Overview
Natural Gas Vehicles were introduced on the market more than ten years ago; nevertheless, today's market share of compressed natural gas (CNG) vehicles is relatively small but rapidly increasing. The market introduction of dedicated (mono-fuel) CNG vehicles requires the development of technologies able to solve problems today not yet solved concerning gas storage, gas feeding, combustion system and after treatment and, at the same time, to take into account the quality of natural gas.
Security of Energy Supply
From this point of view, natural gas represents a real alternative to crude oil being available in large quantities also in countries different from the Middle East.
Clean Fuel
Natural gas is a clean fuel since toxic compounds like sulphur, or potential toxic, like benzene and higher molecular weight hydrocarbons, or highly reactive such as olefins, are absent.
Reduced Greenhouse Gases
The highest hydrogen content of methane molecule, with respect to any other hydrocarbon based fuel, allows achieving a substantial reduction of the carbon dioxide (CO2) exhausted by NG vehicles of about 23% compared to gasoline.
Main objective of Integrated gas powertrain (InGas) Collaborative Project was to deploy a custom designed engine integrated with specific aftertreatment systems applied to a light duty vehicle able to achieve a 10% higher fuel conversion efficiency than that of a corresponding 2006 diesel vehicle and complying with an emission level lower than Euro 6. Additional features are advanced storage systems and vehicle architectures, as well as multi-grade fuel tolerance and fuel flexibility.
To achieve the InGas targets, three main combustion technologies were compared:
- Sub-Project A1 CNG technologies for passenger cars developed a natural gas car powered by a 1.4 liter displacement engine using the sequential multi-point port gas injection and following the stoichiometric approach;
- Sub-Project A2 Turbo DI CNG engine developed a natural gas car powered by a 1.8 liter displacement engine using the direct gas in-cylinder injection and following a lean burn approach;
- Sub-Project A3 Boosted lean burn gas engine developed a natural gas light-duty vehicle powered by a 1.9 liter displacement engine using port gas injection or low pressure direct gas injection and following the ultra-lean combustion approach.
Three main enabling technologies were compared and assessed:
- Sub-Project B0 Fuels for advanced CNG engines defined / supplied the gas mixture of the requested quality, conduct analysis and propose solutions in order to affect in a flexible way storage, combustion, after treatment and performance of the CNG vehicles;
- Sub-Project B1 Gas storage for passenger car CNG engine developed advanced gas storage and filling systems including specific components and gas sensors;
- Sub-Project B2 After treatment for passenger car CNG engine developed an after treatment system for natural gas vehicles having special regards to CH4 conversion efficiency and NOx abatement under stoichiometric and lean combustion operations.
Funding
Results
The main outcomes of the project are:
- validator vehicle (Fiat Bravo) with innovative 1.4 liter Turbo Charged Port Fuel Injected Multi-air stoichiometric CNG (Compressed Natural Gas) engine;
- validator vehicle (Mercedes E200/NGT) with innovative 1.8 liter Turbo Charged Direct Injected stoichiometric CNG engine and start-stop device;
- after treatment for innovative 1.6 liter Turbo Charged Port Fuel Injected lean burn CNG engine;
- full well-to-tank and combustion analysis versus NG (Natural Gas) composition and innovative NG quality sensor;
- innovative CNG (Compressed Natural Gas) storage module implemented on Fiat Grande Punto with 1.4 liter CNG engine;
- innovative after treatment with an improved 3-way catalyst (with lower precious metal content than conventional one) and heat exchanger to enhance methane conversion efficiency.
Some of the major results are:
- an improved engine performance and improved end torque of CNG engines, this bridges the gap that it had compared to diesel and gasoline engines;
- CO2 emission and fuel consumption of current CNG engines has been improved;
- development of an improved 3-way catalyst;
- an innovative storage system provide halved weight in comparison to conventional solutions, without any penalty in terms of vehicle trunk space and/of safety, at only a small cost increase;
- the project developed technology to adopt 65% of bio methane instead of fossil CNG, thus achieving a well-to-wheel figure equal to zero.
Innovation aspects
Market introduction of dedicated (mono-fuel) CNG vehicles requires the development of technologies able solving problems regarding: gas storage, gas feeding, combustion system and after treatment plus, at the same time, taking into account the quality of natural gas.
Policy implications
Natural gas (NG) is a clean fuel. It represents a real alternative to crude oil, as it is available in large quantities also in countries different from the Middle East. If reserves/production ratio is considered, there are sufficient world reserves of natural gas for the next six decades. This is much more than those of crude oil (about four decades of world reserves). These world reserves are sufficient to allow significant using Natural Gas to power transportation vehicles.
Strategy targets
Innovating for the future (technology and behaviour): Promoting more sustainable development
Policy objectives
The European activities on alternative fuels basically have two policy drivers: (1) security of energy supply and (2) reduction of greenhouse gas emissions. It should be noted that energy efficiency and alternative fuels are complementary approaches.