Experimental investigation on fuel properties and engine characteristics of biodiesel produced from Eruca sativa
- 90 Downloads
This paper aims to consider the potential of Eruca sativa (ES) crops, which is a plant with a short production cycle and drought tolerance, for biodiesel feedstock source and to compare exhaust emissions and engine performance of using its biodiesel blends with pure diesel. Thus, ES methyl ester was produced through a transesterification reaction by using KOH as a catalyst. The fatty acid composition of ES biodiesel was determined by FTIR and GC–MS analysis and its properties were compared with ASTM biodiesel standard and regular diesel. The GC–MS analysis showed that oleic and palmitic acids were the main compounds in ES methyl ester. Then, biodiesel blends were injected into a single-cylinder 4-stroke diesel engine at various speeds. Experimental tests revealed that using ES methyl ester led to reductions in HC and CO emissions substantially and NOx emissions moderately, whereas there was a minor rise in CO2 emissions. Moreover, a slight decrease in engine power and an increase in specific fuel consumption (5.3%) occurred, which are acceptable due to the reduction of exhaust emissions. Based on the results, ES biodiesel has the capability to apply in CI engines and to diminish emissions.
KeywordsEruca sativa Methyl ester GC–MS FTIR Exhaust emissions Engine performance
X% biodiesel + (100 − X)% diesel
Fatty acid methyl ester
Revolutions per minute
Fossil fuel as a source of GHG has adverse effects on the atmosphere and is recognized as a cause of climate change and its severe impacts on human life. Hence, extensive investments and researches have been done to obtain suitable renewable sources of energy. Over the past few years, there has been substantial attention to biodiesel as an alternative energy source.
Several studies have been conducted to find efficient methods for producing biodiesel from different feedstocks. The transesterification process was used for the conversion of various sources of oils to methyl esters, such as waste oils [1, 2, 3], vegetable oils [4, 5, 6, 7], animal fats [8, 9, 10], and algae or microalgae [11, 12, 13]. It was demonstrated that selecting a proper feedstock plays an important role in the quality of biodiesel. Some researchers focused on the optimum conditions of the transesterification process for different catalysts and biodiesel feedstocks. Lin et al.  presented optimum conditions to produce crude rice bran biodiesel with a sulphuric acid catalyst. Their experimental tests were performed in optimum reaction at 60 °C with methanol/RBO molar ratio 6:1 and 0.9 wt.% of KOH for 60 min. Silitonga et al.  found that the best conditions for the transesterification of Schleichera oleosa oil were at 55 °C with 1 wt.% of KOH and NaOH and 1 wt.% of methoxide as the catalyst for 90 min. Vahid et al.  evaluated MgO as the active phase of the biodiesel production process and achieved the conversion of 95 percent of sunflower oil to biodiesel. Armenta et al.  found that sodium ethoxide was more effective than KOH for transesterification of fish oil. Cheng et al.  compared four solid acid catalysts to convert lipids of microalgae into fatty acid methyl esters (FAME), in which sulfonated graphene oxide had a maximum conversion efficiency among them. In Hossain et al.  investigation, microalgae biocrude extracted by hydrothermal liquefaction (HTL) contained the same oxygen and 10% lower calorific value compared to microalgae FAME. Kaisan et al.  compared specifications of cotton, jatropha and neem biodiesels. They established that heating values, cetane numbers, and flash points of all three feedstocks were consistent with standards.
Although several articles have demonstrated that using biodiesel in engines reduces gas emissions, some studies have reported different behavior for different biodiesel feedstocks. Experimental investigation on the engine fuelled with Jatropha methyl ester observed a substantial drop in CO, whereas there was a slight growth in NOx emissions [7, 17]. These results were different from that of using castor and soybean biodiesel into the diesel engine since CO and HC emissions increased . Randazzo et al.  considered soybean biodiesel blends and the effects of anhydrous ethanol as an additive. Their results revealed that by increasing the biodiesel concentration in the fuel blend, CO and HC emissions declined, while CO2 and NOx emissions rose. Besides, anhydrous ethanol could reduce NOx and CO2 emissions. Based on the result of Buyukkaya  tests, for rapeseed biodiesel with B5 and B20 proportions, CO emissions were 32% lower than that of pure diesel, whereas fuel consumption increased by 11%. Vedaraman et al.  injected palm biodiesel in a diesel engine and found that CO and HC emissions reduced 28% and 30% for B20 blend, respectively, and NOx emissions were almost the same as diesel fuel. In a study by Li et al. , heteropoly acid salt was used as the catalyst for Eruca sativa Gars biodiesel. In their tests, while HC and CO emissions were less than pure diesel, higher BSFC and NOx were observed. In another investigation, a common-rail diesel engine with B30 and B70 blends of waste cooking oil biodiesel was tested by Lapuerta et al. . They found a slight rise in NOx emissions and a sharp reduction in total HC and smoke opacity emissions. Dhamodaran et al.  compared biodiesels of rice bran, cottonseed, and neem oils with varying degrees of unsaturation. All of those feedstocks reduced the CO and PM emissions. In another study, Márcio et al.  observed that the lowest CO2 emissions with waste frying oil and palm biodiesels occurred in lower biodiesel concentrations while soybean biodiesel had different behavior. Jaliliantabar et al.  compared physicochemical properties, combustion and emission characteristics of coffee, brassica, and cardoon biodiesels in a CI engine. Their experimental results showed that different characteristics of methyl ester had different effects on the performance, emissions and combustion parameters of the engine. In addition, the oxygen content of the brassica biodiesel was considerably higher compared with cardoon and coffee biodiesels which reduced the CO and HC emissions. Maps of performance and emissions with using waste cooking oil biodiesel observed that HC emissions were highly related to engine speed; however, CO and PM depended on engine load . Besides, some researchers  modeled a diesel engine using biodiesel with the artificial neural network to predict brake power, fuel consumption, and exhaust emissions.
