- Email: [email protected]
Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash
Materials Today: Proceedings xxx (xxxx) xxx
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash P. Rajakrishnamoorthy ⇑, D. Karthikeyan, C.G. Saravanan Department of Mechanical Engineering, Annamalai University, Annamalai Nagar 608002, India
a r t i c l e
i n f o
Article history: Received 23 April 2019 Received in revised form 29 July 2019 Accepted 6 August 2019 Available online xxxx Keywords: SI engine Emission reduction Catalyst ZSM5 zeolite Fly ash
a b s t r a c t The present investigation deals with the synthesis of ZSM-5 zeolite from coal fly ash and using it as a catalytic convertor for the reduction of NOx in gasoline powered engine. Copper and cobalt doped zeolite coated in ceramic monolith shows better active for the instantaneous reduction of NOx compared to the conventional catalytic convertor. Experiment was conducted on twin-cylinder petrol engine with eddy current dynamometer and emissions were measured through AVL DI-gas analyzer. The outcome results exposed that in-house made Cu-ZSM5 and Co-ZSM5 is showing 59% compared to the commercial catalytic converter. The best conversion efficiency NOx, CO and HC were observed. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials Engineering and Characterization 2019.
1. Introduction In worldwide, fossil fuels are depleting because of its continuous usage in automobiles. Similarly, the pollution levels in the air also resemble increasing trends. Particularly usage of automobiles has all fields such as power generation, industries, transportation, mining, buildings construction etc. These vehicles emitted more pollutant to create environmental pollutions. It is affecting human health, global warming, ozone layer depletion, and infertile land. Many researchers have been doing their research to control vehicles emissions like NOx, CO, HC, and CO2. The synthetic zeolite was more suitable when compared to natural zeolite since it has a uniform molecule estimate and a tremendous mixture of substance properties. Fly ash is a solid waste which is generated from coal-fired power plant during the coal ignition process. It is the main raw material for the synthesis of zeolite. To synthesis zeolite from coal fly ash is an interesting process, with having ecological related applications. It is observed that the zeolite A can be synthesized from various sources and one of the beneficial sources is the flyash [1]. Flyash particle in refined as well as zeolite form has very important application to remove the metal from the industrial wastes [2]. The coal fly ash can be utilized for the construction purpose but the synthesis of zeolite-like material is an environmentfriendly process [3]. The synthesis of zeolite in an efficient way at ⇑ Corresponding author. E-mail address: [email protected] (P. Rajakrishnamoorthy).
small scale is carried out treating the fly ash with NaOH & KOH in hydrothermal treatment, but the excellent results for the zeolite formation were obtained by means of KOH [4]. The SiO2 and Al2O3 concentration in the flyash is more responsible for the type of zeolite formation and the crystallization [5]. The flyash particle was subjected to hydrothermal activation with NaOH and KOH and the zeolites A and P were obtained using NaOH [6]. The calcium binding capacity of the synthesized zeolite 4A from the coal fly ash by alkaline hydrothermal treatment was compared with the commercial 4A zeolite and the results were found to be identical [7]. The high crystalline zeolite Na-P1 was successfully synthesized and the impeller design agitation speed in the formation was discussed by Dakalo Mainganye et al. [8]. Researches have been done to find out the mechanism of the fusion of the alkali and flyash in the formation of zeolite [9]. The catalytic convertor invention has been successfully implemented in the vehicles for the emission control, but also it has some limitations because of its adaptability in the low cost vehicles [10]. The Iron exchanged X zeolite has been successfully tested to check its ability to reduce the emission in the SI engine and the results obtained shows better conversion of hazardous emission than the conventional emission [11]. The same X type of zeolite was incorporated with copper and Nickel to find its efficiency to reduce emission in the SI engine and it shows better reduction of the emission for a wide range of the air fuel ratio especially for NOX reduction [12]. Metal-doped 13X zeolite and zsm-5 zeolite were tested to find its efficiency to convert the harmful emission into required output and the results show that these
https://doi.org/10.1016/j.matpr.2019.08.097 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials Engineering and Characterization 2019.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
2
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
types of catalyst were actually better than the commercial catalytic converter [13,14]. The Iron zeolite was more active in the presence of ammonia to reduce the NOX emission of SI engine [15]. The zsm5 zeolite coating to the monolith and its loading methods and the thickness and the distribution will enhance the conversion rate of emission from the exhaust system [16].
2. Catalyst support Fly ash is the solid waste residue generated from coal, oil and biomass burning. Expansive amounts of fly ash residue are produced in coal-based power plants all through the world consistently. Fly ash remains have an unpredictable compound creation shaped mostly from Silica (SiO2), Alumina (Al2O3), Iron oxides (Fe2O3), Calcium Oxide (CaO), Magnesium Oxide (MgO) and the lower amount of different oxides. In recent years few methodologies have been taken to use fly ash either to decrease the expense of transfer or to reduce the environmental effect. One of the methodologies is the change of fly ash residue to zeolites which have numerous applications, for example, ion-exchange, atomic molecular sieves, adsorbents, and catalysts. Some of the papers demonstrated that different variety of zeolites could be acquired from fly ash remains by treating it with a fluid NaOH arrangement at various curing temperatures. It has been found that the zeolite synthesis from the coal flyash was considered as a solution for the disposal of fly ash, Researchers have successfully developed P type and faujasite zeolite [17]. Also KekaOjha et al., have synthesized an X-zeolite type from the coal flyash and it was characterized using XRD, SEM etc in order to find out its physical and chemical characters [18]. Using Class F coal fly ash zeolite X and Y were prepared and it was examined to test its possibility of adsorbing Sulpher Dioxide in the simulated flue gas and the results are impressive [19]. Zeolites are prepared from the alumino silicate based coal flyash by hydrothermal and the effect of the Silicon to Aluminium ratio in the fly ash on the formation of the synthesized zeolite types were discussed by Miki Inada et al., in their research work [20]. A study experiment on the comparison of the hydrothermal treatment of flyash and low temperature method for the synthesis of zeolite like material have proved that the hydrothermal treatment is more suitable and advantage process [21]. Xiaoping Xuan et al., have investigated the reduction of NOX emission with treated flyash particle with some metals in the presence of ammonia and found that the results obtained using Cu have better selective reduction of NOX compared to Fe, Ni, V [22]. A study proves that the ZSM-5 zeolite can be produced from lignite flyash and rice husk and the TPABr is the primary chemical required to produce the ZSM-5 type of zeolite [23]. Flyash are having high thermal stability, if we add some active components to it, these particles are having a wide range of application in the field of catalytic application [24]. Naturally occurring zeolite particles are having a long reaction time, the properties like the physical and chemical and nature of the raw material, reaction time, temperature will influence the formation of zeolite like material [25]. The temperature variation in the synthesis of zeolite after alkaline treatment will produce four types of zeolite namely zeolilte P, analcime, hydroxyl sodalite and cancrinite at different concentration of NaOH and temperature [26]. Most of the industrial waste water contains heavy metals in it and when it was released into the environment it causes series damage, zeolite finds an application in treating of this water by uptaking the heavy metals in waste water [27]. The fly ash synthesized by various concentration of alkaline treatment in different temperature conditions for the synthesis of zeolite lie material and the product shows that it has adsorption capacity almost equal to that of the 13X zeolite [28]. The NaP1 type zeolite and analcime were synthesized from flyash
