elemental composition (C, H, N, S, O) of asphaltenes isolated from coal liquefaction experiments carried out at different temperatures and tetralin/coal ratios has been determined. The liquefaction experiments were conducted in a 250 ml autoclave, with 10 g of a Spanish subbituminous A coal, for 1 hour, and at 17 ± 1 MPa operating pressure and 400 rpm stirring speed. The liquefaction products were fractionated into oils, asphaltenes and preasphaltenes using pentane, toluene and THF as extractive solvents. The % S and % O are lower in asphaltenes than in coal, while the % C and % N are higher and % H depends on the temperature and tetralin/coal ratio used. On the other hand asphaltenes % C decreases, and % H and % O increase as the tetralin/coal ratio is raised at every temperature except 475 °C, while % S and % N do not have a clear variation.

ISSN:0884-3759    

DOI:10.1080/08843759508947741

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor