Up with Octane and Down with Aromatics: Continuing Health Risks with Petroleum Fuels and the Need for Engine Efficiency

by Bill Brandon (Leaders in Energy) Our country has seen many transitions in travel technologies and fuels. In the first installment I reviewed our transition from 1) barley and oats for our horses and mules to high carbohydrate corn for higher energy and productivity. 2) The transition from corn to liquid fuels for internal combustion engines was next. These liquids were vegetable oils, ethanol, turpentine and petroleum wastes we now call gasoline. 3) We then transitioned from non-standard liquids to straight gasoline with a tetraethyl lead additive to give an octane boost and better performance. 4) We last transitioned from leaded gasoline to unleaded gasoline with aromatics and ethanol as octane boosters.

We now stand at the threshold of a fifth transition. (For electric vehicle enthusiasts, it is not Plug-In Electric Vehicles (PEVs). That will be the sixth transition.)

Today there is fast growing evidence that aromatics are a very serious health concern. Other articles are here, here and here. Aromatics are not only toxic when released as a volatile organic compound (VOC) but also are the primary source of ultrafine particulates (UFP) also called polycyclic aromatic hydrocarbons (PAH). ... They can enter the body through the lungs, into the blood stream and eventually into individual cells. They are thought to contribute to Greenland’s dark ice that lowers reflectivity and advances ice melt. Gasoline is the biggest contributor to UFPs but diesel is also a significant contributor.

The EPA has approved a surprising number of alternative fuels but has done little in the last 20 years to advance standards that push or reward fuels with low health issues (clean), low carbon content and low lifecycle greenhouse gas (GHG) emissions (green) or High Fuel Efficiency.

Those that are able to produce some ‘drop-in fuels’, like Cool Planet Energy, produce fuel with significant amounts (20%) of aromatics. For all of its good qualities of being renewable and creating a valuable ‘bio-char’ for agriculture use, it should not be used as a fuel without removing the aromatics and olefins. Fuels that are ‘green’ are not necessarily ‘clean’.

Common sense would suggest that we should promote fuels that are 1) clean, without adverse health effects, 2) low in GHG emissions, both in its life cycle and tail pipe emissions and 3) capable of high thermal efficiencies to advance Corporate Average Fuel Economy (CAFÉ) standards.

Science and auto manufacturers tell us that we need higher-octane fuel to reach high CAFÉ efficiencies with commensurate performance and vehicle size. The Ford Motor Company has submitted data to the EPA in 2014 indicating that E30 blends can result in increased engine efficiency. Ford engineers represent that a vehicle optimized to run on E30 can have a 3% increase in MPG even though there is a 10% decrease in BTU content. There has been a growing interest in benefits of higher ethanol blends of E30-40.

An 87 octane gasoline with 15% ethanol will allow some aromatics to be removed from the blend stock but will not promote efficiency. If auto manufacturers move to requiring ‘premium gasoline’ to reach CAFE standards, it will reduce these theoretical emission reductions because aromatics would be needed to increase octane. There is an argument to be made that a more rapid introduction of an E30 high performance regular will reduce emissions faster than a universal use of an E15 fuel. Allowing E30 to become the dominant fuel by 2030 with E10 and E15 available (which would allow the RFSII standard to be met); increased engine efficiency and faster inclusion of ethanol and quicker reductions of aromatics will result in lower emissions sooner. All of the benefits that EPA points to will be there but on a faster time schedule and to a greater extent.

The EPA has released an updated version of the MOVES (MOtor Vehicle Emissions Simulator) computer modeling system used for a variety of studies and predictions. Fuel is one segment of this model and E30 has been added to the MOVE 2014 version. EPA went to a Chevron consultant to write an E30 fuel specification that included adjusting distillation temperatures. Here we get into the weeds a bit as the consultant used a ‘match blend’ method while all actual blending is a ‘splash blend’ technique. The ‘match blend’ method used by the Chevron consultant required adding and subtracting molecules to bring the blend up to a petroleum RVP specification through distillation temperatures. To accomplish this, aromatics were added to the blend stock. This resulted in poor emission data for the E30 blend BUT it was not a result of the ethanol but the adjusted blend stock with unnecessarily added aromatics. The EPA was immediately criticized by many including an SAE (Society of Automotive Engineers) report sponsored by GM and FORD. Any study based on this new MOVE modeling system will be inaccurate for E30 fuels.

GM specifically has been pressuring EPA for a method to certify E30 compliant vehicles. The EPA has thrown a meaningless bone to auto manufacturers. They say “…by allowing vehicle manufacturers to request approval for an alternative certification fuel (E30). This could help manufacturers that wish to raise compression ratios to improve vehicle efficiency, as a step toward complying with 2017 and later light-duty greenhouse gas and CAFÉ standards. This in turn could help provide a market incentive to increase ethanol use beyond E10 by overcoming the disincentive of lower fuel economy associated with increasing ethanol concentrations in fuel, and enhance the environmental performance.” How can EPA reconcile this statement with their approval and continued support of the MOVE 2014 test methodology for E30 that would make a logical and economical blend for E30 illegal?

The under-informed may say there is a mandate for ethanol use. Actually the opposite is more true; there is a mandate for petroleum use. We have mandates for Reid vapor pressure (RVP), minimum octane, maximum aromatics, sulfur content, etc. The RFS II is a mandate for renewable sourced fuel with volumetric set asides for fuels with lower life cycle GHG emissions. For comparison purposes, these are based on average 2005 gasoline. While renewable sourced fuels are required to get better with increased volumes, petroleum fuels do not need to do this. In fact petroleum fuels have gotten worst.

The RFS II ends in 2022. What will follow? It is time to start talking about it.

Replace “RINS” to “GINS” to Account for Greenhouse Gas Values for All Fuels?

If we were to adopt a ‘carbon light’ strategy and move to eliminate aromatics to limit ultrafine particulates, and reduce GHGs without overt preferences to renewable or fossil sources, we could change the playing field. John Stock suggested attaching GHG values to RINs. Why not replace them with ‘GINs’ (GHG Intensity Number) applied to all fuels. The Supreme Court has ruled that the EPA has the authority to regulate GHGs; why don’t we do it? Tar sand fuels would be less desirable but Enhanced Oil Recovery (EOR) methods that sequester CO2 would generate more valuable GINs. Field conversion of methane to DME would be encouraged. The average GIN’ value should be mandated to improve over time and market incentives for production could be accomplished through GIN trading values. READ MORE

Extensive reprint courtesy of the author. See Leaders in Energy website for complete article including charts, graphs and tables.