Marten Ternan

Conversion of non-coking coals to coking coals by thermal hydrogenation

Abstract Coking properties are observed in four non-coking coals, a lignite, a subbituminous coal, a semianthracite and an oxidized bituminous coal which had been treated by partial thermal hydrogenation. The effects of temperature, reaction time and hydrogen pressure on liquid and solid product yields are examined. Microscopic examination of the hydrogenated solid residues shows that they all contain structures somewhat spherical in shape which are associated with mesophase development. The dilatation, plastic character and free swelling index of the hydrogenated solid products were considerably better than those of the original coals. Dilatation residues produced from hydrogenated solids exhibited anisotropic structures.

Pyrolysis of pitch derived from hydrocracked athabasca bitumen

The pyrolysis of Athabasca bitumen pitch was investigated to find a better utilization made for this pitch in bitumen gasification processes. Explanations of a compensation effect in the pyrolysis reaction similar to that found in the decomposition of hydrogen peroxide are given. It is suggested that the amount and nature of coal ash or differences in coal hydrocarbon composition (coal macerals) may have some effect on the compensation effect in coal char. (JRD)

Molecular weight distribution of Athabasca bitumen

Abstract A sample of whole Athabasca bitumen has been fractionated by preparative g.p.c. The weights of the fractions have been determined and their molecular weights measured by several methods. In contrast to previously published data, consistent results were obtained using different solvents (THF, be-nzene/water) and using different techniques (v.p.o., f.p.d. and g.c.-m.s.). This has resulted in an accurate definition of the molecular weight distribution of Athabasca bitumen.

Hydrotreating a distillate liquid derived from subbituminous coal using a sulphided CoO-MoO3-Al2O3 catalyst

Abstract A coal-derived heavy naphtha distillate containing 4.76, 0.51 and 0.004 wt% oxygen, nitrogen, and sulphur, respectively, has been hydro-treated. Even with severe processing conditions, the conversions of heteroatom species is less than desired. An empirical equation based on the experimental data indicates greater conversions would be attained at greater pressures and residence time. Severe catalyst deactivation is attributed primarily to carbonaceous deposits. However, smaller concentrations of zinc also accumulate on the catalyst.

Hydrocracking of Athabasca bitumen using Co−Mo catalysts supported on wide pore carbon extrudates

Abstract Conventional catalysts for hydrocracking of bitumen or petroleum residua are supported on alumina. In recent years, carbon has been considered as an alternative support for two reasons. Metal recovery (Mo, Co, Ni, V) from the spent catalyst should be easier if the carbon can be completely combusted. Secondly, experiments with pure compounds have suggested that carbon supports might produce higher conversions than alumina supports. In this study, a real feedstock, Athabasca bitumen, was used to compare a carbon supported catalyst with an alumina supported one. Results showed that conversions using the Co-Mo C catalyst were lower than those obtained using the Co-Mo Al 2 O 3 catalyst. However, when the resuts were compared on the basis of unit catalyst surface area, the pseudo turnover frequencies were larger for the carbon supported catalyst than for the alumina supported one.

Catalytic desulphurization of Athabasca bitumen using hydrogen donors

Abstract The use of hydrogen-donor diluents while catalytically hydrocracking Athabasca bitumen has been studied. No improvement in sulphur removal, nitrogen removal or catalyst life was obtained from their use, contrary to reports in the literature. When the results were compared on the basis of constant reactor size and constant bitumen feed rate, the hydrogen-donor diluents were found to have a negative effect. Variations in the boiling-point range, sulphur content and nitrogen content of the donors only produced marginal changes. It was concluded that hydrogen-donor diluents are not effective processing aides, and therefore should not be used during the catalytic hydrocracking of Athabasca bitumen.