and it has been found the obtained product becomes significant when increasing temperature [29]. Zeolite X, P and S were synthesized from the flyash and the same was used to purify the lubrication oil and the product finds it application in the field of petroleum Industry [30]. Even the stirring process in the pre treatment of flyash to synthesize zeolite lie substance will have its contribution in the formation of the type of zeolite [31]. Four types of zeolite were manufactured from the coal flyash particle by keeping the temperature and reaction time constant and varying the concentration of alkaline content [32]. The synthesized zeolite were coated with monolith and it was tested to find its ability to reduce the emission from the automobiles and the results obtained were impressive than that of the commercial catalytic convertor [33]. In this work, the coal fly ash samples have been collected from NLC thermal power plant, Neyveli, Tamilnadu, India. It was used to convert zsm5 zeolite-like materials. The synthesized ZSM-5 zeolite-like materials supported Cu/Co-ion exchanged ZSM-5 in separate stages for simultaneous reduction of NOx and oxidation of HCs and CO in SI engine exhaust. 3. Catalyst preparation The collected fly ash samples have been screened by a sieve (180 mm) which eliminates larger particles. Then the fly ash was mixed with HCL to enhance the reaction activity for zeolite synthesis. The acid treated fly ash 2.50 g was mixed with a given amount of fumed silica 1.50 g in 40 mL of deionised water. Then sodium hydroxide 1.0 g was added to the mixture while stirring. Finally, TPABr 3.0 g was added to the mixture. After aging, the final mixture was poured in a stainless steel autoclave, which was at 120 °C for 12 h. Then the autoclave was allowed to gradually cool down. The synthesized product was thoroughly filtered and washed with the help of de-ionized water then the product was dried in hot air oven. Again dried product was detemplated in a furnace at 550 °C for 3 h in air with a ramping temperature of 15 °C/min to burn off TPABr. Finally the synthesized product is cooled, the product was completely washed with de-ionized water and dried in an oven at 70 °C for 2 h. 4. Characterization of fly-ash and zeolites 4.1. X-ray fluorescents (XRF) The XRF method is applied to determine the chemical composition of fly ash. The Philips Spectrometer PW1404 is used. Induction source is constituted by an XRD lamp among dual anode (Cr-Au) with the highest power of about 2 kW. Table 1 shows the chemical composition of fly-ash, ZSM5 (IH) and ZSM5 (commercial). It is noticed from Table 1 that there is increase in the percentage of Na2O in the zeolites more contrast Table 1 Chemical composition of fly-ash, synthesized zeolite, commercial zeolite (weight%). Metal oxides
Fly ash
ZSM5 (In-House)
ZSM5 (Commercial)
SiO2 Al2O3 Fe2O3 CaO MgO SO3 Na2O K2O P2O5 TiO2 BaO LOi
53.52 25.61 4.21 2.05 2.15 2.20 0.95 1.52 2.01 2.90 0.90 1.98
71.91 6.41 0.95 0.90 1.01 1.11 14.3 0.84 1.10 1.31 0.21 0.12
70.10 7.20 0.00 0.00 0.00 0.00 18.20 0.00 0.00 0.00 0.00 0.00
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
3
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
to fly-ash. The weight of Na2O is found to increase from 0.95 to 14.35%. This is due to capture of Na+ ions needed to neutralize the negative (ve) charges lying on the aluminate within the zeolite throughout synthesis process (Table 2).
4.2. Scanning electron microscopy (SEM) Scanning Electron Microscopy analysis is carried out by a JEOLJSM 6610LV electron microscope. The samples are initially coated through a thin layer of platinum to avoid charges into the samples. Micrographs of the samples are recorded with a 10–20 kV accelerating voltage. Figs. 1–3 shows the SEM photographs of fly-ash, ZSM5 like material (in-house) and ZSM5 zeolite (commercial). It is observed from the Fig. 2 that the non appearance of spherical elements in ZSM5 like material, indicate high conversion of fly ash into zeolite on hydrothermal treatment. It is to be noted that the fly ash particles have a smooth surface for the reason that the surface is exposed by the aluminosilicate glass phase. Later than hydrothermal treatment the surface of the treated fly-ash becomes rough, which indicates the phase of zeolite. It is also seen that there is no much variation in the crystal structure of ZSM5 (IH) and ZSM5 (commercial). Figs. 4–7 shows the SEM images of various metal doped zeolites and parent zeolites. It is evident from the figure that the microstructures of the metal doped zeolites were completely changed and the particle size is slightly bigger than that of parent zeolites. This is because during ion exchange process the transition metals are distributed or doped on the parent zeolite particles (Figs. 8–10).
Fig. 1. SEM-image of raw fly ash.
Fig. 2. SEM image of synthesis of zsm-5 like zeolite.
4.4. Na+-ion exchange method
4.3. X-ray diffraction (XRD) The crystal structures of the samples are determined by powder X-ray diffraction on a DX-1000 diffractometer using CuKa radiation (k = 0.15406 nm) working at 40 kW and 25 ma. The XRD data are recorded for 2h values between 0° and 100°. The crystalline phases are recognized by evaluation by means of the reference data records since the JCDPS card and ICDD. In this work 7 samples are determined through XRD analysis.
10 g of zsm5 zeolite like powder was mixed with 1000 ml of 0.05 M CuCl2 (Fisher scientific) solution. The mixture combinations were intermittently stirred at warm temperature for 24 h. After the ion exchange mixture was with help of vacuum filtered apparatus and washed with copious amount of distilled water until no free ions particles were available into the filtrate. The important final resultant slurry was dried in oven and then activated by heating
Table 2 Comparison of XRD data obtained on fly ash material with standard JCPDS data. Standard XRD data for SiO2 (JCPDS. No. 89-1668) (2h values)
9.109 20.456 – 26.773 27.365 27.756 – 28.141 36.696 39.517 45.756 – – – – – – –
Standard XRD data for Al2O3 (JCPD S No. 88-0107) (2h values)
– 21.201 21.315 – – – 28.235 – 36.953 40.023 45.988 51.026 57.139 60.686 67.910 76.293 81.136 –
Standard XRD data for CaO (JCPD S No. 82-1690) (2h values)
– – – – – – – – 37.401 – – – – – 67.467 – – 88.659
Standard XRD data for MgO (JCPD S No. 89-7746) (2h values)
– – – – – – – – 36.863 – – – – – – – – –
Powder XRD data For fly ash material (2h values)
I/Io
8.8738 20.9116 21.4366 26.6957 27.1553 27.7921 28.0500 28.6111 36.6172 39.5304 45.8548 50.8024 57.4901 60.0364 68.2064 76.8941 81.1921 90.8898
7 18 3 100 5 8 28 4 6 5 7 4 12 5 4 3 5 5
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
4
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 3. SEM image of commercial zsm5 zeolite.
Fig. 7. Co-ZSM5 (commercial).
Fig. 8. XRD patterns of fly ash. Fig. 4. Cu-ZSM5 (IH).
Fig. 5. Co-ZSM5 (IH). Fig. 9. XRD patterns of ZSM5, Cu-ZSM5, Co-ZSM5 (in-house).
at 500 °C for 6 h. Co-zsm5 Zeolite catalyst was also prepared in the same way as explained above using CoCl2 (Fisher Scientific). 4.5. Cordierite monoliths The suitable specification based cordierite monoliths were purchased from Bocent Advanced Ceramics Co Ltd, China, of cell density 400 CPSI, 0.17 mm wall thickness and dimensions diameter of 90 mm and length of 90 mm. 4.6. Washcoating
Fig. 6. Cu-ZSM5 (Commercial).
