This truck is powered by Diesel and natural gas, very little Diesel and a lot of natural gas, in normal operation in the ratio is 5 to 95. So it has a very small tank for Diesel and a large one for natural gas (picture: driving direction left). The truck is derived from the Volvo FH and apart from the special injection system, there are no Diesel-typical features on the engine itself.

Liquified Natural Gis refueled, which is nothing else than Compressed Natural Gas in liquid form. In Germany, this is difficult to obtain, not so in the Netherlands and in Sweden. It is also widely used in the USA. You could operate such engines with CNG, but would have a significant loss of range.

In this Volvo is the largest LNG tank good for about 1,000 km, in the USA is with bigger tanks even more possible. It is still important that there are not the disadvantages to be suffered in previous conversions from Diesel to natural gas. The Diesel engine remains in principle in its performance and, above all, its torque. So this method is particularly suitable for heavy goods traffic.

The at about -163°C fueled LNG is housed in a double-walled, vacuum-provided tank for a few days, supposedly temperature-resistant. It's own injection system is fed with almost 350 bar now as CNG, warmed up by a heat exchanger with coolant. Shortly before the direct injection, however, it is also connected to the common rail injector like the Diesel support, too.

It has not only two connections, but also two concentric needles, the inner one for natural gas, the outer for Diesel. Thus, the already mentioned mixing ratio can be operated. It is absolutely necessary to inject the Diesel fuel first, because its combustion makes the necessary ignition temperature for the very high-octane natural gas reachenable.

The main advantage, as with other natural gas fueled internal combustion engines, is the lower CO₂ subset. It is promised 20 percent lower, with possibilities to reach 100 percent with biogas, so CO ₂-neutral. You could then extend this with bioDiesel to the entire exhaust emissions.

But what separates this drive from all others is the significantly lower fuel consumption. It is in principle an ever more favorable, monovalent drive, which is thus designed completely for always the same fuel mixture. However, apparently limited in time with enormous losses of performance an emergency operation only possible with Diesel fuel.

The exhaust system is as complicated as in the modern Diesel engine. So you need both, particulate filter and SCR catalyst with AdBlue injection. Thus, the system should only be particularly cost-effective if, as e.g. still in Germany, the price of CNG tax and/or the whole truck is toll-exempt, or less motor vehicle tax required.

It is speculated in pure natural gas trucks on a night driving license because of lower noise. That should be a bit more difficult for this vehicle type here. In addition, it may not, as pure electric vehicles, e.g. be loaded or unloaded in closed halls. In general, because of the LNG, the security requirements and checks are immense.

Take a look at how much space is available behind a standard cab. If you reduce the Diesel tanks of this vehicle and the small one for AdBlue, you can rearrange the brake system laterally on the frame. And what do we use the huge space gained for? Of course for a CNG tank or several, which are connected in parallel.

We could then increase the pressure beyond 200 bar, may be up to 700 bar, as it is for hydrogen. That may contain enough CNG for 1000km range. No liquefaction, and the gas station infrastructure is just emerging in Germany. Of course, refueling takes a little longer, but it does with normal gas stations and large Diesel tanks too.

The genius of the idea shown above is the injector with the two needles. Of course we will keep that and its double injection system, as well as the Diesel engine. As renewable energy advances, we can even experiment with hydrogen instead of natural gas. This will be produced by not directly needed renewable energy.