Description:
OBJECTIVE: Determine the effect on engine performance of introducing hydrogen/syngas into a compression ignition engine and develop a means to produce the hydrogen/syngas in-situ. DESCRIPTION: The Army seeks to improve the fuel efficiency and/or emissions of its compression ignition engines. Compression ignitions engines are utilized across a variety of platforms including, but not limited to, generator sets and vehicles. Research indicates that the dual fuel use of diesel and hydrogen/syngas (carbon monoxide and hydrogen) can improve combustion in compression ignition engines (1,2,3). Recent research and development in the area of catalytic fuel reformers, plasma reformers and other similar devices, indicates that a hydrogen rich stream (or syngas stream) can be produced efficiently from JP-8 in a compact on-board configuration (4,5,6). It has been postulated that hydrogen influences the combustion flame speed allowing for faster combustion at higher peak pressures which results in improved thermal efficiency (7). Thermal efficiency improvements of up to 28 percent have been reported with hydrogen addition8. Additionally, improvements in emissions in terms of NOx, particulate matter, carbon monoxide and smoke have also been reported (1,2,3). Because the addition of hydrogen/syngas appears to greatly improve combustion efficiency, this combustion technique may allow for broader fuel considerations to include renewable biomass based fuels, hydrogenation-derived renewable diesel fuels, and other future postulated synthetic middle distillate fuels. Thus far published research on this topic is limited and the engine performance effects are not always consistent9. This research could have broad implications across military mobility platforms, auxiliary power units and engine driven generators. For military purposes, generation of a hydrogen rich stream on demand via fuel reforming or other means is preferable to carrying hydrogen canisters. When fuel is reformed it is broken down primarily into H2 and CO, also known as syngas. The production of syngas in small quantities via fuel reforming should result in a compact reactor with negligible parasitic energy demands. Results from this research and development program should conclusively address the impact of the use of dual use JP-8/hydrogen fuels (or syngas) in a compression ignition engine through experimental results and design studies resulting in a laboratory demonstration unit and/or research engine test stand that can be delivered to the Government for performance verification. PHASE I: Through experimentation determine the effects of mixing hydrogen and/or syngas with JP-8 on combustion thermal efficiency and emissions. Based on preliminary results, postulate a conceptual design for a fuel reformer or other means to generate in-situ hydrogen and assess system level impacts such as performance, size, weight, safety, scaling and cost. PHASE II: Continue to fully map out engine performance with dual JP-8/hydrogen fuels determining engine operating conditions which result in best performance improvements. Experimentation and testing should also consider engine performance with renewable diesel and jet fuels. Design and fabricate a laboratory demonstrator unit consisting of a compression ignition engine, hydrogen or syngas generator device and means to load the engine. The purpose of the demonstrator unit/test bed is to allow the Government to independently verify performance. PHASE III DUAL USE APPLICATIONS: Conduct design studies to optimize the hydrogen/syngas generator device and diesel engine. Demonstrate physical integration and thermal integration through laboratory demonstrator design, fabrication and test. Compression ignition engines are used in a very broad array of commercial and military applications such as, primary vehicle propulsion, continuous and backup electric power generation, and as prime movers (engine driven compressors, pumps, etc.). Current and future commercial design emphasis is on improving efficiency and reducing emission; this topic specifically addresses these critical technology areas. REFERENCES: 1. Saravanan N, Nagarajan G. Experimental investigation in optimizing the hydrogen fuel on a hydrogen diesel dual-fuel engine. Energy Fuel 2009, 23, 2646-2657. 2. Ramirez-Lancheros R, Darmon A, Moreac G. Simulated impact of the addition of reformate on n-heptane oxidation under engine conditions. Proceeding of the European Combustion Meeting, 2009. 3. Antunes JMG, Mikalsen R, Roskilly AP. An experimental study of a direct injection compression ignition hydrogen engine. Int J Hydrogen Energy 2009, 34, 6516-6522. 4. Zheng J, Song C. Reforming of Liquid Hydrocarbon Fuels for Micro Fuel Cells. Steam Reforming of Pre-reformate from Jet Fuel over Supported Metal Catalysts. American Chemical Society, Fuel Chemistry Division 2003, 48(1), 378. 5. Jubaedi C, Vilekar S, Morgan C, Walsh D, Mastanduno R. ATR Developments for Reformation of Logistis Fuels. 44th Power Sources Conference, 14-17 June 2010, 509-511. 6. Elangovan S, Hartvigsen J, Czernichowski P, Czernichowski A. Sulfur Tolerant Liquid Fuel Reformer. SECA Core Technology Program Workshop, Session: Balance of Platn. Lakewood, CO, October 27, 2005. 7. Bari S, Esmaeil MM. Effect of H2/O2 addition ion increasing the thermal efficiency of a diesel engine. Fuel 2010, 89, 378-383. 8. Saravanan N, Nagarajan G. An experimental investigation of hydrogen-enriched air induction in a diesel engine system. Int J Hydrogen Energy 2009, 33, 1769-1775. 9. Avadhanula VK, Lin C, Witmer D, Schmid J, Kandulapati P. Experimental study of the performance of a stationary diesel engine generator with hydrogen supplementation. Energy Fuel 2009, 23, 5062-5072.
