Grantee Research Project Results
Final Report: Low Temperature Combustion with Reduced PM and NOx Emissions, Achieved by n-Butanol in-Port Injected in an Omnivorous Diesel Engine
EPA Grant Number: SU835542Title: Low Temperature Combustion with Reduced PM and NOx Emissions, Achieved by n-Butanol in-Port Injected in an Omnivorous Diesel Engine
Investigators: Soloiu, Valentin , Harp, Spencer , Muinos, Martin , Simons, Emerald , Naes, Tyler , Gaubert, Remi , Moncada, Jose , Knowles, Aliyah
Institution: Georgia Southern University
EPA Project Officer: Hahn, Intaek
Phase: II
Project Period: August 15, 2013 through August 14, 2015
Project Amount: $90,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2013) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Air Quality , P3 Challenge Area - Chemical Safety , P3 Awards , Sustainable and Healthy Communities
Objective:
The objective of the project is to develop a new engine technology able to reduce drastically and concomitantly the engine NOx and soot by the n-butanol port-fuel injection (PFI) coupled with the direct injection of cotton seed biodiesel obtained from residuals of cotton industry. Another point of investigation is to compare and determine if the dual injection strategy is more effective that utilizing biodiesel n-butanol blends. The purpose of the technology is to replace diesel, reducing the emissions and promoting biofuels for use in the transportation and automotive industries with the scope of alleviating the impact of these industries on the global climate. For people, the idling and low loads are the most harmful regimes in city driving and this technology can make a great difference in terms of soot and NOx emissions at such loads where the diesel particulate filter (DPF) work marginally well because of the low exhaust temperatures. [1] The technology can be achieved with minimal environmental impact and with much better outcomes than corn ethanol because the n-butanol with high heating values can be produced from cellulosic waste. [2] By promoting in this project, n-butanol and cotton seed biodiesel would reduce the dependence on foreign oil while reducing the greenhouse gas emissions, and promoting a prosperous sustainable economic growth and jobs creation. This project will also bring valuable information concerning the energy value of biofuels feed stocks for the ecosystem sustainability and biodiversity. [3]
Summary/Accomplishments (Outputs/Outcomes):
Low temperature combustion was achieved with both alternative and renewable fuels. The fuels used in this study were n-butanol, which is an alcohol fuel that is similar to ethanol, and cotton seed biodiesel. The two fuels are capable of being produced from waste biomass sources, which promotes environmental sustainability and economic prosperity.
Before the combustion and emissions analysis were conducted, the fuel properties of ULSD#2, CS100, n-butanol, and various butanol-biodiesel blends had to be determined. It was found that altering the ratio of n-butanol to biodiesel, a blend could be created that can imitate the viscositytemperature profile of ULSD#2. Fuels, such as biodiesel, that have very high viscosities which can lead to injector clogging, poor flow, and a decrease in mechanical efficiency. When utilizing a supercharger and cooled exhaust gas recirculation, the in-cylinder combustion. The viscosity of the fuels also correlates to spray droplet size and fuel vaporization. The higher the viscosity of the fuel, the larger the spray droplet size and the more heat required to initiate vaporization. This can be an issue with biofuel injection and can lead to wall impingement and an increase in CO and UHC emissions.
When implementing the PCCI combustion strategies (dual injection, binary mixtures), the combustion and emissions characteristics were altered when compared to conventional diesel combustion. Initially, tests were conducted without the use of supercharging and exhaust gas recirculation. In these tests, the binary mixtures exhibited the greatest ignition delay (22 CAD/ 2.61 ms). For the dual injection strategy (utilizing port fuel injection), the heat release was split into two regions of premixed combustion before top dead center. The two peaks of premixed heat release correlate to the combustion of the biodiesel followed by the combustion of nbutanol. When supercharging and EGR was introduced, the split heat release profile diminished and resulted in a single peak of premixed heat release. Low temperature combustion was achieved with temperatures as low as 1300 K. The low temperatures were achieved with the coupling of EGR and supercharging, along with the cooling effect of n-butanol during vaporization. Both the dual injection strategy and binary mixtures were capable of reducing soot and NOX. Yet, the binary mixtures were successful in decreasing UHC by 20%, whereas the dual injection strategy increased UHC by nearly 100%. Carbon monoxide was kept relatively constant for the binary mixtures as the n-butanol concentration increased. With PFI of n-butanol, the CO emissions increased by 1000%. The increase in UHC and CO for the PFI strategy was caused by several factors. The early injection of n-butanol allows the fuel to impact the cylinder wall and enter the crevice regions around the piston. By entering these crevice volumes, the fuel does not combust fully causing a spike in CO and UHC emissions. Another cause was the valve overlap, where a portion of the injected fuel escapes the combustion chamber through the exhaust valve during valve overlap.
The binary mixtures exhibited a greater decrease of soot, NOx, UHC, and CO when compared to both ULSD#2 and the dual injection strategies (port fuel injection of n-butanol). Based on the results for binary mixtures, for 1,000,000 diesel trucks (300 horse power) operating under these conditions for 1 hour/day the technology would reduce soot by 23,800 tons per year. Soot particles can be inhaled and are capable of causing cardiovascular and lung diseases. Therefore, reducing nearly 24,000 tons will improve the health of many citizens and positively impact the environment. Under the same conditions, NOx would be reduced by 950,000 tons per year. NOX is extremely toxic to the environment, producing acid rain, harmful ozone and smog. Similarly, the UHC emissions would be reduced by 27,000 tons per year.
Conclusions:
Overall, the project was a success in reducing harmful emissions. In Phase I, the technology was investigated on an idling engine. Phase II successfully investigated the technology on an engine operating on a midload range.
References:
1. Eastwood, P., & Society of Automotive Engineers. (2008). Particulate emissions from vehicles. Warrendale, PA: Published on behalf of SAE International.
2. Yamamoto, S., Agui, Y., Kawaharada, N., Ueki, H., Sakaguchi, D., and Ishida, M.,
“Comparison of Diesel Combustion between Ethanol and Butanol Blended with Gas Oil” SAE Technical Paper 2012-32-0020, 2012, doi:10.4271/2012-32-0020
3. Bechtold, R. L. (2002). Alternative fuels: Transportation fuels for today and tomorrow. Warrendale, Pa: Society of Automotive Engineers.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
Other project views: | All 17 publications | 2 publications in selected types | All 2 journal articles |
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Luo X, Yu X, Zha K, Jansons M, Soloiu V. In-cylinder wall temperature influence on unburned hydrocarbon emissions during transitional period in an optical engine using a laser-induced phosphorescence technique. SAE International Journal of Engines 2014;7(2):995-1002. |
SU835542 (Final) |
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Soloiu V, Harp S, Watson C, Muinos M, Davoud S, Molina G, Koehler B, Heimberger J, Jansons M, Butts C. Performance of an IDI engine fueled with fatty acid methyl esters formulated from cotton seeds oils. SAE International Journal of Fuels and Lubricants 2015 ;8(2):277-289. |
SU835542 (Final) |
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Supplemental Keywords:
Low Temperature Combustion, Renewable Fuels, Alternative Fuels, Energy, Renewable Energy, Alternative Energy, n-Butanol, Biofuels, Cotton seed biodiesel, Biodiesel, Emissions, Soot, Nitrogen OxidesProgress and Final Reports:
Original AbstractP3 Phase I:
Low Temperature Combustion with Reduced PM and NOx Emissions, Achieved by n-Butanol in-Port Injected in an Omnivorous Diesel Engine | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.