Abstract: The invention relates to a process to separate butadiene dimers from a mixture comprising butadiene dimers and alkyl-3-pentenoate and/or isomers thereof wherein the butadiene dimers are separated from said mixture by distillation in the presence of an alcohol and in that the distillation is effected at a bottom temperature of between 80 and 200° C. Examples of frequent occurring butadiene dimers are 4-vinylcyclohexene and 1,3,7-octatriene. Examples of the alcohol are monohydroxy aliphatic alcohols.

Abstract: Process for the preparation of a sodium paraperiodate wherein an iodine compound is converted into the sodium paraperiodate in the presence of Na.sup.+ ions by means of an alkali metal hydroxide and an alkali metal hypochlorite. The iodine compound is applied in the form of an iodine-containing mixture in which besides the iodine compound in the form of I.sub.2, iodide or iodate compounds, one or more compounds chosen from the group of chlorides, bromides, sulphates, sulphites, carbonates, bicarbonates, nitrates and dissolved organic components are also present. The invention also relates to the preparation of sodium metaperiodate and other alkali and alkali earth metal periodates, wherein the sodium paraperiodate obtained is converted into sodium periodate or into an alkali or alkali earth metal periodate by means of an acid or an alkali and alkali earth metal salt at an elevated temperature. The acid used preferably is HNO.sub.3.

Abstract: The invention relates to a process for the preparation of an oligopeptide or amino acid alkyl ester.HCl salt, the alkyl group being methyl, ethyl, isopropyl or n-propyl, by converting an oligopeptide.HCl salt or amino acid.HCl salt with an alkanol corresponding to the alkyl group under the influence of an acid catalyst, 0.01-0.5 mol HCl relative to the oligopeptide.HCl salt or amino acid.HCl salt in combination with an acid ion exchange resin being used as acid catalyst.

Abstract: A continuous process for separating hydrogen in high purity from a gaseous hydrogen-containing mixture by absorbing in an absorber unit the hydrogen by metal hydride forming particles suspended in an inert liqid and desorbing in a desorber unit the hydrogen from the hydrided particles includes the step of treating the suspension of the hydrided particles before entering the desorber unit to remove dissolved gaseous non-hydrogen components by stripping with hydrogen, preferably with a part of desorbed hydrogen. By this way it is possible to obtain hydrogen having a purity of more than 99.9%.