Butanol as an alternative fuel for Diesel engines Supervisor Co-supervisor Project start Project end Programme Partners Budget Tankai Zhang : Ingemar Denbratt : Karin Munch : : : FFI : Chalmers, Perstorp AB, Scania CV, Statoil, Volvo GTT and Volvo Car : MSEK

Background 2 Problems with using fossil fuels Greenhouse warming Non-renewable Policy issues 25% biofuel in the European transportation fuel consumption shall be achieved by 2030 Butanol has excellent fuel properties Sustainable production Oxygen content Acceptable heating value Good miscibility in Diesel

Fuel Mixtures 3 Component of mixture ABCDEF DieselXXXXXX n-ButanolX X X Iso-Butanol X X X HVO XX Ignition improver XX Existing enginesFuture engines (Partially premixed combustion) All the mixtures are tested in both heavy duty engine and light duty engine. (Conventional combustion)

Goals Conventional combustion More than 80% reduction of particles at constant NOx levels for conventional combustion systems Clarification of how ignition improver influences the formation of emissions. Partially premixed combustion (PPC) Show how PPC can be achieved with Butanol mixtures Achieve gross indicated efficiency of 53% at loads higher than 10 bar BMEP in combination with emissions below Euro 6 levels without after treatment. 4

Test bed with heavy duty engine Engine type Single cylinder from Volvo D12C Bore131 mm Stroke150 mm Valves4 Connecting rod length 260 mm Compression ratio 17:1 Fuel injection system Common rail Nozzle5 holes 5 Operating conditions: A25, B50, C75 and B75 Different mixtures are tested under same engine settings at each operating condition.

Fuel tests results from Statoil n-Butanol (vol%) Diesel (vol%) HVO (vol%) Ignition improver (mg/kg) Density (kg/l) CN Test standard ----D-4052D-613 Component No ,8136< 20 Component No ,837052,0 Component No ,779975,1 ……… … ……… Blend No ,822350,6 Blend No ,808250,3 Blend No ,833851,3 Blend No ,8311~50 ……… … ……… 6 Diesel n-Bu10H n-Bu20H n-Bu10I n-Bu20I Cetane number are tested in Cooperative Fuel Research Engine.

Cylinder pressure 7 Different mixtures have similar and stable cylinder pressure trends. A25 B75 C75 B50

Brake thermal efficiency 8 Similar levels of brake thermal efficiency for various mixtures

Normalized brake specific particulate matter emission 9 PM emission decrease sharply when using more Butanol Oxygen content Lower C/H ratio No Aromatics in HVO

Brake specific NOx emission 10 Euro5: 2,0 g/kWh NOx increase slightly when using more Butanol Oxygen content may lead to higher local temperature

Summary It is possible to adjust the CN of Butanol-Diesel blends with HVO or ignition improver. With the same CN, Butanol/Diesel blends show similar combustion processes compared to pure Diesel. Particulate matter emission of Butanol / Octanol mixture are greatly reduced compared to pure Diesel and NOx can be kept at about the same level. Ignition improver seems to increase the NOx emission. Tests with using 20% n-Butanol, 40% HVO in the Diesel blend show that even production engines can use 60% renewable fuel. 11