Slurry was prepared by Cu-zsm5 zeolite with mixture of 20 wt.%, 2 wt.% colloidal silica and the remaining wt.% of water.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
5
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 10. XRD patterns of ZSM5, Cu-ZSM5, Co-ZSM5 (commercial).
The cordierite monolith member was dipped into the slurry for 1 min and surplus slurry was separated by means of compressed air flowing, throughout the monolith paths for a fixed time of 5 s from both the ends. After that the Cu-zsm5 zeolite based wash coated monolith catalyst member was dried at 120 °C for 2 h. This stepwise procedure, dipping and drying was repetitive process until the ideal amount reached the desired quantity (15% weight of cordierite monoliths members) of wash coat was deposited on the monolith catalysts support. Finally the Cu-zsm5 zeolite based cordierite monolith was calcined at temperature of 500 °C for 5 h. The same procedure followed to prepare Co-zsm5 zeolite based cordierite monoliths. The premeditated calcinations decreased the possibility of crack formation in the wash coat layer. The observance of the washcoat was determined by the help of adherence test, which consists in determining the weight loss of the coated monoliths into an ultrasonic bath. 4.7. Catalytic converter The coated monoliths are housed individually in steel covering with inlet and outlet cones. The zeolite catalytic converters are fabricated as same as commercial catalytic converter. Fig. 11 shows photographic view of all the three catalytic converter. 5. Experimental work The experimental analysis were conducted in the exhaust of a four stroke, twin cylinder, water cooled SI engine. Displacement volume of the engine is 624 cc. Fig. 12 was illustrate the test facilities for this investigation whose specification is given in Table 3. The Nano engine is accumulated on the test bed. The eddy current dynamometer was directly attached with an engine, with proper
Fig. 12. Experimental Setup. 1. Nano Engine, 2. Eddy current dynamometer, 3. Spark Plug, 4. Weighing Balance, 5. Fuel tank, 6. Fuel pump, 7. Air filter, 8. AVL Digas analyser, 9. Pressure transducer, 10. Crank angle encoder, 11. Charge amplifier, 12. Indimeter, 13. Monitor, 14. Catalytic converter.
Table 3 Engine specification. Particulars
Specification
Engine Type Bore diameter Stroke Maximum power Maximum torque Dynamometer constant Compression ratio
Nano Engine Twin Cylinder, 624 cc, MPFI 73.5 mm 73.5 mm 37 bhp @5000 rpm 51 Nm @ 3000 rpm 9549.5 9.5:1
switching and governing facility for loading the engine. The AVLDi gas analyzer was used to measure HC, CO, CO2, O2 and NOx. The temperatures of the Exhaust gas was measured by ChromelAlumel thermocouple fixed at three different points of the convertor. The engine was run at different loads without catalytic converter, (4, 7, 10, 13 and 16 kW) at speed rate of 2500 rpm. In each case, the concentration of HC, CO, CO2, O2 and NOx were calculated. Then the commercial catalytic converter was also fitted in the exhaust manifold of the engine. Therefore the exhaust gases enter into converter through axially. Then the engine was run at the similar load and speed conditions as it was when run without catalytic converter and the concentration of CO, HC, CO2, O2 and NOx were measured in every case. Then, the above working procedure was repeated using Co-zsm5 zeolite and Cu-zsm5 zeolite catalytic convertors. 6. Result and discussion Fig. 13 shows the variation of NOx conversion efficiency with brake power of the engine NOx conversion efficiency is calculated by using the formula below;
NOx conversion efficiency ¼
Fig. 11. Image of commercial and in-house made catalytic converter.
ðInlet NOx Outlet NOxÞ 100 ðInlet NOxÞ
It is seen from the figure that the in-house made Cu-zeolite and Co-zeolite monolith reduce NOx emission significantly high when compared to commercial monolith. It is also seen that at 13 kW load condition a maximum of 59% of NOx the conversion was achieved by Co-zeolite monolith and at lower load condition
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
6
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 13. Percentage reduction of NOx against load.
(3 kW) Cu-zeolite monolith performs better than Co-zeolite monolith. The in-house made catalytic converter was achieved 29% of NOx conversion when compared to the commercial catalytic converter. More percentage reduction in NOx in the presence of oxygen is attributed to the presence of CO and HC in the exhaust gas which acts as reducing agents, reducing NOx into N2 and O2 and oxidizing CO and HC into CO2 by using produced O2 and O2 available in the exhaust gas. Fig. 14 shows the NOx conversion efficiency with the exhaust gas temperature. It is seen from the Fig. 14 that the Cu and Cozeolite catalysts perform differently on low temperatures and at high temperatures the difference is minimum. Cu-zeolite catalyst reduce NOx emission by around 42% at 163 °C and around 59% at 306 °C and after 400 °C the conversion efficiency starts decreases. Co-zeolite catalyst performs better in the temperature range of 352 °C and 453 °C. Figs. 15 and 16 shows the difference between HC and CO conversion efficiency with brake power of the engine. In agreement with the result of many other researchers, the commercial monolith also controls effectively the levels of HC and CO emissions. It is seen from the Fig. 16 that there is no much difference between
Fig. 14. NOx emission against temperature.
Fig. 15. Hydrocarbon against brake power.
Fig. 16. Carbon monoxide against brake power.
commercial and inhouse made zeolite monoliths. It is also observed that a maximum of 88% of CO conversion was achieved by Co-zeolite monolith. This is because the catalyst-assisted the reaction of CO to CO2 with the left over oxygen in the exhaust gas. Similarly a maximum of 85% of HC emission reduction was achieved by Co-zeolite monolith. It appears that decrease of the un-saturated HC can be depicted as a NOx dissociation reaction accruing the catalyst where the unsaturated HC is responsible for the removal of the adsorbed oxygen generated by the NOx dissociation. Fig. 17 clearly shows that the difference in O2 emission discharge with brake power. It is seen from the figure that the volume of O2 emission is considerably decreased in all levels of load conditions. It is evident that apart from the oxygen produced from the NOx dissociation reaction, the engine-out oxygen is effectively utilized to convert CO to CO2. Fig. 18 shows the brake thermal efficiency of catalytic convertor of the engine. It is seen from the graph that there is a small decrease in the brake thermal efficiency compared to commercial catalytic convertor. The reason may be of the wash coating of a thin zeolite layer into the monolith channels.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
7
ment for their cooperation and physical support to perform the experiment successfully. We also like to thank our friends and my family members.
References
Fig. 17. Oxygen against brake power.
Fig. 18. Brake thermal efficiency against brake power.
