Erna J. Beal

Nitrogen compound distribution in middle distillate fuels derived from petroleum, oil shale, and tar sand sources

Nitrogen compounds present in crude sources constitute serious problems both for producers and consumers. For producers, these compounds are responsible for poisoning catalysts during the refining processes. For consumers, these compounds are responsible for the degradation observed in fuels during storage and handling. The quality of petroleum, as measured by °API gravity, continues to decrease in quality. This, coupled with the inevitable use of other crude sources, if used in quantity will further decrease the stability of middle distillate fuels. In this article we present our method for the separation and quantitation of the slate of nitrogen compounds present in middle distillate fuels derived from petroleum, oil shale and tar sand sources. Results from our laboratory indicate that of all of the nitrogen compounds present in middle distillate fuels, the indole type structure is the most deleterious.

An environmentally benign soybean derived fuel as a blending stock or replacement for home heating oil.

The use of bio-derived materials both as fuels and/or as blending stocks becomes more attractive as the price of middle distillate fuels, especially home heating oil, continues to rise. Historically, many biomass and agricultural derived materials have been suggested. One of the most difficult problems encountered with home heating oil is that of storage stability. High maintenance costs associated with home heating oil are, in large part, because of this stability problem. In the present research, Soygold®, a soybean derived fuel, was added in concentrations of 10% – 20% to both a stable middle distillate fuel and an unstable home heating oil. Fuel instability in this article will be further related to the organo nitrogen compounds present. The soy-fuel mixtures proved stable, and the addition of the soy liquid enhanced both the combustion properties, and dramatically improved the stability of the unstable home heating oil.

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.

Determination of liquid and solid phase composition in partially frozen middle distillate fuels

Abstract A liquid-solid separator apparatus was constructed and a method developed for the separation and characterization (g.c.-m.s.) of the crystals and liquid from partially frozen middle distillate fuels. The filtrate data were straightforward, but the precipitate presented problems in interpretation since the waxy crystals entrapped significant amounts of liquid. Since it was not possible to remove all of the entrapped liquid from the precipitate, an indirect method was derived to determine the composition of the liquid-free crystalline material. This required that the fraction of entrapped liquid in the precipitate be known, which could be determined from the g.c. data. Tracer materials in the original fuel were selected which did not crystallize out at the temperatures under study and therefore showed no appreciable concentration change with temperature. These tracer materials were used to estimate the fraction of entrapped liquid in the precipitate. Results obtained by this technique were tested and confirmed by h.p.l.c.

Liquid phase oxidation of organo-sulfur compounds by tert-butyl hydroperoxide and fuel instability reactions

Abstract Polar heteroatomic species have been correlated with storage instability problems in both petroleum and shale derived 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 enhanced in such sediments. Trace levels of certain organo-sulfur compounds, especially sulfonic acids, have been found to significantly alter the deposit formation process. Hydroperoxides have also been implicated in the instability process which would point to free radical mechanisms. 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 organo-sulfur, nitrogen and hydroperoxide compounds employed as dopants in fuels. The most detrimental dopant species were sulfonic acids.

DETERMINATION OF NITROGEN COMPOUND DISTRIBUTION FROM THREE SOURCE FUELS

As part of a world-wide survey of middle distillate fuel instability, three fuels were chosen for detailed GC/MS analysis. These fuels are identified by number and country of origin; FL-2577 was from Burnaby, British Columbia, Canada; FL-2599 was from Abamadj, Kuwait; and FL 2592 was from Chiba, Japan. The organo-nitrogen compounds in the three fuels were separated by mild acid extraction followed by silica gel absorption. This treatment yielded three fractions for each fuel; a basic nitrogen compounds fraction, BNC; a non-basic nitrogen compounds fraction in methylene chloride, mcl, NBNC-mcl; and a non-basic nitrogen compounds fraction in methanol, meoh, NBNC-meoh. The three fractions from each fuel were analyzed by combined capillary gc/ms. The organo-nitrogen compounds from each fraction were identified and quantitated.

Distribution of n-alkanes in partially frozen middle distillate fuels

This work on partially frozen fuels is one of a continuing series of studies on the effect of composition on the freezing properties of hydrocarbon fuels. The method used for this purpose was reported previously. By means of this method the authors were able to determine the composition of the liquid and solid phases in partially frozen mixtures consisting of liquid and of solid crystals plus entrapped liquid. This paper presents the results of this study on five different middle distillate fuels.

THE SYNTHESIS OF ACETALS AND KETALS OF THE REDUCED SUGAR MANNOSE AS FUEL SYSTEM ICING INHIBITORS.

ABSTRACT The current fuel system icing inhibitor additives used in both the military and commercial airlines are ethylene glycol monomethyl ether (EGME) and diethylene glycol monomethyl ether (DiEGME)These deicing compounds are toxic at the concentrations that are required for effective deicing. When fuel system sumps, filters and storage tanks are drained, they contain EGME/DiEGME and create a personnel hazard. Acetals and ketals of reduced sugars represent viable alternatives to glycol based additives. They are inexpensive, fuel stable for at least one year and show similar icing inhibitor characteristics. This paper summarizes the synthesis and fuel studies for these compounds.

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...

STABILITY STUDIES OF A JET FUEL CONTAINING NO ORGANO- SULFUR COMPOUNDS

ABSTRACT Instability, incompatibility, phase separation, or sludge-sediment formation are all terms that denote fuel degradation. Middle distillate fuels continue to have significant instability problems. Specific chemical reaction pathways that initiate the reactions that in turn lead to fuel instability and incompatibility are difficult to isolate. Results from our laboratory indicated that the sedimentation process can be modeled by considering various organo-sulfur oxidation products. These reactions are initiated by a hydroperoxide induced oxidation process. The present research is directed toward a stability study of a jet fuel that has been processed to contain zero weight percent sulfur.