Most of the plants studied in the articles are not capable of growing on drought or disturbed ground and some of them are in competition with food resources such as soybean, castor, palm, and cottonseed. Eruca sativa which is currently cultivated as a native plant in west Asia, Italy, Pakistan, and India is expected to be a potential feedstock for biofuel production, due to its adequate oil contents. Furthermore, Eruca sativa has crops with a short production cycle and drought-tolerant capacity. Literature reviews show that numerous researches have been carried out on producing biodiesel from various feedstocks, so far though limited studies consider ES methyl ester parameters such as optimum production and the influence of biodiesel on performance and emissions of the engine in different blends. In this study, quantities of methyl ester were produced from ES oils with the KOH catalyst and the main parameters including the molar ratio of methanol, temperature, and reaction time were considered. Then, ES biodiesel properties were determined for suitability in CI engines and compared with ASTM D6571 standard. In addition, the effects of the operational range of speed/load on engine performance and emissions were investigated with six different blends of ES biodiesel and compared with neat diesel.
2 Experimental setup and procedure
This experimental study has been done through three consecutive stages including methyl ester production from ES oil, assessment of physicochemical properties of ES biodiesel, and determining engine exhaust emissions and performance.
Technical specifications of the engine
3 LD 510 Lombardini
4-Stroke, Direct Injection, Diesel engine
Stroke volume (cc)
Maximum power (HP@rpm)
Maximum torque (N-m@rpm)
Bore × Stroke (mm)
85 × 90
Forced air cooling
3 Results and discussion
3.1 Fuel characterization
Properties of ES biodiesel, ASTM standard and diesel
Flash point (°C)
Pour point (°C)
− 10 to − 15
Sulfur content (%)
Acid value (mg KOH/g)
Calorific value (MJ/kg)
Fatty acid compositions of ES methyl ester
Contents ES methyl ester (%)
3.2 Exhaust emissions results
3.3 Engine performance results
CO and HC emissions were respectively 30.9% and 38.2% lower.
There was a marginal decrease in NOx emissions by 9.3%.
CO2 emissions were 10.9% higher than that of pure diesel.
The power and obtained torque were slightly lower (4.3%).
In conclusion, ES biodiesel can be used as a partial diesel substitute without modifications in the engine and is particularly attractive from an environmental perspective, which reduces engine emissions.
The authors are thankful for the opportunities in order to use the laboratories in “Islamic Azad University, Tehran North Branch, Faculty of Chemistry” and “Tarbiat Modares University, School of Agriculture”.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.Santya G, Maheswaran T, Yee KF (2019) Optimization of biodiesel production from high free fatty acid river catfish oil (Pangasius hypothalamus) and waste cooking oil catalyzed by waste chicken egg shells derived catalyst. SN Appl Sci 1(2):152. https://doi.org/10.1007/s42452-018-0155-z CrossRefGoogle Scholar
- 12.Mathimani T, Kumar TS, Chandrasekar M, Uma L, Prabaharan D (2017) Assessment of fuel properties, engine performance and emission characteristics of outdoor grown marine Chlorella vulgaris BDUG 91771 biodiesel. Renew Energy 105:637–646. https://doi.org/10.1016/j.renene.2016.12.090 CrossRefGoogle Scholar
- 24.Dhamodaran G, Krishnan R, Pochareddy YK, Pyarelal HM, Sivasubramanian H, Ganeshram AK (2017) A comparative study of combustion, emission, and performance characteristics of rice-bran-, neem-, and cottonseed-oil biodiesels with varying degree of unsaturation. Fuel 187:296–305. https://doi.org/10.1016/j.fuel.2016.09.062 CrossRefGoogle Scholar
- 25.Márcio de Almeida D, da Silva MAV, Franca LS, de Oliveira CM, Alexandre MOL, da Costa Marques LG, de Freitas MAV (2017) Comparative study of emissions from stationary engines using biodiesel made from soybean oil, palm oil and waste frying oil. Renew Sustain Energy Rev 70:1376–1392. https://doi.org/10.1016/j.rser.2016.12.040 CrossRefGoogle Scholar
- 26.Jaliliantabar F, Ghobadian B, Carlucci AP, Najafi G, Ficarella A, Strafella L, De Domenico S (2018) Comparative evaluation of physical and chemical properties, emission and combustion characteristics of brassica, cardoon and coffee based biodiesels as fuel in a compression-ignition engine. Fuel 222:156–174. https://doi.org/10.1016/j.fuel.2018.02.145 CrossRefGoogle Scholar
- 30.Eckhoff RK (2016) Gas and Vapor Cloud Explosions, 2 edn., chap. 2. Gulf Professional Publishing - Elsevier. https://doi.org/10.1016/B978-0-12-803273-2.00002-5.Google Scholar