Biodiesel monitoring

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). 

If PAT is to make a stronger contribution to the production of biofuels and of other non-health bioproducts, one area that needs to move forward is the acceptance by standards monographs (e.g., ASTM) of some PAT monitoring tools (e.g., parametric release of biodiesel with NIR). For instance, accepted and proven techniques for release of many solid dosage forms and other medicines are still not accepted in the biofuels area. 

The Biodiesel Stability (BIOSTAB) project, supported by the European Commission, was initiated in 2001 to establish clear criteria and analytical methods for the monitoring biodiesel fuel stability (Various, 2003 Prankl, 2002). The resulting unified method, EN 14112 (Anon., 2003c) established a means for measuring oxidative stability utilizing the Rancimat or oxidation stability instruments. This test method was essentially developed from standards employed in the fats and oils industry to measure isothermally the induction period for oxidation of fatty derivatives. At present, both biodiesel fuel standards ASTM D 6751 (Anon., 2007a) and EN 14214 (Anon., 2003b) include an oxidative stability specification based on measurement by method EN 14112. 

Despite its many advantages as a renewable alternative fuel, biodiesel presents a number of problems that must be resolved for it to be attractive for more widespread applications. These problems include improving relatively poor cold flow properties, monitoring and maintaining fuel quality... 

It is possible that the need for water removal from methanol is not necessary if the entire system is maintained in a dry state and dry catalysts are used. For example, sodium methoxide brings less water to the reaction than the comparable hydroxide, and commercial methanol can be obtained in an essentially dry state. In the case where dry oil is available for processing, it may be advantageous to produce biodiesel using the dry ingredients and monitor water levels in recovered methanol. 

S. Pinzi, F. Priego-Capote, J. Ruiz-Jimenez, M.P. Dorado, M.D. Luque de Castro, Flow injection analysis-based methodology for automatic on-line monitoring and quality control for biodiesel production, Bioresource Technol. 100 (2009) 421. 

You performed a test reaction in your kitchen to study the kinetics of this process. You were able to monitor the concentration of the oil and found that the concentration dropped from 0.500 M to 0.250 M in 20.0 minutes. It took an additional 40.0 minutes for the concentration of the oil to further drop to 0.125 M. How long will it take for you to convert 97.0% of the oil to biodiesel ... 

Several spectroscopic methods have been used to monitor the levels of heavy metals in man, fossil fuels and environment. They include flame atomic absorption spectrometry (AAS), atomic emission spectroscopy (AES), graphite furnace atomic absorption sp>ectrometry (GFAAS), inductively coupled plasma-atomic emission sp>ectroscopy (ICP/AES), inductively coupled plasma mass spectrometry (ICP/MS), x-ray fluorescence sp>ectroscopy (XRFS), isotope dilution mass spectrometry (IDMS), electrothermal atomic absorption spectrometry (ETAAS) e.t.c. Also other spectroscopic methods have been used for analysis of the quality composition of the alternative fuels such as biodiesel. These include Nuclear magnetic resonance spectroscopy (NMR), Near infrared spectroscopy (NIR), inductively coupled plasma optical emission spectrometry (ICP-OES) e.t.c. 

There are different spectrophotometric techniques for analysis of contaminants in biofuels. Simultaneous detection of the absorption spectrum and refractive index ratio with a spectrophotometer for monitoring contaminants in bioethanol has been carried out by Kontturi et al., 2011. Inductively Coupled Plasma Atomic Emission Spectrometry and optical emission spectral analysis with inductively coupled plasma (ICP-OES) have also been used to analyze biodiesel samples for trace metals (ASTM, 2007 ECS, 2006). An ICP-MS instrument fitted with an octopole reaction system (ORS) was used to directly measure the inorganic contents of several biofuel materials. Following sample prepwation by simple... 

Holcapek, M. Jandera, P. Fischer, J. Prokes, B. Anal3rtical monitoring of the production of biodiesel by high-performance liquid chromatography with various detection methods, J.Chromatogr A., 1999,858, 13-31. 

Ellis, N., Guan, F., Chen, T. and Poon C. 2008. Monitoring biodiesel production (transesterification) using in situ viscometer. Chem. Eng. J. 138(1-3) 200-206. 

Reyman, D., Bermejo, A.S., et al., 2014. A new FTIR method to monitor transesterification in biodiesel production by ultiasonication. Environmental Chemistry Letters 12 (1), 235—240. 

Arzamendi, G., Arguinarena, E., Campo, I., Gandia, L.M., 2006. Monitoring of biodiesel production simultaneous analysis of the transesterification products using size-exclusion chromatography. Chemical Engineering Journal 122, 31—40. 

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