Renewable jet fuels changed in 2016 when regular flight operations of United Airlines started using RjF.  This marked the beginning of commercial-scale usage of the alternate jet fuel by aviation industry.  As of today the commercial viability has been achieved for renewable jet fuels through demonstration of techno-economic feasibility for production path-ways (processes) namely HEFA (Hydro-processed Esters and Fatty Acids) technology and FT (Fischer-Tropsch) technology.

Next in the line is DSHC (Direct Sugar to Hydrocarbons) which is currently undergoing pilot projects for demonstration of its viability. Similarly, development work is under way for renewable jet fuels production through other technologies like HDCJ (Hydro-treated Depolymerized Cellulosic Jet), ATJ (Alcohol to Jet) and APR (Aqueous Phase Reforming).

Renewable Jet Fuels Development

 

Such development projects are now receiving funds from the governments and additional support may be forthcoming in the form of government incentives regarding tax breaks and mandatory use obligations) essentially required for reducing the production-cost-differential of renewable jet fuels and petroleum jet fuel for commercial aviation and aerospace by the EPA has established procedures for analyzing submitted petitions for life cycle GHG emissions associated with new fuel pathways.

Specifications for jet fuels are defined under ASTM D1655 and they mainly focus on performance properties like heat content (BTUs per lb), combustion properties, freezing point, viscosity, thermal stability, material compatibility and related safety hazards.

For standardizing purposes ASTM D7566 is the standard for certification of Synthetic Fuels, which also include renewable jet fuels, in consultation with ASTM D4054 for guidance related to testing as jet fuel alternative RJF. The drop-in RJF need to be additionally certified for equivalence in specification to jet fuels under the ASTM D1655 for direct mixing in aircrafts with being separately tracked for approval.

RJF is now available as a “drop-in” alternate fuel with performance and safety specifications equivalent to petroleum jet fuels. As such, RJF use does not require any modification in jet engines and this provides an opportunity window for the aviation industry to contribute towards reducing emission of greenhouse gases.

After proving its technical viability, the remaining major obstacle for viability of renewable jet fuels is related to production and consumption “scale-up”. This is expected to be overcome soon as commercial airlines start making medium to long-term fuel supply contracts with commercial producers of renewable jet fuels.

Commercial use of RJF will also get a boast as International Civil Aviation Organization (ICAO) has agreed global market based measures (GMBM): “Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) to address any annual increase in total CO2 emissions from international civil aviation (i.e. civil aviation flights that depart in one country and arrive in a different country) above the 2020 levels, taking into account special circumstances and respective capabilities.”

Investments in Renewable Jet Fuels

 

Blending is another area where RJF power generation producers are actively engaged with RSB (Roundtable on Sustainable Biofuels) for certifying blended fuels which are a mix of petroleum fuel and biofuels from special crops grown for the purpose. In South Africa Sunchem’s nicotine-free tobacco plant Solaris is an example of producing RJF through blending of biofuels with petroleum Jet-A fuel.

Such efforts will standardize the production and use of blended RJF while ensuring economic, environmental and social concerns of the society. The biofuel industry is targeting to achieve a 50% reduction in GHG emissions over the life-cycle through use of blended RJF in a ratio of 30% biofuel mixed with 70% of petroleum fuel.

An innovative approach to achieve the economy of scale and to reduce the financial costs in production of RJF is manifested by equity investment by United Airlines and Hong Kong based Cathay Pacific in Fulcrum BioEnergy Inc., Nevada, California.

Both the airlines, Cathay Pacific and United Airlines, in addition to equity investment have long term renewable jet fuels RJF supply contracts with Fulcrum BioEnergy. The Nevada based production facility having a capacity to produce 11 million gallons of fuel is expected to be operational in 2018. It is evident that aviation industry is gearing itself to implement the GMBM by the year 2020 for which renewable jet fuels is the light on the horizon.