Isobutanol: Now on the Radar for USA

April 29, 2018 |

By Jess Hewitt, RIN and Isobutanol Expert, Lee Enterprises Consulting
Special to The Digest

The Environmental Protection Agency (EPA) has opened a comment period for the registration of the use of Isobutanol in gasoline.  Why is this important?  Because since the states banning of the use of MTBE and other ethers in underground tanks, this is the only oxygenate, other than ethanol, allowed to be used in commerce.  This is a significant event as it will allow the US consumer to choose oxygenates.

Many parts of the United States are classified as non-attainment areas, or opt-in areas, for pollution.  They have rules that require the use of Reformulated Gasoline (RFG).  In these RFG areas, no gasoline can be sold in commerce unless it contains an oxygenate.  For many consumers, this means that if they want to buy an ethanol-free gasoline, they are limited to buying very small containers of conventional gasoline – at a cost of up to $28 per gallon.

The ability to choose whether you have ethanol or isobutanol is significant.  Since the introduction of ethanol into the gasoline pool, consumers with small engines with vented fuel systems, have dealt with a host of problems that all begin with ethanol’s nature to attract water.

Consumers concerned about the environment seek an ethanol-free gasoline, but they want to avoid the problems with ethanol.

So why is ethanol so bad for them?  In a modern car, the fuel system is sealed.  When one opens the fuel door, they will see the warnings on the filler cap:  “Caution, Remove Slowly, Fuel Spray May Cause Injury.  Tighten until Cap Clicks.”   These warnings are necessary because the fuel systems in modern cars run in a vacuum condition to prevent atmospheric moisture from coming in contact with the gasoline.  Thus, when we hear the “clicks” on the gas cap, it is confirmation that the cap has sealed the fuel filler tube and that the system can now remove the air and create a vacuum.  That’s also why we may hear the “swish” sound of air entering the tube when we remove the cap.

A sealed fuel system reduces the risk of the ethanol caused water to be pulled into the fuel. Ethanol is hygroscopic.  While it is a bit difficult to explain the term, everyone does know that ethanol and water will mix – as when we have a mixed drink. However, what we may not know is that ethanol’s hygroscopic nature will literally suck water out of the air.

An internet search will reveal some convincing videos about ethanol attracting water into gasoline. Moist air is attracted to the fuel, then starts to condense on the interior of the fuel system. The condensation forms droplets which become streams of water that fall into the gasoline.  We see a similar reaction when we have a glass of iced tea outside and the moist air condenses droplets on the outside of the glass.  Those drops turn into little streams of water, rolling down your glass. This is what happens in your fuel system.

The process will continue until the ethanol has absorbed all the water and becomes saturated.  Then, the ethanol-water mixture can become separated from the gasoline.  This separation of the ethanol-water mix from the gasoline is a significant issue since ethanol is a high-octane additive.  Losing the ethanol from a gallon of gas will mean that the octane is reduced by two octane numbers.  If an engine is designed to run on an 87 octane gasoline and you reduce it to an 85 octane gas, the engine will likely not run properly and could even be damaged.

Secondly, the presence of water in the gasoline and the gas tank present other complications.  The water will have a negative effect on the engine performance and may result insignificant damage to the engine.  Fuels systems can be affected by acids that can form with water in the fuel tank. These acids can degrade metal, fiberglass, rubber hoses and plastic used in fuel systems to the point where they can fail and must be replaced.

Most boaters with an outboard engine have an “ethanol story” to tell.  This is also true of anyone with any small engine that powers off road vehicles, generators and compressors, or other small engines like those used in lawn equipment, chainsaws, Jaws of Life and ATV’s.

The National Marine Manufacturer’s Association (NMMA) has been studying these issues and testing solutions: In 2015, they endorsed the use of gasoline using isobutanol over any ethanol-based gasolines.  They did this at about the same time as the government allowed the sale of E15, a gasoline blend with 15% ethanol.

Back to the Future

Essentially, as a nation, we are regressing back ten years to a time when the USA had a choice of oxygenates. Many oxygenates had long names, but were known by their initials – MTBE, ETBE and TAME.  At that time, using ethanol as an oxygenate rendered the gasoline mixture a “gasohol.”

The ethers that were in use in 2007 are still legal today by federal standards.  However, states have outlawed their use in underground storage tanks.  Isobutanol has not been outlawed and it meets federal standards.  And, isobutanol is available in renewable and non-renewable versions.

I don’t believe the EPA will have any problem registering the Isobutanol based gasoline.  However, they are asking for public comments. Every person, and company, has the right to provide comments about the questions raised by the EPA:

  • The need for additional health-effects testing under the Tier 3 provisions in the regulations, and
  • the need for additional regulatory controls for 16 percent isobutanol in gasoline.

The EPA has invited all comments, stating that “we are seeking public comment regarding any issues we should take into consideration for this registration and any supplemental actions we should consider under the Clean Air Act to further protect public health and welfare.”  Thus, anyone can offer any other comments on the issues.  You can find the EPA Docket Announcement here:

I would think we might see the petroleum industry and the ethanol industry do something they hardly ever do – agree.   They just might agree that Isobutanol requires much testing before being registered for use in gasoline.  I think ardent supporters, like boaters, will positively comment about the additive.  In fact, the NMMA has already filed their comment to support the use of Isobutanol. That’s here. 

