EFFECT OF STERCULIA FOETIDA BIODIESEL ON SINGLE CYLINDER FOUR STROKE DIESEL ENGINE PERFORMANCE AND EMISSIONS

1 Professor, Department of Mechanical Engineering, M.Kumarasamy College of Engineering, Karur, India. Email: ppsethu63@yahoo.com 2 Assistant Professor, Department of Mechanical Engineering, M.Kumarasamy College of Engineering, Karur, India. Email: vijithermal@gmail.com 3 Assistant Professor, Department of Mechanical Engineering, Kongu Engineering College, Perundurai, Erode, India. Email: bemethermal@gmail.com ABSTRACT


INTRODUCTION
Producing and using bio fuels for transportation offer an alternative to fossil fuels and they can help provide solutions to many environmental problems. The recent commitment of many countries to increase bio energy has added an impetus to the search for viable bio fuels [1]. Methanol and ethanol are two viable alternative fuels which possess the potential to be produced from biomass sources. Neither of the fuels are well suited for use in diesel engines, and the use of high compression ratios, ignition improve and the ignition assistance devices are very common [2,3]. Normally, three types of catalysts, such as a strong alkali, a strong acid or an enzyme, can be used in the manufacturing process of the transesterification method. Almost all biodiesel fuels are produced by using base catalyzed transesterification process, as it is a simple process requiring only a low temperature [4], shorter reaction time and less amount of required catalyst [5]. Hence, the strong alkali catalyst is widely used in the transesterification process to produce biodiesel. NaOH, due to its low cost, is widely used in a large scale transesterification [6]. Methanol is used mostly in this chemical reaction due to its superior advantages of high solubility in oil, fast reaction rate, good physical and chemical properties, and low cost [7][8][9]. Two step process of producing biodiesel from pungamia pinnata oil was studied and the effect of FFA level on the production of biodiesel was also studied. Ester content of pungamia methyl esters was determined by high performance liquid chromatography [10]. The another important transesterification method studied from waste fryer grease (WFG) containing 5-6 wt.% free fatty acid (FFA) which was carried out with methanol, ethanol and the mixtures of methanol or ethanol maintained the oil to alcohol molar ratio of 1:6 and initially with KOH as a catalyst. Transesterification of vegetable oil to biodiesel fuel using alkaline catalyst was also referred [11,12].The biodiesel blending ratio was decided from an experimental study with olive oil in DI and IDI engines. They have used 25:75 and 50:50 blends of transesterified olive oil and diesel fuel and observed slightly increased SFC [13] and another Bioblends used soyabean and sunflower oil in a 25% blend with petroleum diesel fuel [14]. Engine performance evaluation of DI and IDI engines with JME [15] and calculated the heat release rate for rapeseed methyl ester (RME) and higher biodiesel combustion rate was observed [16]. The combustion characteristics of neat animal fat, animal fat emulsion with ethanol and water are compared with diesel fuel [17]. The performance of jatropha curcas oildiesel blends in CI engine was observed and reduced the raw oil viscosity by blending with diesel. The biodieseldiesel blends properties are varied from edible and non-edible oil feedstock [18] and an investigation of milkweed (asclepias) I S S N 2 3 2 1 -8 0 7 X V o l u m e 1 2 N u m b e r 1 2 J o u r n a l o f A d v a n c e s i n c h e m i s t r y 4615 | P a g e O c t o b e r 2 0 1 6 w w w . c i r w o r l d . c o m seed oil as an alternative feedstock for the production of a biodiesel fuel was also studied. The authors concluded that conversion of this highly unsaturated oil into methyl ester is an easier process than its conversion into its ethyl ester [19].

Sterculia Foetida
Sterculia foetida trees, fruits and seeds are shown in Fig.1. Normally, sterculia foetida has Grayishwhite bark and reddish fruits. The flowers are 5 lobed green yellowish when they release and soon after turn deep reddish. The red fruits consist of 1 to 5 spreading follicles that are prepared with rigid stinging bristles along the inside margins. Each follicle splits to expose up to 17 blackblue seeds attached to the internal margins.

Extraction of Oil
Before extraction Sterculia foetida oil obtained from sterculia foetida seed have to be washed by water and dried under sunlight. The extraction of crude sterculia foetida oil was done by cutting machine (Heard cell are broken) and then crushed in a expeller machine. During the crushing in the machine, some sugar wastes are added to get maximum amount of oil in the crushing. Fig.2. shows the different preparatory stages of seed before crushing.

Fatty acid composition
Sterculia foetida oil fatty acid level is shown in Fig.4. Raw sterculia foetida oil has maximum percentage of palmitic content, its contribution to the combustion of the oil was also significant level. Oleic acid with a single bound and saturation level contributed enormously to the performance of the fuel [20]. Linoleic is unsaturated -it has 20.9 % of sterculia foetida with higher oxygen rate to oxidation process. The fatty acid level is clearly mentioned in Table 1.

