INGAS 18 months meeting, Paris, 20./ DAIMLER AG INGAS INtegrated GAS Powertrain InGas 18 months meeting May, 20th/21st 2010 Paris, France SPB2

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain 2 References and Targets of SPB2   

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain Comment 1 - SPB2: In the document Annex 1 - DoW pg. 38 it was clearly stated that "For small and mid size engines (<2 liter swept volume)..." while in the 12 month Periodic Report pg. 24 it has been stated that " The required NOx-conversion can be done in only one way by means of a large volume (4 litres) SCR ….". These two conflicting statements need to be explained and deviation from the DoW justified. Answer: - In general there are only two technologies able to reduce NOx under lean conditions with the appropriate efficiency for fullfiling future emissions standards. Each EOM has his own strategy for considering either the NOx- storage system or the urea SCR-technology. The choice is driven by a compromise between required NOx-performance, temperature profile in the considered driving cycles, cost of the system, durability and packaging considerations. - As written in the DoW, our philosophy is to consider the NOx storage technology rather for small engine applications, especially in cases where the required NOx conversion is not too high (in the Dow, objective is >50%). But it is also clear that in the particular case of the CNG engine it has to be proven that it is possible to regenerate the NOx storage catalyst under rich conditions particular to the CNG engine. - One approach consists in the development of engine measures for producing more CO and H2 during the rich spike, which is possible with a flexible DI-system. - It has already been demonstrated (DA2.11) that with changing the injection timing, more CO can be produced with unbalanced cylinder adjustment at lambda=1. - A second aspect to consider is that the NOx storage catalyst is coated on the heat exchanger and takes benefit from its thermal characteristics. - A third possibility is to add a reforming catalyst (not part of DoW) in front of the NOx storage catalyst in order to generate more H2 through steam reforming of methane and WGS. SPB2: Comment 1

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain Answer: - Concerning the statement in the 12-month report, it corresponds to a choice made by SPA3, which is not conflicting with the work performed in SPB2, and which has been done in agreement with SPB2 in order to cover both NOx technologies in the IP. - Furthermore, the objective for NOx reduction in SPA3 is around 90%, and in that case the performance of the urea SCR technology is more suitable than a NOx storage catalyst, especially when considering sulfur poisoning and thermal durability aspects. - Additionally, from a technical point of view, the use of urea SCR in combination with the heat exchanger seems not to be appropriate because of restricted available mixing length in front of the catalyst and plugging risks of the heat exchanger. - However, implementation of the urea SCR system is also very challenging for a CNG application. - Finally, as mentioned in the DoW, the objective in SPB2 for NOx reduction under lean conditions is limited to an assessment of the potential of the NOx storage technology without an implementation on an engine. - All those aspects demonstrate that it makes sense to develop both technologies in parallel in order to assess the potential of both technologies for a CNG application. - There are no deviations from the DoW. SPB2: Comment 1

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain Comment 2 – SPB2: The success of InGas to a large extend is dependent on the development of an efficient catalyst for stoichiometric or lean burn operation to fulfil future EURO6 regulations. The currently proposed solution of a Pd-based catalyst material does not seem to perform better than an available reference case catalyst. Please comment what are today within InGAS the main achievements in methane catalysts development when compared to the state-of-the-art at project start and what convincing ideas should help to find a solution up to the end of the project. Answer: - Developing a new CH4-catalyst with a better lightoff temperature than a high loaded Pd-based catalyst is a huge challenge. Therefore it can not be expected that after 1 year of work the objective can be achieved. However a lot of work has been done at POLIMI and ICSC-PAS in order to find new catalyst formulations able to compete with the reference material or to improve it in terms of activity and cost. Contrary to the comments of the reviewers, some interesting aspects and materials have been identified. - Additionally, the success of InGas is not dependent on the development of a new catalyst but on the development of an integrated heat exchanger. The key innovation is the combination of an improved material with a better temperature management of the catalytic system through integration in a heat exchanger. SPB2: WPB2.2 – Comment 2

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain Answer: Pd-based: - The results from POLIMI showed that Pd-only catalysts supported on CeO2-Al2O3 exhibit the same activity than the TWC reference catalyst with a significantly lower Pd-loading (2% vs. 6%). Due to different preparation routes, the characteristics of the surface, the particle size and the metal-support interactions promote the activity performance. - Furthermore, addition of small amount of Pt at constant Pd loading slightly promotes the activity performance. - Results will be used by Ecocat in order to improve the performance of the reference catalyst. Mixed Oxide: - Concerning the development of catalysts based on mixed oxides, the most active catalysts can be found among hydrotalcite-derived mixed oxide catalysts (MnAl and CuMnAl systems). Deposition of mixed CuMn oxide on a Puralox carrier stabilizes dispersion of spinel phases, and prevents rapid degradation of the catalyst, thus limiting the loss of activity upon ageing. - The developed catalysts perform better than references in the literature but, of course, are not competitive compared to Pd-based materials. - But with regard to cost, it is conceivable that an increased amount of such a catalyst could be used, resulting in lower SV and, consequently, to a better activity in combination with the heat exchanger. SPB2: WPB2.2 – Comment 2

