Process Characterization of the Transesterification of Rapeseed Oil to Biodiesel Using Design of Experiments and Infrared Spectroscopy

Abstract

For optimization of production processes and product quality, often knowledge of the factors influencing the process outcome is compulsory. Thus, process analytical technology (PAT) that allows deeper insight into the process and results in a mathematical description of the process behavior as a simple function based on the most important process factors can help to achieve higher production efficiency and quality. The present study aims at characterizing a well-known industrial process, the transesterification reaction of rapeseed oil with methanol to produce fatty acid methyl esters (FAME) for usage as biodiesel in a continuous micro reactor set-up. To this end, a design of experiment approach is applied, where the effects of two process factors, the molar ratio and the total flow rate of the reactants, are investigated. The optimized process target response is the FAME mass fraction in the purified nonpolar phase of the product as a measure of reaction yield. The quantification is performed using attenuated total reflection infrared spectroscopy in combination with partial least squares regression. The data retrieved during the conduction of the DoE experimental plan were used for statistical analysis. A non-linear model indicating a synergistic interaction between the studied factors describes the reactor behavior with a high coefficient of determination (R²) of 0.9608. Thus, we applied a PAT approach to generate further insight into this established industrial process.

Real-Time Quantification of Meat Paste Constituents Displaying Nonlinear Blending Behavior Including Salt Using an In-Line NIR MEMS Sensor

“…In this work, the complexity of differently composed meat pastes is modeled using model meat mixtures that were systematically varied according to an experimental design. Design of Experiments (DoE) in combination with Response Surface Methodology (RSM) is a powerful statistical tool, − which enables the identification and quantification of statistically significant recipe components as well as synergistic nonlinear blending behavior of mixture components, while requiring only a limited number of experiments making this approach much more effective and informative than conventional one-factor-at-a-time approaches. ,,, The methodology has thus been used in a wide variety of contexts including food technology. − Using a mixture design wherein salt was included as a component in the reference mixtures, the effect of compositional changes in the meat paste on the spectral characteristics in the NIR region was investigated. For this purpose, various meat pastes were produced based on a balanced mixture design with varying amounts of fat, protein, water, and salt and subsequently were analyzed with a novel process analyzer prototype using a MEMS-based NIR sensor.…”