Biodiesel analysis

Abdelnur, P.V., Eberlin, L.S., Sa, G.F., Souza, S.V., and Eberlin, M.N. 2008. Single-shot biodiesel analysis Nearly instantaneous typification and quality control solely by ambient mass spectrometry, AwaZ. Chem., 80 7882-7886. 

G. F. de Souza, V. Eberlin, M.N. Single-Shot Biodiesel Analysis Nearly Instantaneous Typification and Quality Control Solely by Ambient Mass Spectrometry. Anal. Chem. 2008, 80, 7882-7886. 

Notably, however, any comparison of biodiesel vs. bioethanol should be done with great caution, because analysis of an industry such as that related to biofuels is a very complex task and all conclusions are country dependent. It may be interesting, however, to compare the energy balance and environmental impact in producing biodiesel from oilseed rape and bioethanol from wheat crops [4], Table 9.3 reports this comparison. The energy balance for bioethanol is more positive than for biodiesel, in particular when straw is utilized, mainly due to the higher yield... 

EPA(US Environmental Proteetion Agency). 2002. A comprehensive analysis of biodiesel impaets on exhaust emissions. Draft Technical Report, EPA420-P-02-001, October 2002. EPA, Washington, DC. 

A further example of process quality monitoring and reactor batch profiling using NIRS comes with oleo-chemical and biodiesel production. An established use of FT-NIR analysis (AOCS Method Cd le 01) is the determination of the key vegetable oil processing parameters - iodine value (IV) and percentage trans fat content (%Trans) (Figure 5.38). 

Senatore, A., M. Cardone, V. Rocco, and M.V. Prati. 2000. A Comparative Analysis of Combustion Process in D.I. Diesel Engine Fueled with Biodiesel and Diesel Fuel. Report No. 2001-01-0691. Warrendale, Pa. Society of Automotive Engineers. 

Regression analysis of CFPP and LIFT versus CP data sets combining results for biodiesel and biodicscl/pctrodicsel blends with those for formulations treated with CFI additives yielded the following equations ... 

Many advances have been made in development of P-DSC and other thermal analysis techniques in the study of oxidation reactions in fatty derivatives such as biodiesel. Kinetic parameters and phase transitions associated with oxidative degradation may be rapidly and accurately determined. However, the applicability of P-DSC may be limited in analysis of fuel formu-... 

Although there are numerous publications on the effect of natural and synthetic antioxidants on the stability of oils and fats used as food and feed, until recently relatively little publicly available information was available on the effect of antioxidants on the oxidative stability of biodiesel. One of the earliest studies reporting of the effects of antioxidants on biodiesel was that of Du Plessis et aL (1985), which examined storage stability of sunflower oil methyl esters (SFME) at various temperatures for 90 d. Effects of air temperature, presence of light, addition of TBHQ (see Figure 1.1) and contact with steel were evaluated by analysis of free fatty acid content, PV, kinematic viscosity, anisidine value, and induction period. Addition of TBHQ delayed oxidation of samples stored at moderate temperatures (<30°C). In contrast, under unfavorable (50°C) conditions, TBHQ was ineffective. 

Stavinoha and Kline (2001) adapted ASTM method D 6186 (Oxidation Induction Time of Lubricating Oils by Pressure Differential Scanning Calorimetry [P-DSC]) for analyzing the oxidative stability of SME treated with antioxidants. This report concluded that isothermal P-DSC analysis is suitable for screening the effectiveness of antioxidants for treating biodiesel. 

Dunn, R. O. 2006b. Oxidation Kinetics of Biodiesel by Non-Isothermal Pressurized-Differential Scanning Calorimetry. In Proc., 34th Annual NATAS Conference. Bowling Green KY North American Thermal Analysis Society. 

USEPA. 2002. A Comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions. Draft Technical Report 420-P-02-001. (See http //www.epa.gov/otaq/models/ analysis/biodsl/p02001.pdf)... 

