Addendum to the article “Viscosity data for kukersite shale gasoline fractionsˮ

The evaluation of experimental data is based on the disclosure of essential information related to data measurement. A recent paper published in the journal Oil Shale presented experimental viscosity data on narrow boiling range fractions, prepared by distillation from a wide gasoline fraction of Kukersite oil shale pyrolysis oil (from an industrial plant). However, the article suffers from a deficiency of experimental description coupled with somewhat of an oversimplification of derivation of viscosity data from capillary viscometer measurements. Therefore, this addendum or short commentary supplemental article provides additional experimental information desirable for data evaluation and interpretation, along with corresponding corrections to the data

The interlayer cohesive energy of graphite from thermal desorption of polyaromatic hydrocarbons

We have studied the interaction of polyaromatic hydrocarbons (PAHs) with the basal plane of graphite using thermal desorption spectroscopy. Desorption kinetics of benzene, naphthalene, coronene and ovalene at sub-monolayer coverages yield activation energies of 0.50 eV, 0.85 eV, 1.40 eV and 2.1 eV, respectively. Benzene and naphthalene follow simple first order desorption kinetics while coronene and ovalene exhibit fractional order kinetics owing to the stability of 2-D adsorbate islands up to the desorption temperature. Pre-exponential frequency factors are found to be in the range $10^{14}$-$10^{21} s^{-1}$ as obtained from both Falconer--Madix (isothermal desorption) analysis and Antoine's fit to vapour pressure data. The resulting binding energy per carbon atom of the PAH is $52\pm$5 meV and can be identified with the interlayer cohesive energy of graphite. The resulting cleavage energy of graphite is $61\pm5$~meV/atom which is considerably larger than previously reported experimental values.Comment: 8 pages, 4 figures, 2 table

Experiment-related comments and corrections to the article "Viscosity data for kukersite shale gasoline fractions"

The recent paper "Viscosity data for kukersite shale gasoline fractions" [1], published in the scientific-technical journal Oil Shale by Baird and co-workers, presented experimental viscosity data on narrow boiling range fractions, prepared by distillation from a wide gasoline fraction of Kukersite oil shale pyrolysis oil (from an industrial plant). However, the article suffers deficiency of experimental description together with somewhat of an oversimplification of derivation of viscosity data from capillary viscometer measurements. Therefore, this short commentary supplemental article (i.e. addendum) provides additional experimental information desirable for data evaluation and interpretation, along with corresponding corrections to the data

Predicting fuel properties using chemometrics: a review and an extension to temperature dependent physical properties by using infrared spectroscopy to predict density

Although the use of chemometric methods to predict fuel quality properties has received wide attention over the past three decades, as seen from the review included with thisarticle, no studies were found about predicting temperature dependent properties of fuels.Since our research is focused on determining thermodynamic properties, rather than qualityproperties, taking temperature dependencies into account became even more important. Todetermine if accurate predictions could be obtained over a range of temperatures, the densitiesof over 300 fuel samples (mostly narrow boiling range oil fractions, considered here aspseudocomponents) were measured and predicted. An alternative fuel (a phenol-rich oil shaleoil) was studied because the property prediction methods developed for conventionalpetroleum samples often give poor results for this and other alternative fuels. The temperaturedependence of density for these fuel samples was modelled using a linear equation based onthe density at 20 °C and the slope of the density-temperature relationship. Support vectorregression was used to predict these parameters for each sample from its infrared spectrum.Then these parameters were used to predict the densities at other temperatures. Densitiesspanned the range from 0.713 to 1.088 g/cm 3 , and the root mean squared error of the predictedvalues was 0.004660 g/cm 3 , which is a relative error of less than 1%. In addition to theexperimental portion, a literature review is included, which contains an assessment of theaccuracy of chemometric methods for predicting many fuel properties

VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content

Desulfurization, denitrogenation and deoxygenation of shale oil

Producing valuable transportation fuels from shale oil has long been a goal, but to meet modern environmental regulations significant upgrading is required to remove heteroatoms. The large quantities of sulfur, nitrogen and oxygen in shale oil is one of the major obstacles that limit its use. Unlike petroleum upgrading, where desulfurization is the main process, for shale oils denitrification and deoxygenation are also important. This review compiles and summarizes the extensive research that has been performed on removing sulfur, nitrogen and oxygen from shale oil. By far the most widely researched method has been hydrotreatment, but work done with other methods is also presented

The composition of kukersite shale oil

Pyrolysis oils are usually considered as substitutes for crude oil; however, they can also be sources of valuable compounds. One such pyrolysis oil is shale oil obtained by pyrolysis of kukersite oil shale. K shale oil consists mainly of aromatic structures with straight alkyl side chains. For samples with comparable boiling point distributions, kukersite shale oil is more aromatic than petroleum and many other shale oils. Sulfur, nitrogen, and oxygen are often incorporated into the ring structures, with much of the oxygen also present as phenolic hydroxyl groups. To evaluate the potential for producing some specific compounds from kukersite shale oil foundational data on the composition is needed. Here we analyze new data on the elemental composition and infrared spectrum of kukersite shale oil to investigate its composition. To get detailed information on how the composition of the oil changes depending on the average molecular weight of the oil fraction, the shale oil was separated into narrow boiling fractions using distillation. The results show that the nitrogen content in kukersite shale oil increases with the boiling temperature, with the heaviest fractions containing about 0.3 wt%. Sulfur content reaches a maximum of almost 2 wt% for fractions boiling between 150 and 190 °C, and heavier fractions contain about 0.7 wt%. Similarly, the proportion of hydroxyl groups in kukersite shale oil peaks in the fraction boiling at about 320 °C, with heavier fractions containing more aromatic and alkyl functional groups. The elemental composition of kukersite shale oil is also compared to that of other shale oils