In our view, there are a lot of good arguments in favour of natural gas as a fuel: The alternative fuel burns cleaner than conventional fuels and is therefore environmentally friendly. The emission of nitrogen oxides and particulate matter is almost completely avoided when natural gas is used as a fuel. The emission of nitrogen oxides is around 96 % lower compared to a diesel vehicle. Compared to comparable petrol cars, natural gas-fuelled cars emit around 15 % less CO2. With the admixture of 20 % waste-derived biomethane (average share in natural gas fuel in recent years) even improves the GHG balance by more than 30 %. Compared to modern direct-injection petrol engines, particulate emissions from natural gas are 99 % lower. The "softer" combustion of natural gas also reduces engine noise by up to 50 %.
In petrol engines designed for natural gas with a three-way catalytic converter, such as that of the Fiat Ducato, the methane slip is well below one per cent and therefore poses few problems. This does not apply to converted diesel engines (dual-fuel engines), which have a valve overlap that is unfavourable for gas operation.
In addition, natural gas can be substituted 100 % by biomethane. This can further improve the already good environmental balance: According to dena, using 100 % biomethane reduces CO2 emissions by up to 100 % compared to petrol cars. Already today, biomethane is offered at many petrol stations. The problem of methane slip through ignition jet engines, as often used for the conversion of biomethane into electricity, has also been solved in Germany, at least to a large extent, and will be further reduced in the future.
Methane slip at compressor stations is due to a lack of technical maintenance as well as a lack of regulations. However, the problems can be solved easily and cheaply by closing leaks or flaring the methane at the point of leakage.
Another renewable fuel provides additional security for the future: synthetic natural gas, which is produced from surplus wind and solar energy.