Methane Powered Heavy Duty Engine with Low Fuel Consumption and Euro VI Emission Compliance N. Sadokhina 1, G. Smedler 2, U. Nylén 3, M. Olofsson 4, L. Olsson 1 Partners: 1. Chalmers University of Technology, 412 96, Göteborg, Sweden 2. Johnson Matthey AB, 421 31, Västra Frölunda, Sweden 3. Scania CV AB, 151 87 Södertälje, Sweden 4. AVL MTC Motortestcenter AB, Box 223, 13623, Haninge, Sweden Project duration: 213-4-1-215-1-1 Program: Energy and Environment Funding: 6 472 8 SEK Picture downloaded from http://www.scania.com/group/en/scania-adds-united-kingdom-to-its-growing-gas-market/
Advantages of natural gas Natural gas is mainly composed of methane. Natural gas impurity content (ex: S) is low. Natural gas vehicles emit less: CO 2 ; NO x ; Particulate matters (PM); Volatile Organic Compounds (VOC). 2
Aim and results The target is to address the problem of combining low energy-specific fuel consumption with low green house gases (GHG) and very low toxic emissions for a state-of-the-art compressed natural/bio gas (CNG/CBG) engine. This project supports the introduction of renewable fuels for Euro VI vehicles. CNG/CBG powered engines were tuned to meet Euro VI emissions standard. Reduction of CO 2 emissions by 1 % was achieved. Catalyst development and mechanistic studies were performed. Kinetic model of exhaust system under lean combustion was developed. 3
Laboratory scale tests 1. Sample preparation The powder of catalyst contained 3.2 wt.% of Pd and.6 wt.% Pt on 2 wt.% Ce-Al 2 O 3 was washcoated on a ceramic monolith (4 cpsi; l = 2 mm, d = 21 mm; washcoat 5 mg) 2. Sample pretreatment Reduction T = 5 o C; 2% H 2 ; Ar; 3 min Lean/rich/lean cycle T = 7 o C Lean:.3% CO;.5% NO;.5% CH 4 ; 8% O 2 ; 5% H 2 O; Ar; 6 min Rich: 2% H 2 ; 5% H 2 O; Ar; 2 min Ageing T = 7ºC; 8% O 2 ; 5% H 2 O; Ar; 3 min 3. Methane oxidation activity tests 4
Kinetic model Aim: To develop a kinetic model that can describe methane oxidation and the water inhibition effect. There are 2 reactions included in the model: R1: CH 4 + 2 O 2 CO 2 + 2 H 2 O R2: 2 S + H 2 O +.5 O 2 2 S OH The rate equations and kinetic parameters are retrieved by fitting to experimental data. 5
Temperature-programmed methane oxidation 1 75 T up T down Inlet gas composition:.5% CH 4 ; 8% O 2 ; 5% H 2 O (if added); Ar. 5 CH 4 + O 2 25 2 3 4 5 6 7 Catalyst temperature ( o C) 6
Temperature-programmed methane oxidation 1 75 T up T down Inlet gas composition:.5% CH 4 ; 8% O 2 ; 5% H 2 O (if added); Ar. 5 CH 4 + O 2 25 CH 4 + O 2 + H 2 O 2 3 4 5 6 7 Catalyst temperature ( o C) 6
Temperature-programmed methane oxidation 1 75 Model T up T down Inlet gas composition:.5% CH 4 ; 8% O 2 ; 5% H 2 O (if added); Ar. 5 CH 4 + O 2 25 CH 4 + O 2 + H 2 O 2 3 4 5 6 7 Catalyst temperature ( o C) 6
Temperature-programmed methane oxidation 1 Model T up T down 75 Inlet gas composition:.5% CH 4 ;.5% NO;.3% CO; 8% O 2 ; 5% H 2 O; Ar. 5 25 CH 4 + O 2 + H 2 O + CO + NO 2 3 4 5 6 7 Catalyst temperature ( o C) 7
