Theory and practice of diagnostics of fire hazardous modes of operation of catalytic converters

Introduction. The wide-scale use of catalytic converters and particulate filters in automobile engines has aggravated the problem of their ignition and updated the research and methodological framework for the examination of causes of fire emergency modes (FEMs) of operation of fuel catalytic units (FCUs). The relationship between the FEMs of the FCU operation and failures of the fuel equipment, wear of the cylinder-piston group of engines and deviations in fuel compositions was confirmed. The goal was to develop a diagnostic method for fire hazardous modes of operation of FCUs of vehicles.

Methodology. A model of oxidative catalysis underway in the FCU has been proven rational. The model is used to calculate the thermo-catalytic efficiency and heat generation in the active layer of the γ-Al2O3 platinum catalyst depending on the temperature of exhaust gases (EG), concentrations of CO, CH and soot. It has been found out that catalysis can theoretically develop in four limit domains: internal kinetic domain, internal diffusion domain, external diffusion domain, and external kinetic domain.

Results and discussion. Experimental and computational studies have shown the probability of emergence of breakdown vehicles with a multiple excess of soot emissions and thermal stresses. A 10‑fold increase in CO, CH and soot in EG rises the thermal performance of the catalytic reaction from 17,282 to 491,907 kJ/h, creating a fire hazard in a KamAZ engine. To identify a FEM, the diagnostic method based on the «free acceleration» (FA) mode according to GOST 33997–2016 is proposed. The procedure is supplemented with maximum revolutions and restrictions (0.5 s) of the FA mode time. The latter is necessary for the guaranteed operation of the engine in the «full load mode». The method was applied in the course of the fire engineering studies on a Ford Mondeo car having a TDCi (Common Rail System) diesel engine and a catalytic particulate filter. Laboratory examination and analytical studies have found that the main reason for the operation of FCU in emergency (due to environmental and fire hazards) modes is the corrosion of precision parts of the fuel equipment accumulated during its long-term operation. Progressive corrosion is caused by excessive sulfur and moisture content in fuel and oil.

Conclusions. It’s been proven that the emergency heating of a catalytic converter causes a sharp rise in the car combustion risk. The authors have proposed an original method for the diagnostics of fire-hazardous modes of operation of catalytic converters based on procedures set in GOST 33997–2016 (ТР ТС 018/2011).

1. Al-Delaimy W., Ramanathan V., Sorondo M. Health of people, health of planet and our responsibility: Climate change, air pollution and health. Springer, 2020; 417. DOI: 10.1007/978-3-030-31125-4

2. Lozhkin V., Lozhkina O., Dobromirov V. A study of air pollution by exhaust gases from cars in well courtyards of Saint Petersburg. Transportation Research Procedia. 2018; 36:453-458. DOI: 10.1016/j.trpro.2018.12.124

3. Alegbeleye O.O., Opeolu B.O., Jackson V.A. Polycyclic aromatic hydrocarbons: A critical review of environmental occurrence and bioremediation. Environmental Management. 2017; 60(4):758-783. DOI: 10.1007/s00267-017-0896-2

4. Lozhkina O.V., Lozhkin V.N. Estimation of nitrogen oxides emissions from petrol and diesel passenger cars by means of on-board monitoring: effect of vehicle speed, vehicle technology, engine type on emission rates. Transportation Research Part D: Transport and Environment. Elsevier Science Publishing Company, Inc. 2016; 47:251-264. DOI: 10.1016/j.trd.2016.06.008

5. Lozhkin V.N. Theory and practice of in-place diagnostics and catalytic neutralization of diesel exhaust gases : dissertation of the Doctor of Technical Sciences. Saint Petersburg, 1995; 444. (rus).

6. Shancita I., Masjuki H., Kalam M., Fattah I.R., Rashed M., Rashedul H. A review on idling reduction strategies to improve fuel economy and reduce exhaust emissions of transport vehicles. Energy Conversion and Management. 2014; 88:794-807. DOI: 10.1016/j.enconman.2014.09.036

7. Baturin S.A., Lozkin V.N., Keiser E. Experimentelle Flammen temperaturbestimmung in Zulinder schnelldrehender Diselmotoren. Kraftfahrzeingtechnik. 1979; 2:44-46. (ger).