7. Conclusion The In-house made zeolite based converters perform better than that of commercial converter. The Cu-ZSM5 Zeolite based monolith showed the best low temperature NOx reduction performance, while the Co-zeolite monolith provided the best high temperature NOx conversion. CO and HC emissions were significantly reduced at all levels of load conditions. It is also observed that the trends for percent reduction in HC and CO are almost similar in speed test. Back pressure increased transversely the catalyst bed is well within the adequate limits. During 50 h of experimental evaluation of Catalytic Convertor, no appreciable deactivation of convertor was observed. Acknowledgement The Authors would like to acknowledge to the head of the department, Mechanical Engineering, Annamalai University for his continuous support to carry this experiment successfully in our department lab. We also extend our gratitude to all the nonteaching faculty members of the mechanical engineering depart-
[1] Ivan Petrov, Todor Michalev, Synthesis of Zeolite A: A Review – HAEXHB TPELOBE HA PECEHCRBZ EHBBEPCBTET –, nov 51, cepbz 9.1- 30 -2012. [2] R.S. Blissett, N.A. Rowson, Review article – a review of the multi-component utilization of coal fly ash, Fuel 97 (2012) 1–23. [3] X. Querol, N. Moreno, J.C. Umaña, A. Alastuey, E. Hernandez, A. López-Soler, F. Plana, Synthesis of zeolites from coal fly ash: an overview, Int. J. Coal Geol. 50 (1–4) (2002) 413–423. [4] A. Carlos, R. Rios, D. Craig, B. Williams, L. Clive, B. Roberts, A comparative study of two methods for the synthesis of fly ash-based sodium and potassium type zeolite, Fuel 88 (2009) 1403–1416, Elsevier. [5] Faizul Che Pa, Mohd. Zaheruddin Kasmuin, Suhaina Ismail, Norlia Baharun, Hydrothermal synthesis of zeolites from fly ash, J. Nucl. Relat. Technol. 4 (Special Edition) (2007) 87–91. [6] Annie Shoumkova, Valeria Stoyanova, Zeolites formation by hydrothermal alkali activation of coal fly ash from thermal power station ‘‘Maritsa 3’’, Bulgaria, Fuel 103 (2013) 533–541. [7] K.S. Hui, C.Y.H. Chao, Single phase, high crystalline, chamfered-edge zeolite 4A synthesized from coal fly ash for use as a builder in detergents, J. Hazard. Mater. B 137 (2006) 401–409. [8] Dakalo Mainganye, Tunde Victor Ojumu, Leslie Petrik, Synthesis of zeolites NaP1 from South African coal fly ash: effect of impeller design and agitation, Materials 6 (2013) 2074–2089, https://doi.org/10.3390/ma6052074. [9] Bhagwanjee Jha, D.N. Singh, Kannan Iyer, Synthesis of zeolites by flyash-alkali interaction, Proceedings of Indian Geotechnical Conference, December 15–17, 2011, Kochi (Paper No. R-243). [10] Jan Kaspar, Paolo Fornasiero, Neal Hickey – automotive catalytic convertors; current status and some perspectives, Catal. Today 77 (2003) 419–449. [11] Randip K. Das, Souvik Bhattacharyya, M. DuttaGupta, B.B. Ghosh, Theoretical and experimental analysis of iron-exchanged X-zeolite catalyst for SI engine emission control, Exp. Therm. Fluid Sci. 19 (1999) 214–222. [12] Souvik Bhattacharyya, Randip K. Das, Catalytic reduction of NOx in gasoline engine exhaust over copper- and nickel-exchanged X-zeolite catalysts, Energy Convers. Manage. 42 (2001) 2019–2027. [13] Swati Bhimasenrao Wadawadagi, Reddy C. Venkataramana, Experimental Investigations on Reduction of CO and HC in SI Engine with Catalytic Converter, 20076555 (JSAE), 2007-32-0055(SAE), 2007. [14] B.B. Ghosh, P.K. Santra, P.P. Ghosh, T. Banerjee, A. Ghosh, S. Ramanujam, Catalytic Reduction of SI Engine Emissions Using Cu-ION Exchange ZSM-5 – SAE Paper No. 2001-26-0013. [15] Joseph R. Theis, Selective Catalytic Reduction for Treating the NOx Emissions from Lean-Burn Gasoline Engines: Performance Assessment, SAE Paper No. 2008-01-0810. [16] Juan M. Zumaro, Maria A. Ulla, Eduardo E. Miro, Zeolite washcoating onto Cordierite honeycomb reactors for environmental applications, Chem. Eng. J. 106 (2005) 25–33. [17] W.-H. Shih, H.-L. Chang, Z. Shen, Conversion of class-F. Fly ash into zeolites, Mater. Res. Soc. Symp. Proc. 371 (1995) 39–44. [18] Keka Ojha, Narayan C. Pradhan, Amar Nath Samanta, Zeolite from fly ash: synthesis and characterization, Bull. Mater. Sci. 27 (6) (2004) 555–564. [19] Anand Srinivasan, Michael W. Grutzeck, The adsorption of SO₂ by zeolites synthesized from flyash, Environ. Sci. Technol. 33 (1999) 1464–1469. [20] Miki Inada, Yukari Eguchi, Naoya Enomoto, Junichi Hojo, Synthesis of zeolite from coal fly ashes with different silica-alumina composition, Fuel 84 (2005) 299–304. [21] Wajcieh Franus, Characterisation of X-type zeolite prepared from coal flyash, Pol. J. Environ. Stud. 21 (2) (2012) 337–343. [22] Xiaoping Xuan, Changtao Yue, Shuyuan Li, Qiang Yao, Selective catalytic reduction of NO by ammonia with fly ash catalyst, Fuel 82 (2003) 525–579. [23] Metta Chareonpanich, Teerapong Namto, Paisan Kongkachuichay, Jumras Limtrakul, Synthesis of ZSM-5 zeolite from lignite fly ash and rice husk ash, Fuel Process. Technol. 85 (2004) 1623–1634. [24] Shaobin Wang, Application of solid ash based catalysts in heterogeneous catalysis, Environ. Sci. Technol. 42 (2008) 7055–7063. [25] U. Barth-Wirsching, H. Hoeller, Experimental studies of zeolite formation conditions, Eur. J. Mineral. 1 (1989) 489. [26] C.F. Lin, H.-C. His, Resource recovery of waste fly ash: synthesis of zeolite-like materials, Environ. Sci. Technol. 29 (1995) 1109–1117. [27] X. Querol, N. Moerno, J.C. Umana, A. Alastuery, E. Hernandez, A. Lopez-Soler, F. Plana, Synthesis of zeolites from coal fly ash: and overview.1, J .Coal Geol. 50 (2002) 413. [28] F. Mondragon, F. Rincon, L. Sierra, J. Escobar, J. Ramirez, J. Fernandez, New perspectives for coal ash utilization. Synthesis of zeolitic materials, Fuel 69 (1990) 263–266. [29] Z. Adamczyk, B. Bialecka, Hydrothermal synthesis of zeolites from polish coal fly ash, Pol. J. Environ. Stud. 14 (6) (2005) 71–719.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
8
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
[30] Arkadiusz Derkowski, Wojciech Franus, Elzbieta B. Eran, Adriana Czimerova, Properties and potential applications of zeolite materials produced from fly ash using simple method of synthesis, Powder Technol. 166 (2006) 47–54. [31] Hidekazu Tanaka, Atsushi Fujii, Effect of stirring on the dissolution of coal fly ash and synthesis of pure-form Na-X and X-zeolites by two-step process, Adv. Powder Technol. 20 (5) (2009) 473–479.
