摘要:

A generalized viscosity correlation has been used to predict the viscosity-temperature relationship of bitumen mixed with various proportions of diluents such as GCOS synthetic crude, mobil solvent and naphtha. The results showed that the correlation can accurately predict the viscosities of bitumen-diluent mixtures based on a single viscosity measurement at 30°C and one atmosphere. For 300 experimental points, the correlation yielded an overall average absolute deviation between predicted and experimental values of 8.7%. It is found that the correlation gave high percent errors for mixtures with high disparity in viscosity between bitumen and diluent.

ISSN:0884-3759    

DOI:10.1080/08843759508947700

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A gravimetric method using an eledrodynamic balance was developed for the measurement of transport properties such as the diffusion coefficient, D, solubility, S, and permeability, P, for oxygen into thin layers of asphalt materials deposited on aggregate and glass particles. Glass spheres and aggregate particles in the 14 to 50 μm size range coated with asphalt materials (AAB1, AAG1, and AAK1) were suspended contactless in the balance to measure D, S, and P in the temperature range 21 to 61° C. Transport parameters were determined from the changes in the particle mass due to the uptake of oxygen by the asphalt coating on glass spheres and nonspherical aggregate particles.

ISSN:0884-3759    

DOI:10.1080/08843759508947701

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The results of solid-state13C NMR study aimed at evaluating the chemical changes and extent of upgrading achieved in the thermal treatment of two western Canadian low rank coals are discussed. The coals were thermally treated at varying temperatures (200 - 500°C) using different process media (nitrogen, steam and products of combustion)

ISSN:0884-3759    

DOI:10.1080/08843759508947702

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Assam coal was subjected to solvent extraction studies using 40 solvents belonging to different class, group and functionality. Boiling point of a solvent was found to have no relation with extractability of coal at atmospheric pressure, excepting within the same class, group and functionality of solvents. Boiling point should not be used for classifying the coal extractability, rather chemical nature of solvent should be used. Cetene (high boiling α-olefin), anthracene oil, liquid paraffin (through thermochemical dissociative extraction) and ethylenediaraine (simple extraction) were found to give good extraction yields from Assam coal. Successive extraction of coal was possible only using anthracene oil or ethylenediaraine. Chemical interaction of these solvents with coal which renders the enhanced amount of coal extractable through stepwise extractions has been discussed. Mechanism and molecular dynamics of solvent extraction of coal in AO, α-olefins etc. has been explained. This is a novel finding in coal chemistry. Stepwise extraction could cut short the total extraction time in anthracene oil. Anthracene oil and high boiling α-olefins extractions result in molecular fluidization of coal macromolecules under ambient pressure. Successive extractions of coal in low boiling solvents ( < 250°C) did not modify on the highest extraction yield of coal in the solvent used in the sequence, whereas in case of successuve chemical dissociative extractions it did.

ISSN:0884-3759    

DOI:10.1080/08843759508947703

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Effect of anthrecene oil, quinoline and liquid paraffin extraction on the swelling of Assam coal has been studied to find out the degree of cross-linking in the pretreated coals, and to assess the molecular effect of the these solvents in the solid mass of coal, on the flexibility of coal macromolecular aggregation and molecular dynamism. Effect of successive extractions using anthracene oil-quinoline-liquid paraffin sequence, on the extraction of volatilizable components i.e. volatile matter (VM) contents and removal of toxic mineral matter contents of Assam coal has been studied. A relation of C % and VM % in coal with extraction yields through this successive extraction of different coals has been suggested. About 50 - 76% of the total VM present in the original coal can be extracted by the successive solvent extractive disintegration of coal, which was more than that through pyrolysis of coal at 600°C. Recovery of VM renders the combustion of residual coal free of pollution. The solvent refined coal is also obtained as a clean fuel. Thus, the process affords the segregation of toxic mineral matter microconstituents. Solvent extraction should be introduced as the essential coal preparation step to remove the premium organic products from coal before firing it in boilers.

ISSN:0884-3759    

DOI:10.1080/08843759508947704

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

After preextraction with ethanol-benzene (1:2) in a Soxhlet apparatus Tunçbilek lignite was extracted with dioxane at 330°C in an autoclave at different pressures and for different exposure times. The extracts were fractionated and many of the compounds they contain were identified by gas chromatography/mass spectrometry. The formation and yields of these compounds are discussed in terms of the structure of the parent fuel and the mechanism of extraction.

ISSN:0884-3759    

DOI:10.1080/08843759508947705

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Polar Heteroatomic species have been correlated with incompatibility reactions in middle distillate fuels. Instability is defined as the formation of filterable sediments and fuel insoluble gums. Heteroatoms (oxygen, nitrogen and sulfur) have been found to be greatly enriched in such sediments. Trace levels of certain organo-sulfur compounds, especially sulfonic acids in model fuel systems, have been found to significantly increase deposit formation. The effectiveness of organic amines as additives suggests that acid/base chemistry is also involved in the formation of deposits. This paper reports on a study of p-ethylbenzene sulfonic acid reacting with 3-methyl indole in model systems. A possible reaction mechanism and a proposed structure for the product is reported. The results of the model system are contrasted to results from previous actual fuel systems.

ISSN:0884-3759    

DOI:10.1080/08843759508947706

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Four bituminous coals were comprehensively separated by column chromatography into a number of fractions. Four aromatic hydrocarbon fractions of each tar were analyzed by FTIR spectroscopy, and the 900-700 cm−1spectral region was evaluated. This spectral region was found to be composed of at least 14 separate bands, which were resolved by using self-deconvolution and curve-fitting procedures. The bands near 821 cm−1, 791 cm−1, and 784 cm−1were proposed to originate from rocking vibrations of aliphatic C-H bonds. For the tar samples with a proton aromaticity between 0.21 and 0.37, these bands account for on average 12% of the total integral intensity of the 900-700 cm−1region. This percentage cannot likely be neglected in a correct quantitative evaluation of the region and calculation of the aromatic hydrogen concentration. However, a correct resolution of the bands can be very difficult in the FTIR spectra of a complex material, such as coal.

ISSN:0884-3759    

DOI:10.1080/08843759508947707

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor