In situ aberration corrected-transmission electron microscopy of magnesium oxide nanocatalysts for biodiesels

Biofuels are promising renewable energy sources and can be derived from vegetable oil feedstocks. Although solid catalysts show great promise in plant oil triglyceride transesterification to biodiesel, the identification of active sites and operating surface nanostructures created during their processing is essential for the development of efficient heterogeneous catalysts. Systematic, direct observations of dynamic MgO nanocatalysts from a magnesium hydroxide-methoxide precursor were performed under controlled calcination conditions using novel in situ aberration corrected-transmission electron microscopy at the 0.1 nm level and quantified with catalytic reactivity and physico-chemical studies. Surface structural modifications and the evolution of extended atomic scale glide defects implicate coplanar anion vacancies in active sites in the transesterification of triglycerides to biodiesel. The linear correlation between surface defect density (and therefore polarisability) and activity affords a simple means to fine tune new, energy efficient nanocatalysts for biofuel synthesis. © 2009 Springer Science+Business Media, LLC.

Aplicação de espectroscopia no infravermelho médio e calibração multivariada para quantificação de adulterantes e teor em biodiesel de óleo de palma com óleo de soja, soja residual e diesel

In this work, it was developed and validated methodologies that were based on the use of Infrared Spectroscopy Mid (MIR) combined with multivariate calibration Square Partial Least (PLS) to quantify adulterants such as soybean oil and residual soybean oil in methyl and ethyl palm biodiesels in the concentration range from 0.25 to 30.00 (%), as well as to determine methyl and ethyl palm biodiesel content in their binary mixtures with diesel in the concentration range from 0.25 to 30.00 (%). The prediction results showed that PLS models constructed are satisfactory. Errors Mean Square Forecast (RMSEP) of adulteration and content determination showed values of 0.2260 (%), with mean error (EM) with values below 1.93 (%). The models also showed a strong correlation between actual and predicted values, staying above 0.99974. No systematic errors were observed, in accordance to ASTM E1655- 05. Thus the built PLS models, may be a promising alternative in the quality control of this fuel for possible adulterations or to content determination.