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Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel
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Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel Erinc¸ Uludamar Adana Science and Technology University, Department of Automotive Engineering, 01250 Adana, Turkey
article info
abstract
Article history:
Owing to high growth rate, being non-edible, and environmental friendliness; microalgae is
Received 20 December 2017
a promising third generation biodiesel raw material. In this study, hydrogen and hydroxy
Received in revised form
gas aspirated compression ignition engine which was fuelled with microalgae biodiesel
10 January 2018
and low sulphur diesel fuel blend were investigated in order to evaluate their combined
Accepted 12 January 2018
effect. The results showed that the brake power and torque output of the test engine
Available online xxx
decreased with microalgae biodiesel usage. Moreover, microalgae biodiesel addition results in lower carbon monoxide and nitrogen oxides emissions, and higher carbon dioxide. The
Keywords:
introduction of hydrogen and hydroxy gas compensated the decrement of torque and
HHO
power output and increment of carbon dioxide emission. The study enlightened that usage
Hydrogen
of microalgae biodiesel with hydrogen and hydroxy gas addition is a very promising
Microalgae biodiesel
combination from the environmental viewpoint.
Engine performance
© 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Exhaust emissions
Introduction Increasing world population, industrialization, and transportation demand lead to excessive use of fossil fuels [1]. Thus, the resource of fossil fuels is face to the threat of depletion in all over the world [2]. Due to its high thermal efficiency, application of diesel engine is getting more and more. Therefore, many countries have set the targets to increase the production of biofuels to decrease the usage of fossil-based fuels [3,4]. Alternative fuels have gained great attention by the community since it has the advantage of being environmentally cleaner and sustainability [5,6]. Among alternative to fossil-based diesel fuels, biodiesel and their blends have a major advantage; there is little or no need to modify diesel engines which are already in use, since the fuel properties of most biodiesel similar to conventional diesel fuel [7e10]. Environmental friendliness and similarity of fuel properties
make biodiesel a very popular alternative fuel [11e13]. Animal fats, edible and non-edible vegetable oils can be utilized for biodiesel production [14,15]. First generation of biofuels were produced from the feedstocks of human such as sunflower, olive, corn, palm, soybean, rapeseed oils etc. Production from such sources would lead the communities to suffer from nutrition [16,17]. Therefore, second generation of biodiesel was taken place. In this generation, fuels were produced from non-edible feedstocks, waste oils, animal fats, Jatropha oil, Karanja etc. [18]. Although the feedstocks are non-edible, the problem arises when second generation crops occupy too many agricultural land which lessen the food production [19]. The latest trend of biodiesel production is from algae. The approach calls as third generation [20]. Due to its fast grow rate and high amount of oil contamination algae is considered as promising biodiesel feedstock [21]. Although the oil content of algae is generally 20e50% by weight, some species can yield 80% oil of dry
E-mail address: [email protected]. https://doi.org/10.1016/j.ijhydene.2018.01.075 0360-3199/© 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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biomass and the doubling time of biomass is up to two days [22,23]. Another advantage of algae is ability to grow on nonarable area [24]. Macroalgae and microalgae are the two types of algae. Macroalgae also known as seaweeds are classified into three groups which are named as Phaeophyceae, Rhodophyceae, and Chlorophyceae whereas, Chlorophyceae, Cyanophyceae, Chryosophyceae, Xanthophyceae and Bacillariophyceae are some types of microalgae [25,26]. Since cultivation of microalgae is easier than macroalgae by mass culture methods, microalgae is more favourite [27]. Hydroxy gas (HHO) also known as Brown's gas is another alternative fuel source. Essentially, the gas produced from the electrolysis process of water thus, it contains hydrogen (H2) and oxygen (O2) molecules. The gas usually utilizes as a supplementary fuel to liquid fuels since the self-ignition temperature of hydrogen is too high to use it solely as a fuel source in conventional diesel engines [28]. The researchers who carried out their experiments on conventional diesel engines used HHO gas as secondary fuel as a performance and emission improver. Arat et al. (2016) were studied with HHO. The results showed that HHO addition improved the brake torque, brake power, and brake specific fuel consumption by 2.7%, 3.18%, and 17.4%, respectively compared with conventional diesel fuel. CO, CO2 and NOx emissions were also lowered by HHO gas addition [29]. Another research was carried out by Ozcanli et al. (2017). They investigated the effect of the gas with Castor biodiesel. According to their results, NOx emissions increased with HHO addition when the engine was primarily fuelled with biodiesel blend [30]. Ismail et al. (2018) compared three different HHO dry cell to supply engine. Experiments indicated to 15% reduction of fuel consumption, 17% and 27% reduction of CO and HC emissions, respectively and 15% and 1% increment of oxygen and CO2 [31]. Uludamar et al. (2017) were focused on the vibration characteristic of a diesel engine when it was fuelled with HHO and biodiesel blends [14]. Furthermore, they predicted the effect of fuel properties and HHO amount with ANN approach. The average decrement of vibration acceleration of engine block was measured as 1.23% with 2 l/min, 2,34% with 4 l/min, and 3,54% with 6 l/min flow rates of HHO gas into the intake air. Hydrogen is a promising alternative fuel [32,33]. The major advantage of hydrogen is on environmental impact. However, since hydrogen has a high self-ignition temperature similar to HHO gas, there must be another fuel as an ignition source to start combustion of hydrogen in diesel engines. Thus, hydrogen can be used as secondary fuel [34,35]. In literature, there is numerous number of studies about hydrogen usage in diesel engine. Chiriac and Apostolescu (2013) were used 20% rapeseed methyl ester as primary fuel and hydrogen as second fuel. In the experiments, they observed that higher NOx emission formation and lower smoke and CO emission formation with hydrogen aspiration under 60% load condition [36]. Szwaja and Grab-Rogalinski (2009) were deal with hydrogen combustion. They found out that addition of hydrogen shorten the diesel ignition lag [37]. In literature, researchers generally fuelled diesel engine with first and second generation of biodiesel [38e42]. The oils of such biodiesel bring about their disadvantages in
application. Therefore, in present study, it is aimed to evaluate the performance and emission characteristic of an unmodified diesel engine which was fuelled with diesel and microalgae-diesel fuel blend with HHO and hydrogen enrichment through intake manifold. The fuel properties of microalgae biodiesel and its blend with low sulphur diesel (LSD) fuel were determined.
Material and method Determination of fuel properties Fuel properties of the test fuels were measured in C ¸ ukurova University Automotive Engineering Department with Kyoto Electronics DA-130, Zeltex ZX440, Saybolt Universal Viscosimeter, Tanaka MPC-102, Tanaka Automated PenskyMartens Closed Cup Flash Point Tester. Kyoto Electronics DA-130 which has ±0.001 g/cm3 was used for measurement of density of the test fuels. Cetane number is the parameter about the fuel's ignition quality [43]. In the measurements, Zeltex ZX440 was used for cetane number determination. Viscosity of the test fuels, which is the major drawback property of most of the biodiesel fuel is measured with the Saybolt Universal Viscosimeter [44,45]. Cold fuel properties of the biodiesel fuel is another disadvantage for some biodiesel fuels. The biodiesels which produced from palm, rapeseed and safflower biodiesels has higher pour and cloud point than conventional diesel fuel, whereas castor biodiesel has the lower [46e49]. Cloud point is the point of wax cloud crystals first appears in fuel during the cooling and the pour point is the temperature which the fuel loses its flow characteristic [50]. The cold properties of the test fuels were determined by Tanaka MPC-102. The process, stock and logistic safety of the fuels depend on their flash point [51]. The biodiesel fuels from different sources have usually higher flash point than conventional diesel fuel [52]. In the study, the flash point of the fuels was measured with Tanaka Automated Pensky-Martens Closed Cup Flash Point Tester.
Production of biodiesel The microalgae oil that used to produce microalgae biodiesel was obtained from the Chlorella protothecoides. The oil was converted to biodiesel fuel via transesterification reaction. In the process, the oil was heated to 55 C while methanol as reactant and sodium hydroxide as catalyst were mixed in another beaker until the sodium hydroxide was dissolved in methanol. The homogeneous mixture was added into the flask that contains the heated oil. The mixture was stirring for 1.5 h. After the transesterification step, the methyl ester was poured into the separation funnel in order to separate crude methyl ester from the glycerine. The methyl ester waited inside the funnel for 8 h before the separation. After the separation, the crude methyl ester was washed with warm water for 3 times and then heated up to 105 C to vaporize water from the crude methyl ester. At the last step, filtering operation was carried out in order to remove small impurities.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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Experimental engine The engine experiments were conducted on a 4-stroke 4cylinder diesel engine. Fuel line of the engine and fuel tank were cleaned before the change of liquid fuel. After the cleanup process, the engine was run with the new fuel for a while in order to completely sweep away the remaining ex-fuel. When the engine became stable at high speed with low load, the data were started to record until the engine become nearly unstable under the high load. A hydraulic dynamometer was used for measuring the torque and power output of the test engine. Measurements were repeated three times for each experimental set. The properties of the experimental engine were presented in Table 1. The experimental layout is illustrated in Fig. 1. Exhaust emissions of the experimental engine was measured with MRU Delta 1600-V gas analyser. The analyser is capable to measure CO, NO and NO2 emissions. NO, and NO2 come together to form NOx emissions.
