The staff of the California Air Resources Board (ARB) is holding a public meeting on 23 April in Sacramento to discuss regulatory concepts for establishing fuel requirements for alternative diesel fuels (ADF), including biodiesel, renewable diesel and other emerging diesel fuel substitutes.
ARB’s goal is to conduct public meetings leading to the development of a regulatory proposal for consideration by the Board this fall. Staff anticipates the regulatory concepts would involve new alternative diesel fuel provisions, as well as amendments to the existing diesel fuel regulation to accommodate the new ADF requirements and to update outdated provisions. This effort is not directed at other existing transportation fuel programs, such as those for compressed natural gas, liquefied natural gas, liquefied petroleum gas, hydrogen, or electricity.
At the April meeting, ARB staff will discuss its biodiesel literature search, completed and on-going emissions research studies, as well as preliminary regulatory concepts for ADFs. ARB staff posted a white paper describing its initial regulatory concepts for an ADF regulation.
With the advent of the federal Renewable Fuels Standard (RFS) and the California Low Carbon Fuel Standard (LCFS), fuel suppliers will now look to expand their product slates to include more renewable and low carbon replacements for conventional gasoline and diesel. While more innovation may be anticipated in ensuing years of lower carbon and higher renewable fuel standards, there are already notable innovations today. Biodiesel, with its unique chemistry, has the potential to replace conventional petroleum diesel and can be considered an ADF. Likewise, other innovative diesel fuel replacements are entirely hydrocarbon based and may be used as blendstocks to produce commercial CARB petroleum diesel. The latter innovations include renewable diesel, gas to liquid (GTL) diesel and other synthetic diesels.
Some of these diesel fuel substitutes legally exist in commerce today and are controlled through industry consensus standards. Such fuels-related industry consensus standards seek mainly to address both vehicle performance and fuel production quality issues. By contrast, the multimedia impacts from the substitute diesel fuels are generally addressed by state or federal government agencies.
The ARB’s current diesel fuel regulations are geared toward providing a pathway for certifying hydrocarbon-based variations on petroleum diesel formulations, but they are ill-suited to providing a market pathway for newer, innovative alternative diesel fuels that are now coming into California in limited quantities. Over the past several years, California Air Resources Board (CARB) staff has endeavored to solicit stakeholder input via meetings and public workshops regarding the need for new regulations to address this gap. Likewise, staff has conducted essential research to understand the air quality impacts of biodiesel and various other diesel fuel substitutes. Much of this information had previously been presented at prior workshops. Based on stakeholder information and conclusions drawn from research, staff has developed regulatory concepts described below for establishing certainty for innovative fuels providers by setting forth a reasonable, multi-option process for getting their fuels approved for sale by ARB.—“Draft Regulation Concepts”
For purposes of this proposed rulemaking, ARB will consider B5 (5% biodiesel) blends a legal California diesel fuel with no emissions mitigation required. ARB is working with the University of California at Riverside to develop data to determine whether there are significant adverse air-related impacts from the use of B5 blends sufficient to warrant mitigation in the future.
Further, CARB staff suggests that it would be appropriate to allow the use of compliant hydrocarbon-based renewable diesel and synthetic diesels either as neat fuels, or as blendstocks in the production of conventional petroleum CARB diesel fuel. A CARB biodiesel/renewable diesel study showed that renewable and synthetic diesels have comparable or better emission characteristics as compared to conventional petroleum-based CARB diesel.
While over time, ARB staff intends to develop regulations to establish a list of CARB recognized ADFs, biodiesel will be the first fuel to be formally recognized. ARB staff is this proposing a conceptual outline for fuel quality, blending, labeling and record-keeping, as well as enforceability.
Among the changes, staff proposes to amend California code to include the “B20-ready” diesel specifications; to update the diesel certification program (including updated certification engine); and other minor updates and changes. Staff also proposes to amend the certification program to include specific health and toxicity tests that were previously only required when additives were used. Additionally, staff proposes to add a cap limit of 28% by mass, aromatic hydrocarbon content.