Process Intensification via Structured Catalysts: Production of Sugar Alcohols

With the aid of structured catalysts and reactors, such as monoliths, solid foams, and 3D printed structures, the limitations of conventional slurry and packed-bed reactors can be surmounted. Multiphase mathematical models were presented for solid foam structures and the models were verified for the hydrogenation of arabinose, galactose, and xylose to the corresponding sugar alcohols. High product selectivities were obtained in batch and continuous experiments. Three kinetic models were considered: a competitive adsorption model, a semi-competitive adsorption model as well as a non-competitive adsorption model for sugar monomers and hydrogen. The models gave a good reproduction of the data, but the semi-competitive adsorption model was the most plausible one because of the size difference between adsorbed sugar and hydrogen molecules. Sugar alcohols are used in alimentary, pharmaceutical, and cosmetic products. Sugar monomers obtained by hydrolysis of hemicelluloses can be hydrogenated to sugar alcohols by using structured catalysts in continuous operation. A multiscale modeling approach is applied to predict the behavior of the intensified sugar hydrogenation process. image