Result and discussion Some physical properties of LSD, MB20 and hydrogen fuels were given in Table 2. The properties also compared with EN 590 diesel and EN 14214 biodiesel standards. Table 1 e Specification of the experimental engine. Engine brand Model Cylinder configuration Total cylinder volume Cylinder bore Cylinder stroke Maximum power output Maximum torque output
Mitsubishi 4D34-2A In line 4 3907 cc 104 mm 115 mm 89 HP at 3200 rpm 295 Nm at 1800 rpm
3
Blend of diesel-microalgae biodiesel has higher density value than low sulphur diesel fuel. The result also indicates that the microalgae biodiesel has higher density than LSD fuel. Cetane number which is one of the crucial fuel properties is measured as lower in MB20 than diesel fuel. Moreover, kinematic viscosity determination indicates that the viscosity is higher with biodiesel blend. On the other hand, the blend has advantages on the fuel properties of flash point and pour point. Variation of torque output versus engine speed is shown in Fig. 2. In the experiments, usage of MB20 resulted with 4.1% lower torque value as overall. However, introduction of HHO and hydrogen gases improved torque output of the engine when it was fuelled with LSD and MB20. When the engine was run with LSD fuel, 1.3% and 0.7% increment were observed with the introduction of HHO and hydrogen, respectively and 2.6% increment with HHO and 2.1% increment with hydrogen were measured with MB20 fuel. The gas additions were compensated the reduction of torque output which caused by MB20 was compensated by HHO and hydrogen addition up to 1.6% with HHO and 2.1% with hydrogen. Higher heating value and faster flame speed of hydrogen and enhanced combustion with both hydrogen and oxygen molecules may cause the improvement of engine torque output [53,54]. The reason of the diminished torque value with MB20 blend may due to its less lower heating value when it is compared to LSD's lower heating value [23]. The rise of torque output of the engine may direct effect on engine power output. Adding HHO and hydrogen were ascended the power output as 1.1% and 0.4%, respectively with LSD fuel. When the engine run with the biodiesel blend, 2.5% and 2.1% increment were measured with HHO and hydrogen addition, respectively. Without any addition gas, compared to LSD, brake power output of the engine was 4.1% lower with MB20 blend. The brake power output of the engine versus engine speed was presented in Fig. 3.
Fig. 1 e Experimental layout.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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All experimental fuel addition to LSD fuel led to diminish trend on CO emission formation. Primary reasons of CO emission formation are inadequate combustion and lack of oxygen molecule during the expansion stroke [8,55]. Therefore, extra oxygen content of HHO and MB20 has an effect on less CO emission formation. Moreover, due to its fast flame speed of hydrogen also decreased the CO emission. Measurements illustrated that CO emissions decreased by 9.82%, 4.12%, and 1.82% with the biodiesel blend, and introduction of HHO and hydrogen to diesel fuel, respectively. Addition of HHO and hydrogen resulted 4.56% and 0.84% lower CO emissions, respectively when the main fuel was MB20. Fig. 4 shows the result of CO emission versus engine speed (see Fig. 5). Due to lack of carbon atom in HHO and hydrogen, carbon availability in the combustion reduced [56]. Therefore, less CO and CO2 formation occurred with the addition of the gases. Compared to unaspirated gas flow, CO2 formation lowered by 1.36% and 2.00% with HHO and hydrogen aspiration when the engine primary fuel was LSD fuel. With MB20 fuelling, the effect of HHO was 1.23% and hydrogen was 1.76%. Compared to LSD fuel, 2.88% increment of CO2 emission was observed
with MB20 fuel usage. Molecular component and balance of CO and CO2 result with opposite behaviour of these emissions. Oxygen content of fuel plays an important role on the interchange of CO and CO2 emissions. Extra oxygen content of biodiesel may impact on the increment of CO2 emission by the use of MB20 with respect to LSD [57e59]. NOx emissions formation according to engine speed were illustrated in Fig. 6. NOx is one of the most detrimental emission for a diesel engine [60,61]. NOx formation is related to oxygen concentration, reaction temperature and residence time [62,63]. Although compared to LSD fuel, many biodiesels tend to increase NOx emissions, in the experiments 8.87% decrement were obtained with MB20. This trend may due to poorer combustion characteristic which is resulted in higher viscosity and density of the biodiesel blend [21]. Resemble results were presented by Al-lwayzy and Yusaf (2017), and Tuccar and Aydın (2013) [22,23]. NOx emissions went up to 3.37% and 4.81% with HHO addition when the engine was fuelled with LSD and MB20, respectively. Similarly, hydrogen addition to diesel fuel caused to increment of NOx by 2.89% and 4.59% with MB20. In the measurements, it observed that
Table 2 e Test fuel properties. Fuel property
LSD
EN 590
MB20
EN 14214
Hydrogen
Density (kg/m3) Cetane number Viscosity (mm2/s) Pour point ( C)
843 58.0 2.4 8
820e845 >51 2.0e4.5 e
853 55.3 2.8 10
0.0837 e e e
Flash point ( C) Lower heating value (MJ/kg)
56 42.5
>55 e
75 41.8
860e900 >51 3.5e5.0 Summer < 4.0 Winter < 1.0 >120 e
e 119.93
Fig. 2 e Torque output versus engine speed. Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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Fig. 3 e Brake power output versus engine speed.
Fig. 4 e CO emission versus engine speed.
the range between NOx emissions values of different test fuels are wider at low engine speed where the engine load is higher. Higher in-cylinder temperature and faster burning rate of hydrogen contribute to increase of NOx emission with HHO
and hydrogen addition [64]. The reason of the less difference at low load may explain with the replacement of intake air with hydrogen gas which influences on the reduction of nitrogen molecules in the combustion [65].
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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Fig. 5 e CO2 emission versus engine speed.
Fig. 6 e NOx emissions versus engine speed.
Conclusion As a third-generation biodiesel, microalgae biodiesel is a promising energy source. Thereby, this study deals with a diesel engine which is fuelled by LSD and MB20 as main fuel and HHO and hydrogen aspiration through intake manifold as secondary fuel. From the study, the following conclusion can be drawn.
MB20 can run the diesel engine without any modification. The fuel similar to LSD also assured this result. Torque and power output of the engine was decreased 4.1% with MB20 usage. However, HHO and hydrogen addition compensated the decrement in torque and power output. Compared to LSD, MB20 improved CO and NOx emission by 9.82% and 8.87%, respectively. Average increment of CO2 emission were measured as 2.88%. However, addition of the gases eliminated the increment up to 1.07%.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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HHO and hydrogen additions were diminished CO and CO2 emission since the gases do not contain any carbon atom. Although NOx emission increment was not significant with the addition of HHO and hydrogen at low load, the difference became wider at high engine load.
