The available natural gas deposits are unambiguously higher than those of crude oil. There are countries as for example Italy where natural gas with about 400,000 users (2005) is accepted substantially better than
in Germany (30,000 users). The modern injection systems with lambda control are advantageous, as they have the possibility to compensate differences in the natural gas quality. At the moment also the filling station
network is growing which is especially important because the range is actually lower at the moment. At the end of the year 2006, e.g., in Germany the ratio of normal to natural gas filling stations is 15: 1. Apart from the
locking mechanism of the clutch the refuelling does not differ very much from usual refuelling (see figure). However, a little, because the fingers remain - in comparison, e.g., to the diesel oil, more cleanly and the tank
is filled according to the pressure ratio at the respective filling station differently full.
How it works
The energy density of natural gas from methane ethane (approx. 90 to 10%) amounts with the lowest carbon content of all hydrocarbons to only about 60% of petrol. To the diesel oil the distance is even bigger.
Expressed in volume the tank size quadruples. Therefore, with one tank filling of an average bivalent vehicle you manage only a bit more than half what the same car would manage with petrol operation. The filling
station nearby is used more often.Also here something is different. Though the tank process does not produce any unpleasant gases, however, lasts about twice as long. The expenditure for the filling station is
bigger, because the natural gas must be dried first and filtered, before it is compressed to approx. 200 bar in the accumulator. Indeed, no tanker is necessary if the gas station is connected to the gas network.
Favourably for monovalent (only natural gas running) operation is the very high engine octane rating of 120. With it even a low consumption saving and increase in output should be possible if the engine is slightly
altered accordingly. A bivalent system which effects via the knock sensor the ignition cannot use this potential completely. We might put our hopes on the variable compression. Also the filling capacity and with it the
range can be improved. Though the filling pressures probably are not raised that fast, but like in the plane technology, it is possible to make use of cross-beams and other (unthreatened) parts of the car body for
filling. The more potential buyers there are, the more the car industry will react to them with the construction of vehicles.