[32] M. Chigondo, U. Guyo, M. Shumba, F. Chigondo, B. Nyamunda, M. Moyo, T. Nharingo, Synthesis and characterisation of zeolites from coal fly ash (CFA), IRACST-Eng. Sci. Technol. 3 (4) (2013), ISSN:2250-3498. [33] D. Karthikeyan, C.G. Saravanan, Experimental analysis of flyash based, ionexchanged zeolite as catalyst for S.I engine emission control, J. KONES Power Train Transp. 20 (3) (2013), 229-235.E.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash P. Rajakrishnamoorthy ⇑, D. Karthikeyan, C.G. Saravanan Department of Mechanical Engineering, Annamalai University, Annamalai Nagar 608002, India
a r t i c l e
i n f o
Article history: Received 23 April 2019 Received in revised form 29 July 2019 Accepted 6 August 2019 Available online xxxx Keywords: SI engine Emission reduction Catalyst ZSM5 zeolite Fly ash
a b s t r a c t The present investigation deals with the synthesis of ZSM-5 zeolite from coal fly ash and using it as a catalytic convertor for the reduction of NOx in gasoline powered engine. Copper and cobalt doped zeolite coated in ceramic monolith shows better active for the instantaneous reduction of NOx compared to the conventional catalytic convertor. Experiment was conducted on twin-cylinder petrol engine with eddy current dynamometer and emissions were measured through AVL DI-gas analyzer. The outcome results exposed that in-house made Cu-ZSM5 and Co-ZSM5 is showing 59% compared to the commercial catalytic converter. The best conversion efficiency NOx, CO and HC were observed. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials Engineering and Characterization 2019.
1. Introduction In worldwide, fossil fuels are depleting because of its continuous usage in automobiles. Similarly, the pollution levels in the air also resemble increasing trends. Particularly usage of automobiles has all fields such as power generation, industries, transportation, mining, buildings construction etc. These vehicles emitted more pollutant to create environmental pollutions. It is affecting human health, global warming, ozone layer depletion, and infertile land. Many researchers have been doing their research to control vehicles emissions like NOx, CO, HC, and CO2. The synthetic zeolite was more suitable when compared to natural zeolite since it has a uniform molecule estimate and a tremendous mixture of substance properties. Fly ash is a solid waste which is generated from coal-fired power plant during the coal ignition process. It is the main raw material for the synthesis of zeolite. To synthesis zeolite from coal fly ash is an interesting process, with having ecological related applications. It is observed that the zeolite A can be synthesized from various sources and one of the beneficial sources is the flyash [1]. Flyash particle in refined as well as zeolite form has very important application to remove the metal from the industrial wastes [2]. The coal fly ash can be utilized for the construction purpose but the synthesis of zeolite-like material is an environmentfriendly process [3]. The synthesis of zeolite in an efficient way at ⇑ Corresponding author. E-mail address: [email protected] (P. Rajakrishnamoorthy).
small scale is carried out treating the fly ash with NaOH & KOH in hydrothermal treatment, but the excellent results for the zeolite formation were obtained by means of KOH [4]. The SiO2 and Al2O3 concentration in the flyash is more responsible for the type of zeolite formation and the crystallization [5]. The flyash particle was subjected to hydrothermal activation with NaOH and KOH and the zeolites A and P were obtained using NaOH [6]. The calcium binding capacity of the synthesized zeolite 4A from the coal fly ash by alkaline hydrothermal treatment was compared with the commercial 4A zeolite and the results were found to be identical [7]. The high crystalline zeolite Na-P1 was successfully synthesized and the impeller design agitation speed in the formation was discussed by Dakalo Mainganye et al. [8]. Researches have been done to find out the mechanism of the fusion of the alkali and flyash in the formation of zeolite [9]. The catalytic convertor invention has been successfully implemented in the vehicles for the emission control, but also it has some limitations because of its adaptability in the low cost vehicles [10]. The Iron exchanged X zeolite has been successfully tested to check its ability to reduce the emission in the SI engine and the results obtained shows better conversion of hazardous emission than the conventional emission [11]. The same X type of zeolite was incorporated with copper and Nickel to find its efficiency to reduce emission in the SI engine and it shows better reduction of the emission for a wide range of the air fuel ratio especially for NOX reduction [12]. Metal-doped 13X zeolite and zsm-5 zeolite were tested to find its efficiency to convert the harmful emission into required output and the results show that these
https://doi.org/10.1016/j.matpr.2019.08.097 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Materials Engineering and Characterization 2019.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
2
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
types of catalyst were actually better than the commercial catalytic converter [13,14]. The Iron zeolite was more active in the presence of ammonia to reduce the NOX emission of SI engine [15]. The zsm5 zeolite coating to the monolith and its loading methods and the thickness and the distribution will enhance the conversion rate of emission from the exhaust system [16].
2. Catalyst support Fly ash is the solid waste residue generated from coal, oil and biomass burning. Expansive amounts of fly ash residue are produced in coal-based power plants all through the world consistently. Fly ash remains have an unpredictable compound creation shaped mostly from Silica (SiO2), Alumina (Al2O3), Iron oxides (Fe2O3), Calcium Oxide (CaO), Magnesium Oxide (MgO) and the lower amount of different oxides. In recent years few methodologies have been taken to use fly ash either to decrease the expense of transfer or to reduce the environmental effect. One of the methodologies is the change of fly ash residue to zeolites which have numerous applications, for example, ion-exchange, atomic molecular sieves, adsorbents, and catalysts. Some of the papers demonstrated that different variety of zeolites could be acquired from fly ash remains by treating it with a fluid NaOH arrangement at various curing temperatures. It has been found that the zeolite synthesis from the coal flyash was considered as a solution for the disposal of fly ash, Researchers have successfully developed P type and faujasite zeolite [17]. Also KekaOjha et al., have synthesized an X-zeolite type from the coal flyash and it was characterized using XRD, SEM etc in order to find out its physical and chemical characters [18]. Using Class F coal fly ash zeolite X and Y were prepared and it was examined to test its possibility of adsorbing Sulpher Dioxide in the simulated flue gas and the results are impressive [19]. Zeolites are prepared from the alumino silicate based coal flyash by hydrothermal and the effect of the Silicon to Aluminium ratio in the fly ash on the formation of the synthesized zeolite types were discussed by Miki Inada et al., in their research work [20]. A study experiment on the comparison of the hydrothermal treatment of flyash and low temperature method for the synthesis of zeolite like material have proved that the hydrothermal treatment is more suitable and advantage process [21]. Xiaoping Xuan et al., have investigated the reduction of NOX emission with treated flyash particle with some metals in the presence of ammonia and found that the results obtained using Cu have better selective reduction of NOX compared to Fe, Ni, V [22]. A study proves that the ZSM-5 zeolite can be produced from lignite flyash and rice husk and the TPABr is the primary chemical required to produce the ZSM-5 type of zeolite [23]. Flyash are having high thermal stability, if we add some active components to it, these particles are having a wide range of application in the field of catalytic application [24]. Naturally occurring zeolite particles are having a long reaction time, the properties like the physical and chemical and nature of the raw material, reaction time, temperature will influence the formation of zeolite like material [25]. The temperature variation in the synthesis of zeolite after alkaline treatment will produce four types of zeolite namely zeolilte P, analcime, hydroxyl sodalite and cancrinite at different concentration of NaOH and temperature [26]. Most of the industrial waste water contains heavy metals in it and when it was released into the environment it causes series damage, zeolite finds an application in treating of this water by uptaking the heavy metals in waste water [27]. The fly ash synthesized by various concentration of alkaline treatment in different temperature conditions for the synthesis of zeolite lie material and the product shows that it has adsorption capacity almost equal to that of the 13X zeolite [28]. The NaP1 type zeolite and analcime were synthesized from flyash
