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Gasoline From Thin Air
disco_tracy writes "An enzyme found in the roots of soybeans could be the key to cars that run on air. If perfected, the tech could lead to cars partially powered on their own fumes. Even further into the future, vehicles could draw fuel from the air itself. Quoting: 'The new enzyme can only make two and three carbon chains, not the longer strands that make up liquid gasoline. However, Ribbe thinks he can modify the enzyme so it could produce gasoline. ... [Perfecting this process] won't happen anytime soon... "It's very, very difficult," to extract the vanadium nitrogenase, said Ribbe.'
It converts carbon monoxide, which is even less abundant.
200W? The flow through a gasoline fuel hose can be expressed in watts if you care to. Gasoline has about 32 megajoules per liter. Maximum gas pump in the US is 10 gallons per minute, or 0.63 liters per second. Thus the energy flow rate is 20 megajoules per second -- that is, 20 megawatts. If a gasoline engine is only 1/4 as efficient as an electric engine and there are no charging losses, you can derate that to 5 MW to get the equivalent electric power needed. So, you can keep that 20 amps... provided you're willing to charge at 250,000V. Good luck with that.
The higher compression means that the they must be built stronger. AKA more expensive.
Also they use a high pressure fuel injection system which is also more expensive and complex than a simple spark plug and carb.
So yes they tend to be more expensive to build and more complex.
But they do not need to have their spark plugs replaced or have your typical tune up.
Thing is that modern electronic ignition and spark plugs have made gas engines also about as user low maintenance as a diesel.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
they're electricaly simpler, but their fuel injection is enormously more complicated than a carburator. a diesel requires one really strong fuel pump to bring the pressure to above 10 atm, then it takes one individual small pump per cylinder, synced to respective engine piston, to inject the fuel at pressures higher than the air pressure inside the combustion chamber. that's one of the reasons diesels were always a hulluva more expensive than gasoline engines.
electronic fuel injection on both gasoline and diesel levels the playing field somewhat, but diesels are still more expensive to build because of the higher compression. this requires much stronger blocks, heads, seams, moving parts, fuel pump and really strong pipes between the pump and the injectors.
What ? Me, worry ?
Modern diesel engines are exactly as complex as modern petrol engines. No mainstream petrol engines now use carboretters (that I know of). The only big disadvantage with diesel engines is that they are heavier - they require a little more ironmongery.
Diesel engines are generally simpler to run and way less sensitive to water. There's a reason all commercial vehicles are diesels. The weight is also a reason why we haven't seen diesel bikes hitting the mainstream yet either.
Essentially, with current engine design, the _only_ disadvantage to diesels is their weight. That and their performance characteristics - you don't get high reving fun diesels.
there is also the issue of cold climates, as under those conditions the piston needs to be heated (usually electrically) so to get the diesel mix to ignite at all. Luckily, modern engines do so automatically as part of the ignition sequence, tho earlier one had to turn it on manually (and if forgotten, i suspect it could drain the battery).
comment first, facts later. http://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm
Its right there in the summary. "Ribbe thinks he can modify the enzyme so it could produce gasoline" THINKS? *reads article*. "The new enzyme can only make two and three carbon chains" Wait.. how many carbon chains do we need? *googles* oh. http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/question1051.htm "The chains from C7H16 through C11H24 are blended together and used for gasoline" 7-11. So basically ... they are nowhere close. Tell me when they are dealing with efficiency issues of generating the gasoline or developing a system in which to recycle it. This is non-news. If they were talking about refining the tech they have to produce propane (which is what they accomplished) it would still be on the "oh another alternative energy idea that will probably still fall flat on it's face due to cost, efficiency etc"
insert funny sig here
Split a pack up into, say, 10 separate packs which can go into arbitrary locations, and you 10x the connection problem, double the combined cost of the battery packs for the vehicle (because of the overhead on packs as small as you'll end up with), increase its weight, and increase the cost of the pack swapper several times over.
No, there can't. Here, let's list the first EVs that come to my mind and then look at their pack needs:
Nissan Leaf: As a five-seater sedan, the pack exists between the belly pan and the floor near the center of the vehicle, which is a very efficient use of space (and is the sort of thing that Better Place is trying to do for swapping). Since it's a pure EV, it needs a high energy, low power battery. Since it's a low-end EV, the pack is short-range (a nominal 100 miles)
Chevy Volt: As a narrow four-seater designed for a lot of internal room without a high profile, the pack can't fit under the floor. So the pack is T-shaped, running down the center tunnel and under the back seats. Since it's a plug-in hybrid, it needs a high power, low energy battery (these cells are typically more expensive).
Aptera 2e: As an unusual shaped composite two seat three wheeler (to get aerodynamics far superior to conventional cars, albeit with less mainstream looks), the CG must be kept very low and fit within the contours. The pack goes under and behind the two seats of the vehicle, next to the rear taper of the underbelly.
Toyota RAV4: No details announced yet, but as an electric SUV, its pack will need to be larger and deliver more power than sedans need, but as a mass-market vehicle, it will still need to be made from an affordable chemistry.
Tesla Roadster: Since it's rear-wheel drive, you need the weight over the rear wheels. As a consequence, the battery pack is located in the rear and takes up part of the trunk space. As a high-end vehicle, the nominal ~250 miles range requires a pack more expensive than most people in lower-end cars could afford. Since the market is high end consumers, a shorter lifespan chemistry is acceptable so long as the vehicle delivers on its range and power needs (and hence, that's what's used).
Tesla Model S: Rear-wheel drive, but an entirely different shape and weight distribution profile, which the battery must be matched for. Three pack size options are available depending on how much the consumer wants to pay (160 to 300 miles range).
Lightning GT: Since this car is all about high performance and extremely short charge times, they need to use a chemistry like the titanates. These are very low energy density, extremely high power output, and very expensive -- not a general purpose battery pack.
I can keep going if you'd like. The simple facts are that even if you freeze battery tech in time, you can't come close to starting to standardize. Let alone what happens as battery tech continues to advance.
And the main issue is that it's Totally Unnecessary. The concept has been effectively supplanted by rapid charging, which has no inventory or standardization problems. There are some companies with money invested into the notion that are holding out, but it's a tech proposal with no impetus behind it any more.
"I like your Christ. I do not like your Christians. Your Christians are so unlike your Christ." - Gandhi