Heavy Duty Gas Turbines enjoy a wide fuel capability that makes them increasingly popular power generation tools in several branches of the industry. Among Alternative Fuels for gas turbines is a group of “Aromatic Fuels”. These fuels are presently virtually unknown but they offer interesting prospects namely for captive power in the refining and petrochemistry. Until now there has been a limited awareness of the combustion issues posed by Aromatic Fuels especially in the high temperature, medium pressure conditions of gas turbine combustors. This apparent disinterest is tied to various issues namely: - smoke problems faced by the aviation sector during the 70’s that were caused by “aromatic jet fuels”; - the supremacy of natural gas that monopolizes R&D combustion efforts for power applications. The success of light aromatics in spark engines as substitutes for lead-based RON improvers has been stopped by the ban of aromatics in car fuels. Toxicity is thus another blemish of aromatic fuels. Chemically, aromatic fuels involve a wide diversity of molecules in structure and size, ranging from simple mono-aromatics (one benzene ring) to poly-aromatics (up to 3 condensed benzene rings). The general combustion problem posed by aromatic fuels lies in the high thermal stability of the benzene ring in oxidative conditions and its propensity to condense on itself and to form soot particles. In addition, the high Auto Ignition Temperature and Delay of Aromatic Fuels make them improper for combustion in Diesel engines and require large residence time in atmospheric flames. Interestingly, it appears that, with their hot and lean diffusion flames and relatively oxidizing combustion zones, Heavy Duty Gas Turbines exhibit a remarkable ability to break and cleanly burn out these molecules. The paper presents this new class of gas turbine fuels, outlines their market rationale and offers key combustion considerations to ensure clean utilization. It also summarizes the experience gathered by a gas turbine manufacturer in the combustion of BTX, C9+ and LCO type fuels. It also outlines the chemical mechanisms that underlie the clean combustion of aromatic fuels in gas turbine chambers.

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