8. Kaiser E.W., Siegl W.O., Trinker F.H., Cotton D.F., Cheng W.K., Drobot K. Effect of engine operating parameters on hydrocarbon oxidation in the exhaust port and runner of a spark-ignited engine. SAE Technical Paper Series. 1995. DOI: 10.4271/950159

9. Gao J., Tian G., Sorniotti A. On the emission reduction through the application of an electrically heated catalyst to a diesel vehicle. Energy Science and Engineering. 2019; 7(6):2383-2397. DOI: 10.1002/ese3.416

10. Lozhkina O.V., Onishchenko I.A. Methodology for assessing emissions of hazardous components of exhaust gases during the start-up and warm-up of motor vehicle engines in the climatic conditions of the Arctic. Bulletin of St. Petersburg University of the State Fire Service of the Ministry of Emergency Situations of Russia. 2020; 3:30-37. URL: https://elibrary.ru/item.asp?id=44108901 (rus).

11. Costagliola M.A., Prati V., Mariani A., Unich A., Morrone B. Gaseous and particulate exhaust emissions of hybrid and conventional cars over legislative and real driving cycles. Energy and Power Engineering. 2015; 7(5):181-192. DOI: 10.4236/epe.2015.75018

12. Gänzler A.M., Casapu M., Doronkin D.E., Maurer F., Lott P., Glatzel P. et al. Unravelling the different reaction pathways for low temperature co oxidation on Pt/CeO2 and Pt/Al2O3 by spatially resolved structure–activity correlations. The Journal of Physical Chemistry Letters. 2019; 10(24):7698-7705. DOI: 10.1021/acs.jpclett.9b02768

13. Gao J., Tian G., Sorniotti A. Review of thermal management of catalytic converters to decrease engine emissions during cold start and warm up. Applied Thermal Engineering. 2019; 147:177-187. DOI: 10.1016/j.applthermaleng.2018.10.037

14. Leman A.M., Jajuli A., Feriyanto D., Rahman F., Zakaria S. Advanced catalytic converter in gasoline engine emission control: A review. MATEC Web of Conferences. 2017; 87:02020. DOI: 10.1051/matecconf/20178702020

15. Khan S.R., Zeeshan M., Iqbal S. Thermal management of newly developed non-noble metal-based catalytic converter to reduce cold start emissions of small internal combustion engine. Chemical Engineering Communications. 2018; 205(5):680-688. DOI: 10.1080/00986445.2017.1412311

16. Getsoian A.B., Theis J.R., Lambert C.K. Sensitivity of three-way catalyst light-off temperature to air-fuel ratio. Emission Control Science and Technology. 2018; 4(3):136-142. DOI: 10.1007/s40825-018-0089-3

17. Kannepalli S., Gremminger A., Tischer S., Deutschmann O. Optimization of axial catalyst loading in transient-operated zone-structured monoliths: Reduction of cumulative emissions in automotive oxidation catalysts. Chemical Engineering Science. 2017; 174:189-202. DOI: 10.1016/j.ces.2017.09.013

18. Gao J., Tian G., Sorniotti A. On the emission reduction through the application of an electrically heated catalyst to a diesel vehicle. Energy Science & Engineering. 2019; 7(6):2383-2397. DOI: 10.1002/ese3.416

19. Ning J., Yan F. Temperature control of electrically heated catalyst for cold-start. Emission Improvement. IFAC-PapersOnLine. 2016; 49(11):14-19. DOI: 10.1016/j.ifacol.2016.08.003

20. Tsinoglou D.N., Weilenmann M. A simplified threeway catalyst model for transient hot-mode driving cycles. Ind. Eng. Chem. Res. 2009; 48(4):1772-1785. DOI: 10.1021/IE801032