Valorisation of kraft lignin by using vanillin and lignin-based polyurethanes: Use of the biorefinery concept

In kraft pulp mills, the capacity of the recovery boiler is very often a limiting factor to the increase of the pulp production. Until several decades ago, an upgrade to boiler system for dealing with higher quantities of black liquor was the only alternative. The possibility of lignin extraction from black liquor seems to be much more attractive, either for energy production or combustion elsewhere, or to serve as feedstock for chemicals production. Since the beginning of the 90’s, associate Laboratory LSRE/LCM has been focused on overcoming expansion limitations in pulp industries and, in this work, we show an alternative to this industry segment for the utilization of lignin and producing high added value chemicals from renewable biomass materials. Based on the biorefinery concepts, an integrated process for producing vanillin from kraft lignin oxidation has been proposed and each of the needed unit operations has been investigated to provide a deeper scientific understanding on this subject.FCT - projects POCTI/EQU/33198/99, POCI/EQU/61738/2004 and Grant SFRH/BD/18415/2004. CYTED IV.17/2002-2006. Luso-French actions F13/06 and F32/08

Separation of racemic chiral drugs using immobilized CHIRALPAK IA: methodology for preparative scale development

Immobilized stationary phases represent a new perspective for analytical as well as preparative scale separation of chiral species. In this study, the basic data necessary for further development of the production-scale processes using CHIRALPAK IA columns were acquired. The new immobilized chiral stationary phase CHIRALPAK IA has proven to be useful for the chiral separations of propranolol, metoprolol, guaifenesin, and -Tetralol enantiomers. A broad range of standard and non-standard solvents used as components of mobile phases were tested and their influence on the separations was evaluated. A satisfactory separation considering further utilization of simulated moving bed chromatography was found for propranolol, guaifenesin, and -tetralol using the following mobile phases n-Heptane/methanol/ethanolamine (05/95/0.1, v/v/v), n-Heptane/ethanol (85/15, v/v) and n-Heptane/DCM (85/15, v/v), respectively. Inverse size exclusion chromatography was implemented to measure the porosity of the column using the set of polystyrene standards. The multicomponent adsorption equilibrium was characterized by linear + Langmuir model for -Tetralol and linear model for propranolol and guaifenesin due to their limited solubility in selected mobile phases. The isotherm model was successfully validated by comparison of pulse profiles obtained by solving the mathematical model and those obtained experimentally

An integrated process to produce high value-added phenolic compounds from kraft lignin

This work has been awarded with the prize for the best poster communication.The implementation of biorefineries for the production of chemicals as well as materials and energy products is the key to ensure a sustainable future for the chemical and allied industries. LSRE has been working with lignin based bio-refining for near two decades with pioneering work on the subject. A Research & Development Program on the production of phenolic aldehydes, in particular vanillin, from Kraft lignin has been developed for many years. In this work, the strategy is to combine reaction engineering and separation processes for converting lignin from spent liquors into added-value aldehydes. The major result is an integrated process of vanillin production from Kraft lignin. The integrated process is based on three main steps. The first step consists on the alkaline lignin oxidation, in which valuable information can be found to decide the best conditions for the vanillin production. Considering the further isolation of vanillate from the oxidized solution, important results have been reached in the framework of ultra-filtration process, and equilibrium and kinetic adsorption studies. The degraded lignin resulting from membrane process can be considered for obtaining lignin-based polyurethanes materials.POCTI/EQU/33198/99, POCI/EQU/61738/2004, CYTED IV.17/2002-2006 e ACÇÃO LUSO-FRANCESA F13/06

Um processo integrado para produzir compostos fenólicos de elevado valor acrescentado a partir de lenhina kraft

Neste trabalho, apresenta-se a estratégia que combina a engenharia de reacções e processos de separação para converter lenhina, obtida de licores processuais, em aldeídos de elevado valor acrescentado. O principal resultado é um processo integrado de produção de vanilina a partir de lenhina Kraft. O processo de integração é baseado em três etapas principais. A primeira etapa consiste na oxidação alcalina da lenhina em um reactor de borbulhamento com leito estruturado. Previamente, um extenso trabalho sobre a oxidação de lenhina em reator descontúnuo, incluindo a determinação das leis cinéticas de oxidação da lenhina e a optimização das condições de reação, foi realizado. Importantes informações para decidir sobre as melhores condições para a produção de vanilina foram publicadas. O projecto, a construção e a operação de um reator contínuo para a oxidação de lenhina foram executados. A produção de vanilina parece ser dependente das características estruturais da lenhina e limitada pela taxa de transferência de oxigênio para o líquido no reator. Considerando-se a etapa de recuperação da vanilina da solução oxidada, resultados importantes foram alcançados no âmbito do processo de ultrafiltração (UF), e estudos de adsorção de equilíbrio e cinética.FCT (projects POCTI/EQU/33198/99 and POCI/EQU /61738/2004 and grant SFRH/BD/18415/2004), CYTED (Project IV.17) and French-Portuguese Scientific Cooperation (Actions F1-3/06 and F-32/08