Hydrogen Motor

BMW Hydrogen 7

BMW Hydrogen 7 (2007)

I do not remember going to an auto show in Germany without seeing a prototype BMW hydrogen. For more than 30 years to work on hydrogen at the Munich manufacturer, and whenever I asked the question (and I asked each time), I responded that soon, cars would be available to customers. But over the past 3 years, I had felt that things accelerated, and I think it was in 2004 that told me that there would be a hydrogen version of the current generation of Round 7. BMW had previously made a model of Mini hydrogen, but progress usually comes from the top, and the series is rightly on the basis of a BMW 760 Li is gone. Although, let it now, it is very small series, because so far, only the production of 100 cars had been decided. First delivery in April 2007, availability in Munich, Berlin, Tokyo, Los Angeles and. Where there are hydrogen stations, or anywhere in France (!) Add also that BMW Hydrogen 7 will be sold, since cars are only available through leasing, the same rate that a BMW 760 Li with a comprehensive maintenance contrac.

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Yes, hydrogen at the same price as gasoline, and even butter money for butter, since this car is bivalent. Or bi-fuel as they say more fluently. It also works well on petrol than hydrogen. Really both, curves of power and torque are virtually identical, which is in itself an achievement, both the combustion of hydrogen is different from that of gasoline. But that has not been without concession.The V12 of the normal 760 (petrol) provides 445 horsepower, it could do the same with hydrogen, but the ability to be bivalent reduced its power to 260 hp and torque to 391 Nm.

Either the power of a 3 litres, and a couple of 4 liters at BMW. This is the price to pay for the establishment of a network of hydrogen stations. But already, with a top speed of 230 km / h and an acceleration of 0 to 100 km / h in 9.5 s, it remains at the wheel of a car that will not be ridiculous on the autobahn. And what is equally important that the performance of a limousine high fly as it is autonomy. With its 2 tanks, the car can travel over 650 km. Approximately 450 km of petrol, with a tank of 74 litres, and over 200 km on hydrogen, with its reservoir of 8 kg.

To store this hydrogen, BMW has made the best technical choice, that of liquid hydrogen. For motorists, this is the best solution, because liquid hydrogen is denser than hydrogen gas. That is to say that for a tank of a given volume, there is more than liquid hydrogen gas. If instead of its liquid hydrogen tank, the BMW Hydrogen 7 had a reservoir of hydrogen gas at a pressure of 350 bars, it would contain less than 3 kg of fue. So everything is proceeding smoothly, except in terms of overall performance, it takes more energy for liquid hydrogen that compress. But of course, this does not prevent the production of liquid hydrogen on a fully renewable and environmentally friendly.


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This choice of liquid hydrogen can also keep a safe normal, and this series 7 meets all applicable safety standards. She underwent the same tests as other BMW production is guaranteed by an auto factory, and there is no question as we did before some conversion kits gas. It is a car designed with all the seriousness expected of a BMW. This is important because liquid hydrogen requires a perfect isolation, as evidenced by the hose with which it was full: a real horn elephant!

On board the car, the passengers did not make the fuel is used, even the driver unaware if there were a warning to him indicate. He was invited to ride with hydrogen, is the main fuel, but it can always switch to using a button on the steering wheel. And in case of fuel exhaustion, the car switches itself of fuel to another. This feature is all the more necessary because the car is greedy. We can not forget that this car is a superb gear great luxury, with a princely equipment, including doors with assisted closure, soft and automatic.

16/17 l/100 km gasoline, and almost 4 km kg/100 hydrogen. It is therefore an opportunity to compare the performance of a heat engine with a fuel cell (CAP), as the GM Sequel (tested recently) also has an 8-kg tank of hydrogen. And though less perrformant, he travelled 480 km with the same amount of fuel. But n'enterrons not the engine, which retains the virtues of reliability, ease of maintenance, cost, and that has certainly not said its last word, since it still awaits the hydrogen engine monovalent, and totally optimized for this fuel.

But already, which means that BMW Hydrogen 7 is the end of hydrocarbons alternative. The LPG was killed by diesel, which rejects 10/15% less CO2 than him, but he remains the natural gas (CNG). A good fuel, CNG, since it allows an engine ignition for CO2 emissions almost equal to that of a diesel or lower 20/25%. But What logic, a convert gasoline to make the walk CNG and reduce its emissions by 20/25%, if for a little more expensive - costs for a reservoir highest pressure, food and more sophisticated engine management - on can now be converted to hydrogen that reduces emissions by over 99%.

Hydrogen 7

Indeed, with hydrogen, the BMW does almost as water vapour. As there is more carbon in the fuel, CO2 emissions should even be zero, but with the possible drop of oil that can pass through the exhaust, we limit ourselves to write that they are reduced more than 99%. The same is true for all toxic pollutants, including nitrogen oxides (NOx), as BMW is super champion to optimize the burning of its engines, and the latter takes place upstream where temperatures are formed NOx. Therefore, the near-perfect, with the only drawback of having to refuel every 200 km. The BMW 760 Li is not a small car journalist, and this even less Hydrogen 7 is a car big boss who will only have to ask his driver to go refuel when needed. And seated in the rear, the big boss will have the satisfaction not pollute during his travels, while continuing to benefit from an auto highest level. Neither Mercedes or Lexus can offer him that.