Scott W., and Furman, N. H. (ed.). 1961. Scott s Standard Methods of Chemical Analysis (5th ed., vol. 1, pg. 604). Princeton, NJ D. Van Nostrand Company Inc. Shibasaki-Kitakawa, N., Honda, H., Kuribayashi, H., Toda, T., Fukumura, T., and Yonemoto, T. 2007. Biodiesel production using anionic ion-exchange resin as heterogeneous catalyst. Bioresour. Technol., 98(2), 416-421. 

Shieh et al. (2003) indicated a biodiesel transesterification using soybean oil and methanol and commercial immobilized lipase from R. miehei (Lipozyme IM-77). The response surface analysis showed that the following variables were important reaction time, temperature, enzyme amount, molar ratio of methanol to soybean oil, and added water content on percentage weight conversion to soybean oil methyl ester by transesterification. The optimum yield based on ridge max analysis gave a 92.2% weight conversion. 

The optimum synthesis of enzymatic biodiesel was determined by the ridge max analysis (SAS, 1990). The method of ridge analysis computes the estimated ridge of maximum response for increasing radii from the center of original design. The ridge max analysis (Table 9.6) indicated that maximum molar conversion was 99.4 4.6% at 12.4h, 38.0°C, 42.3% enzyme amount, 3.5 1 substrate molar ratio, and 7.2% added water content at the distance of the coded radius 0.8. 

Reactions converting acids to esters or vice versa and the exchange of ester groups are among the most widely used in fatty acid and hpid chemistry (Figure 4). They find applications from microscale preparation of methyl esters for GC analysis to the industrial production of oleochemicals and biodiesel. The exchange of groups attached to the fatty acid carboxyl is usually an equihbrium process driven to one product by an excess of one reactant or the removal of one product, and it is usually... 

As animal fats are a potential feedstock for biodiesel production, Cummins et al. (142) assessed the danger of a human contracting CJD as a result of the use of tallow as a fuel in diesel engines. They concluded that the risk was several orders of magnitude less than the rate of spontaneous appearance of CJD. Thus, scientific analysis indicates that processed (i.e., rendered) animal fat is not an agent of transmission of BSE. Nonetheless, especially in the United Kingdom, the public remains skeptical. This has in some cases led to less use of animal fats in feed applications. Especially in the United Kingdom, the BSE epidemic has reduced the amount of domestically available tallow (because of condemnation) and increased the use of other lipids in place of animal fats. 

Official methods of chemical analysis of conventional diesel are often not adequate to characterize biodiesel. Tests for the levels of sulfur and aromatic components in biodiesel are useful but usually reveal that the concentrations of compounds containing these atoms or functional groups are very low. Analysis of biodiesel chemistry can reveal characteristics conferred by the source of the oU, the method of manufacture, and duration of storage (20, 21). For example, free and bound glycerol is measured to ascertain if biodiesel has been completely formed during synthesis. Fatty acid content, residual soaps, iodine value, peroxide value, and fatty acid composition all may reflect the quality of biodiesel (Table 1) but are unimportant and inapplicable in conventional diesel fuel quality determination. 

Another example regards an aspect discussed before on the sustainability of land use for biofuels. We have already remarked the various problems in this analysis that can be summarized, in a simplified form, in reply to the question which use is the most sustainable for one ha of land. There are different possible options to produce (i) bioliquids (by fast pyrolysis), bioethanol or biodiesel, (ii) food, (iii) chemicals, (iv) electricity or (v) to feed animals. There are more options (e.g., biogas) but the present already allow a good comparison, although theoretical (land productivity depends on several factors and, for example, palms to produce the vegetable oil raw material for biodiesel is not locally in competition with the production of bioethanol from biomasses for which different climate and land characteristics are required). 

Despite these limitations, the eco-efficiency analysis provides a good bases for discussion. Figure 5.8 compares different alternatives, showing that, for example, the use of biomass for electricity production via the conventional combustion route is not different, in terms of eco-efficiency, with respect to biodiesel, while bioethanol is slightly worse. The best situation is for vitamin B2 by fermentation, but clearly the dimension of the market between vitamin B2 and biofuels is completely different. 

Figure 8.8 LCA analysis comparison of green diesel versus FAME biodiesel and a petroleum diesel energy consumption per unit of diesel energy.

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