Shale turbine fuel

Synthetic fuels derived from shale or coal will have to supplement domestic suppHes from petroleum someday, and aircraft gas turbine fuels producible from these sources have been assessed. Shale-derived fuels can meet current specifications if steps are taken to reduce the nitrogen levels. However, extracting kerogen from shale rock and denitrogenating the jet fuel are energy-intensive steps compared with petroleum refining it has been estimated that shale jet fuel could be produced at about 70% thermal efficiency compared with 95% efficiency for petroleum (25). Such a difference represents much higher cost for a shale product. 

Shale jet fuel - [AVIATION AND OTHER GAS TURBINE FUELS] (Vol 3)... 

Cowan, M.J., and L.J. Jenkins. 1981b. The Toxicity of Grade JP-5 Aviation Turbine Fuel, A Comparison Between Petroleum and Shale-Derived Fuels. Pp. B2/1-B2/7 in Toxic Hazards in Aviation. Papers presented at the Aerospace Medical Panel Specialists Meeting, Toronto, Canada, Sept. 15-19 1980. AGARD-CP-309, France Advisory Group for Aerospace Research Development. 

The U.S. Navy has been involved for some time in the development of Navy fuels from alternative sources (shale oil, tar sands and coal). As a part of this effort, the Naval Research Laboratory and the Naval Air Propulsion Center have been studying the characteristics of these fuels (.1, 2). NKL and NAPC are currently participating in a program to characterize the products from the Shale-II refining process conducted by the Standard Oil Company of Ohio (SOHIO) at their refinery in Toledo, Ohio. This paper is concerned with a part of this program and is a surrmary of the work on the physical and related properties of three military type fuels derived from shale JP-5 and JP-8 jet turbine fuels, and diesel fuel marine (DEM) (3, 5). Another paper of this symposium (6) will discuss the chemical characterization of the fuels. 

SHALE OIL PRODUCTS VS PETROLEUM PRODUCTS TURBINE FUEL... 

Synthetic liquid fuels derived from coal and shale will differ in some characteristics from conventional fuels derived from petroleum. For example, liquid synfuels are expected to contain significantly higher levels of aromatic hydrocarbons, especially for coal-derived fuels, and higher levels of bound nitrogen. These differences can affect the combustion system accepting such fuels in important ways. In continuous combustors, i.e. gas turbines, the increased aromatics content of coal-derived fuels is expected to promote the formation of soot which, in turn, will increase radiation to the combustor liner, raise liner temperature, and possibly result in shortened service life. Deposit formation and the emission of smoke are other potential effects which are cause for concern. Higher nitrogen levels in synfuels are expected to show up as increased emissions of N0X (NO+NO2) An earlier paper presented results of an experimental study on the effect of aromatics and combustor... 

H-Coal, and EDS middle distillates, and hydrotreated Paraho shale oil residual were tested in a subscale 5-inch diameter, staged rich-lean combustor at conditions representative of baseload and part power settings of 30-MW utility combustion turbine. A minimum NO emission level corrected to 15% oxygen of approximately 35 ppmv was attained for all the fuels despite fuel bound nitrogen levels of up to 0.8 percent by weight. 

Testing of the Shale-II JP-5 jet fuel, which is currently underway in four different gas turbine engines, shows good combustion performance. No problems have been encountered. Likewise, testing of ship steam boilers, marine gas turbines, and diesel engines on the Shale-II diesel fuel marine (DFM) is demonstrating highly acceptable performance. 

Lilley [7], The discussion here is limited primarily to the fluid dynamics aspects and aimed at alternative fuels with different physical and chemical properties than conventional fossil fuels. Here, the following three flow domains are of particnlar importance and can be distinguished in any multiphase combustion system flowfields connected with injection of fuel and air, flow regions dominated by free convection currents located far away from burners, and flow along the cooled walls of the combustion zone. Extensive reviews of the application of the classical turbulent combustion modeling methods have been presented for fossil fuels. For alternative fuels, it has been pointed out that there are major differences in the combustion of coal-derived liquids and shale oil in gas turbine combustors. Texts include Bartok and Sarofim [10] and Keating [11]. 

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