(621ed) Online Raman Spectroscopy Analysis Technique for Monitoring Biofuel Reaction Using Heterogeneous Layered Double Hydroxide Catalyst

Online Raman Spectroscopy Analysis Technique for Monitoring Biofuel Reaction Using Heterogeneous Layered Double Hydroxide Catalyst

Obakore Agbroko, Keyvan Mollaeian, William E Holmes, Tracy J Benson

            An online Raman spectroscopic technique has been developed to monitor biofuel production using a heterogeneous catalyst.  The transesterification of canola oil with dimethyl carbonate (DMC) was performed using Mg-Al Layered Double Hydroxide (LDH) that had been grafted with triazabicyclodecene giving the catalyst dual basic and acidic functionality.  A Raman fiber optic probe (Perkin Elmer Flex 400 with a 785 nm laser) was inserted into a 500 mL three-neck flask for in situ analysis of the reaction medium.  Since the reaction reactants/products mixture was of similar chemical nature and the use of a heterogeneous catalyst complicated analysis, a deconvolution algorithm was constructed to differentiate between the Raman peaks and optimize the quantitative analysis using Gaussian distribution.   Peak heights were compared against an external calibration curve using DMC, canola oil, and methyl oleate.  The developed Raman method was validated through gas chromatography analysis of the reaction to develop a kinetic curve.