Norbert Berkowitz

The oil sands of Alberta

Northern Albertas oil-sand deposits contain some 143 Gt (900 × 109 bbl) of bitumen from which at least 36 Gt (250 × 109 bbl) of marketable light ‘synthetic crude oil’ are expected to be ultimately producible. Representing Canadas largest potential ‘petroleum’ reservoir, and of a size large enough to be compared with the total recoverable oil reserves of the Middle East, these deposits may become the countrys principal source of future petroleum supplies. This review briefly describes the geological setting of the oil sands, and the methods by which bitumen can be extracted and upgraded; outlines current and planned commercial projects; and notes some of the factors bearing on future exploitation of the oil sands.

Studies on the structure of coals. 3. Some inferences about skeletal structures

Contrary to the classic (and current) view that coal is a predominantly aromatic solid, its skeletal carbon arrangements appear to be largely made up of non-aromatic structures. Recent evidence from oxidation of coal with sodium hypohalite — a specific reagent which, among other matters, clearly differentiates between Sp2 and Sp3 carbon — indicates that these structures are modified bridged tricycloalkane systems or polyamantanes. Some properties of a structural model developed from polyamantane configurations are briefly explored. And parenthetically it is noted that assignment of a non-aromatic structure to coal is not inconsistent with extant experimental evidence now regarded as pointing to aromatic structure, since data are generally interpreted on the assumption that a high degree of aromaticity is likely.

Distribution of chemisorbed oxygen in mildly oxidized caking coal

Abstract A high-volatile A bituminous coal was oxidized with 18 O 2 at 100 °C for 72 h and the resultant ‘oxycoal’ heat-treated at atmospheric pressure and in vacuo at temperatures up to 430 °C. The 18 O content was determined in the ‘oxycoal’ before and after heat treatment, and in extracts and residues obtained from chloroform extraction of heat-treated ‘oxycoal’. In addition, unheated ‘oxycoal’ was extracted with pyridine and chloroform, and [ 18 O] was measured in the α-, β- and γ-fractions. The results support the view that decreased yields of chloroform-soluble matter (and corresponding loss of plasticity) associated with oxidation are mainly due to condensation reactions which reactive oxygen-bearing groups undergo during heat treatment, and that the extent of these reactions is markedly sensitive to pressure.

Effects of boron trifluoride sorption on the caking properties of coal

Abstract Reversible and irreversible sorption of boron trifluoride by a suite of low- and medium-volatile bituminous (caking) coals was investigated. Extraction of irreversibly sorbed BF 3 with diethyl ether was used to test the hypothesis that BF 3 interacts with coal by forming adducts. An approximately rectilinear but inverse relation between residual sorbed BF 3 and the free swelling index was found.

Reactions of coal with discharge-generated (excited) nitrogen species☆

Reaction between coal and nitrogen in a discharge furnishes hydrogen cyanide and smaller amounts of cyanogen, as well as some carbon monoxide and carbon dioxide; the cumulative yields of hydrogen cyanide and cyanogen depend upon rank. The apparent activation energies for formation of hydrogen cyanide and cyanogen are in the order of 2–4 kcal mol−1 but increase sharply to ≈13–14 kcal mol−1 at ≈200 °C (possibly coincident with incipient thermal decomposition of the coal). The cyanogen/hydrogen cyanide ratio increases with rank, and also depends upon the reaction temperature — falling with increasing temperature up to ≈200 °C, and thereafter rising progressively. Rate measurements and i.r. spectral changes accompanying the reaction suggest that hydrogen cyanide is mainly formed from non-aromatic carbon-hydrogen configurations in the coal, and that cyanogen derives for the most part from aromatic carbon — though some can also be generated from non-aromatic ue5fcCH in competition with formation of hydrogen cyanide.

Reactions of coal with nitrogen/ hydrogen mixtures in a discharge☆

In-discharge reaction of coal with nitrogen/hydrogen mixtures rather than nitrogen alone raises rates of hydrogen cyanide generation by a factor of 10–50, and makes hydrogen cyanide account for ≈70–90% of the total product-gas volume. From these results and parallel tests with a pure carbon, it is concluded that enhanced formation of hydrogen cyanide is controlled by transient hydrogenation of aromatic carbon and consequent creation of additional (non-aromatic) reaction centres which can be abstracted by N∗.

Reaction of Coal with Nitrogen in a Microwave Discharge

The reaction between nitrogen and coal in microwave discharge system at low pressure was studied, using two Japanese coals, 4 Canadian coals and a spectroscopic carbon.HCN, CO and small quantities of (CN) 2 were the main gaseous products. Although reactivity-expressed as a function of total gaseous product yieldtended to vary in an, inverse sense with coal rank, (CN) 2/HCN ratio generally increased with rank. The Japanes coals yielded slightly more product gas and higher (CN) 2/HCN ratios than the Canadian coals, possibly because of their greater content of low molecular weight volatile matter which can easily react with active nitrogen in the gas phase. The reaction of several model hydrocarbons under similar conditions suggests that in low-rank coals the aliphatic structure was largely, while in high-rank coals some of the aromatic structure was affected. Activation energies for formation of HCN and (CN) 2 increased sharply above 230°C, probably due to an interaction of volatile matter with active nitrogen superimposing itself upon the normal surface reaction.