John V. Cooney

CHARACTERIZATION AND STABILITY PROPERTIES OF POLAR EXTRACTS DERIVED FROM A RECENT SHALE LIQUID

ABSTRACT A shale fuel of marginal stability has been used as a source of nitrogen-rich polar extracts. Polar compounds were isolated by mild acid extraction followed by silica gel adsorption and were identified by GC/HS. Alkyl substituted pyridines were the prevalent class of compounds present in most extracts. The effects of adding these shale derived fractions as dopants to a stable shale diesel fuel (0-11) were examined in terms of sediment formation and peroxide number under accelerated storage stability test conditions. The activities of the extracts in inducing fuel instability were correlated with their composition.

MECHANISMS OF WITTIG REACTIONS; A NEW POSSIBILITY FOR SALT-FREE REACTIONS

Abstract Spin paired diradicals have been implicated as unstable intermediates in a wide variety of reaction mechanisms. A critical evaluation of the available sterochemical. kinetic and spectroscopic data is found to be consistent, for some Wittig reactions, with a mechanism that involves the intermediacy of a spin paired diradical. The proposed mechanism not only addresses the major stereochemical considerations around the phosphorus atom during the course of the Wittig reaction, but also provides a rational accounting of the observed cis olefin stereospecificity.

MECHANISMS OF SYNFUEL DEGRADATION. I. EFFECTS OF ORGANIC NITROGEN COMPOUNDS ON THE STABILITY OF A SHALE DERIVED DIESEL FUEL

ABSTRACT A reliable accelerated fuel stability teat regimen has been developed and applied to the study of the storage stability of a shale derived diesel fuel marine (DFM). The results of a survey of nitrogen compounds as dopants in a stable shale DFM base fuel indicate that 3ome pyrroles and indoles may play significant roles in storage stability. A complete stability test matrix has been developed for the temperatures of 43, 65 and 80°C, for time periods between A and 179 days, and for a ten-fold concentration range of a model dopant, 2,5-dimethylpyrrole (DMP). Stability was defined by the amount of total insoluble material (filterable sediment and adherent gum) produced after stress, and also by the amount of titratable peroxide present in the filtrates of stressed fuel samples. A very regular pattern for insolubles formation was found within the test matrix. Deposit formation rates exhibited a first-order dependence on DMP concentration, with an apparent activation energy of 11-12 kcal/mol. The sedim...

Oxygen absorption by 2,5-dimethylpyrrole doped shale diesel fuel: Measurement under conditions of accelerated storage

The absorption of oxygen by thermally stressed samples of a shale-derived diesel fuel containing an active dopant was conveniently monitored by means of a gas buret assembly. The depletion of soluble 2,5-dimethylpyrrole in the fuel was correlated with oxygen uptake in doped fuel samples at temperatures of 65 and 80 °C. The observation of induction periods in DMP-promoted fuel instability were noted. The auto-oxidation of DMP in the fuel was confirmed to be first order in DMP with an approximate activation energy of 11–12 kcal mol−1, in agreement with earlier gravimetric studies.

CHEMICAL FACTORS AFFECTING INSOLUBLES FORMATION IN SHALE DERIVED DIESEL FUEL

ABSTRACT Detrimental changes in fuel properties with time have been a continuing problem in the use of middle distillate fuels. Instability of diesel fuels is usually defined by the formation of insoluble sediments and gums. Gravimetric stability tests have been conducted at 43° and 80°C, respectively, using three model nitrogen heterocycles, 2-methylpyridine, 2,6-di methyl quinoline, and dodecahydrocarbazole, as dopants in an otherwise stable shale diesel fuel. Potential interactive effects have been defined for these three model nitrogen heterocycles in the stable fuel in the presence of a second model dopant, t-butyl hydroperoxide. 2-Methyl pyridine and 2,6-dimethyl quinoline were inactive and only 2-methyl pyridine showed slight positive interactive effects. Dodecahydro-carbazole formed large amounts of insolubles by itself and exhibited positive interactive effects.

MECHANISMS OF SYNFUEL DEGRADATION. 3. INTERACTIVE EFFECTS IN NITROGEN COMPOUND INDUCED STORAGE INSTABILITY IN SHALE DERIVED DIESEL FUEL

ABSTRACT Deterioration in fuel quality upon storage has been a continuing problem in the utilization of middle distillate fuels. For diesel fuels. Instability is usually defined by the formation of insoluble sediments and gums and by the accumulation of hydroperoxides. Gravimetric accelerated storage stability tests conducted with model compounds as dopants in otherwise stable distillate fuels have demonstrated that oxidative condensation reactions of polar heterocylces are deleterious to stability. In particular, nitrogen containing aromatics (pyrroles, pyridinea, indoles, etc.) appear to be very harmful. Correlation of model dopant studies with results obtained with actual unstable fuels has indicated that autoxidation processes are usually not isolated reactions but are sensitive to the presence of other fuel constituents. In an effort to learn more about potential interactive effects, we have examined the autoxidation of two model compounds, 2, 5-dimethylpyrrole and 3-methylindole, in a shale diesel f...

Pyrolysis reactions of long chain alkyl pyridines

ABSTRACT The presence of n-alkanes in jet fuel can be explained if large n-alkanes are present in the crude oil source. Quantities of large n-alkanes present in crudes made from shale are insufficient, however, to explain the amounts found (up to 37%) in jet fuel made from these crudes. Although possible precursors to small n-alkanes are branched alkanes or substituted cyclic compounds, this paper shows that attack in the side chain of model pyridine compounds, similar to those found in shale crudes, affords a path to significant yields of n-alkanes. This study shows free radical attack at the alpha and gamma positions in the side chain to be favored. The major initial product distribution can be explained on the basis of Fabuss-Smith-Satterfield theory.