[13]
[14]
references
[1] Valente Bueno A, Paulinia Bento Pereira M, Victor de Oliveira Pontes J, Murilo Tavares de Luna F, Loureiro Cavalcante Jr C. Performance and emissions characteristics of castor oil biodiesel fuel blends. Appl Therm Eng 2017;125:559e66. https://doi.org/10.1016/j.applthermaleng.2017.06.114. [2] Tosun E, Ozgur T, Ozgur C, Ozcanli M, Serin H, Aydin K. Comparative analysis of various modelling techniques for emission prediction of diesel engine fueled by diesel fuel with nanoparticle additives. Eur Mech Sci 2017;1:15e23. [3] Boutesteijn C, Drabik D, Venus TJ. The interaction between EU biofuel policy and first- and second-generation biodiesel production. Ind Crop Prod 2017;106:124e9. https://doi.org/ 10.1016/j.indcrop.2016.09.067. [4] Murphy F, Devlin G, Deverell R, McDonnell K. Potential to increase indigenous biodiesel production to help meet 2020 targets e an EU perspective with a focus on Ireland. Renew Sustain Energy Rev 2014;35:154e70. https://doi.org/10.1016/ j.rser.2014.03.046. [5] Bayındır H, Zerrakki M, Ik I, Argunhan Z, Yu¨cel HL, Aydın H. Combustion, performance and emissions of a diesel power generator fueled with biodiesel-kerosene and biodieselkerosene-diesel blends. Energy 2017;123:241e51. https:// doi.org/10.1016/j.energy.2017.01.153. [6] Fazal MA, Suhaila NR, Haseeb ASMA, Rubaiee S, Al-Zahrani A. Influence of copper on the instability and corrosiveness of palm biodiesel and its blends: an assessment on biodiesel sustainability. J Clean Prod 2017;171:1407e14. https://doi.org/ 10.1016/j.jclepro.2017.10.144. [7] Hasan MM, Rahman MM. Performance and emission characteristics of biodieselediesel blend and environmental and economic impacts of biodiesel production: a review. Renew Sustain Energy Rev 2017;74:938e48. https://doi.org/ 10.1016/j.rser.2017.03.045. [8] Kathirvelu B, Subramanian S, Govindan N, Santhanam S. Emission characteristics of biodiesel obtained from jatropha seeds and fish wastes in a diesel engine. Sustain Environ Res 2017;27:283e90. https://doi.org/10.1016/j.serj. 2017.06.004. [9] C¸elebi K, Uludamar E, Tosun E, ßafak Yıldızhan S, Aydın K, € Ozcanlı M. Experimental and artificial neural network approach of noise and vibration characteristic of an unmodified diesel engine fuelled with conventional diesel, and biodiesel blends with natural gas addition. Fuel 2017;197:159e73. https://doi.org/10.1016/j.fuel.2017.01.113. [10] Takase M, Zhao T, Zhang M, Chen Y, Liu H, Yang L, et al. An expatiate review of neem, jatropha, rubber and karanja as multipurpose non-edible biodiesel resources and comparison of their fuel, engine and emission properties. Renew Sustain Energy Rev 2015;43:495e520. https://doi.org/ 10.1016/j.rser.2014.11.049. [11] Sundus F, Fazal MA, Masjuki HH. Tribology with biodiesel: a study on enhancing biodiesel stability and its fuel properties. Renew Sustain Energy Rev 2017;70:399e412. https://doi.org/ 10.1016/j.rser.2016.11.217. [12] Liu H, Ma X, Li B, Chen L, Wang Z, Wang J. Combustion and emission characteristics of a direct injection diesel engine
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
7
fueled with biodiesel and PODE/biodiesel fuel blends. Fuel 2017;209:62e8. https://doi.org/10.1016/j.fuel.2017.07.066. ı Biyodizelinin Motor Ses Seviyesine Olan C¸alik A. Pamuk Yag Etkilerinin Incelenmesi Investigation of Effects of Cotton Oil Biodiesel on Engine Noise Level. C¸ukurova Univ J Fac Eng Archit Mu¨h Mim Fak Derg 2017;32:147e52. Uludamar E, Tosun E, Tu¨ccar G, Yıldızhan S‚, C¸alık A, Yıldırım S, et al. Evaluation of vibration characteristics of a hydroxyl (HHO) gas generator installed diesel engine fuelled with different dieselebiodiesel blends. Int J Hydrogen Energy 2017;42:23352e60. https://doi.org/10.1016/j.ijhydene.2017. 01.192. Zhou JH, Cheung CS, Leung CW. Combustion, performance and emissions of ULSD, PME and B50 fueled multi-cylinder diesel engine with naturally aspirated hydrogen. Int J Hydrogen Energy 2013;38:14837e48. https://doi.org/10.1016/ j.ijhydene.2013.08.128. Bhuiya MMK, Rasul MG, Khan MMK, Ashwath N, Azad AK. Second generation biodiesel : potential alternative to- edible oil-derived biodiesel. Energy Procedia 2014;61:1969e72. https://doi.org/10.1016/j.egypro.2014.12.054. Saladini F, Patrizi N, Pulselli FM, Marchettini N, Bastianoni S. Guidelines for emergy evaluation of first, second and third generation biofuels. Renew Sustain Energy Rev 2016;66:221e7. https://doi.org/10.1016/j.rser.2016.07.073. Zhong W, Xuan T, He Z, Wang Q, Li D, Zhang X, et al. Experimental study of combustion and emission characteristics of diesel engine with diesel/secondgeneration biodiesel blending fuels. Energy Convers Manag 2016;121:241e50. https://doi.org/10.1016/j.enconman.2016. 05.033. Sakthivel R, Ramesh K, Purnachandran R, Shameer PM. A review on the properties, performance and emission aspects of the third generation biodiesels. Renew Sustain Energy Rev 2017:1e23. https://doi.org/10.1016/j.rser.2017.10.037. Srinophakun P, Thanapimmetha A, Rattanaphanyapan K, Sahaya T, Saisriyoot M. Feedstock production for third generation biofuels through cultivation of Arthrobacter AK19 under stress conditions. J Clean Prod 2017;142:1259e66. https://doi.org/10.1016/j.jclepro.2016.08.068. Satputaley SS, Zodpe DB, Deshpande NV. Performance, combustion and emission study on CI engine using microalgae oil and microalgae oil methyl esters. J Energy Inst 2017;90:513e21. https://doi.org/10.1016/j.joei.2016.05.011. Tu¨ccar G, Aydın K. Evaluation of methyl ester of microalgae oil as fuel in a diesel engine. Fuel 2013;112:203e7. https:// doi.org/10.1016/j.fuel.2013.05.016. Al-Lwayzy SH, Yusaf T. Diesel engine performance and exhaust gas emissions using Microalgae Chlorella protothecoides biodiesel. Renew Energy 2017;101:690e701. https://doi.org/10.1016/j.renene.2016.09.035. Islam MA, Heimann K, Brown RJ. Microalgae biodiesel: current status and future needs for engine performance and emissions. Renew Sustain Energy Rev 2017;79:1160e70. https://doi.org/10.1016/j.rser.2017.05.041. Jambo SA, Abdulla R, Mohd Azhar SH, Marbawi H, Gansau JA, Ravindra P. A review on third generation bioethanol feedstock. Renew Sustain Energy Rev 2016;65:756e69. https://doi.org/10.1016/j.rser.2016.07.064. Milano J, Ong HC, Masjuki HH, Chong WT, Lam MK, Loh PK, et al. Microalgae biofuels as an alternative to fossil fuel for power generation. Renew Sustain Energy Rev 2016;58:180e97. https://doi.org/10.1016/j.rser.2015.12.150. Razzak SA, Ali SAM, Hossain MM, deLasa H. Biological CO2 fixation with production of microalgae in wastewater e a review. Renew Sustain Energy Rev 2017;76:379e90. https:// doi.org/10.1016/j.rser.2017.02.038.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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[28] Yilmaz AC, Uludamar E, Aydin K. Effect of hydroxy (HHO) gas addition on performance and exhaust emissions in compression ignition engines. Int J Hydrogen Energy 2010;35:11366e72. https://doi.org/10.1016/j.ijhydene.2010. 07.040. € [29] Arat HT, Baltacioglu MK, Ozcanli M, Aydin K. Effect of using Hydroxy e CNG fuel mixtures in a non-modified diesel engine by substitution of diesel fuel. Int J Hydrogen Energy 2016;41:8354e63. https://doi.org/10.1016/j.ijhydene.2015. 11.183. [30] Ozcanli M, Akar MA, Calik A, Serin H, Using HHO. (Hydroxy) and hydrogen enriched castor oil biodiesel in compression ignition engine. Int J Hydrogen Energy 2017;42:23366e72. https://doi.org/10.1016/j.ijhydene.2017.01.091. [31] Ismail TM, Ramzy K, Abelwhab MN, Elnaghi BE, Abd ElSalam M, Ismail MI. Performance of hybrid compression ignition engine using hydroxy (HHO) from dry cell. Energy Convers Manag 2018;155:287e300. https://doi.org/10.1016/ j.enconman.2017.10.076. [32] Dhole AE, Yarasu RB, Lata DB, Priyam A. Effect on performance and emissions of a dual fuel diesel engine using hydrogen and producer gas as secondary fuels. Int J Hydrogen Energy 2014;39:8087e97. https://doi.org/10.1016/ j.ijhydene.2014.03.085. [33] Count W, Submitted T, Id P. State of art of hydrogen usage as a fuel on aviation 2017;2:20e30. doi:10.26701/ems.364286. [34] Yilmaz IT, Demir A, Gumus M. Effects of hydrogen enrichment on combustion characteristics of a CI engine. Int J Hydrogen Energy 2017;42:10536e46. https://doi.org/10.1016/ j.ijhydene.2017.01.214. [35] Pan H, Pournazeri S, Princevac M, Miller JW, Mahalingam S, Khan MY, et al. Effect of hydrogen addition on criteria and greenhouse gas emissions for a marine diesel engine. Int J Hydrogen Energy 2014;39:11336e45. https://doi.org/10.1016/ j.ijhydene.2014.05.010. [36] Chiriac R, Apostolescu N. Emissions of a diesel engine using B20 and effects of hydrogen addition. Int J Hydrogen Energy 2013;38:13453e62. https://doi.org/10.1016/j.ijhydene.2013. 07.095. [37] Szwaja S, Grab-Rogalinski K. Hydrogen combustion in a compression ignition diesel engine. Int J Hydrogen Energy 2009;34:4413e21. https://doi.org/10.1016/j.ijhydene.2009. 03.020. [38] Li B, Li Y, Liu H, Liu F, Wang Z, Wang J. Combustion and emission characteristics of diesel engine fueled with biodiesel/PODE blends. Appl Energy 2017;206:425e31. https:// doi.org/10.1016/j.apenergy.2017.08.206. [39] Zareh P, Zare AA, Ghobadian B. Comparative assessment of performance and emission characteristics of castor, coconut and waste cooking based biodiesel as fuel in a diesel engine. Energy 2017;139:883e94. https://doi.org/10.1016/j.energy. 2017.08.040. [40] Chhabra M, Sharma A, Dwivedi G. Performance evaluation of diesel engine using rice bran biodiesel. Egypt J Phys 2017;26:511e8. https://doi.org/10.1016/j.ejpe.2016.07.002. [41] Tongroon M, Suebwong A, Kananont M, Aunchaisri J, Chollacoop N. High quality jatropha biodiesel (H-FAME) and its application in a common rail diesel engine. Renew Energy 2017;113:660e8. https://doi.org/10.1016/j.renene. 2017.06.006. [42] Uyumaz A. Combustion, performance and emission characteristics of a DI diesel engine fueled with mustard oil biodiesel fuel blends at different engine loads. Fuel 2018;212:256e67. https://doi.org/10.1016/j.fuel.2017.09.005. [43] Kessler T, Sacia ER, Bell AT, Mack JH. Artificial neural network based predictions of cetane number for furanic biofuel additives. Fuel 2017;206:171e9. https://doi.org/ 10.1016/j.fuel.2017.06.015.
