Thanks for your comments, etmax. Jet fuel and jet engines used commercially are quite different from car engines & fuels for same: much simpler, much better understood. They are also highly regulated, including the percentages of blends. Jet biofuels are chemically identical to jet petro-based fuels. That's why they're called "drop in." Because of all this, biofuels are happening much faster in this market than in markets for use by private cars. For more information, I suggest you check out the other blogs we've posted and the links given in them to sources detailing these subjects.
My car has a rating label attached near the fuel cap that says it's rated for up to 85% Ethanol yet when I had issues with fouled injectors they said I was using bad fuel which caused it.
I said if it's rated for 85% Ethanol then given that the highest blend at the pump is only 15% I'm at a loss to understand how I could have used bad fuel. In any case I do only use 91 Octane.
With a previous vehicle I did tests on specific drives with higher octane (98) and fuels up to 15% Ethanol and found that the higher Octane fuel does not improve economy by the amount of the price difference. Likewise the price reduction for 15% Ethanol was met by a greater than the cost savings fuel consumption resulting in standard 91 octane being the most cost effective. The drive BTW was a >500km trip where conditions from one trip to the next are virtually identical.
What does this have to do with your post?
Well I was just wondering whether Boeing has taken these factors into account in their study? Is the "New" bio fuel more sustainable only environmentally (important of course) or cost wise as well? A jet turbine may well behave differntly with different fuels, but I of course have no opportunity to try it.
ciaccio39, the term "drop-in" means the process doesn't have to be changed; it says nothing about the item being dropped in. It's been used for decades in a manufacturing context to describe a part or material that can be "dropped in" to an existing process without the need to modify that process. In the context of fuel, it means the engine doesn't have to be changed. To answer your question about blends, this is standard practice and we state in the blog that a blend of up to 50 percent biofuel is now allowed. The newer fuels approach or meet 50 percent, vs older ones that constituted more like 10 or 15% of the blend.
Ann, I may have read about the use of corn waste, but it slipped my mind. And I see all of those posted links but I don't chase them, so if the discussin is in a blog that I don't follow I miss it.
The beauty of using sugar cane waste is that it is not a food for humans, unlike corn, and so it would not bid-up food prices. At least not directly. Possibly they do use it for something.
My other idea, from many years back, was to use municiple sewerage and garbge in a fermenter to produce usable amounts of methane. It would need to be large scale to be economical and that would take lots of land, it seems. So I don't think that anybody has tried it, at least not that I have heard of.
William, you're talking about corn stover, which is the leftover rough waste after corn ears have been harvested. It's a very promising second-generation feedstock for biofuels, as we've discussed in other DN blogs (just search the site on "corn stover"). As with other second-generation feedstocks, though, there are several infrastructure issues yet to be solved, such as collection and distribution, establishing a market and pricing, etc. As we've mentioned elsewhere in similar discussions, government subsidies help an industry get started and once it's established, they can be reduced or removed. This has worked quite well in Europe and Japan for alternative energy, which is one of the reasons both those regions are well ahead of the US in that field.
jeffbiss, thanks for your comments. I agree about palm oil production--there's nothing sustainable about about it: harvesting practices tend to wreck local economies as well as endanger wildlife, and it's even unhealthy to consume it. Sustainable or green diesel is, very specifically, only made according to principles put out by the two organizations mentioned in the article, regarding considerations such as derived from non-food crops and not competing with food crops for soil or water, for example.
If this effort helps protect wildife and its habitat, then it will be a big step forward. Currently, there is a big problem in the perception of "sustainable" when used with regards to fuels such as palm oil as the source of "susainable" diesel (see Orangutans – victims of "sustainable" palm oil and Orangutans - Victims of 'sustainable' palm oil in Indonesia). The RSB does account for wildlife, in Principle 7 Conservation,so there is hope. I just hope that there are enforcement teeth to ensure that wildlife is not negatively affected.
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