Transesterification of Sterculia foetida oil
Sterculia foetida oil was mixed with 15 % of methanol and 2% of KOH catalyst. Electrical motor running at 200 rpm is used to agitate the solution. Reactor temperature is maintained at 55 o C, in this process continuously up to 6 hours. During the process one small drop (0.5%) of sulfuric acid was added with the solution. After the treatment the solution is kept in rest position for 5 hours in normal temperature. Finally by products like glycerol and soap were separated. Then, the produced biodiesel was washed with water, two times in a separation funnel.

Experimental procedure
In this experimental investigation, four strokes, single cylinder, water cooled, direct injection constant speed (1500), naturally aspirated VCR kirloskar made diesel engine is used. Engine cylinder bore of 87mm and stroke of 110mm; the compression ratio of 15:1 to 18:1 and manufacture's recommended injection timing and injection pressure of 23 o crank angle before TDC and 201 bar respectively are taken. Further, 1500 engine rpm and 17:1 compression ratio are considered.

Data Acquisition System
The cylinder pressure at each crank angle is measured and stored by a digital data acquisition system. It consists of a Kistler water-cooled flush mounted piezoelectric pressure transducer in conjunction with Kistler charge amplifier for converting the electric charge into voltage. It measures and stores up to 200 cycles engine pressure histories. The measured data is analyzed with the online data or stored for postprocessing.

RESULTS AND DISCUSSIONS
The discussion of the results and interpretation of diesel and Sterculia foetida biodiesel blend on diesel engine performance, combustion and emission. The engine maximum load was calculated and it was applied 20%, 40%, 60%, 80% and 100% and the biodiesel blend was prepared with diesel like B25, B50, B75, and B100.  Comparing these two results, the diesel fuel produced effective power in diesel engine compare with biodiesel blends. Biodiesel B25 blend consumed minimum fuel and produced same power which is produced by diesel. The SFC values of biodiesel higher than the diesel owing to the lower calorific values of biodiesel. More biodiesel was required to produce same power output owing to higher viscosity, poor air fuel mixing, higher volatility and calorific value. The higher viscosity gives impact on fuel spray characteristics.

Emission analysis
Normally the HC, CO, CO2, NOx, and smoke pollutants consider primarily in the internal combustion engine emissions. Engine load increases with increasing engine exhaust gas temperature. Fig 11 shows that the diesel fuel produced maximum exhaust gas temperature at entire engine load due to higher heat release in diesel fuel it's clearly indicated in fig 8. Normally the HC, CO, CO2, NOx, and smoke pollutants are considered primarily in the internal combustion engine emissions. Engine load increases with increasing engine exhaust gas temperature. Fig 11 shows that the diesel fuel produced maximum exhaust gas temperature at entire engine load due to higher heat release in diesel fuel it's clearly indicated in fig 8. Fig 12 shows that the CO for diesel and different blend of biodiesel with different engine load. The entire biodiesel blend produced maximum CO compare with base diesel fuel. The biodiesel concentration causes to increase the CO pollutant.    The higher CO in the engine exhaust gas of the fuel may be endorsed to the fuel spray system. Biodiesel has higher viscosity compare with diesel. In this viscosity reduces the injection system penetration rate and atomization process. The biodiesel is not easy to mixing with air it cause to create locally rich mixture.   higher viscosity compare than diesel. In this viscosity reduces the injection system penetration rate and atomization process. The biodiesel is not easy to mixing with air it cause to create locally rich mixture.
Fig 13 shows that variation of HC for different biodiesel concentration with different engine load. The maximum HC notified with base diesel fuel at entire engine load. It does clearly explain the incomplete combustion. Fig 14 shows that the CO2 pollutant production. CO2 level increases with increasing engine load. The B25 produced minimum CO2 level in the biodiesel blend. Fig 15 shows the excess oxygen level. Excess oxygen level decreases with increasing engine load. Excess oxygen level decrease CO2 level increases because CO react with oxygen its gives CO2.

CONCLUSION
In this investigation, the different biodiesel blends B25, B50, B75, and B100 supplied to single cylinder diesel engine to analyze the engine performance, combustion and emission analysis. The different biodiesel blends supplied with different engine load.
On comparing the performance, combustion and emission of different biodiesel blends with different engine load were drawn:


Compare BTE and SFC values of B25 closer to the base diesel fuel results  B25 produced maximum heat release and maximum cylinder peak pressure compare with other biodiesel blends  The maximum HC produced in B25 fuel compare with all other biodiesel blend.  CO, CO2, NOx, smoke produced minimum level in B25 fuel compare with all other blends