Biodiesel blends

Substantially higher than conventional diesel fuel BOCLE and HFRR values both improve in biodiesel blends. 

Very poor biodiesel and biodiesel blends do not shed water as effectively as conventional diesel fuel fuel haze, gelling, and low-temperature handling problems can develop if biodiesel is contaminated with water in storage and transport. Poor double bonds present in the methyl ester compounds are active sites for oxidation and condensation reactions peroxide values can increase fuel darkening and deposit formation in storage systems can occur the addition of oxidation inhibitors to biodiesel helps improve storage stability. 

Biodiesel is a olean burning alternative fuel produced from domestic, renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to oreate a biodiesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Biodiesel is simple to use, biodegradable, non-toxic, and essentially free of sulfur and aromatics. 

Fontaras G, Kousoulidou M, Karavalakis G, Tzamkiozis Th, Pistikopoulos P, Ntziachristos L, Stoumas S, Samaras Z (2010) Effects of low concentration biodiesel blend application on modem passenger cars. Part 1 feedstock impact on regulated pollutants, fuel consumption and particle emissions. Environ Pollut 158 1451-1460... 

Chiu, C. W., Schumacher, L. G., and Suppes, G. J. 2004. Impact of Cold Flow Improvers on Soybean Biodiesel Blend. Biomass and Bioenergy, 27,485 491. 

Stavinoha, L. L., and Howell, S. 1999. Potential Analytical Methods for Stability Testing of Biodiesel and Biodiesel Blends. In Soa Automot. Eng. Spea Publ. SP-1482, Alternative Fuels 1999 (pp. 79-83). Warrendale PA Society of Automotive Engineers (Paper No. 1999-01-3520). 

Despite the differences in the chemical composition, biodiesel has physical-chemical properties that are similar to diesel, showing a decrease in the emission of C02, SOx and unburned hydrocarbons during the combustion process when compared to fossil fuels (Crabbe et al, 2001). For these reasons it is possible to use biodiesel blended with diesel without significant changes to engines, with important decrease in the emission of pollutant gases. 

Stability tests developed for petrodiesel fuels reportedly are not suitable for biodiesel or biodiesel blends with petrodiesel (Canakci et al., 1999 Stavinoha Howell, 1999 Westbrook Stavinoha, 2003), however, appropriate modification may render them useful. Another study (Bondioli et al., 2003) states that the petrodiesel method ASTM D4625 (Standard Test Method for Distillate Fuel Storage Stability at 43°C (110°F) is suitable but not fast. 

McCormick, R.L. A. Williams J. Ireland M. Brimhall R.R. Hayes. Effects of Biodiesel Blends on Vehicle Emissions. Fiscal Year 2006Annual Operating Plan—Milestone 10.4. National Renewable Energy Laboratory. NREL/MP-540-40554, October 2006. 

Tat, M.E. J.H. Van Gerpen. Biodiesel blend detection using a fuel composition sensor. Appl. Engin. Agric. 2003,19. 125-131. 

Terry, B. R.L. McCormick M. Natarajanm. Impact of Biodiesel Blends on Fuel System Component Durability. SAETechn. Pap. Ser. 2006-01-3279 2006. 

Krishna, C.R. Biodiesel blends in space heating equipment. National Renewable Energy Laboratory Upton, NY, NREL/SR-510-33579, 2001. 

Various biodiesel blends, which include different ratios of biodiesel and diesel from crude oil, can be used in vehicles depending upon the vehicle s requirement and weather conditions. A 20% biodiesel will provide a higher octane rating, superior lubricity, significant emission reductions, and less toxic emissions will virtually eliminate visible soot emissions and will have similar fuel consumption, horsepower, and torque. Premium biodiesel is a fuel manufactured from vegetable oils by a transesterification process. Soybean oil is currently the leading source of vegetable oil for biodiesel manufacture in the United States. 

Wang, W. G., D. W. Lyons, N. N. Clark, M. Gautam, and P. M. Norton. 2000. Emissions from Nine Heavy Trncks Fneled by Diesel and Biodiesel Blend without Engine Modification. Environmental Science Technology 34 (6) 933-939. 

Rawat, D. S., G. Joshi, B. Y. Lamba, A. K. Tiwari, and S. Mallick. 2014. Impact of additives on storage stability of Karanja (Pongamia Pinnata) biodiesel blends with conventional diesel sold at retail outlets. Fuel 120 30-37. 

Wear Scar Diameter of Mustard Biodiesel Blends and Retro Diesel Using ASTM D6079 Method (HFRR)... 

FIGURE 12.7 Chemical solution model for biodiesel blends. 

ASTM Standard specification for diesel fuel oU, biodiesel blend (B6 to B20). 2008. In Annual Book of ASTM Standards, ASTM International, West Conshohocken, Method D7467-08a. 

The specifications for biodiesel are designed to ensure that consumers will not experience operational problems from the fuel s use. ASTM and European Union have standard specifications designed for BlOO FAME used in biodiesel blending, which include GC (gas chromatographic analysis), elemental analysis, as well as physicochemical properties of the produced biodiesel [3,4]. Quality fuel will provide the consumer with improved air quality and enhanced operability. Poor quality fuel will create operability problems and increased maintenance activity. It is really necessary to look for newer approaches for the production of biodiesel particularly for variable quality feed stock employing nonedible oils or used flying oils. 

Trakampruk, W., and Pomtangjitlikit. S. Pahn oil biodiesel synthesized with potassium loaded calcined hydrotalcite and effect of biodiesel blend on elastomer properties. i en Energy 33, 1558-1563 (2008). 

Fig. 13.1 Simplified schematic of how to obtain biodiesel and biodiesel blends...

Figure 13.1 summarizes the most common way to obtain biodiesel and biodiesel blends. Blends are denoted by acronyms such as BIO, meaning 10% of alkyl ester of VO and 90% petrodiesel. The B designates biodiesel. BlOO means 100% alkyl ester of VO. Biodiesel blends are usually found at low percentages of alkyl ester of VO rather than 100 %. 

Palm oil methyl ester presents an onset of crystallization above 0 °C (i.e. 6 °C) and a steep crystallization slope (Fig. 13.3a). Thus, its cold flow properties will be poorer than those of the rapeseed methyl ester. The crystallized fractions (CFs) determined at -15 °C for MEl, ME2 and DF are 2.3,1.5 and 25.9%, respectively. These percentages were calculated using the enthalpy of crystallization of DF (210 J/g) obtained elsewhere [9]. The same linear relation obtained for diesel fuels has been used for biodiesel and biodiesel blends ... 

The cold flow properties of diesel fuel and biodiesel blends are given in Table 13.4. As can be seen from these results, there is almost no influence when ME2 is blended with DF. This situation changes when MEl is blended with DF, where the quantity of precipitated crystals and the cold flow parameters are higher than those of neat DF and increase when MEl is increased from 10 to 30%. As was expected after the analyses of the pure compounds, blends of MEl with DF have lower cold flow parameters compared with blends of ME2 with DF. 

Table 13.4 Cold flow parameters of DF and biodiesel blends by DSC (AHcryst. = 210 J/g)...

Fig. 13.5 Visualization of crystallization of pure compounds (DF and ME2) and corresponding biodiesel blends at —15 °C by thermomicroscopy...

DF and Biodiesel Blends Impact of Cold Flow Improver... 

Fig. 13.7 Comparison of crysttd morphology at —15 °C between biodiesel blends (DF/ME2) with and without cold flow improver (additive A)...

---