Comparative analysis of green diesel versus petro-diesel in compression ignition engine

Abstract

Biofuel based energy is likely to be promoted to reduce the dependency on fossil fuels. The most common alternative fuel is FAME biodiesel that is produced by trans esterifi cation. But some disadvantages are also associated with biodiesel; new technologies are under investigation for the production of other biofuels. In the present study green diesel was produced by hydro processing of waste cooking oil. The performance and emission characteristics of green diesel were investigated in single cylinder CI engine. The results were also compared by the corresponding results obtained by conventional diesel fuel. The engine was tested in a series of steady state operating conditions at different load by keeping constant speeds of 1500 rev/min. The performance parameters like brake thermal effi ciency (BTE %), specifi c fuel consumption (SFC in kg/h) and emissions parameters like HC, CO 2 , CO and NOX emissions were investigated. It was observed that BTHE of green diesel is 23% and 21.76% for petro diesel at 20% load, at 40% load it is 34.24% for green diesel and 25.8% for petrol diesel at 60% load it is 35.93% for green diesel and 31.74 for petro diesel at 80% load it is 38.24 for green diesel and 31.66 % for petro diesel at 100% load it is 31.6% for both green diesel and petro diesel These results show that BTHE increases for green diesel fuels at all load except full load condition. From the results, it was found that for green diesel BSFC(kg/kwh) is1.83 for green diesel and 2.57 for petro diesel at no load condition and at full load it is 0.267for green diesel and 0.270 for petro diesel which is less as compare to petro diesel. It was observed that CO (%VOL) at load (%) 20,40,60,80,100 for green diesel are 0.06, 0.03,0.02,0.02,0.03 and for petro diesel are 0.06,0.04,0.03,0.03 and 0.04 respectively. It is observed that HC (PPM) emission at load (%

Green Diesel: Biomass Feedstocks, Production Technologies, Catalytic Research, Fuel Properties and Performance in Compression Ignition Internal Combustion Engines

“…Green diesel has been tested as a CI engine fuel in various studies . In the majority of them it was reported that, when compared to petroleum diesel, green diesel decreases both the maximum cylinder pressure and the rate of pressure increase [224][225][226][227][228][229][230]. The lower maximum pressures and the lower rates of pressure increase are attributed to the higher cetane number of green diesel which shortens the ignition delay period and the premixed combustion phase, in agreement to the conclusions of the previous discussion.…”

“…The same authors also observed that green diesel reduces the brake specific fuel consumption (bsfc) of the engine when comprised by either normal or branched saturated hydrocarbons. This was also reported in numerous other investigations [224,230,231,[233][234][235][236][237][238] and is especially important since bsfc is the ratio of the mass of the fuel consumed per brake power output. The lower bsfc values translate into higher fuel economy during engine operation and also to lower emissions, since less fuel is burned for the same power output.…”

“…However, Neste also reported that the difference between individual engines was so large that some bus or truck engines showed lower solid particulates by 47% and a slight increase of the NO x emissions. In a similar study Kumar et al [230] reported 25-30% lower CO emissions at part load, almost constant CO 2 emissions at all loads, 25-30% lower HC emissions at low and part load, 5-15% lower NO X emissions at all loads and 49-75% lower smoke at all loads. Two phenomena were considered responsible for the lower emissions.…”

“…In most research reports green diesel was found able to increase the brake thermal efficiency of the engine by up to 10%. For example, Kumar et al [230] have tested green diesel in a 661 cm 3 single cylinder engine and observed that it increased the brake thermal efficiency from 21.76 to 23% at 20% load, from 25.8 to 34.24% at 40% load, from 31.74 to 35.9% at 80% load and from 31.6 to 31.66% at full load conditions at 1500 rpm. This is attributed to the higher calorific value and to the lower ignition delay which shifts the combustion process so that a larger fuel fraction to be oxidized near the TDC.…”

Biodiesel at the Crossroads: A Critical Review

“…When assessing this technology, it is mandatory to consider as a fundamental aspect and the main advantage, the possibility of obtention in the existing refineries [391,392]. Thus, application of the co-processing method of oils and fats of any quality, together to fossil diesel, in hydrocracking facilities, has notable advantages over the conventional methods of biodiesel production currently applied.…”