LIQUEFIED NATURAL GAS (LNG) THE FUTURE OF TRUCKING
Nothing futuristic, but a real opportunity to reduce fuel consumption for transport vehicles currently in circulation by 15%: it’s the Dual Fuel system, developed by an Italian company, Ecomotive Solutions
LNG’s arrival in Italy could soon result in a real revolution for the Italian road transport sector. And we're not talking about soon-to-be-built futuristic trucks, but of those currently circulating on our roads. The idea - who would have thought? - stems from the motor racing world, and the experience of an Italian company, the Holdim group, present throughout the world and specialized in developing electronic tuning systems to increase the performance of racing vehicles. That is how Ecomotive Solutions was born, through a joint effort with the company’s sports division known by the brand Dimsport: "We realized, in the end - says Roberto Roasio, head of the company’s alternative fuels department - that the same technologies used to increase vehicle performances could also be used to reduce fuel consumption and emissions". From a combination of expertise and the idea of using LNG as fuel, the Dual Fuel technology was born, i.e. the simultaneous use of liquefied natural gas and diesel on transport vehicles, which, through lower prices and a relatively simple technology especially in terms of maintenance, can reduce fuel consumption by 15-20%, without the typical range limitations of vehicles fueled only by natural gas.
The liquid spark plug
"Dual Fuel technology in its first version - continues Roasio - is actually 40 years old: it was used on board tankers, where there was the need to reuse portions of liquid natural gas that during the voyage became gaseous through overheating". The use of dual fuel diesel-natural gas (liquid or gaseous) technology on diesel vehicles “was not immediate: the problem is that a diesel engine, unlike a petrol engine, has no spark plugs and ignites through compression. And it does so at temperatures far too low for Natural Gas which ignites at 537 ° C". And here is where Ecomotive Solutions came up with a plan. "Through the manifold, during the phase of intake we introduce gas together with air, through a controlled injection system, thus creating a mixture of air and natural gas. At this point, in the compression phase, our electronic system determines the correct amount of diesel to be injected to ignite the mixture of air and natural gas. In other words, we remove diesel and inject gas, leaving a small amount of diesel to act as a kind of ‘liquid spark plug’". This however implies that "the air-gas mixture is not always able to burn completely. There are situations where it is better to rely on diesel, as in a normal diesel engine. Hence the reason for choosing a Dual Fuel system".
The system is the same for both liquid (LNG) or compressed (CNG) natural gas. In both cases, however, this requires a highly developed electronic system. And here is where the twenty-year experience of the Holdim group and Dimsport in motorsports comes into play. The conversion kit from diesel to Dual Fuel includes, in addition to the installation of CNG or LNG tanks (in the latter case a heat exchanger is also necessary), an additional D-Gid control unit, usually under or inside the cabin: this manages the injection system, which continuously adjusts the gas-air mixture depending on the conditions of the engine, while, at the same time, communicating with the engine control unit for supplying the diesel. “The new device is able to interact perfectly with the engine control unit " explains Roasio. To complete the kit there are a pressure regulator and gas injectors.
It does everything
Very well, but how does the system work from the point of view of the driver? "It's very simple. The driver does not have to do anything. It’s the system that decides when to use diesel or LNG. Usually, on open roads, LNG replaces Diesel up to 90% of the volume used, especially on flat roads as well as mountain passes. Diesel, on the other hand, is used during acceleration, when you need maximum power and a consistent combustion". On mixed urban-suburban roads, for example, the ratio is 50/50 diesel-gas. " Furthermore, thanks to a button in the cab, the Dual Fuel system can be activated or deactivated manually, switching to diesel only. Torque and power are "absolutely not altered, as our tests extensively demonstrate". Thus, limited power output, one of the greatest limitations of trucks fueled only with natural gas, falls away, seeing that nowadays power output does not exceed 320-340 hp. But above all, mileage, the real Achilles heel of all trucks driven by natural gas, is effectively stretches, and we'll see by how much. In addition to reducing fuel consumption, noise and emissions, "the Dual Fuel system also needs very little maintenance, even when compared to diesel engines, thanks to a 50% reduction of carbon residues determined by the use of LNG, unlike petrol cars with Dual Fuel systems, where maintenance doubles: it is enough to replace a filter every year, maybe during normal vehicle maintenance procedures, without any additional downtime”.
The Dual Fuel system, as already stated, works with both LNG and CNG. But the real news is the arrival of LNG on the Italian market. What are the advantages of its use compared to compressed gas? "With CNG, at least 4 cylinders of 150-200 liters need to be used to ensure a mileage of 750 km. LNG needs just one, usually between 200 and 500 liters ". Quite a difference, which dramatically cuts the space problem on lorries, increasingly complicated given the abundance of after-treatment systems on Euro 5 and Euro 6 vehicles. Moreover, costs are further reduced, seen the higher heating value of LNG compared to CNG. But if Italy is at the forefront of CNG technology and distribution (with 1051 distributors we are the first in Europe, clearly ahead of Germany and Austria), for LNG we are still well behind. The only recently opened facility available is in Piacenza, while Northern Europe and Spain can already count on an extensive network. To be blamed is the absence, on Italian soil, of a port terminal capable of receiving LNG tankers carrying liquefied natural gas, which our country prefers to re-gasify on offshore plants and then distribute on national soil by pipeline. Therefore, in Piacenza, liquefied natural gas arrives by truck from Barcelona. "Initially only 5 prototypes of Iveco Stralis Dual Fuel, owned by LC3 Trucking, used to fill up in Piacenza. Then a few vehicles from Northern Europe started calling there as well and now also the Spanish carriers responsible for transporting LNG. Now LC3 just bought another 50 Dual Fuel vehicles. It takes 30 vehicles for an LNG service station to survive economically. And with 7 large service stations distributed throughout the country, I tell you that Italy would run on LNG". To further develop this resource, Ecomotive Solutions is trying to involve a few Italian biogas producers, a sector in which Italy has earned the top spot in Europe in recent years, as well as promoting agreements with the a few inland terminals to build some LNG filling stations in these strategic National transport infrastructures.
Ecomotive Solutions has also started test trials in collaboration with FAI Conftrasporto of Brescia and with a small trucking company also based in Brescia, Ghidini Rok, which has turned one of its Euro 5 Stralis into a Dual Fuel vehicle. A crucial detail, because the Dual Fuel technology can be applied to all vehicles but not to Euro 6 vehicles yet: "solutions for them are currently being studied" says Roasio. Ghidini Rok has, however, opted for CNG, since it does not operate in the area of Piacenza. Well, while maintaining intact the vehicle performance, fuel consumption has been drastically reduced, with a cut in fuel costs - between CNG and diesel – of 15%". All "in the face of an initial investment of 12 thousand euro. And without even compromising the payload of the vehicle, since by law CNG fueled trucks or dual fuel vehicles benefit from a 15% bonus on the tare in the eventuality of controls by the traffic police".