Catalytic Pyrolysis of Lignin Model Compound (Ferulic Acid) over Alumina: Surface Complexes, Kinetics, and Mechanisms

Studies of the thermochemical properties of the important model compound of lignin-ferulic acid (FA) and its surface complexes are substantial for developing technologies for catalytic pyrolysis of renewable biomass into biofuels and lignin-derived chemicals as well as for bio-oil upgrading. In this work, the catalytic pyrolysis of ferulic acid over alumina was studied by temperature-programmed desorption mass spectrometry (TPD MS), in situ FT-IR spectroscopy, thermogravimetric analysis, and DFT calculations. We established that both the carboxyl group and the active groups (HO and CH3O) of the aromatic ring interact with the alumina surface. We calculated the kinetic parameters of formation of the main products of catalytic pyrolysis: 4-vinylguaiacol, guaiacol, hydroxybenzene, benzene, toluene, cresol, naphthalene, and PACs. Possible methods of their forming from the related surface complexes of FA are suggested.

The preparation of Al2O3-Na2SO4 composites derived from local kaolin through an alkaline destruction combined with sulphatization method

Composites of Na2SO4 is promising for solid electrolyte application. In this initial study, composites of Al2O3/Na2SO4 were successfully synthesized from local kaolin through an alkaline destruction method combined with sulphatization. The composites were characterized including thermal behaviour, mineral phases, chemical composition, FT-IR spectra, and microstructures. The composites consist of a-Al2O3 and Na2SO4 phases after calcination at 1300 °C. This phenomenon is confirmed by the XRF and FT-IR result. The composite consists of Al2O3 and Na2SO4 as major components, accounting 41.98% and 47.09% of the total, respectively. Meanwhile, SiO2 is found as the impurity, accounting 2.86% of the total. The vibration modes of Al-O bonds are detected at 995.27 and 524.46 cm1, whereas the SO4 bands appear at 1111.00 and 617.22 cm1. Na2SO4 exhibits a rod-like particle that cover the alumina surface in the morphology.