Coke formation during simultaneous hydrocracking of bitumen and hydrogenation of coal

Abstract Conventional catalysts are rapidly fouled with coke deposits when they are used to hydrocrack residual oils. The work reported here was part of an investigation on the removal of coke-forming compounds from residual oils prior to their contact with catalysts. Semianthracite coal particles have been added to a reaction mixture of hydrogen and Athabasca bitumen at 13.9 MPa and 723 K, to provide a large surface area on which coke could deposit. Agglomeration of coal particles occurred during hydrogenation in the absence of bitumen, but did not occur when bitumen, coal, and hydrogen were all present together in the reaction system. A solid mass of coke formed when bitumen was hydrocracked in the absence of coal particles, but did not form when the bitumen was present with coal and hydrogen. These observations illustrate one of the advantages of processing bitumen and coal simultaneously. The solid particles from hydrocracking experiments, coal hydrogenation experiments, and experiments on coal carbonization were examined petrographically. It was found that coke formed from Athabasca bitumen has a different microstructure from that formed from semi-anthracite coal. On the basis of these studies it was concluded that semi-anthracite coal was converted to coke similar to that normally made from low-volatile bituminous coal. Simultaneously coke formed from the bitumen was deposited on the exterior of the particles.

n-Hexadecane Fuel for a Phosphoric Acid Direct Hydrocarbon Fuel Cell

The objective of this work was to examine fuel cells as a possible alternative to the diesel fuel engines currently used in railway locomotives, thereby decreasing air emissions from the railway transportation sector. We have investigated the performance of a phosphoric acid fuel cell (PAFC) reactor, with n-hexadecane, C16H34 (a model compound for diesel fuel, cetane number = 100). This is the first extensive study reported in the literature in which n-hexadecane is used directly as the fuel. Measurements were made to obtain both polarization curves and time-on-stream results. Because deactivation was observed hydrogen polarization curves were measured before and after n-hexadecane experiments, to determine the extent of deactivation of the membrane electrode assembly (MEA). By feeding water-only (no fuel) to the fuel cell anode the deactivated MEAs could be regenerated. One set of fuel cell operating conditions that produced a steady-state was identified. Identification of steady-state conditions is significant because it demonstrates that stable fuel cell operation is technically feasible when operating a PAFC with n-hexadecane fuel.

EFFECT OF H-MORDENITE ZEOLITE AS A COMPONENT IN CO-MO-AL2O3 HYDROPROCESSING CATALYSTS USED FOR THE CONVERSION OF BOSCAN HEAVY OIL

Abstract The effect of H-mordenite zeolite as a component in Co-Mo-Al 2 O 3 hydroprocessing catalysts has been studied. Catalysts containing up to 20% H-mordenite were used for hydrocracking Boscan heavy oil at 13.9 MPa. Although the acidic sites on the external surface of the zeolite crystals were expected to increase cracking reactions, little effect on conversion was observed. As the H-mordenite content of the catalyst increased, the bulk density and the specific surface area of the catalysts decreased substantially. When the reaction results were expressed on the basis of constant residence time and constant catalyst surface area there was an increase in the reaction parameter with increasing H-mordenite content of the catalyst. It was also found that coke deposition increased with the increasing H-mordenite content of the catalyst. These two observations suggest that H-mordenite caused an increase in the number of acidic sites in the catalyst. The results indicate that catalysts with H-mordenite would produce greater conversions than catalysts without H-mordenite, if the extrudates could be prepared in such a way that the catalyst bulk density does not change when the H-mordenite is added.

The influence of infrared radiation on acetylene conversion

Abstract Acetylene conversion was studied by comparing the experimental results obtained using an infrared furnace with those obtained using a resistance furnace. The infrared furnace offered a rapid heating capability, for example, 100 °C s −1 compared with 20–35 °C min −1 for most resistance furnaces. It was found that infrared radiation increases the conversion of acetylene in both thermal and catalytic reactions although infrared furnaces were not suitable for measuring the effect of temperature on reactions which are influenced by infrared radiation.