and it has been found the obtained product becomes significant when increasing temperature [29]. Zeolite X, P and S were synthesized from the flyash and the same was used to purify the lubrication oil and the product finds it application in the field of petroleum Industry [30]. Even the stirring process in the pre treatment of flyash to synthesize zeolite lie substance will have its contribution in the formation of the type of zeolite [31]. Four types of zeolite were manufactured from the coal flyash particle by keeping the temperature and reaction time constant and varying the concentration of alkaline content [32]. The synthesized zeolite were coated with monolith and it was tested to find its ability to reduce the emission from the automobiles and the results obtained were impressive than that of the commercial catalytic convertor [33]. In this work, the coal fly ash samples have been collected from NLC thermal power plant, Neyveli, Tamilnadu, India. It was used to convert zsm5 zeolite-like materials. The synthesized ZSM-5 zeolite-like materials supported Cu/Co-ion exchanged ZSM-5 in separate stages for simultaneous reduction of NOx and oxidation of HCs and CO in SI engine exhaust. 3. Catalyst preparation The collected fly ash samples have been screened by a sieve (180 mm) which eliminates larger particles. Then the fly ash was mixed with HCL to enhance the reaction activity for zeolite synthesis. The acid treated fly ash 2.50 g was mixed with a given amount of fumed silica 1.50 g in 40 mL of deionised water. Then sodium hydroxide 1.0 g was added to the mixture while stirring. Finally, TPABr 3.0 g was added to the mixture. After aging, the final mixture was poured in a stainless steel autoclave, which was at 120 °C for 12 h. Then the autoclave was allowed to gradually cool down. The synthesized product was thoroughly filtered and washed with the help of de-ionized water then the product was dried in hot air oven. Again dried product was detemplated in a furnace at 550 °C for 3 h in air with a ramping temperature of 15 °C/min to burn off TPABr. Finally the synthesized product is cooled, the product was completely washed with de-ionized water and dried in an oven at 70 °C for 2 h. 4. Characterization of fly-ash and zeolites 4.1. X-ray fluorescents (XRF) The XRF method is applied to determine the chemical composition of fly ash. The Philips Spectrometer PW1404 is used. Induction source is constituted by an XRD lamp among dual anode (Cr-Au) with the highest power of about 2 kW. Table 1 shows the chemical composition of fly-ash, ZSM5 (IH) and ZSM5 (commercial). It is noticed from Table 1 that there is increase in the percentage of Na2O in the zeolites more contrast Table 1 Chemical composition of fly-ash, synthesized zeolite, commercial zeolite (weight%). Metal oxides
Fly ash
ZSM5 (In-House)
ZSM5 (Commercial)
SiO2 Al2O3 Fe2O3 CaO MgO SO3 Na2O K2O P2O5 TiO2 BaO LOi
53.52 25.61 4.21 2.05 2.15 2.20 0.95 1.52 2.01 2.90 0.90 1.98
71.91 6.41 0.95 0.90 1.01 1.11 14.3 0.84 1.10 1.31 0.21 0.12
70.10 7.20 0.00 0.00 0.00 0.00 18.20 0.00 0.00 0.00 0.00 0.00
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
3
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
to fly-ash. The weight of Na2O is found to increase from 0.95 to 14.35%. This is due to capture of Na+ ions needed to neutralize the negative (ve) charges lying on the aluminate within the zeolite throughout synthesis process (Table 2).
4.2. Scanning electron microscopy (SEM) Scanning Electron Microscopy analysis is carried out by a JEOLJSM 6610LV electron microscope. The samples are initially coated through a thin layer of platinum to avoid charges into the samples. Micrographs of the samples are recorded with a 10–20 kV accelerating voltage. Figs. 1–3 shows the SEM photographs of fly-ash, ZSM5 like material (in-house) and ZSM5 zeolite (commercial). It is observed from the Fig. 2 that the non appearance of spherical elements in ZSM5 like material, indicate high conversion of fly ash into zeolite on hydrothermal treatment. It is to be noted that the fly ash particles have a smooth surface for the reason that the surface is exposed by the aluminosilicate glass phase. Later than hydrothermal treatment the surface of the treated fly-ash becomes rough, which indicates the phase of zeolite. It is also seen that there is no much variation in the crystal structure of ZSM5 (IH) and ZSM5 (commercial). Figs. 4–7 shows the SEM images of various metal doped zeolites and parent zeolites. It is evident from the figure that the microstructures of the metal doped zeolites were completely changed and the particle size is slightly bigger than that of parent zeolites. This is because during ion exchange process the transition metals are distributed or doped on the parent zeolite particles (Figs. 8–10).
Fig. 1. SEM-image of raw fly ash.
Fig. 2. SEM image of synthesis of zsm-5 like zeolite.
4.4. Na+-ion exchange method
4.3. X-ray diffraction (XRD) The crystal structures of the samples are determined by powder X-ray diffraction on a DX-1000 diffractometer using CuKa radiation (k = 0.15406 nm) working at 40 kW and 25 ma. The XRD data are recorded for 2h values between 0° and 100°. The crystalline phases are recognized by evaluation by means of the reference data records since the JCDPS card and ICDD. In this work 7 samples are determined through XRD analysis.
10 g of zsm5 zeolite like powder was mixed with 1000 ml of 0.05 M CuCl2 (Fisher scientific) solution. The mixture combinations were intermittently stirred at warm temperature for 24 h. After the ion exchange mixture was with help of vacuum filtered apparatus and washed with copious amount of distilled water until no free ions particles were available into the filtrate. The important final resultant slurry was dried in oven and then activated by heating
Table 2 Comparison of XRD data obtained on fly ash material with standard JCPDS data. Standard XRD data for SiO2 (JCPDS. No. 89-1668) (2h values)
9.109 20.456 – 26.773 27.365 27.756 – 28.141 36.696 39.517 45.756 – – – – – – –
Standard XRD data for Al2O3 (JCPD S No. 88-0107) (2h values)
– 21.201 21.315 – – – 28.235 – 36.953 40.023 45.988 51.026 57.139 60.686 67.910 76.293 81.136 –
Standard XRD data for CaO (JCPD S No. 82-1690) (2h values)
– – – – – – – – 37.401 – – – – – 67.467 – – 88.659
Standard XRD data for MgO (JCPD S No. 89-7746) (2h values)
– – – – – – – – 36.863 – – – – – – – – –
Powder XRD data For fly ash material (2h values)
I/Io
8.8738 20.9116 21.4366 26.6957 27.1553 27.7921 28.0500 28.6111 36.6172 39.5304 45.8548 50.8024 57.4901 60.0364 68.2064 76.8941 81.1921 90.8898
7 18 3 100 5 8 28 4 6 5 7 4 12 5 4 3 5 5
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
4
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 3. SEM image of commercial zsm5 zeolite.
Fig. 7. Co-ZSM5 (commercial).
Fig. 8. XRD patterns of fly ash. Fig. 4. Cu-ZSM5 (IH).
Fig. 5. Co-ZSM5 (IH). Fig. 9. XRD patterns of ZSM5, Cu-ZSM5, Co-ZSM5 (in-house).
at 500 °C for 6 h. Co-zsm5 Zeolite catalyst was also prepared in the same way as explained above using CoCl2 (Fisher Scientific). 4.5. Cordierite monoliths The suitable specification based cordierite monoliths were purchased from Bocent Advanced Ceramics Co Ltd, China, of cell density 400 CPSI, 0.17 mm wall thickness and dimensions diameter of 90 mm and length of 90 mm. 4.6. Washcoating
Fig. 6. Cu-ZSM5 (Commercial).
Slurry was prepared by Cu-zsm5 zeolite with mixture of 20 wt.%, 2 wt.% colloidal silica and the remaining wt.% of water.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
5
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 10. XRD patterns of ZSM5, Cu-ZSM5, Co-ZSM5 (commercial).
