Refinery Integration of By-Products from Coal-Derived Jet Fuels

Abstract

The final report summarizes the accomplishments toward project goals during length of the project. The goal of this project was to integrate coal into a refinery in order to produce coalbased jet fuel, with the major goal to examine the products other than jet fuel. These products are in the gasoline, diesel and fuel oil range and result from coal-based jet fuel production from an Air Force funded program.The main goal of Task 1 was the production of coal-based jet fuel and other products that would need to be utilized in other fuels or for non-fuel sources, using known refining technology. The gasoline, diesel fuel, and fuel oil were tested in other aspects of the project.Light cycle oil (LCO) and refined chemical oil (RCO) were blended, hydrotreated to removed sulfur, and hydrogenated, then fractionated in the original production of jet fuel. Two main approaches, taken during the project period, varied where the fractionation took place, in order to preserve the life of catalysts used, which includes 1) fractionation of the hydrotreated blend to remove sulfur and nitrogen, followed by a hydrogenation step of the lighter fraction, and 2) fractionation of the LCO and RCO before any hydrotreatment. Another aspect was to hydrotreat decant oil for testing of the delayed coker. The yield and quality of jet fuel and the quality of all fuels were better when hydrotreating the whole blend to remove sulfur and nitrogen and fractionating gasoline and jet fuel for further hydrogenation. When fractionating the RCO and LCO before any hydrotreatment, the yield of jet fuel and diesel fuel decreased, and the yield of the fuel oil increased and was a low quality.Task 2 involved assessment of the impact of refinery integration of JP-900 production on gasoline and diesel fuel. Fuel properties, ignition characteristics and engine combustion of model fuels and fuel samples from pilot-scale production runs were characterized. The model fuels used to represent the coal-based fuel streams were blended into full-boiling range fuels to simulate the mixing of fuel streams within the refinery to create potential "finished" fuels. The representative compounds of the coal-based gasoline were cyclohexane and methyl cyclohexane, and for the coal-base diesel fuel they were fluorine and phenanthrene. Both the octane number (ON) of the coal-based gasoline and the cetane number (CN) of the coal-based diesel were low, relative to commercial fuels (~60 ON for coal-based gasoline and ~ 20 CN for coal-based diesel fuel). Therefore, the allowable range of blending levels was studied where the blend would iv achieve acceptable performance. However, in both cases of the coal-based fuels, their ignition characteristics may make them ideal fuels for advanced combustion strategies where lower ON and CN are desirable. The ignition characteristics and reaction pathways were examined for these fuels in a modified octane rating engine used as a form of rapid compression machine and in an ignition quality tester (IQT). Methyl cyclohexane was observed to...