€ [44] Yıldızhan S‚, Uludamar E, C¸alık A, Dede G, Ozcanlı M. Fuel properties, performance and emission characterization of waste cooking oil (WCO) in a variable compression ratio (VCR) diesel engine. Eur Mech Sci 2017;1:56e62. € [45] C¸elebi K, Uludamar E, Ozcanlı M. Evaluation of fuel consumption and vibration characteristic of a compression ignition engine fuelled with high viscosity biodiesel and hydrogen addition. Int J Hydrogen Energy 2017;42:23379e88. https://doi.org/10.1016/j.ijhydene.2017.02.066. rez W, Marı´n J, del Rı´o J, Pen ~ a J, Rios L. Upgrading of palm [46] Pe oil renewable diesel through hydroisomerization and formulation of an optimal blend. Fuel 2017;209:442e8. https://doi.org/10.1016/j.fuel.2017.08.013. €g u¨t H. Effects of using ethanol-biodiesel-diesel fuel [47] Aydın F, O in single cylinder diesel engine to engine performance and emissions. Renew Energy 2017;103:688e94. https://doi.org/ 10.1016/j.renene.2016.10.083. [48] Buyukkaya E. Effects of biodiesel on a di diesel engine performance, emission and combustion characteristics. Fuel 2010;89:3099e105. https://doi.org/10.1016/j.fuel.2010.05.034. [49] Mejı´a JD, Salgado N, Orrego CE. Effect of blends of diesel and palm-castor biodiesels on viscosity, cloud point and flash point. Ind Crop Prod 2013;43:791e7. https://doi.org/10.1016/ j.indcrop.2012.08.026. [50] Dwivedi G, Sharma MP. Impact of cold flow properties of biodiesel on engine performance. Renew Sustain Energy Rev 2014;31:650e6. https://doi.org/10.1016/j.rser.2013.12.035. [51] Mahmudul HM, Hagos FY, Mamat R, Adam AA, Ishak WFW, Alenezi R. Production, characterization and performance of biodiesel as an alternative fuel in diesel engines e a review. Renew Sustain Energy Rev 2017;72:497e509. https://doi.org/ 10.1016/j.rser.2017.01.001. [52] Modiba E, Osifo P, Rutto H. Biodiesel production from baobab (Adansonia digitata L.) seed kernel oil and its fuel properties. Ind Crop Prod 2014;59:50e4. https://doi.org/10.1016/ j.indcrop.2014.04.044. € se H, Ciniviz M. An experimental investigation of effect on [53] Ko diesel engine performance and exhaust emissions of addition at dual fuel mode of hydrogen. Fuel Process Technol 2013;114:26e34. https://doi.org/10.1016/j.fuproc.2013.03.023. € [54] Baltacioglu MK, Arat HT, Ozcanli M, Aydin K. Experimental comparison of pure hydrogen and HHO (hydroxy) enriched biodiesel (B10) fuel in a commercial diesel engine. Int J Hydrogen Energy 2016;41:8347e53. https://doi.org/10.1016/ j.ijhydene.2015.11.185. [55] Yilmaz N, Atmanli A, Vigil FM. Quaternary blends of diesel, biodiesel, higher alcohols and vegetable oil in a compression ignition engine. Fuel 2018;212:462e9. https://doi.org/10.1016/ j.fuel.2017.10.050. [56] Jhang S-R, Chen K-S, Lin S-L, Lin Y-C, Cheng WL. Reducing pollutant emissions from a heavy-duty diesel engine by using hydrogen additions. Fuel 2016;172:89e95. https:// doi.org/10.1016/j.fuel.2016.01.032. [57] Tan YH, Abdullah MO, Nolasco-Hipolito C, Zauzi NSA, Abdullah GW. Engine performance and emissions characteristics of a diesel engine fueled with dieselbiodiesel-bioethanol emulsions. Energy Convers Manag 2017;132:54e64. https://doi.org/10.1016/j.enconman.2016. 11.013. [58] Hoseini SS, Najafi G, Ghobadian B, Rahimi A, Yusaf T, Mamat R, et al. Effects of biodiesel fuel obtained from Salvia macrosiphon oil (ultrasonic-assisted) on performance and emissions of diesel engine. Energy 2017;131:289e96. https:// doi.org/10.1016/j.energy.2017.04.150. [59] Serin H, Yıldızhan S‚. Influence of the compression ratio on the performance and emission characteristics of a vcr diesel engine fuelled with alcohol blended fuels. Eur Mech Sci 2017;1:39e46.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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[60] Uludamar E, Afak Yıldızhan S, Aydın K, Ozcanlı MV. Vibration, noise and exhaust emissions analyses of an unmodified compression ignition engine fuelled with low sulphur diesel and biodiesel blends with hydrogen addition. Int J Hydrogen Energy 2016. https://doi.org/10.1016/ j.ijhydene.2016.03.179. [61] Velmurugan K, Sathiyagnanam AP. Impact of antioxidants on NOx emissions from a mango seed biodiesel powered DI diesel engine. Alexandria Eng J 2016;55:715e22. https:// doi.org/10.1016/j.aej.2015.10.004. [62] Wei L, Cheng R, Mao H, Geng P, Zhang Y, You K. Combustion process and NOx emissions of a marine auxiliary diesel engine fuelled with waste cooking oil biodiesel blends. Energy 2017;144:73e80. https://doi.org/10.1016/j.energy. 2017.12.012.
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[63] He B-Q. Advances in emission characteristics of diesel engines using different biodiesel fuels. Renew Sustain Energy Rev 2016;60:570e86. https://doi.org/10.1016/j.rser. 2016.01.093. [64] Zhou JH, Cheung CS, Leung CW. Combustion, performance and emissions of a diesel engine with H2, CH4 and H2eCH4 addition. Int J Hydrogen Energy 2014;39:4611e21. https:// doi.org/10.1016/j.ijhydene.2013.12.194. € z Y, Sandalci T, Yu¨ksek L, Dalkilic¸ AS. Engine [65] Karago performance and emission effects of diesel burns enriched by hydrogen on different engine loads. Int J Hydrogen Energy 2015;40:6702e13. https://doi.org/10.1016/j.ijhydene.2015. 03.141.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel Erinc¸ Uludamar Adana Science and Technology University, Department of Automotive Engineering, 01250 Adana, Turkey
article info
abstract
Article history:
Owing to high growth rate, being non-edible, and environmental friendliness; microalgae is
Received 20 December 2017
a promising third generation biodiesel raw material. In this study, hydrogen and hydroxy
Received in revised form
gas aspirated compression ignition engine which was fuelled with microalgae biodiesel
10 January 2018
and low sulphur diesel fuel blend were investigated in order to evaluate their combined
Accepted 12 January 2018
effect. The results showed that the brake power and torque output of the test engine
Available online xxx
decreased with microalgae biodiesel usage. Moreover, microalgae biodiesel addition results in lower carbon monoxide and nitrogen oxides emissions, and higher carbon dioxide. The
Keywords:
introduction of hydrogen and hydroxy gas compensated the decrement of torque and
HHO
power output and increment of carbon dioxide emission. The study enlightened that usage
Hydrogen
of microalgae biodiesel with hydrogen and hydroxy gas addition is a very promising
Microalgae biodiesel
combination from the environmental viewpoint.