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain Outlook WPB2.2: - For future development, combining mixed oxides and especially perovskite-type materials with Pd will represent one interesting route. As reported by Cataler Corporation and Daihatsu Motor Co., the incorporation of Pd in a perovskite structure can stabilize the Pd-particles and consequently improve the reactivity of the system through the design of an intelligent catalyst. - Another approach will consider the incorporation of Au in Pd-based catalysts. It is well known that Au in well dispersed form exhibits a high activity for CO oxidation even at very low temperatures but suffers from thermal ageing. In the last years a lot of progress has been made in the stabilisation of Au nano-particles in combination with Pd as oxidation catalyst (Nanostellar). Through the early oxidation of CO, coupled with engine measures as described in DA2.11, the exhaust system can be heated more rapidly, leading to a faster CH4 lightoff. - In conclusion, developing completely new formulations with low lightoff temperature, especially for methane oxidation, can not be achieved easily within one year of development. However interesting aspects have been identified and will be used by Ecocat in order to improve the reference catalyst. New ideas, as described previously, will be investigated in the next months. SPB2: WPB2.2 – Comment 2 Outlook

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain SPB2: WPB2.3 – Comment 3 Integrated heat exchanger Comment 3 – SPB2: For the burner concept a critical point is seen in the available catalytically coated heat exchanger area for methane conversion. This is for example far less than in a porous medium. Furthermore, to assess validity of this approach, more details on the computer model used for concept development are required. Please supply additional information. Answer: - Separate presentation from M. Rink/ F. Ayad (USTUTT, Delphi)

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain InGas: Overall Assessment

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain  In reviewing the individual partner contributions it became evident to the reviewers that the contribution of ECOCAT due to delayed start of work currently is behind schedule.  However, the issue of a low temperature methane oxidation catalyst is still an open question. Up to now all investigated catalyst materials show less activity than the reference catalyst of ECOCAT.  SPB2: This deals with the development of an after treatment system for natural gas vehicles having special demands to methane conversion efficiency and NOx abatement under lean combustion conditions. WPB2.2: The development of a new CH4 catalyst with a better light-off temperature than a high-loaded Pd-based catalyst turns out to be a huge challenge. So far all catalyst materials investigated have not shown better performance than the reference catalyst of ECOCAT. To remedy the situation it was suggested by the Consortium members that future work should concentrate on Pd/Zk/Al formulations with a support based on Cerium-Oxide. Also Pd/Au materials will be investigated. WPB2.3: The exhaust gas after treatment system of this technology pathway is based on a heat exchanger containing a PROMEOS burner for catalyst heating. The complete hardware is manufactured by DELPHI. A laboratory prototype is already finished and tests at USTUTT have just started. Some problems are seen concerning thermal stresses within the proposed system and the counteraction of the burner gases with the exhaust gas stream. Also fooling of catalyst surfaces due to burner start-up operations might be critical. InGas: Overall Assessment

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain DB2.6 Deliverables are considered as important as periodic reports, reflecting the work progress SPB2: Deliverables - Milestones

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain Deliverables – Milestones until E2010 Engine test bench at AVL No delay expected for: DB2.13 „Vehicle/EAT/strategy to SPA2“ DB2.14 „Results summary/assessment“ MB2.2 (Potential heat exchanger concept demonstrated)

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain SPB2: Road Map Catalyst Development

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain SPB2: Road Map HEX

INGAS 18 months meeting, Paris, 20./ INGAS INtegrated GAS Powertrain Open issues: WP B2.2: Reference material: Ref 1: K g/cft washcoat, Pt/Pd/Rh = 0/39/1 Ref 2: Pt/Pd/Rh = 1/38/1 Coating of new materials: CuMn2O4/Al2O3 Pd/Al2O3-CeO2 WP B2.3: Canning of monoliths (Katcon) 2d lab HEX with TWC/NSC coating (when?, NSC feasible?, does it make sense on lab scale?) 2d bench HEX with TWC or TWC/NSC? (when?, with burner or heating device or flaps?) WP B2.4: Test program monoliths Test program HEX Engine? Rich spike, lean? Injection timing for CO/H2 production? Availability dynamic test bench --  demonstrator WP B2.5: shift from Vehicle to engine test bench (AVL)? SPB2: Open issues