Today is the eleventh and final post in this Monday series of subjects covered during my summer 2014 interview of Bill Reinert, recently retired energy engineer for Toyota who played a key role in the development of the Prius and then assumed the role of future transportation planning of alternative-fueled vehicles at Toyota. See his full bio here. –Kay M.
K.M.: Years ago you said, “Using ethanol for fuel is like electing the dumbest kid in school as Class President.” Do you still stand behind that statement?
Reinert: Yes, I still stand behind that statement. Ethanol has remarkably destructive properties in your gas tank, especially on cars and engines that aren’t driven very much, like seasonal boats. It is hydroscopic so it absorbs water and the water gets throughout the fuel system and dirt or debris that’s normally in your tank gets emulsified. That gets plated out in your fuel system and your car runs very poorly. This has been documented time and time again, and it’s especially bad for cars or applications that aren’t designed for high levels of ethanol. It really has no upside and when we consider all of the damage that it does to our ecosystems, it is done for no good reason. I don’t believe anybody in the scientific community or at the Department of Energy (DOE) is seriously looking at bioethanol from corn except for the politicians.
I don’t think people realize how much energy is in oil and gas, and the amount of acreage necessary to make even small replacements is huge. And cellulosic ethanol, by the way, is a dream that will remain a dream.
K.M.: Ethanol got its window of opportunity as a methyl teriary-butyl ether (MTBE) replacement, because MTBE was added to gasoline to help prevent air pollution and then it was discovered that it was a water pollutant and a carcinogen. Now, ethanol advocates like to tell us that we need ethanol as an octane booster in our gasoline. Are there good alternatives to ethanol that might be used as octane boosters instead? What would you pick?
Reinert: I’d pick the bioethers. They’re not water contaminants and their half-life in the troposphere is very small. With a little more study I think they can make a contribution in improving the cetane and the octane of the fuels and thus allow us to use them in the most advanced engines that we have right now. The trade off with ethanol as an octane enhancer is that it’s hydroscopic and I would never make that choice, plus it has such a giant footprint. In comparison, we can make these ethers pretty quickly and pretty easily.
The bioethers, dimethyl ether (DME) and diethyl ether (DEE), are synthesis gases made from waste products. Since they’re not a fermentation product like corn ethanol is, all of the carbon gets turned into fuel whereas in fermentation, only the carbon that is converted into sugar gets used for fuel. DEE can be used in gasoline engines as an octane enhancer and DME could be used to increase the cetane of diesel, or, it could replace diesel altogether.
Octane boosters help prevent pinging in the advanced gasoline engines since we’ve increased the combustion pressure so high that the fuel pre-ignites. This means that new gasoline engines have started to resemble diesel engines.
And in order to reduce the nitrogen oxide emissions from the diesel engine, we are reducing its combustion ratio, making it more like the gasoline engine. However, this produces soot, which DME can help to prevent.
I’ve had some wonderful conversations with Steve Chu and others at the Department of Energy and what they want is a drop-in gasoline replacement. Ideally, we would be given optimum specifications, or fixed properties, for gasoline and diesel. There would be multiple pathways to arrive at those specifications, such as through syngas. This could be done through a Defense Advanced Research Projects Agency (DARPA) grant. The fuel you’d want to pick in the end would be the one with the lowest societal costs. This is what we really need to be doing, but unfortunately, we’re not doing it.
To see last week’s interview subject on the best ways to power cars, including the pros and cons of using batteries, hybrid technology, ICEs, or fuel cells, click here.
I hope you have enjoyed this series for the valuable resource and the wealth of information that it has provided. Today marks its final day.