Isothermal methane oxidation at 45 C 1 75% 8 6 4 2 A: CO region 3 6 9 12 15 18 21 24 27 3 33 36 39 42 45 Experiment Time (min) Steps CO:.7;.5 and.1 vol.%; Standard inlet gas composition (crosshatched):.5% CH 4 ;.5% NO;.3% CO; 8% O 2 ; 5% H 2 O; Ar. 8
Isothermal methane oxidation at 45 C 75% 66% 1 8 6 4 2 A: CO region B: CH 4 region 3 6 9 12 15 18 21 24 27 3 33 36 39 42 45 Experiment Time (min) Standard inlet gas composition (crosshatched):.5% CH 4 ;.5% NO;.3% CO; 8% O 2 ; 5% H 2 O; Ar. Steps CO:.7;.5 and.1 vol.%; CH 4 :.12;.8 and.2 vol.%; 8
Isothermal methane oxidation at 45 C 75% 66% 53% 1 8 6 4 2 A: CO region B: CH 4 region C: O 2 region 3 6 9 12 15 18 21 24 27 3 33 36 39 42 45 Experiment Time (min) Standard inlet gas composition (crosshatched):.5% CH 4 ;.5% NO;.3% CO; 8% O 2 ; 5% H 2 O; Ar. Steps CO:.7;.5 and.1 vol.%; CH 4 :.12;.8 and.2 vol.%; O 2 : 14; 5 and.14 vol.%; 8
Isothermal methane oxidation at 45 C 75% 66% 53% 48% 1 8 6 4 2 A: CO region B: CH 4 region C: O 2 region D: NO region 3 6 9 12 15 18 21 24 27 3 33 36 39 42 45 Experiment Time (min) Standard inlet gas composition (crosshatched):.5% CH 4 ;.5% NO;.3% CO; 8% O 2 ; 5% H 2 O; Ar. Steps CO:.7;.5 and.1 vol.%; CH 4 :.12;.8 and.2 vol.%; O 2 : 14; 5 and.14 vol.%; NO:.11;.8 and.2 vol.%; 8
Isothermal methane oxidation at 45 C 75% 66% 53% 48% 1 8 6 4 2 A: CO region B: CH 4 region C: O 2 region D: NO region E: H 2 O region 3 6 9 12 15 18 21 24 27 3 33 36 39 42 45 Experiment Time (min) Standard inlet gas composition (crosshatched):.5% CH 4 ;.5% NO;.3% CO; 8% O 2 ; 5% H 2 O; Ar. Steps CO:.7;.5 and.1 vol.%; CH 4 :.12;.8 and.2 vol.%; O 2 : 14; 5 and.14 vol.%; NO:.11;.8 and.2 vol.%; H 2 O: 11; 9 and 2 vol.%. 8
Isothermal methane oxidation at 45 C 75% 66% 53% 48% 1 8 6 4 2 A: CO region B: CH 4 region C: O 2 region D: NO region E: H 2 O region 3 6 9 12 15 18 21 24 27 3 33 36 39 42 45 Experiment Model Time (min) Standard inlet gas composition (crosshatched):.5% CH 4 ;.5% NO;.3% CO; 8% O 2 ; 5% H 2 O; Ar. Steps CO:.7;.5 and.1 vol.%; CH 4 :.12;.8 and.2 vol.%; O 2 : 14; 5 and.14 vol.%; NO:.11;.8 and.2 vol.%; H 2 O: 11; 9 and 2 vol.%. 8
Conclusions Overall: The heavy duty spark ignited EuroV gas engine was recalibrated and fuel efficiency increased by 1%. To handle the emissions two different combustion strategies in combination with two newly developed exhaust aftertreatment systems (provided by JM) were used. Catalyst development and mechanistic studies were performed. Kinetic model: A kinetic model that can describe methane oxidation and the effect of water inhibition was developed. The water inhibits the methane oxidation by: Adsorption on active sites Formation of inactive surface species
Acknowledgement This work was done within the FFI project Methane Powered Heavy Duty Engine with Low Fuel Consumption and Euro VI Emission Compliance as a collaboration between Johnson Matthey AB, Scania CV AB, AVL MTC Motortestcenter AB and the Competence Centre for Catalysis. The Swedish Energy Agency (FFI 37179-1) is gratefully acknowledged for its financial support.