Engine performance
© 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Exhaust emissions
Introduction Increasing world population, industrialization, and transportation demand lead to excessive use of fossil fuels [1]. Thus, the resource of fossil fuels is face to the threat of depletion in all over the world [2]. Due to its high thermal efficiency, application of diesel engine is getting more and more. Therefore, many countries have set the targets to increase the production of biofuels to decrease the usage of fossil-based fuels [3,4]. Alternative fuels have gained great attention by the community since it has the advantage of being environmentally cleaner and sustainability [5,6]. Among alternative to fossil-based diesel fuels, biodiesel and their blends have a major advantage; there is little or no need to modify diesel engines which are already in use, since the fuel properties of most biodiesel similar to conventional diesel fuel [7e10]. Environmental friendliness and similarity of fuel properties
make biodiesel a very popular alternative fuel [11e13]. Animal fats, edible and non-edible vegetable oils can be utilized for biodiesel production [14,15]. First generation of biofuels were produced from the feedstocks of human such as sunflower, olive, corn, palm, soybean, rapeseed oils etc. Production from such sources would lead the communities to suffer from nutrition [16,17]. Therefore, second generation of biodiesel was taken place. In this generation, fuels were produced from non-edible feedstocks, waste oils, animal fats, Jatropha oil, Karanja etc. [18]. Although the feedstocks are non-edible, the problem arises when second generation crops occupy too many agricultural land which lessen the food production [19]. The latest trend of biodiesel production is from algae. The approach calls as third generation [20]. Due to its fast grow rate and high amount of oil contamination algae is considered as promising biodiesel feedstock [21]. Although the oil content of algae is generally 20e50% by weight, some species can yield 80% oil of dry
E-mail address: [email protected]. https://doi.org/10.1016/j.ijhydene.2018.01.075 0360-3199/© 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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biomass and the doubling time of biomass is up to two days [22,23]. Another advantage of algae is ability to grow on nonarable area [24]. Macroalgae and microalgae are the two types of algae. Macroalgae also known as seaweeds are classified into three groups which are named as Phaeophyceae, Rhodophyceae, and Chlorophyceae whereas, Chlorophyceae, Cyanophyceae, Chryosophyceae, Xanthophyceae and Bacillariophyceae are some types of microalgae [25,26]. Since cultivation of microalgae is easier than macroalgae by mass culture methods, microalgae is more favourite [27]. Hydroxy gas (HHO) also known as Brown's gas is another alternative fuel source. Essentially, the gas produced from the electrolysis process of water thus, it contains hydrogen (H2) and oxygen (O2) molecules. The gas usually utilizes as a supplementary fuel to liquid fuels since the self-ignition temperature of hydrogen is too high to use it solely as a fuel source in conventional diesel engines [28]. The researchers who carried out their experiments on conventional diesel engines used HHO gas as secondary fuel as a performance and emission improver. Arat et al. (2016) were studied with HHO. The results showed that HHO addition improved the brake torque, brake power, and brake specific fuel consumption by 2.7%, 3.18%, and 17.4%, respectively compared with conventional diesel fuel. CO, CO2 and NOx emissions were also lowered by HHO gas addition [29]. Another research was carried out by Ozcanli et al. (2017). They investigated the effect of the gas with Castor biodiesel. According to their results, NOx emissions increased with HHO addition when the engine was primarily fuelled with biodiesel blend [30]. Ismail et al. (2018) compared three different HHO dry cell to supply engine. Experiments indicated to 15% reduction of fuel consumption, 17% and 27% reduction of CO and HC emissions, respectively and 15% and 1% increment of oxygen and CO2 [31]. Uludamar et al. (2017) were focused on the vibration characteristic of a diesel engine when it was fuelled with HHO and biodiesel blends [14]. Furthermore, they predicted the effect of fuel properties and HHO amount with ANN approach. The average decrement of vibration acceleration of engine block was measured as 1.23% with 2 l/min, 2,34% with 4 l/min, and 3,54% with 6 l/min flow rates of HHO gas into the intake air. Hydrogen is a promising alternative fuel [32,33]. The major advantage of hydrogen is on environmental impact. However, since hydrogen has a high self-ignition temperature similar to HHO gas, there must be another fuel as an ignition source to start combustion of hydrogen in diesel engines. Thus, hydrogen can be used as secondary fuel [34,35]. In literature, there is numerous number of studies about hydrogen usage in diesel engine. Chiriac and Apostolescu (2013) were used 20% rapeseed methyl ester as primary fuel and hydrogen as second fuel. In the experiments, they observed that higher NOx emission formation and lower smoke and CO emission formation with hydrogen aspiration under 60% load condition [36]. Szwaja and Grab-Rogalinski (2009) were deal with hydrogen combustion. They found out that addition of hydrogen shorten the diesel ignition lag [37]. In literature, researchers generally fuelled diesel engine with first and second generation of biodiesel [38e42]. The oils of such biodiesel bring about their disadvantages in
application. Therefore, in present study, it is aimed to evaluate the performance and emission characteristic of an unmodified diesel engine which was fuelled with diesel and microalgae-diesel fuel blend with HHO and hydrogen enrichment through intake manifold. The fuel properties of microalgae biodiesel and its blend with low sulphur diesel (LSD) fuel were determined.
Material and method Determination of fuel properties Fuel properties of the test fuels were measured in C ¸ ukurova University Automotive Engineering Department with Kyoto Electronics DA-130, Zeltex ZX440, Saybolt Universal Viscosimeter, Tanaka MPC-102, Tanaka Automated PenskyMartens Closed Cup Flash Point Tester. Kyoto Electronics DA-130 which has ±0.001 g/cm3 was used for measurement of density of the test fuels. Cetane number is the parameter about the fuel's ignition quality [43]. In the measurements, Zeltex ZX440 was used for cetane number determination. Viscosity of the test fuels, which is the major drawback property of most of the biodiesel fuel is measured with the Saybolt Universal Viscosimeter [44,45]. Cold fuel properties of the biodiesel fuel is another disadvantage for some biodiesel fuels. The biodiesels which produced from palm, rapeseed and safflower biodiesels has higher pour and cloud point than conventional diesel fuel, whereas castor biodiesel has the lower [46e49]. Cloud point is the point of wax cloud crystals first appears in fuel during the cooling and the pour point is the temperature which the fuel loses its flow characteristic [50]. The cold properties of the test fuels were determined by Tanaka MPC-102. The process, stock and logistic safety of the fuels depend on their flash point [51]. The biodiesel fuels from different sources have usually higher flash point than conventional diesel fuel [52]. In the study, the flash point of the fuels was measured with Tanaka Automated Pensky-Martens Closed Cup Flash Point Tester.
Production of biodiesel The microalgae oil that used to produce microalgae biodiesel was obtained from the Chlorella protothecoides. The oil was converted to biodiesel fuel via transesterification reaction. In the process, the oil was heated to 55 C while methanol as reactant and sodium hydroxide as catalyst were mixed in another beaker until the sodium hydroxide was dissolved in methanol. The homogeneous mixture was added into the flask that contains the heated oil. The mixture was stirring for 1.5 h. After the transesterification step, the methyl ester was poured into the separation funnel in order to separate crude methyl ester from the glycerine. The methyl ester waited inside the funnel for 8 h before the separation. After the separation, the crude methyl ester was washed with warm water for 3 times and then heated up to 105 C to vaporize water from the crude methyl ester. At the last step, filtering operation was carried out in order to remove small impurities.
