Dennis R. Hardy

Heterogeneous catalytic CO2 conversion to value-added hydrocarbons

The impact that anthropogenic CO2 is having on the environment has been thoroughly documented over the last 20 years. Many different technologies have been proposed to reduce its impact on global warming such as geological sequestration. However, an interesting and attractive alternative would be the recycling of the gas into energy-rich molecules. Iron rather than cobalt catalysts, based on the Fischer–Tropsch technology, have shown the greatest promise in converting CO2 to value-added hydrocarbons. The addition of co-catalysts is, however, essential to fine tune the product distribution to the more desired alkene products. The role that both the promoter and support play on the catalysts activity is reviewed.

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.

The feasibility and current estimated capital costs of producing jet fuel at sea using carbon dioxide and hydrogen

A comparative cost/benefit and energy balance analysis addresses the critical scientific and technical challenges that impact the economic feasibility of synthesizing up to 100 000 gal per day of jet fuel at sea using carbon dioxide (CO2) and hydrogen (H2) from the sea. Included in this analysis are the capital cost, operation and maintenance, and electrical generation cost for synthesizing jet fuel at sea using either ocean thermal energy conversion or nuclear power processes as the energy source. The results suggest that jet fuel could be produced at sea for

Effects of pressure on the recovery of CO2 by phase transition from a seawater system by means of multilayer gas permeable membranes.

3 to

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

6/gal. Comparing these costs with current and historical prices of fuel purchased by the Department of Defense provides insight into the economic and operational benefits of a sea-based fuel synthesis process for the Navy.

Analysis of upgraded SRC-11 and H-coal liquid products

Using seawater doped with sodium bicarbonate and Celgard 2400 gas permeable membranes, bicarbonate ion disproportionates to carbon dioxide and carbonate when gaseous carbon dioxide is first removed from the seawater solution by diffusion through gas permeable membranes at elevated water pressures. The permeability of CO(2) by phase transition from bicarbonate solutions at pressures above 100 psi is only possible due to the use of multiple gas permeable membrane layers. The multiple layers minimize water permeability at pressures below and above the Young-Laplace bubble point of single membrane layers, however the gas permeability efficiency and rate are greatly decreased.

Determination of corrosion inhibitor/lubricity enhancer additives in jet fuels by size-exclusion chromatography

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.

Storage stability of diesel fuel marine: relation to e.s.r. measurements

Abstract Upgraded coal-derived liquids obtained from catalytic hydroprocessing of SRC-11 and H-coal syncrudes have been studied by i.r., p.m.r., g.c.-m.s., and silica gel chromatography. With increase in residence time, nitrogen, oxygen and aromatics decrease, while naphthenes increase substantially. All the upgraded liquids show low viscosity at 298 K (1.3–1.4 mN s m −2 ), even though saturate and aromatic fractions varied with processing severity. In the aromatic-1 fraction, 1 -ring aromatics increase, and 3-ring aromatics decrease, with increase in severity of hydroprocessing. G.c.-m.s. analyses indicate a marked qualitative similarity for saturate and aromatic fractions irrespective of syncrude source. Only the heavier end of the aromatic-1 fraction is noticeably different. Tentative identifications based on m.s. and g.c. retention times are made for most of the significant components. 600 M Hz p.m.r. spectra of the upgraded SRC-11 and H-coal liquids appear identical, but the n.m.r. difference technique revealed slight differences between the two liquids in concentrations of certain species.

Insoluble sediment formation in middle distillate diesel fuel: further evidence concerning the role of in situ fuel acidity

Abstract Improvements in techniques for the qualitative and quantitative determination of commercial corrosion inhibitor/lubricity enhancer additives which contain linoleic acid derivatives are described. These include a procedural modification to use 100-, rather than 250-ml volumes of sample and extractant, and an external calibration using known pure compounds. Quantitative results for concentrations of active ingredients in six commercial corrosion inhibitors are given. The extraction technique has also been used as a possible compositional assessment of the lubricity of jet fuels by quantification of the higher-molecular-weight acidic components via high-resolution size-exclusion chromatography. Quantification of the corrosion inhibitor additive is possible at levels as low as 2 ppm (v/v) in jet fuel.