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Vladislav Rybakov
Vladislav Rybakov

A Comprehensive Guide to Fuels and Combustion by S.P. Sharma

A bench-scale transesterification reactor has already beendesigned and indigenous canola oil bio diesel and castor oil bio diesel havebeen produced successfully as reported in two separate investigations [12,14]. These fuels were then tested in a compression-ignition engine at blendratio of 10% with mineral diesel fuel [13]. Castor oil bio diesel showedbetter engine performance than canola oil bio diesel whereas overall, biodiesel blends gave better environmental performance than mineral diesel fuel.

Fuels And Combustion Sp Sharma.pdf


Engine performance was measured using 100% High Speed Diesel (HSD)and 10% bio diesel (with 90% diesel) only. This blend ratio was in line withthe target imposed by the Government of Pakistan to blend up to 10% biodiesel with mineral diesel for the automobile sector by the year 2015. Engineperformance measurements were done in accordance with the procedures outlinedin the literature [3]. After the engine reached a steady working condition(after start up, the engine is run on the test fuel for at least 30 minuteswithout taking any measurements in order to clean the inlet and exit linesfrom previously tested fuel and combustion products, respectively), enginebrake power, torque applied and exhaust temperature were measured andanalyzed for all fuel types.

Prices related to reagents were obtained from the local market.Seed prices were obtained and updated from Empress Market, Karachi, Pakistan.Labour and distribution costs were estimated by taking an average of typicalrates within the region of Sindh. The delivered costs of both fuels,including seed cost, oil extraction, and bio diesel production, were comparedwith the cost of diesel fuel. The study did not include the evaluation offixed capital costs involved in the construction of processing plant andauxiliary facilities. The economic assessment was completed with theinclusion of the distribution and retailer costs.

Table 2 compares the major properties of jatropha bio diesel withcommercialized diesel fuel, premium diesel from Pakistan State Oil Co.Limited. As shown in Table 2, the bio diesel used in this study showed ahigher density, kinematic viscosity, cetane number, and flash point incomparison to diesel fuel. In terms of engine performance, this meant thatbio diesel was less superior to its mineral counterpart but much safer tostore. The calorific value is a critical property of fuels intended for usein weight-limited craft such as airplanes, surface effect vehicles, andhydrofoils. The range bomb calorimeter was used for the purpose in PakistanState Oil's fuel testing laboratories.

The emissions from all three bio diesel blended at 10% withmineral diesel in compression-ignition engines, were monitored along with theperformance of 100% mineral diesel. Figure 1 shows a definite trend is thatthe least CO2 emissions are due to mineral diesel fuel whereas higheremissions were for jatropha bio diesel fuel. This is because in dieselengines without exhaust gas recirculation (EGR), the combustion of bio dieselalmost always results in higher CO2 in exhaust gases in comparison to dieselfuel combustion regardless of fuel injection type used [14]. This is due tothe presence of more carbon atoms as well as higher oxygen content in biodiesel fuel. This is particularlymore significant for jatropha bio dieselshowing its superiority over the other bio diesel fuel types used in thisresearch. Results from Figure 2 show that least CO emissions are due toblended jatropha bio diesel whereas converse for blended canola bio diesel.Castor oil bio diesel did not seem to fare very well in this experimenteither.




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