In this study, waste olive cake (OC) was utilized as the raw material for the production of biosorbents by chemical treatment and its adsorption capacity for zinc ion was evaluated. Tests were conducted with the total biomass (T) and with the fraction > 2.00 mm (P), in order to determinate the influence of this fractionation step on subsequent treatments. Two chemical agents were used: sulfuric acid and sodium hydroxide. The parameters studied include physical and chemical properties of materials, contact time, pH, adsorbent dose and initial concentrations. The kinetic data were best fitted to the pseudo-second order model. Zinc binding is strongly pH dependent, with more zinc ions bound at a higher pH (5-7 in a range of 3-7). Both Langmuir and Freundlich models are well suited to fit the data on sorption of zinc by OC. Data on sorption of zinc by waste olive cake treated with sulfuric acid (OC-H) was better described by the Freundlich model. Zinc sorption by waste olive cake treated with sodium hydroxide (OC-OH) was better described by the Langmuir model. Results show OC-OH is a biosorbent with a superior adsorption capacity for zinc than OC-H. The maximum adsorption capacity obtained from the Langmuir isotherms increases in the order (mg/g): OC-HT (14), OCT (22) and OC-OHT (27). Results also indicate that the previous fractionation step doesn´t produce a biosorbent with a superior adsorption capacity. Full article

The selective hydrogenation of dimedone (1) to the corresponding monoketone 2 over palladium and Amberlyst 15^® is reported. The product is a synthetic building block for the fragrance and pharmaceutical industry. Advantages of the new catalytic procedure are the high catalyst activity and selectivity, less by-product formation, avoidance of the presence of acid, and consequently, less salt formation due to the omission of a neutralization step. Using a substrate/catalyst ratio of >100 compound 2 can be synthesized in 97% yield at full conversion. Recycling of the catalyst several times has been shown to be feasible without any detectable decrease in selectivity. Full article

Methanetrisulfonic acid had been prepared for the first time over 140 years ago, but it was used only scarcely in chemical transformations. In the course of our activities dealing with key-steps of industrial syntheses of vitamins, e.g. economically important vitamin E (acetate), we found that methanetrisulfonic acid is an extremely effective catalyst in a variety of reactions. Examples of its applications are Wagner-Meerwein rearrangements, Friedel-Crafts alkylations and ring closures, as well as acylation reactions. Use of this catalyst in truly catalytic amounts (0.04-1.0 mol%) resulted in highly selective transformations and yields over 95%. (Remark by the authors: We are describing only one example each for the various types of reactions. Therefore, it would be more appropriate to write (here and in the Introduction and in the Conclusion sections): “Wagner-Meerwein rearrangement, Friedel-Crafts alkylation and ring closure, as well as acylation reactions”) Full article

An example for a process that can, in principle, be improved by the application of a catalyst is the synthesis of poly(2-methyl-propene)s (“polyisobutenes”), which are important for numerous industrial applications. Each year several 100,000 t are produced. The production of low-molecular weight polyisobutenes by means of cationic initiation by an excess of Lewis acids is well established. Typically, these initiators require the usage of solvents like chloroform, dichloromethane and ethylene and temperatures far below 0 °C (–100 °C in the case of ethylene as solvent). Solvent stabilized transition metal complexes with weakly coordinating counter anions overcome these drawbacks and thus are not only more efficient, but also more environmentally benign: they can be applied at ambient temperature and in non chlorinated solvents at low concentrations. Full article