Hydroisomerization of long chain paraffins for the production of branched alkanes has recently been intensively studied due to a large availability of these compounds. The most interesting research topics have been the development of novel bifunctional catalysts to maximize the yield of isomers and to suppress the cracking reactions. Since both of these reactions are catalyzed by Brønsted acid sites, the optimum catalyst exhibits equal amounts of metal and acid sites, and it facilitates rapid mass transfer. Thus, several hierarchical and nano-shaped zeolites have been developed, in addition to composite catalysts containing both micro- and mesoporous phases. In addition to catalyst development, the effect of the reactant structure, optimal reaction conditions, catalyst stability and comparison of batch vs continuous operations have been made.

Developing a structured catalyst was performed successfully, and carbon-coated aluminum foam-supported ruthenium catalysts were prepared. Seven different characterization techniques such as scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed reduction, inductively coupled plasma-mass spectrometry, carbon monoxide chemisorption, and nitrogen physisorption were applied on the solid catalysts. The carbon-coated foams were checked for their mechanical stability, and the results indicated that the foam catalysts were mechanically stable. The Ru/C foam catalysts were used in a multiphase reactor setup, which had six tubular reactors working in parallel. Continuous hydrogenation of d-glucose, l-arabinose, and a mixture of l-arabinose and d-galactose was studied in the experimental setup. Through investigating different reaction parameters, the temperatures 100–110 °C and the liquid flow rates 0.5–1 mL/min were found to be suitable for catalyst screening and activity testing. The experiments were carried out at 20 bar hydrogen pressure. The continuous hydrogenation experiments were successful, the reproducibility was good, and the foam catalysts were stable. High selectivities of the desired products, sugar alcohols and sugar alcohol mixtures, were obtained.

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