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Experimental engine The engine experiments were conducted on a 4-stroke 4cylinder diesel engine. Fuel line of the engine and fuel tank were cleaned before the change of liquid fuel. After the cleanup process, the engine was run with the new fuel for a while in order to completely sweep away the remaining ex-fuel. When the engine became stable at high speed with low load, the data were started to record until the engine become nearly unstable under the high load. A hydraulic dynamometer was used for measuring the torque and power output of the test engine. Measurements were repeated three times for each experimental set. The properties of the experimental engine were presented in Table 1. The experimental layout is illustrated in Fig. 1. Exhaust emissions of the experimental engine was measured with MRU Delta 1600-V gas analyser. The analyser is capable to measure CO, NO and NO2 emissions. NO, and NO2 come together to form NOx emissions.
Result and discussion Some physical properties of LSD, MB20 and hydrogen fuels were given in Table 2. The properties also compared with EN 590 diesel and EN 14214 biodiesel standards. Table 1 e Specification of the experimental engine. Engine brand Model Cylinder configuration Total cylinder volume Cylinder bore Cylinder stroke Maximum power output Maximum torque output
Mitsubishi 4D34-2A In line 4 3907 cc 104 mm 115 mm 89 HP at 3200 rpm 295 Nm at 1800 rpm
3
Blend of diesel-microalgae biodiesel has higher density value than low sulphur diesel fuel. The result also indicates that the microalgae biodiesel has higher density than LSD fuel. Cetane number which is one of the crucial fuel properties is measured as lower in MB20 than diesel fuel. Moreover, kinematic viscosity determination indicates that the viscosity is higher with biodiesel blend. On the other hand, the blend has advantages on the fuel properties of flash point and pour point. Variation of torque output versus engine speed is shown in Fig. 2. In the experiments, usage of MB20 resulted with 4.1% lower torque value as overall. However, introduction of HHO and hydrogen gases improved torque output of the engine when it was fuelled with LSD and MB20. When the engine was run with LSD fuel, 1.3% and 0.7% increment were observed with the introduction of HHO and hydrogen, respectively and 2.6% increment with HHO and 2.1% increment with hydrogen were measured with MB20 fuel. The gas additions were compensated the reduction of torque output which caused by MB20 was compensated by HHO and hydrogen addition up to 1.6% with HHO and 2.1% with hydrogen. Higher heating value and faster flame speed of hydrogen and enhanced combustion with both hydrogen and oxygen molecules may cause the improvement of engine torque output [53,54]. The reason of the diminished torque value with MB20 blend may due to its less lower heating value when it is compared to LSD's lower heating value [23]. The rise of torque output of the engine may direct effect on engine power output. Adding HHO and hydrogen were ascended the power output as 1.1% and 0.4%, respectively with LSD fuel. When the engine run with the biodiesel blend, 2.5% and 2.1% increment were measured with HHO and hydrogen addition, respectively. Without any addition gas, compared to LSD, brake power output of the engine was 4.1% lower with MB20 blend. The brake power output of the engine versus engine speed was presented in Fig. 3.
Fig. 1 e Experimental layout.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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All experimental fuel addition to LSD fuel led to diminish trend on CO emission formation. Primary reasons of CO emission formation are inadequate combustion and lack of oxygen molecule during the expansion stroke [8,55]. Therefore, extra oxygen content of HHO and MB20 has an effect on less CO emission formation. Moreover, due to its fast flame speed of hydrogen also decreased the CO emission. Measurements illustrated that CO emissions decreased by 9.82%, 4.12%, and 1.82% with the biodiesel blend, and introduction of HHO and hydrogen to diesel fuel, respectively. Addition of HHO and hydrogen resulted 4.56% and 0.84% lower CO emissions, respectively when the main fuel was MB20. Fig. 4 shows the result of CO emission versus engine speed (see Fig. 5). Due to lack of carbon atom in HHO and hydrogen, carbon availability in the combustion reduced [56]. Therefore, less CO and CO2 formation occurred with the addition of the gases. Compared to unaspirated gas flow, CO2 formation lowered by 1.36% and 2.00% with HHO and hydrogen aspiration when the engine primary fuel was LSD fuel. With MB20 fuelling, the effect of HHO was 1.23% and hydrogen was 1.76%. Compared to LSD fuel, 2.88% increment of CO2 emission was observed
with MB20 fuel usage. Molecular component and balance of CO and CO2 result with opposite behaviour of these emissions. Oxygen content of fuel plays an important role on the interchange of CO and CO2 emissions. Extra oxygen content of biodiesel may impact on the increment of CO2 emission by the use of MB20 with respect to LSD [57e59]. NOx emissions formation according to engine speed were illustrated in Fig. 6. NOx is one of the most detrimental emission for a diesel engine [60,61]. NOx formation is related to oxygen concentration, reaction temperature and residence time [62,63]. Although compared to LSD fuel, many biodiesels tend to increase NOx emissions, in the experiments 8.87% decrement were obtained with MB20. This trend may due to poorer combustion characteristic which is resulted in higher viscosity and density of the biodiesel blend [21]. Resemble results were presented by Al-lwayzy and Yusaf (2017), and Tuccar and Aydın (2013) [22,23]. NOx emissions went up to 3.37% and 4.81% with HHO addition when the engine was fuelled with LSD and MB20, respectively. Similarly, hydrogen addition to diesel fuel caused to increment of NOx by 2.89% and 4.59% with MB20. In the measurements, it observed that
Table 2 e Test fuel properties. Fuel property
LSD
EN 590
MB20
EN 14214
Hydrogen
Density (kg/m3) Cetane number Viscosity (mm2/s) Pour point ( C)
843 58.0 2.4 8
820e845 >51 2.0e4.5 e
853 55.3 2.8 10
0.0837 e e e
Flash point ( C) Lower heating value (MJ/kg)
56 42.5
>55 e
75 41.8
860e900 >51 3.5e5.0 Summer < 4.0 Winter < 1.0 >120 e
e 119.93
Fig. 2 e Torque output versus engine speed. Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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Fig. 3 e Brake power output versus engine speed.
Fig. 4 e CO emission versus engine speed.
the range between NOx emissions values of different test fuels are wider at low engine speed where the engine load is higher. Higher in-cylinder temperature and faster burning rate of hydrogen contribute to increase of NOx emission with HHO
and hydrogen addition [64]. The reason of the less difference at low load may explain with the replacement of intake air with hydrogen gas which influences on the reduction of nitrogen molecules in the combustion [65].
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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Fig. 5 e CO2 emission versus engine speed.
Fig. 6 e NOx emissions versus engine speed.
Conclusion As a third-generation biodiesel, microalgae biodiesel is a promising energy source. Thereby, this study deals with a diesel engine which is fuelled by LSD and MB20 as main fuel and HHO and hydrogen aspiration through intake manifold as secondary fuel. From the study, the following conclusion can be drawn.
MB20 can run the diesel engine without any modification. The fuel similar to LSD also assured this result. Torque and power output of the engine was decreased 4.1% with MB20 usage. However, HHO and hydrogen addition compensated the decrement in torque and power output. Compared to LSD, MB20 improved CO and NOx emission by 9.82% and 8.87%, respectively. Average increment of CO2 emission were measured as 2.88%. However, addition of the gases eliminated the increment up to 1.07%.
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HHO and hydrogen additions were diminished CO and CO2 emission since the gases do not contain any carbon atom. Although NOx emission increment was not significant with the addition of HHO and hydrogen at low load, the difference became wider at high engine load.