The cordierite monolith member was dipped into the slurry for 1 min and surplus slurry was separated by means of compressed air flowing, throughout the monolith paths for a fixed time of 5 s from both the ends. After that the Cu-zsm5 zeolite based wash coated monolith catalyst member was dried at 120 °C for 2 h. This stepwise procedure, dipping and drying was repetitive process until the ideal amount reached the desired quantity (15% weight of cordierite monoliths members) of wash coat was deposited on the monolith catalysts support. Finally the Cu-zsm5 zeolite based cordierite monolith was calcined at temperature of 500 °C for 5 h. The same procedure followed to prepare Co-zsm5 zeolite based cordierite monoliths. The premeditated calcinations decreased the possibility of crack formation in the wash coat layer. The observance of the washcoat was determined by the help of adherence test, which consists in determining the weight loss of the coated monoliths into an ultrasonic bath. 4.7. Catalytic converter The coated monoliths are housed individually in steel covering with inlet and outlet cones. The zeolite catalytic converters are fabricated as same as commercial catalytic converter. Fig. 11 shows photographic view of all the three catalytic converter. 5. Experimental work The experimental analysis were conducted in the exhaust of a four stroke, twin cylinder, water cooled SI engine. Displacement volume of the engine is 624 cc. Fig. 12 was illustrate the test facilities for this investigation whose specification is given in Table 3. The Nano engine is accumulated on the test bed. The eddy current dynamometer was directly attached with an engine, with proper
Fig. 12. Experimental Setup. 1. Nano Engine, 2. Eddy current dynamometer, 3. Spark Plug, 4. Weighing Balance, 5. Fuel tank, 6. Fuel pump, 7. Air filter, 8. AVL Digas analyser, 9. Pressure transducer, 10. Crank angle encoder, 11. Charge amplifier, 12. Indimeter, 13. Monitor, 14. Catalytic converter.
Table 3 Engine specification. Particulars
Specification
Engine Type Bore diameter Stroke Maximum power Maximum torque Dynamometer constant Compression ratio
Nano Engine Twin Cylinder, 624 cc, MPFI 73.5 mm 73.5 mm 37 bhp @5000 rpm 51 Nm @ 3000 rpm 9549.5 9.5:1
switching and governing facility for loading the engine. The AVLDi gas analyzer was used to measure HC, CO, CO2, O2 and NOx. The temperatures of the Exhaust gas was measured by ChromelAlumel thermocouple fixed at three different points of the convertor. The engine was run at different loads without catalytic converter, (4, 7, 10, 13 and 16 kW) at speed rate of 2500 rpm. In each case, the concentration of HC, CO, CO2, O2 and NOx were calculated. Then the commercial catalytic converter was also fitted in the exhaust manifold of the engine. Therefore the exhaust gases enter into converter through axially. Then the engine was run at the similar load and speed conditions as it was when run without catalytic converter and the concentration of CO, HC, CO2, O2 and NOx were measured in every case. Then, the above working procedure was repeated using Co-zsm5 zeolite and Cu-zsm5 zeolite catalytic convertors. 6. Result and discussion Fig. 13 shows the variation of NOx conversion efficiency with brake power of the engine NOx conversion efficiency is calculated by using the formula below;
NOx conversion efficiency ¼
Fig. 11. Image of commercial and in-house made catalytic converter.
ðInlet NOx Outlet NOxÞ 100 ðInlet NOxÞ
It is seen from the figure that the in-house made Cu-zeolite and Co-zeolite monolith reduce NOx emission significantly high when compared to commercial monolith. It is also seen that at 13 kW load condition a maximum of 59% of NOx the conversion was achieved by Co-zeolite monolith and at lower load condition
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
6
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 13. Percentage reduction of NOx against load.
(3 kW) Cu-zeolite monolith performs better than Co-zeolite monolith. The in-house made catalytic converter was achieved 29% of NOx conversion when compared to the commercial catalytic converter. More percentage reduction in NOx in the presence of oxygen is attributed to the presence of CO and HC in the exhaust gas which acts as reducing agents, reducing NOx into N2 and O2 and oxidizing CO and HC into CO2 by using produced O2 and O2 available in the exhaust gas. Fig. 14 shows the NOx conversion efficiency with the exhaust gas temperature. It is seen from the Fig. 14 that the Cu and Cozeolite catalysts perform differently on low temperatures and at high temperatures the difference is minimum. Cu-zeolite catalyst reduce NOx emission by around 42% at 163 °C and around 59% at 306 °C and after 400 °C the conversion efficiency starts decreases. Co-zeolite catalyst performs better in the temperature range of 352 °C and 453 °C. Figs. 15 and 16 shows the difference between HC and CO conversion efficiency with brake power of the engine. In agreement with the result of many other researchers, the commercial monolith also controls effectively the levels of HC and CO emissions. It is seen from the Fig. 16 that there is no much difference between
Fig. 14. NOx emission against temperature.
Fig. 15. Hydrocarbon against brake power.
Fig. 16. Carbon monoxide against brake power.
commercial and inhouse made zeolite monoliths. It is also observed that a maximum of 88% of CO conversion was achieved by Co-zeolite monolith. This is because the catalyst-assisted the reaction of CO to CO2 with the left over oxygen in the exhaust gas. Similarly a maximum of 85% of HC emission reduction was achieved by Co-zeolite monolith. It appears that decrease of the un-saturated HC can be depicted as a NOx dissociation reaction accruing the catalyst where the unsaturated HC is responsible for the removal of the adsorbed oxygen generated by the NOx dissociation. Fig. 17 clearly shows that the difference in O2 emission discharge with brake power. It is seen from the figure that the volume of O2 emission is considerably decreased in all levels of load conditions. It is evident that apart from the oxygen produced from the NOx dissociation reaction, the engine-out oxygen is effectively utilized to convert CO to CO2. Fig. 18 shows the brake thermal efficiency of catalytic convertor of the engine. It is seen from the graph that there is a small decrease in the brake thermal efficiency compared to commercial catalytic convertor. The reason may be of the wash coating of a thin zeolite layer into the monolith channels.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
7
ment for their cooperation and physical support to perform the experiment successfully. We also like to thank our friends and my family members.
References
Fig. 17. Oxygen against brake power.
Fig. 18. Brake thermal efficiency against brake power.
