Abstract: A process for purifying an aqueous stream from a Fischer-Tropsch reaction that includes feeding the aqueous stream to a system that includes a distillation column equipped with a partial condenser and a total condenser, at least partially condensing the vaporized stream leaving the head of the distillation column and collecting a first distillate in which in heavier by-products, totally condensing the remaining portion of the vaporized stream leaving the partial condenser and collecting a liquid stream which is returned to the distillation column as a reflux and removing a purified aqueous stream from the bottom of the distillation column.

Abstract: The present invention relates to a process for the purification of an aqueous stream coming from the Fischer-Tropsch reaction which comprises:—feeding of the aqueous stream containing the organic by-products of the reaction to a system consisting of a distillation column equipped with a partial condenser and a total condenser;—partial condensation of the vaporized stream leaving the head of the column and collection of a first distillate enriched in the heavier by-products;—total condensation of the vaporized stream leaving the partial condenser and collection of a liquid stream which is partly sent back to the distillation column as reflux whereas the remaining part is collected as distillate;—extraction of the purified aqueous stream from the bottom of the distillation column.

Abstract: A process for separating mixtures of hydrocarbon isomers on molecular sieves, including providing columns which include molecular sieves and function alternatively as secondary adsorption, primary adsorption, and desorption devices, feeding the mixtures of hydrocarbon isomers to a column functioning as the primary adsorption device for adsorbing isomers with greater selectivity towards the molecular sieves, feeding effluent of the mixtures from the column functioning as the primary adsorption device to a column functioning as the secondary adsorption device for adsorbing remaining isomers with greater selectivity, discharging isomers with a lower selectivity from the column functioning as the secondary adsorption device and a desorbing agent therein, feeding a desorbing agent to the column functioning as the desorption device, discharging isomers with a greater selectivity towards the molecular sieves and the desorbing agent in the column functioning as the desorption device.

Abstract: Process for the separation of 2,6-dimethylnaphthalene from mixtures containing it, comprising the following operations: crystallization by the addition of a solvent and cooling of the mixture to a temperature higher than the formation value of the first eutectic; removal of the mother liquor by repeated washings; dissolution of the solid obtained; crystallization by cooling; filtration.

Abstract: A process for separating hydrocarbon isomers in gas phase on molecular sieves, including feeding mixtures of hydrocarbon isomers to a primary adsorption column configured to adsorb isomers with a greater selectivity towards the molecular sieves, feeding effluent from the primary adsorption column to a secondary adsorption column configured to adsorb remaining isomers with a greater selectivity towards the molecular sieves and discharge a stream containing isomers with a lower selectivity towards the molecular sieves, feeding desorbing agent to a desorption column configured to discharge a stream containing isomers with a greater selectivity towards the molecular sieves and the desorbing agent, feeding the stream from the secondary adsorption column to a distillation unit configured to recover the desorbing agent for recycling to the desorption column, feeding the stream from the desorption column to another distillation unit configured to recover the desorbing agent for recycling to the desorption column.

Abstract: Process for the separation of 2,6-dimethylnaphthalene from mixtures containing it, comprising the following operations:

Abstract: An integrated process for the simultaneous production of alkyl tert-butyl ethers and 1-butene, comprising feeding a C.sub.4 hydrocarbon stream to an etherification unit and recycling the remaining stream to the same unit after possible separation of the 1-butene and treatment in an isomerization section to convert the remaining butenes into isobutene, a molecular sieve separation unit operating with the hydrocarbons in the vapour phase being incorporated into the cycle.