I also expect to see various comments from consumers endorsing the need for the registration as a way of offering choices in oxygenates.  For those who are serious about making the gasoline mixture, I expect to see some comments about the need for refiners and blenders to produce the gasoline blendstock called Reformulated Gasoline Blendstock for Oxygen Blending (RBOB) that can be blended with ethanol or isobutanol.  Ten years ago, when refiners created the RBOB, they produced a “Product Transfer Document (PTD)” that would allow blending of any alcohol oxygenate.  But since the switch to ethanol, many refiners and blenders created an exclusive RBOB that could only be used with ethanol.

I find it difficult to believe that refiners are making RBOB exclusively for use with ethanol. However, it is happening and our anecdotal survey of refiners says that many will not change their PTD to allow use of Isobutanol.

When asked why they will not create gasoline blendstock for Isobutanol the answers are almost always the same, and some are surprising:

  • “We use ethanol as our only oxygenate so no need to change”;
  • “Isobutanol costs three times the cost of ethanol;, it is not economical to use it”;
  • “We only have one tank for an oxygenate and it is in service for ethanol”.

These factors will weigh down the use of Isobutanol in the short term and the blending might stay where it is now – downstream of the petroleum terminal delivery system.

Much Isobutanol is blended into gasoline outside of the terminal system by a combination of gasoline retailers and oxygenate blenders.  Currently, Gulf Racing Fuels is making an off-road Isobutanol-gasoline mixture for boats called “Gulf Marine”.  Due to the factors listed above, the fuel is splash blended on petroleum transporters to get it to the retailer.

Retailers understand that there is a demand for this product and the price is nearly completely inelastic – for a small segment of the marketplace.  Consumers who want ethanol-free fuel are given the choice of a quart of pure gas at a hardware store that sells for the equivalent of $28 per gallon, or they can find a gasoline retailer who offers an Isobutanol-blended gasoline for about $4-5 per gallon. The market is proven, but retailers are stymied by the lack of infrastructure to blend the gasoline.

There are hot spots for Isobutanol use in the following RFG areas:

  • East Coast coastal counties from Maryland to Maine;
  • Chicago area;
  • Louis market;
  • Dallas/Fort Worth;
  • Houston/Galveston; and
  • Southern California.

Refiners and blenders able to make gasoline for blending with isobutanol should have no trouble finding retailers willing to market the ethanol-free gasoline.

Refiners and Pipelines

There will be much discussion about Isobutanol-blended gasoline going into pipelines.  Remember that pipelines approved the transportation of gasoline with non-hygroscopic alcohols more than ten years ago.  However, the pipeline has to deliver the fuel into a tank at the terminus of the pipeline and if that tank has RBOB dedicated to ethanol then no Isobutanol-blended gasoline can enter the tank.  So, although pipelines can carry the blend they don’t have anywhere to deliver it.

Gasoline Retailers: Mixing Ethanol and Isobutanol is a No-no

One of the other reasons that the new gas will be limited in distribution is the EPA’s no blend rule. The EPA will not allow ethanol and isobutanol gasolines to be mixed together at any point prior to retail purchase.   Any gasoline retailer using what is commonly referred to as a “blender pump or dispenser” will not be able to offer a midgrade product if ethanol-based gasoline is also offered.  You see, in most gas stations three grades of gasoline are offered, regular, mid-grade and premium.  There are only two storage tanks and one contains regular and the other contains premium.  The dispenser mixes the two together to make the mid-grade gas.

This means that any retailer who offers a premium isobutanol gasoline alongside an ethanol-based regular gas cannot produce a mid-grade combination due to the EPA restriction. Most retailers simply turn off the blender make the mid-grade 100% premium and price it accordingly.

Public Comments

Look for the majority of public comments to be positive as consumers now know the product can be made and they are willing to pay the price for the fuel.  The gasoline retailers will also support the fuel’s registration so that they can offer the product at the retail pump.  The same group will complain about the EPA no mix restriction.  There will be some discussion about the Product Transfer Document (PTD) being exclusive for ethanol and requesting the EPA to somehow convince refiners to make an “any alcohol” PTD again.

We may also see some states offer comments as they know their constituents want an ethanol-free gasoline especially in the RFG areas.  There may be some discussion of pump labeling requirements as currently there are no federal requirements, and state requirements are not universal.

We will likely hear from the makers of the Isobutanol-based gasoline about the need for registration to spur refiners and blenders to make more infrastructure available for making the gasoline.  And we will see negative comments from the petroleum industry about having to make allowances for a new boutique fuel.  Ethanol producers, who do have the capability of converting their facilities to make Isobutanol, will probably attack this product while defending their own product, and downplaying the negative effects of ethanol in gasoline.


I believe the outcome will be that EPA requires Tier 2 and 3 testing of the gasoline additive.  Major industry groups will align themselves on one side or the other and this issue may well see opposing members agreeing with their historic foes.  I believe that consumer demand will become apparent to the EPA which will hopefully cause reconsideration of the restrictions on the use of this fuel.  As the legislation is founded in rules legislation, the EPA may be limited as to what they can do.  I do not believe that the EPA will be able to change the PTD rule, despite the likelihood that any gasoline blendstock that qualifies ethanol for blending could also produce a gasoline within specification for isobutanol. All in all, I think the comments will be educational and interesting and readers should expect to see a summary of these comments next month.

About the Author: Jess Hewitt is a member of Lee Enterprises Consulting, the world’s premier bioeconomy consulting group, with more than 100 consultants and experts worldwide who collaborate on interdisciplinary projects, including the types discussed in this article.  The opinions expressed herein are those of the author, and do not necessarily express the views of Lee Enterprises Consulting.







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