[13]
[14]
references
[1] Valente Bueno A, Paulinia Bento Pereira M, Victor de Oliveira Pontes J, Murilo Tavares de Luna F, Loureiro Cavalcante Jr C. Performance and emissions characteristics of castor oil biodiesel fuel blends. Appl Therm Eng 2017;125:559e66. https://doi.org/10.1016/j.applthermaleng.2017.06.114. [2] Tosun E, Ozgur T, Ozgur C, Ozcanli M, Serin H, Aydin K. Comparative analysis of various modelling techniques for emission prediction of diesel engine fueled by diesel fuel with nanoparticle additives. Eur Mech Sci 2017;1:15e23. [3] Boutesteijn C, Drabik D, Venus TJ. The interaction between EU biofuel policy and first- and second-generation biodiesel production. Ind Crop Prod 2017;106:124e9. https://doi.org/ 10.1016/j.indcrop.2016.09.067. [4] Murphy F, Devlin G, Deverell R, McDonnell K. Potential to increase indigenous biodiesel production to help meet 2020 targets e an EU perspective with a focus on Ireland. Renew Sustain Energy Rev 2014;35:154e70. https://doi.org/10.1016/ j.rser.2014.03.046. [5] Bayındır H, Zerrakki M, Ik I, Argunhan Z, Yu¨cel HL, Aydın H. Combustion, performance and emissions of a diesel power generator fueled with biodiesel-kerosene and biodieselkerosene-diesel blends. Energy 2017;123:241e51. https:// doi.org/10.1016/j.energy.2017.01.153. [6] Fazal MA, Suhaila NR, Haseeb ASMA, Rubaiee S, Al-Zahrani A. Influence of copper on the instability and corrosiveness of palm biodiesel and its blends: an assessment on biodiesel sustainability. J Clean Prod 2017;171:1407e14. https://doi.org/ 10.1016/j.jclepro.2017.10.144. [7] Hasan MM, Rahman MM. Performance and emission characteristics of biodieselediesel blend and environmental and economic impacts of biodiesel production: a review. Renew Sustain Energy Rev 2017;74:938e48. https://doi.org/ 10.1016/j.rser.2017.03.045. [8] Kathirvelu B, Subramanian S, Govindan N, Santhanam S. Emission characteristics of biodiesel obtained from jatropha seeds and fish wastes in a diesel engine. Sustain Environ Res 2017;27:283e90. https://doi.org/10.1016/j.serj. 2017.06.004. [9] C¸elebi K, Uludamar E, Tosun E, ßafak Yıldızhan S, Aydın K, € Ozcanlı M. Experimental and artificial neural network approach of noise and vibration characteristic of an unmodified diesel engine fuelled with conventional diesel, and biodiesel blends with natural gas addition. Fuel 2017;197:159e73. https://doi.org/10.1016/j.fuel.2017.01.113. [10] Takase M, Zhao T, Zhang M, Chen Y, Liu H, Yang L, et al. An expatiate review of neem, jatropha, rubber and karanja as multipurpose non-edible biodiesel resources and comparison of their fuel, engine and emission properties. Renew Sustain Energy Rev 2015;43:495e520. https://doi.org/ 10.1016/j.rser.2014.11.049. [11] Sundus F, Fazal MA, Masjuki HH. Tribology with biodiesel: a study on enhancing biodiesel stability and its fuel properties. Renew Sustain Energy Rev 2017;70:399e412. https://doi.org/ 10.1016/j.rser.2016.11.217. [12] Liu H, Ma X, Li B, Chen L, Wang Z, Wang J. Combustion and emission characteristics of a direct injection diesel engine
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
7
fueled with biodiesel and PODE/biodiesel fuel blends. Fuel 2017;209:62e8. https://doi.org/10.1016/j.fuel.2017.07.066. ı Biyodizelinin Motor Ses Seviyesine Olan C¸alik A. Pamuk Yag Etkilerinin Incelenmesi Investigation of Effects of Cotton Oil Biodiesel on Engine Noise Level. C¸ukurova Univ J Fac Eng Archit Mu¨h Mim Fak Derg 2017;32:147e52. Uludamar E, Tosun E, Tu¨ccar G, Yıldızhan S‚, C¸alık A, Yıldırım S, et al. Evaluation of vibration characteristics of a hydroxyl (HHO) gas generator installed diesel engine fuelled with different dieselebiodiesel blends. Int J Hydrogen Energy 2017;42:23352e60. https://doi.org/10.1016/j.ijhydene.2017. 01.192. Zhou JH, Cheung CS, Leung CW. Combustion, performance and emissions of ULSD, PME and B50 fueled multi-cylinder diesel engine with naturally aspirated hydrogen. Int J Hydrogen Energy 2013;38:14837e48. https://doi.org/10.1016/ j.ijhydene.2013.08.128. Bhuiya MMK, Rasul MG, Khan MMK, Ashwath N, Azad AK. Second generation biodiesel : potential alternative to- edible oil-derived biodiesel. Energy Procedia 2014;61:1969e72. https://doi.org/10.1016/j.egypro.2014.12.054. Saladini F, Patrizi N, Pulselli FM, Marchettini N, Bastianoni S. Guidelines for emergy evaluation of first, second and third generation biofuels. Renew Sustain Energy Rev 2016;66:221e7. https://doi.org/10.1016/j.rser.2016.07.073. Zhong W, Xuan T, He Z, Wang Q, Li D, Zhang X, et al. Experimental study of combustion and emission characteristics of diesel engine with diesel/secondgeneration biodiesel blending fuels. Energy Convers Manag 2016;121:241e50. https://doi.org/10.1016/j.enconman.2016. 05.033. Sakthivel R, Ramesh K, Purnachandran R, Shameer PM. A review on the properties, performance and emission aspects of the third generation biodiesels. Renew Sustain Energy Rev 2017:1e23. https://doi.org/10.1016/j.rser.2017.10.037. Srinophakun P, Thanapimmetha A, Rattanaphanyapan K, Sahaya T, Saisriyoot M. Feedstock production for third generation biofuels through cultivation of Arthrobacter AK19 under stress conditions. J Clean Prod 2017;142:1259e66. https://doi.org/10.1016/j.jclepro.2016.08.068. Satputaley SS, Zodpe DB, Deshpande NV. Performance, combustion and emission study on CI engine using microalgae oil and microalgae oil methyl esters. J Energy Inst 2017;90:513e21. https://doi.org/10.1016/j.joei.2016.05.011. Tu¨ccar G, Aydın K. Evaluation of methyl ester of microalgae oil as fuel in a diesel engine. Fuel 2013;112:203e7. https:// doi.org/10.1016/j.fuel.2013.05.016. Al-Lwayzy SH, Yusaf T. Diesel engine performance and exhaust gas emissions using Microalgae Chlorella protothecoides biodiesel. Renew Energy 2017;101:690e701. https://doi.org/10.1016/j.renene.2016.09.035. Islam MA, Heimann K, Brown RJ. Microalgae biodiesel: current status and future needs for engine performance and emissions. Renew Sustain Energy Rev 2017;79:1160e70. https://doi.org/10.1016/j.rser.2017.05.041. Jambo SA, Abdulla R, Mohd Azhar SH, Marbawi H, Gansau JA, Ravindra P. A review on third generation bioethanol feedstock. Renew Sustain Energy Rev 2016;65:756e69. https://doi.org/10.1016/j.rser.2016.07.064. Milano J, Ong HC, Masjuki HH, Chong WT, Lam MK, Loh PK, et al. Microalgae biofuels as an alternative to fossil fuel for power generation. Renew Sustain Energy Rev 2016;58:180e97. https://doi.org/10.1016/j.rser.2015.12.150. Razzak SA, Ali SAM, Hossain MM, deLasa H. Biological CO2 fixation with production of microalgae in wastewater e a review. Renew Sustain Energy Rev 2017;76:379e90. https:// doi.org/10.1016/j.rser.2017.02.038.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
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i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y x x x ( 2 0 1 8 ) 1 e9
[28] Yilmaz AC, Uludamar E, Aydin K. Effect of hydroxy (HHO) gas addition on performance and exhaust emissions in compression ignition engines. Int J Hydrogen Energy 2010;35:11366e72. https://doi.org/10.1016/j.ijhydene.2010. 07.040. € [29] Arat HT, Baltacioglu MK, Ozcanli M, Aydin K. Effect of using Hydroxy e CNG fuel mixtures in a non-modified diesel engine by substitution of diesel fuel. Int J Hydrogen Energy 2016;41:8354e63. https://doi.org/10.1016/j.ijhydene.2015. 11.183. [30] Ozcanli M, Akar MA, Calik A, Serin H, Using HHO. (Hydroxy) and hydrogen enriched castor oil biodiesel in compression ignition engine. Int J Hydrogen Energy 2017;42:23366e72. https://doi.org/10.1016/j.ijhydene.2017.01.091. [31] Ismail TM, Ramzy K, Abelwhab MN, Elnaghi BE, Abd ElSalam M, Ismail MI. Performance of hybrid compression ignition engine using hydroxy (HHO) from dry cell. Energy Convers Manag 2018;155:287e300. https://doi.org/10.1016/ j.enconman.2017.10.076. [32] Dhole AE, Yarasu RB, Lata DB, Priyam A. Effect on performance and emissions of a dual fuel diesel engine using hydrogen and producer gas as secondary fuels. Int J Hydrogen Energy 2014;39:8087e97. https://doi.org/10.1016/ j.ijhydene.2014.03.085. [33] Count W, Submitted T, Id P. State of art of hydrogen usage as a fuel on aviation 2017;2:20e30. doi:10.26701/ems.364286. [34] Yilmaz IT, Demir A, Gumus M. Effects of hydrogen enrichment on combustion characteristics of a CI engine. Int J Hydrogen Energy 2017;42:10536e46. https://doi.org/10.1016/ j.ijhydene.2017.01.214. [35] Pan H, Pournazeri S, Princevac M, Miller JW, Mahalingam S, Khan MY, et al. Effect of hydrogen addition on criteria and greenhouse gas emissions for a marine diesel engine. Int J Hydrogen Energy 2014;39:11336e45. https://doi.org/10.1016/ j.ijhydene.2014.05.010. [36] Chiriac R, Apostolescu N. Emissions of a diesel engine using B20 and effects of hydrogen addition. Int J Hydrogen Energy 2013;38:13453e62. https://doi.org/10.1016/j.ijhydene.2013. 07.095. [37] Szwaja S, Grab-Rogalinski K. Hydrogen combustion in a compression ignition diesel engine. Int J Hydrogen Energy 2009;34:4413e21. https://doi.org/10.1016/j.ijhydene.2009. 03.020. [38] Li B, Li Y, Liu H, Liu F, Wang Z, Wang J. Combustion and emission characteristics of diesel engine fueled with biodiesel/PODE blends. Appl Energy 2017;206:425e31. https:// doi.org/10.1016/j.apenergy.2017.08.206. [39] Zareh P, Zare AA, Ghobadian B. Comparative assessment of performance and emission characteristics of castor, coconut and waste cooking based biodiesel as fuel in a diesel engine. Energy 2017;139:883e94. https://doi.org/10.1016/j.energy. 2017.08.040. [40] Chhabra M, Sharma A, Dwivedi G. Performance evaluation of diesel engine using rice bran biodiesel. Egypt J Phys 2017;26:511e8. https://doi.org/10.1016/j.ejpe.2016.07.002. [41] Tongroon M, Suebwong A, Kananont M, Aunchaisri J, Chollacoop N. High quality jatropha biodiesel (H-FAME) and its application in a common rail diesel engine. Renew Energy 2017;113:660e8. https://doi.org/10.1016/j.renene. 2017.06.006. [42] Uyumaz A. Combustion, performance and emission characteristics of a DI diesel engine fueled with mustard oil biodiesel fuel blends at different engine loads. Fuel 2018;212:256e67. https://doi.org/10.1016/j.fuel.2017.09.005. [43] Kessler T, Sacia ER, Bell AT, Mack JH. Artificial neural network based predictions of cetane number for furanic biofuel additives. Fuel 2017;206:171e9. https://doi.org/ 10.1016/j.fuel.2017.06.015.