7. Conclusion The In-house made zeolite based converters perform better than that of commercial converter. The Cu-ZSM5 Zeolite based monolith showed the best low temperature NOx reduction performance, while the Co-zeolite monolith provided the best high temperature NOx conversion. CO and HC emissions were significantly reduced at all levels of load conditions. It is also observed that the trends for percent reduction in HC and CO are almost similar in speed test. Back pressure increased transversely the catalyst bed is well within the adequate limits. During 50 h of experimental evaluation of Catalytic Convertor, no appreciable deactivation of convertor was observed. Acknowledgement The Authors would like to acknowledge to the head of the department, Mechanical Engineering, Annamalai University for his continuous support to carry this experiment successfully in our department lab. We also extend our gratitude to all the nonteaching faculty members of the mechanical engineering depart-
[1] Ivan Petrov, Todor Michalev, Synthesis of Zeolite A: A Review – HAEXHB TPELOBE HA PECEHCRBZ EHBBEPCBTET –, nov 51, cepbz 9.1- 30 -2012. [2] R.S. Blissett, N.A. Rowson, Review article – a review of the multi-component utilization of coal fly ash, Fuel 97 (2012) 1–23. [3] X. Querol, N. Moreno, J.C. Umaña, A. Alastuey, E. Hernandez, A. López-Soler, F. Plana, Synthesis of zeolites from coal fly ash: an overview, Int. J. Coal Geol. 50 (1–4) (2002) 413–423. [4] A. Carlos, R. Rios, D. Craig, B. Williams, L. Clive, B. Roberts, A comparative study of two methods for the synthesis of fly ash-based sodium and potassium type zeolite, Fuel 88 (2009) 1403–1416, Elsevier. [5] Faizul Che Pa, Mohd. Zaheruddin Kasmuin, Suhaina Ismail, Norlia Baharun, Hydrothermal synthesis of zeolites from fly ash, J. Nucl. Relat. Technol. 4 (Special Edition) (2007) 87–91. [6] Annie Shoumkova, Valeria Stoyanova, Zeolites formation by hydrothermal alkali activation of coal fly ash from thermal power station ‘‘Maritsa 3’’, Bulgaria, Fuel 103 (2013) 533–541. [7] K.S. Hui, C.Y.H. Chao, Single phase, high crystalline, chamfered-edge zeolite 4A synthesized from coal fly ash for use as a builder in detergents, J. Hazard. Mater. B 137 (2006) 401–409. [8] Dakalo Mainganye, Tunde Victor Ojumu, Leslie Petrik, Synthesis of zeolites NaP1 from South African coal fly ash: effect of impeller design and agitation, Materials 6 (2013) 2074–2089, https://doi.org/10.3390/ma6052074. [9] Bhagwanjee Jha, D.N. Singh, Kannan Iyer, Synthesis of zeolites by flyash-alkali interaction, Proceedings of Indian Geotechnical Conference, December 15–17, 2011, Kochi (Paper No. R-243). [10] Jan Kaspar, Paolo Fornasiero, Neal Hickey – automotive catalytic convertors; current status and some perspectives, Catal. Today 77 (2003) 419–449. [11] Randip K. Das, Souvik Bhattacharyya, M. DuttaGupta, B.B. Ghosh, Theoretical and experimental analysis of iron-exchanged X-zeolite catalyst for SI engine emission control, Exp. Therm. Fluid Sci. 19 (1999) 214–222. [12] Souvik Bhattacharyya, Randip K. Das, Catalytic reduction of NOx in gasoline engine exhaust over copper- and nickel-exchanged X-zeolite catalysts, Energy Convers. Manage. 42 (2001) 2019–2027. [13] Swati Bhimasenrao Wadawadagi, Reddy C. Venkataramana, Experimental Investigations on Reduction of CO and HC in SI Engine with Catalytic Converter, 20076555 (JSAE), 2007-32-0055(SAE), 2007. [14] B.B. Ghosh, P.K. Santra, P.P. Ghosh, T. Banerjee, A. Ghosh, S. Ramanujam, Catalytic Reduction of SI Engine Emissions Using Cu-ION Exchange ZSM-5 – SAE Paper No. 2001-26-0013. [15] Joseph R. Theis, Selective Catalytic Reduction for Treating the NOx Emissions from Lean-Burn Gasoline Engines: Performance Assessment, SAE Paper No. 2008-01-0810. [16] Juan M. Zumaro, Maria A. Ulla, Eduardo E. Miro, Zeolite washcoating onto Cordierite honeycomb reactors for environmental applications, Chem. Eng. J. 106 (2005) 25–33. [17] W.-H. Shih, H.-L. Chang, Z. Shen, Conversion of class-F. Fly ash into zeolites, Mater. Res. Soc. Symp. Proc. 371 (1995) 39–44. [18] Keka Ojha, Narayan C. Pradhan, Amar Nath Samanta, Zeolite from fly ash: synthesis and characterization, Bull. Mater. Sci. 27 (6) (2004) 555–564. [19] Anand Srinivasan, Michael W. Grutzeck, The adsorption of SO₂ by zeolites synthesized from flyash, Environ. Sci. Technol. 33 (1999) 1464–1469. [20] Miki Inada, Yukari Eguchi, Naoya Enomoto, Junichi Hojo, Synthesis of zeolite from coal fly ashes with different silica-alumina composition, Fuel 84 (2005) 299–304. [21] Wajcieh Franus, Characterisation of X-type zeolite prepared from coal flyash, Pol. J. Environ. Stud. 21 (2) (2012) 337–343. [22] Xiaoping Xuan, Changtao Yue, Shuyuan Li, Qiang Yao, Selective catalytic reduction of NO by ammonia with fly ash catalyst, Fuel 82 (2003) 525–579. [23] Metta Chareonpanich, Teerapong Namto, Paisan Kongkachuichay, Jumras Limtrakul, Synthesis of ZSM-5 zeolite from lignite fly ash and rice husk ash, Fuel Process. Technol. 85 (2004) 1623–1634. [24] Shaobin Wang, Application of solid ash based catalysts in heterogeneous catalysis, Environ. Sci. Technol. 42 (2008) 7055–7063. [25] U. Barth-Wirsching, H. Hoeller, Experimental studies of zeolite formation conditions, Eur. J. Mineral. 1 (1989) 489. [26] C.F. Lin, H.-C. His, Resource recovery of waste fly ash: synthesis of zeolite-like materials, Environ. Sci. Technol. 29 (1995) 1109–1117. [27] X. Querol, N. Moerno, J.C. Umana, A. Alastuery, E. Hernandez, A. Lopez-Soler, F. Plana, Synthesis of zeolites from coal fly ash: and overview.1, J .Coal Geol. 50 (2002) 413. [28] F. Mondragon, F. Rincon, L. Sierra, J. Escobar, J. Ramirez, J. Fernandez, New perspectives for coal ash utilization. Synthesis of zeolitic materials, Fuel 69 (1990) 263–266. [29] Z. Adamczyk, B. Bialecka, Hydrothermal synthesis of zeolites from polish coal fly ash, Pol. J. Environ. Stud. 14 (6) (2005) 71–719.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097
8
P. Rajakrishnamoorthy et al. / Materials Today: Proceedings xxx (xxxx) xxx
[30] Arkadiusz Derkowski, Wojciech Franus, Elzbieta B. Eran, Adriana Czimerova, Properties and potential applications of zeolite materials produced from fly ash using simple method of synthesis, Powder Technol. 166 (2006) 47–54. [31] Hidekazu Tanaka, Atsushi Fujii, Effect of stirring on the dissolution of coal fly ash and synthesis of pure-form Na-X and X-zeolites by two-step process, Adv. Powder Technol. 20 (5) (2009) 473–479.
[32] M. Chigondo, U. Guyo, M. Shumba, F. Chigondo, B. Nyamunda, M. Moyo, T. Nharingo, Synthesis and characterisation of zeolites from coal fly ash (CFA), IRACST-Eng. Sci. Technol. 3 (4) (2013), ISSN:2250-3498. [33] D. Karthikeyan, C.G. Saravanan, Experimental analysis of flyash based, ionexchanged zeolite as catalyst for S.I engine emission control, J. KONES Power Train Transp. 20 (3) (2013), 229-235.E.
Please cite this article as: P. Rajakrishnamoorthy, D. Karthikeyan and C. G. Saravanan, Emission reduction technique applied in SI engines exhaust by using zsm5 zeolite as catalysts synthesized from coal fly ash, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.097