Exhaust gas assisted reforming of rapeseed methyl ester for reduced exhaust emissions of CI engines.

The nitrogen oxides (NOxx) emissions of compression ignition (CI) engines fueled with biodiesel are generally higher compared to conventional diesel fuelling. Previous research work in CI engines has shown that the partial replacement of hydrocarbon fuels by hydrogen combined with exhaust gas recirculation (EGR) can reduce NOxx and smoke emissions without significant changes to the engine efficiency. In the present study, the production of hydrogen-rich gas by catalytic exhaust gas assisted fuel reforming of rapeseed methyl ester (RME) has been investigated experimentally as a way to provide the required hydrogen for the reduction of biodiesel emissions. For comparison, tests with ultra low sulphur diesel (ULSD) were also performed. The reforming experiments were carried out in a mini reactor supplied with exhaust gas from a single cylinder CI engine. In all cases, the reactor inlet temperature was kept at 290∘∘C which was chosen as a typical low exhaust gas temperature of diesel engines operating at part load. The engine operating condition (speed, load) was the same in all the tests and the reactor product gas was examined as a function of the reactor fuel flow rate and the composition of fuel and engine exhaust gas. Up to 17% hydrogen content of the reformer product was achieved and the results indicated that the main reactions in the reformer were the exothermic complete oxidation of part of the fuel and the endothermic steam reforming reaction. Reforming of RME produced more hydrogen with higher fuel conversion efficiency compared to ULSD reforming.

[1]  Vittorio Rocco,et al.  A Comparative Analysis of Combustion Process in D.I. Diesel Engine Fueled with Biodiesel and Diesel Fuel , 2000 .

[2]  R. F. Stebar,et al.  Emission control with lean operation using hydrogen-supplemented fuel , 1974 .

[3]  Miroslaw L. Wyszynski,et al.  On-board generation of hydrogen-rich gaseous fuels—a review , 1994 .

[4]  Chris Sharp,et al.  The Effect of Biodiesel Fuels on Transient Emissions from Modern Diesel Engines, Part I Regulated Emissions and Performance , 2000 .

[5]  A. Megaritis,et al.  Hydrogen enrichment: A way to maintain combustion stability in a natural gas fuelled engine with exhaust gas recirculation, the potential of fuel reforming , 2001 .

[6]  Nicos Ladommatos,et al.  The Effect of Exhaust Gas Recirculation on Soot Formation in a High-Speed Direct-injection Diesel Engine , 1996 .

[7]  Nicos Ladommatos,et al.  The Effect of Exhaust Gas Recirculation on Combustion and NOx Emissions in a High-Speed Direct-injection Diesel Engine , 1996 .

[8]  André L. Boehman,et al.  Behavior of a diesel injection system with biodiesel fuel , 2003 .

[9]  K. F. Hansen,et al.  Chemical and Biological Characteristics of Exhaust Emissions from a DI Diesel Engine Fuelled With Rapeseed Oil Methyl Ester (RME) , 1997 .

[10]  J. Houseman,et al.  A TWO-CHARGE ENGINE CONCEPT: HYDROGEN ENRICHMENT , 1974 .

[11]  K. Hohn,et al.  Partial oxidation of methanol at millisecond contact times , 2003 .

[12]  Robert L. McCormick,et al.  Transient Emissions from No. 2 Diesel and Biodiesel Blends in a DDC Series 60 Engine , 1996 .

[13]  A. Megaritis,et al.  Application of Exhaust Gas Fuel Reforming in Compression Ignition Engines Fueled by Diesel and Biodiesel Fuel Mixtures , 2003 .

[14]  M. Krumpelt,et al.  Hydrogen from hydrocarbon fuels for fuel cells , 2001 .

[15]  L. G. Schumacher,et al.  Engine Exhaust Emissions Evaluation of a Cummins L10E When Fueled with a Biodiesel Blend , 1995 .

[16]  N. Clark,et al.  Emissions from nine heavy trucks fueled by diesel and biodiesel blend without engine modification , 2000 .

[17]  Ather A. Quader,et al.  Advanced Engine Management Using On-Board Gasoline Partial Oxidation Reforming for Meeting Super-ULEV (SULEV) Emissions Standards , 1999 .

[18]  Jesper Schramm,et al.  Reduction of UHC-emissions from Natural Gas Fired SI-engine - Production and Application of Steam Reformed Natural Gas , 2000 .

[19]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[20]  G. Leblanc,et al.  A Before Treatment Method for Reduction of Emissions in Diesel Engines , 2000 .

[21]  A. Heinzel,et al.  Reforming of natural gas—hydrogen generation for small scale stationary fuel cell systems , 2002 .

[22]  R. Chiriac,et al.  A Study of Combustion of Hydrogen-Enriched Gasoline in a Spark Ignition Engine , 1996 .