The staff of the California Air Resources Board (ARB) staff is considering including alternative jet fuel (AJF) in the Low Carbon Fuel Standard (LCFS). ARB staff is hosting a public working meeting today to consider the matter.
In 2009, the ARB approved the LCFS regulation to reduce the carbon intensity (CI) of transportation fuel used in California by at least 10% by 2020 from a 2010 baseline. In 2015, the Board re-adopted the LCFS to address procedural issues, which began implementation on 1 January 2016. The LCFS sets annual carbon intensity standards—which reduce over time—for gasoline, diesel, and the fuels that replace them.
Fuels and fuel blendstocks that have a CI higher than the applicable standard generate deficits. Correspondingly, fuels and fuel blendstocks with CIs below the standard generate credits. Compliance is achieved when a regulated party—usually the fuel producer—uses credits to offset its deficits. (The importer of the fuel is the regulated party if the fuel is produced out-of-state.)
Producers of certain fuels are exempt and may voluntarily “opt-in” to the regulation in order to receive credits. Credit trading in the LCFS occurs between regulated parties.
Exemptions to the LCFS currently are:
Alternative fuel that is not a biomass-based fuel or that is supplied by all providers of that particular fuel at an aggregated volume of less than 420 million MJ/year.
Military tactical vehicles and tactical support equipment.
ARB staff is now considering developing a proposal to allow alternative jet fuel (AJF) to generate LCFS credits as an opt-in fuel. Conventional jet fuel would not be subject to the regulation and would not generate deficits. As part of this, ARB would not develop a new set of specifications for jet fuel.
AJFs are drop-in fuels which can replace a portion of conventional jet fuels without the need to modify aircraft engines and the existing fuel distribution infrastructure. When blended with conventional jet fuel, AJFs have the same performance characteristics as conventional jet fuel. Feedstocks include both renewable and non-renewable sources.
There are five main types of AJFs currently within the ASTM International Standard D7566 specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons:
Fischer-Tropsch Hydroprocessed Synthetic Paraffinic Kerosene (FT-SPK); maximum blend 50%
Synthesized Paraffinic Kerosene from Hydroprocessed Esters and Fatty Acids (HEFA-SPK); maximum blend 50%
Synthesized Kerosene with Aromatics Derived by Alkylation of Light Aromatics from Non-Petroleum Sources (SPK/A); maximum blend 50%
Alcohol-to-Jet Synthetic Paraffinic Kerosene (ATJ-SPK); maximum blend 30%
Synthesized Iso-Paraffins Produced from Hydroprocessed Fermented Sugars (SIP); maximum blend 10%
The use of AJFs offers a number of benefits, including reduction in global greenhouse gas emissions; significant reduction in PM and SOx (e.g., earlier post); and a slight reduction in NOx.
The CA-GREET models would be used to calculate the CI of alternative jet fuel pathways as well as the 2010 baseline for conventional jet fuel.
ARB staff’s initial thinking is to allow producers or importers of AJF to opt in as credit generators, and to allow credit generation for AJF loaded to all planes in California, whether the destinations are in-state or out-of-state. Credits could also be generated for military use of AJF.
A potential rulemaking would go into effect 1 January 2019.