Bio-jet Fuel

Abstract

The crude oils are processed in a refinery to make a host of useful products; including gasoline, diesel, jet fuel, petrochemicals, and asphalt components. Kerosene is produced as a straight run product but is also produced through hydroprocesses, especially from heavier crude oil feedstocks. Kerosene jet fuel is a hydrocarbon fuel composed almost entirely of hydrogen and carbon elements. The hydrocarbon composition consists mainly of paraffins (iso and normal), cycloparaffins (naphthenes), and aromatics. Aviation jet fuel produced from different feeds and processes will have different ratios of these hydrocarbon components. Combustion of Aviation Turbine fuel or jet fuel (Jet-A1) for aviation purpose has contributed to “global warming” leading to a proposed blending of “Biojet” to reduce the carbon footprint. In 2009 a new ASTM specification (D7566-09, Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons) was developed for aviation turbine fuels. The specification allows for a maximum of a 50% blend of Biojet with conventional jet fuel. While Bioethanol and Biobutanol, a proven biofuel for the automobiles, were found unsuitable biofuel for aviation purpose due to a mismatch in ASTM D7566-09 specifications. Several technological options have emerged on intensive R&D efforts globally. Such technologies used plant seed oil, waste cooking oil, animal fat, agricultural residues, and MSW as feedstock to produce renewable hydrocarbon fraction as drop-in fuel known as “Biojet”. Basic advantage of using plant or agricultural waste based feedstock instead if crude oil is the minimization of carbon footprint in the aviation fuel. However, several challenges have emerged to meet the stringent specifications of aviation fuel and challenges being addressed to ascertain Biojet as sustainable, cost-effective, and green aviation fuel.