Experimental Evaluation of Various Biofuel-Diesel Blends as Diesel Engine Fuels

1. Experimental Evaluation of Various Biofuel-Diesel Blends as Diesel Engine Fuels Georgios Fontaras and Zissis Samaras Laboratory of Applied Thermodynamics / Aristotle University of Thessaloniki

2. Outline • Biofuels in Europe now and in the future • Effect of biofuel blending on air quality • Measurements and evaluation conducted by LAT on SVO and biodiesel blends • Conclusions • Future activity

3. Biofuels in Europe, 2006 Biodiesel 71.6% Ethanol 16.3% Others 12.1% • Increasing use of biofuels under EU policy framework • Important share of “other” biofuels (mainly SVO) Source: EUROBSERV’ERBiofuels Barometer 2007

4. Future trends • 35Mtoebiofuels required in 2020 from which 75% diesel substitutes and 25% gasoline • Where these fuels will come from? The current skepticism appears justified. • Limited resources, best available practices for the transition period from first to second generation technologies Source: European Biofuels Technology Platform 2008

5. Impact of biofuels on emissions and air quality Is this a realistic picture of what should be expected in Europe in the near future? • Studies indicate positive results on exhaust emissions from biodiesel introduction except on NOx • Most studies based on older engines, or different quality diesel • Few data regarding real world operation • What about non regulated pollutants? Source: US EPA

6. LAT experimental activities • Evaluation of biofuels on exhaust emissions, regulated and non regulated • Application of B10 EN14214blends from various raw materials on a Euro 3 Common rail passenger car for 17000km • Application of unesterified cottonseed oil on the same vehicle for 11000km • a raw material of great importance for Greece which is not preferred by biodiesel factories • derived from specialized refining and treatment process • Utilization of legislated and real world simulation (Artemis) driving cycles • Combustion analysis on test bench engine • Overall environmental performance

7. Measurements timeline • Cottonseed oil application (10% v/v) for 11000km, 2 baseline sets of measurements at the beginning and the end, 3 intermediate sets for test fuels • Application of B10 blends from various raw materials for 17000km

8. Driving cycles employed

9. CO2 emissions

10. CO emissions

11. HC emissions Presence of biodiesel significantly affects cold start emissions

12. NOx emissions Different behavior for the various B10 blends

13. PM emissions Important trend towards lower PM with biodiesel not observed with SVO

14. Particle number distributions for cottonseed oil Particle size distribution at 90kph Particle size distribution at 120kph SVO suppresses nucleation mode

15. Particle number distributions various B10 blends Particle size distribution at 90kph Particle size distribution at 120kph Most B10 suppress nucleation mode particles

16. Engine Measurements • Engine: • PSA 2.2 DW12A TED4 Common Rail • Measurements: • CO2, Fuel Consumption • HC, CO, NOx, PM • In Cylinder Pressure • Protocol: • Baseline Measurements with Diesel • Measurements with 10%v/v blend • Various points corresponding to the engine operation over ARTEMIS protocol Operation Points Measured

17. Pressure measurements results (1/2) In Cylinder Pressure Calculated Heat Release In cylinder pressure data indicated limited variations in the combustion process in most operating points

18. Pressure measurements results (2/2) In Cylinder Pressure Calculated Heat Release Idle and low loads operation indicated differentiations; Need for different engine control strategies

19. Overall environmental performance Non watered energy crops assumed

20. Conclusions 1/2 • Biofuels especially diesel substitutes will increase in the fuels market in the years to come • The effect of biofuels should be accounted for when calculating emissions from road transport • Low concentration blends of cottonseed oil have a small effect on regulated pollutants except on cold start and limited impact on engine operation • B10 effect can vary depending on driving conditions and raw material. Negative effect on cold start • Positive effect on PM • NOx increased for some fuels and decreased for others • Limited effects observed on engine operation –noise, odor-

21. Conclusions 2/2 • Particle size distribution was affected by the presence of biofuels leading by suppressing nucleation in most cases • Engine measurements indicated small differentiations on combustion process, there is need for different engine management in some cases • Overall environmental impact should always be taken into account and can vary under different geographical and climatic conditions • A complete strategy taking into account all factors should be adopted at local and European level for optimal biofuels use in order to avoid social impacts

22. On going - Future activities • Extensive evaluation of SVO on emissions and vehicle performance for low blends – almost finished • Investigation of biodiesel effect based both on origin and concentration levels • Special attention on non regulated pollutant emissions such as particle number and characterization • Carbonyl compounds • PAHs and Nitro-PAHs • Update of existing monitoring and inventorying tools for accurate future impact assessment • Evaluation and modeling of combustion and after treatment devices operation with oxygenated fuels • Synthetic biofuels study on test bench engines and vehicles

23. Thank you for your attention! george@auth.gr