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beechcraftted

Isobutanol - the next gen biofuel

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Long time lurker, infrequent poster here. I live up here in WI. and my company sells some machinery & eqpt. to BRP (Bombardier Recreational Products / Can-Am, Rotax, Evinrude, Ski-Doo) at their research facility in Sturtevant, WI. They just received an award and were named the 2014 winner of WI Business Friend of the Environment.

 

Being a big E-85 fan, I was curious about their thoughts on ethanol, and had a LONG discussion with one of the product managers. They are going all in on Isobtanol and view ethanol as a first generation biofuel to be used primarily as an additive only.

 

He described to me that isobutanol has a longer hydrocarbon chain length and is closer to gasoline than ethanol. He added that isobutanol has 98% of the energy density of gasoline, it does not readily absorb water and can be mixede at any proportion with gasoline. It can be shipped in the existing gasoline infrastructure and it can be produced from plant matter not connected to food supplies.

 

BRP has spent millions (and I mean Millions) to reduce emissions on their 2 cycle (E-Tec) engines and have achieved emissions lower than a 4 cycle engine in some applications.

 

They cosider ethanol a "past" technology fuel and consider isobutanol the "current" generation alternative fuel and are going all in toward that end. These guys are very knowledgable on fuels and are not "small potatoes" operating on the fringe. I can't tell you how adamant they are that isobutanol is the fuel of the future.

 

Very interesting conversations.

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Am I correct in stating here is no full scale isobutanol commercial plants at this time frame.  The conversion of an ethanol plant to isobutanol will cost something like $40 million dollars?   Gevo is a major backer of this but faces a significant cash shortage and where will the needed funds come from?  The "higher" BTU content of isobutanol sounds good but will the optimized gasoline engines suffer 20% fuel economy losses because the oxygen sensors detect such in the fuel and force additional fuel?

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Hello Beech.. yeah as Billy was pointing out I don't think anyone is even doing full scale Isobutanol yet.. It's a long long road of political and legislative battles to get a fuel to Market AND the investments .  There are no vehicles approved to even run on butanol..and as far as I cna tell EPA would have  a few years of testing before it could even be approved

 

Isobutanol does have some advantages but also has a lower Octane rating than Ethanol .. around 96 compared to 107 for ethanol(meaning you can get higher compression out of ethanol than butanol)

 

Looking at your post though Beech .. looks like they are looking at it specifically from a small engine standpoint ?

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Yeah, after talking to SteveV about all the research his company has done with Detroit, ethanol's main points are high octane and clean air. Butanol can't compete on those two aspects. E30 is probably the closest to perfect----100 octane characteristics, clean burning, and miles per gallon in an optimized engine.

Edited by cessna

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Looked into this a while back. While it takes 10 gallons of water to produce one gallon of ethanol, using bakers yeast and a few gallons less using a hardier strain of yeast, you can reuse the water as is, or release it back to the environment without issue. Isobutanol uses 100 gallons to produce one gallon of fuel, leaves the water toxic and it must be treated before being used for fuel production or released back to the environment. Its made with bacteria and they are far more sensitive to living in their own waste than yeast. The toxicity of the fuel is also an issue, because spills would be hazardous just like gasoline. Im not sure how easy it is to put out a fire fed by isobutanol, but ethanol takes simple water while gasoline takes foam.

 

That isobutanol doesnt absorb water means rusted fuel tanks and water in fuel system problems just like gasoline, ethanol absorbs water but allows you to burn it. it mixes readily and causes no harm to anything until you get over 35% water in the fuel, and then it is only untreated/non anodized soft aluminum. Im not sure of its corrosive properties, so that might be a non issue. 

 

The food vs fuel is useless since most of the feedstocks we can use for ethanol production are not food for humans. Kudzu, cattails, and other weeds grow profusely and yield far more ethanol than corn does. The water issue is of bigger concern with butanol because it requires so much more and requires treatment before reuse or release. Sure we can make it, but at a cost of drinking water and more expense due to treatment after producing butanol.

 

Having a far lower octane means less power potential, less efficiency, and needing larger engines due to lower compression ratios. I didnt look into its latent heat of vaporization characteristics but I doubt it will be as efficient as ethanol at cooling the intake charge. Sure butanol is higher than gasoline, but that isnt saying much. How does it run under boost and heavy loads? What emissions does it have? Does it leave a carbon deposit in the engine under combustion like gasoline does, or is it clean burning like ethanol producing only CO2 and H2O? 

 

Lastly the BTU content is a red herring, as BTU is simply heating one pound of water one degree. Engines are not designed to merely heat water, its a byproduct of combustion and gasoline is still below 20% efficient, meaning it wastes 80% of its energy heating the engine, water, and air around it than powering whatever its being burned in. Ethanol is 40% efficient in the real world, 42% in the lab, at least according to the US Navy who tested it back in WWII. That means it only wastes 60% of its energy heating things up, which is part of why ethanol runs cooler. Candle wax and bees wax have high BTU content too, but they arent really good fuels for transportation engines. The comparatively paltry BTU deficiency of ethanol is nothing compared to the wasted energy of gasoline. So freaking what if butanol has almost as much BTU as gasoline, we arent heating water with it.

My big issue is the water used in production and the lower octane. High compression engines are more efficient, which is why compression ratios have been creeping upwards and why we have direct injection showing up now, because its a bandaid for the crappy octane of gasoline. We are trying to get more from the fuel we burn, and squeezing it harder does that, the problem is gasoline cant stand being squeezed very hard and it explodes too soon, which requires retarded timing, lower compression ratios, and shedding as much heat as possible to prevent detonation. Carbon build up from gasoline negatively impacts the propensity to preignite, as well as wearing out the engine sooner. It remains to be seen how isobutanol fares in comparison. It might be a decent bandaid for gasoline engines, but it cant compete with ethanol in many areas.

 

I think the biggest reason butanol has backing is that not any old Joe can produce it easily and cheaply in his back yard. They can control the production entirely, because the bacteria that make it will kill you if you try to make it yourself like you can make ethanol. the amount of water required makes it prohibitively expensive for the average Joe to to produce it, and the environmental impact would be massive if they started dumping the left over waste water. Think Canadian Tar Sands ecological nightmare and tailings escaping into rivers. Ethanol spills kill bacteria, but little else, and its biodegradable with sunlight and easily diluted with water.

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