Overview
The TRIPTIC-H project meets the following key requirements:
- Reduce CO2 emissions: the combined use of hybridization and of a homogeneous GDI engine contributes to achieving the target of 95 g CO2/km by 2020
- Meeting the expectations of the French "plan particules" that targets 30% cutting of fine particles in the air in 2015, as required by the French "Grenelle de l'Environnement"
- Respect the future Euro 6 limits in term of mass and number of particles emitted by the GDI engines, and also Euro 7 with the likely adoption of the WLTP cycle
- Anticipate the requirements in terms of strength / durability, and on-board diagnostics
- Provide a possible extension to the counting of particle less than 23 nm diameter
That project aims:
- To characterize the particles (including ultrafine) from a homogeneous GDI engine among the most advanced in the preferred modes of the electrically hybridized applications
- To develop innovative systems of after treatment at material level, filtration principle and catalytic formulation
- To validate the prototypes first at the laboratory scale and then at the engine scale
- To develop engine strategies that enhance continuous oxidation without soot accumulation
- To develop strategies for active regeneration, if any, the most appropriate in terms of the duration / efficiency / fuel consumption
From the characterization of the fine particles emitted to the design of dedicated emission control prototypes for GDI engines
At first, advanced characterization of gaseous and particulate emissions is carried out on an engine test bench with a gasoline direct injection engine. The emitted particles are analysed with several analysers (DMS500, SMPS, SMPS E). In parallel, particles samplings are carried out in the exhaust in order to perform offline analyses at the laboratory (particle size and structure, chemical composition, ...)
Then, based on this characterization, the solutions developed integrate advanced filtration concepts and catalytic formulations promoting continuous regeneration of the particulate filter. The proposed innovations are made and tested first at the laboratory scale and separately. Afterwards comes a synthesis phase of filtration and catalytic functions, still at the laboratory scale. These prototypes are then tested on a synthetic gas bench equipped with a particle generator to validate their performance both from the point of view of catalytic conversion, particulate filtration efficiency and generated backpressure.
Following these tests in laboratories, full size prototypes are built based on the results obtained. Obtaining such prototypes requires a good knowledge of the production process in order to achieve good adhesion of different materials while preserving the catalytic phases, whose integrity is the guarantee of proper operation of the unit. The successful completion of this process is validated by scanning electron microscopy.
Finally, full size prototypes are tested on the test bench to validate their performance in terms of particle filtration and conversion of gaseous pollutants. This test phase is also an opportunity to check that the pressure drop created by the filter is compatible with the requirements of the proper functioning of a petrol engine.
Funding
Results
The characterization of particulate emissions task has highlighted the solid nature of the exhaust emitted particles. This observation leads us to filtration systems with high filtration efficiency, such as membranes in order to reduce particulate number emissions at the engine exhaust.
Work on catalytic materials guides us towards two relevant solutions: The first, based on the perovskite materials, and the second - called microcell - coupling of ionic and electronic conduction mechanisms and precious metals.
On perovskite materials, the work showed that the addition of silver can both improve the textural properties of the material and promote the catalytic oxidation of soot through the presence of Ag2O in the surface. For the microcell solution, electronic and ionic conductor type Cerium oxide - Gadolinium coated with Palladium and Rhodium showed the best catalytic performance in particular regarding NOx, CO and propane emissions. Particles, in turn, are oxidized from 400 ° C with this formulation.
The work continues now with the integration of these catalytic formulations in the particulate filter membrane, first at the laboratory scale and then at the full scale.