€ [44] Yıldızhan S‚, Uludamar E, C¸alık A, Dede G, Ozcanlı M. Fuel properties, performance and emission characterization of waste cooking oil (WCO) in a variable compression ratio (VCR) diesel engine. Eur Mech Sci 2017;1:56e62. € [45] C¸elebi K, Uludamar E, Ozcanlı M. Evaluation of fuel consumption and vibration characteristic of a compression ignition engine fuelled with high viscosity biodiesel and hydrogen addition. Int J Hydrogen Energy 2017;42:23379e88. https://doi.org/10.1016/j.ijhydene.2017.02.066. rez W, Marı´n J, del Rı´o J, Pen ~ a J, Rios L. Upgrading of palm [46] Pe oil renewable diesel through hydroisomerization and formulation of an optimal blend. Fuel 2017;209:442e8. https://doi.org/10.1016/j.fuel.2017.08.013. €g u¨t H. Effects of using ethanol-biodiesel-diesel fuel [47] Aydın F, O in single cylinder diesel engine to engine performance and emissions. Renew Energy 2017;103:688e94. https://doi.org/ 10.1016/j.renene.2016.10.083. [48] Buyukkaya E. Effects of biodiesel on a di diesel engine performance, emission and combustion characteristics. Fuel 2010;89:3099e105. https://doi.org/10.1016/j.fuel.2010.05.034. [49] Mejı´a JD, Salgado N, Orrego CE. Effect of blends of diesel and palm-castor biodiesels on viscosity, cloud point and flash point. Ind Crop Prod 2013;43:791e7. https://doi.org/10.1016/ j.indcrop.2012.08.026. [50] Dwivedi G, Sharma MP. Impact of cold flow properties of biodiesel on engine performance. Renew Sustain Energy Rev 2014;31:650e6. https://doi.org/10.1016/j.rser.2013.12.035. [51] Mahmudul HM, Hagos FY, Mamat R, Adam AA, Ishak WFW, Alenezi R. Production, characterization and performance of biodiesel as an alternative fuel in diesel engines e a review. Renew Sustain Energy Rev 2017;72:497e509. https://doi.org/ 10.1016/j.rser.2017.01.001. [52] Modiba E, Osifo P, Rutto H. Biodiesel production from baobab (Adansonia digitata L.) seed kernel oil and its fuel properties. Ind Crop Prod 2014;59:50e4. https://doi.org/10.1016/ j.indcrop.2014.04.044. € se H, Ciniviz M. An experimental investigation of effect on [53] Ko diesel engine performance and exhaust emissions of addition at dual fuel mode of hydrogen. Fuel Process Technol 2013;114:26e34. https://doi.org/10.1016/j.fuproc.2013.03.023. € [54] Baltacioglu MK, Arat HT, Ozcanli M, Aydin K. Experimental comparison of pure hydrogen and HHO (hydroxy) enriched biodiesel (B10) fuel in a commercial diesel engine. Int J Hydrogen Energy 2016;41:8347e53. https://doi.org/10.1016/ j.ijhydene.2015.11.185. [55] Yilmaz N, Atmanli A, Vigil FM. Quaternary blends of diesel, biodiesel, higher alcohols and vegetable oil in a compression ignition engine. Fuel 2018;212:462e9. https://doi.org/10.1016/ j.fuel.2017.10.050. [56] Jhang S-R, Chen K-S, Lin S-L, Lin Y-C, Cheng WL. Reducing pollutant emissions from a heavy-duty diesel engine by using hydrogen additions. Fuel 2016;172:89e95. https:// doi.org/10.1016/j.fuel.2016.01.032. [57] Tan YH, Abdullah MO, Nolasco-Hipolito C, Zauzi NSA, Abdullah GW. Engine performance and emissions characteristics of a diesel engine fueled with dieselbiodiesel-bioethanol emulsions. Energy Convers Manag 2017;132:54e64. https://doi.org/10.1016/j.enconman.2016. 11.013. [58] Hoseini SS, Najafi G, Ghobadian B, Rahimi A, Yusaf T, Mamat R, et al. Effects of biodiesel fuel obtained from Salvia macrosiphon oil (ultrasonic-assisted) on performance and emissions of diesel engine. Energy 2017;131:289e96. https:// doi.org/10.1016/j.energy.2017.04.150. [59] Serin H, Yıldızhan S‚. Influence of the compression ratio on the performance and emission characteristics of a vcr diesel engine fuelled with alcohol blended fuels. Eur Mech Sci 2017;1:39e46.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075
i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y x x x ( 2 0 1 8 ) 1 e9
[60] Uludamar E, Afak Yıldızhan S, Aydın K, Ozcanlı MV. Vibration, noise and exhaust emissions analyses of an unmodified compression ignition engine fuelled with low sulphur diesel and biodiesel blends with hydrogen addition. Int J Hydrogen Energy 2016. https://doi.org/10.1016/ j.ijhydene.2016.03.179. [61] Velmurugan K, Sathiyagnanam AP. Impact of antioxidants on NOx emissions from a mango seed biodiesel powered DI diesel engine. Alexandria Eng J 2016;55:715e22. https:// doi.org/10.1016/j.aej.2015.10.004. [62] Wei L, Cheng R, Mao H, Geng P, Zhang Y, You K. Combustion process and NOx emissions of a marine auxiliary diesel engine fuelled with waste cooking oil biodiesel blends. Energy 2017;144:73e80. https://doi.org/10.1016/j.energy. 2017.12.012.
9
[63] He B-Q. Advances in emission characteristics of diesel engines using different biodiesel fuels. Renew Sustain Energy Rev 2016;60:570e86. https://doi.org/10.1016/j.rser. 2016.01.093. [64] Zhou JH, Cheung CS, Leung CW. Combustion, performance and emissions of a diesel engine with H2, CH4 and H2eCH4 addition. Int J Hydrogen Energy 2014;39:4611e21. https:// doi.org/10.1016/j.ijhydene.2013.12.194. € z Y, Sandalci T, Yu¨ksek L, Dalkilic¸ AS. Engine [65] Karago performance and emission effects of diesel burns enriched by hydrogen on different engine loads. Int J Hydrogen Energy 2015;40:6702e13. https://doi.org/10.1016/j.ijhydene.2015. 03.141.
Please cite this article in press as: Uludamar E, Effect of hydroxy and hydrogen gas addition on diesel engine fuelled with microalgae biodiesel, International Journal of Hydrogen Energy (2018), https://doi.org/10.1016/j.ijhydene.2018.01.075