Abstract: A process for obtaining a fuel for internal combustion engines from a hydrocarbon charge, comprising a step (a) for distillation (D1) in which a bottom product (Q1) is obtained via a line 3 and in which a top product (T1) is obtained via a line 2, a step (b) of liquid/liquid extraction (LE) using a solvent (S1) to obtain a raffinate to (R1), (line 5) and an extract from which product (Q1) an extract (E1) is obtained (line 6) and a raffinate, a step c) of separating (D2) the raffinate (R1) enabling a product (Q2) to be obtained via line 7, which product has a low solvent (S1) content, and a step (d) of hydrotreatment (HDS) in which the mixture of the products (T1) and (Q2) are subjected to hydrotreatment with a hydrogen partial pressure of less than 10 megapascals, to obtain a product (P) (line 9) which has improved qualities and which contains less than 500 ppm by weight sulphur.

Abstract: A reactive distillation process which makes it possible, in the same enclosure, to carry out a catalytic reaction and isolate by distillation the sought product, in which the liquid phase containing the reagents passes from bottom to top through at least one catalyst bed, without the vapor phase of the distillation traversing said catalyst beds. These operating characteristics occur in a reactive distillation zone (C) including an alternation of distillation cells (D) having one or more trays (5) and reaction cells (R) containing the catalyst beds and designed in such a way that the liquid phase flowing from a distillation tray (5) flows above an overflow ( 7) through a downpipe (6) and approaches the base of the catalyst bed (8), traverses the latter in a downward flow and is then allowed to flow over a distillation tray (5) of the following distillation cell (D), so that the distillation vapor circulating from bottom to top through the distillation trays (5) does not traverse said reaction cells (R).

Abstract: For separating ETBE and ethanol the following principal stages are employed:(1) Extraction of ethanol by water, the raffinate being ETBE saturated in water and the extract an ethanol/water mixture containing a small proportion of ETBE;(2) Concentration of the above mixture, the distillate being a mixture close to the ethanol/water azeotrope in composition and containing a very small proportion of ETBE;(3) Heteroazeotropic distillation of this distillate in two coupled columns with an overhead decanter, this distillation using ETBE as azeotroping agent; the residue of the first column being ethanol which is ca. 99% by mole and the residue of the second column being practically pure water, this water and the water recovered during the concentration stage being used as extraction solvent in stage (1).Stage (3) may be an ethanol dehydration unit using ETBE as dehydrating agent.

Abstract: The separation of ethyl tertiobutyl ether from mixtures with ethanol is based on heteroazeotropic distillation with water as the entrainer using two distillation columns, coupled with an overhead decanter. Purified ethanol is collected from the bottom of the first column and purified ETBE from the bottom of the second column. The separation method may be incorporated into an ETBE production unit in which isobutene (contained in a C.sub.4 -cut from steam cracking, catalytic cracking, or dehydrogenation of isobutane) is etherified by ethanol. Ethanol separated from the ETBE is then recycled to the etherification zone.

Abstract: For the separation of tert. butyl ethyl ether from mixtures with ethanol, there are provided two distillation stages, the first being carried out at a pressure p.sub.1 equal to or higher than 1 bar, the second at a pressure p.sub.2 below p.sub.1 by a value .DELTA.p or 0.5 to 12 bars, p.sub.2 then being 0.5 to 10 bars. The second column distillate is partly supplied as reflux to the head of the second column and is in part recycled to the head of the first column. The purified TBEE is collected at the bottom of the first column and the purified ethanol at the bottom of the second column.This separation process can be integrated into a TBEE production unit comprising etherification by ethanol of the isobutylene contained in a C.sub.4 fraction from a catalytic cracking or steam cracking stage. The ethanol separated from the TBEE is then recycled to the etherification zone.

Abstract: The invention relates to a process for hydrocarbon fractionation and extraction making it possible to obtain a petrol with an improved octane number and a kerosene with an improved smoke point.According to the invention a charge with a final boiling point of at least 220.degree. C. is fractionated into three fractions:a light petrol containing less than 10% aromatics and boiling points at 25.degree. to 80.degree. C.,a medium petrol (80.degree. C. and at the most 150.degree. C.), whose end point is determined by a nitrogen content below 50 ppm,a heavy petrol with an end point equal to or below 220.degree. C.,be a selective liquid solvent aromatics are then extracted from the heavy petrol producing a refined product which is poured into the kerosene pool or diesel fuel,the solvent is regenerated by reextraction using light petrol so as to produce an aromatics-enriched petrol fraction with an improved octane number.

Abstract: Process for dehydrating aliphatic alcohols admixed with water wherein the alcohols-water mixture is subjected to a first fractionation in the presence of a selective solvent, giving a vapor effluent containing dehydrated light alcohols and a liquid phase containing heavy alcohols, water and the selective solvent, said liquid phase being subjected to a second fractionation giving as vapor effluent an hetero-azeotropic mixture of water and heavy alcohols and, as liquid effluent, the selective solvent, which is fed back, said hetero-azeotropic mixture being condensed and separated into:(a) a light phase of high alcohol content which is subjected to a third fractionation giving a vapor effluent which is fed back and dehydrated heavy alcohols as liquid effluent, and(b) a heavy phase which is subjected to a fourth fractionation giving a vapor effluent which is fed back and water as liquid effluent.

Abstract: Process for producing methyl tert-butyl ether (MTBE) by reacting methanol with the isobutene present in a C.sub.4 cut in a proportion from 10 to 60%, wherein said cut, admixed with methanol is contacted, in a first reaction zone, with an acid catalyst in the conditions of etherification of isobutene by methanol unit 93 to 98% of the isobutene has been converted, the reaction product is fractionated under at least 10 bars to a bottom fraction consisting essentially of MTBE and a top fraction which is contacted, in a second reaction zone, with an acid catalyst, under the conditions of etherification of isobutene by methanol, until at least 99% of the initial isobutene has been converted, the resulting product is washed with water and separated into a residual C.sub.4 cut which is discharged and an aqueous phase wherefrom methanol is recovered by distillation.

Abstract: Process for isolating methyl tert-butyl ether contained in the reaction product of methanol with a C.sub.4 hydrocarbon cut containing isobutene, comprising fractionating said reaction product by introducing it at an intermediate point of a distillation zone, recovering methyl tert-butyl ether at the bottom thereof and, at the top thereof, a mixture of C.sub.4 hydrocarbons with methanol which is washed with water and condensed and wherefrom is separated a condensed C.sub.4 hydrocarbon fraction, a portion of which is fed back as reflux to the top of the distillation zone and another portion discharged, and separating the remaining water-methanol mixture by distillation.

Abstract: Process for producing and isolating methyl-tert-butyl ether (MTBE) comprising etherifying isobutene, contained in a C.sub.4 hydrocarbons mixture, with methanol in the presence of a recycle stream of C.sub.5 and/or C.sub.6 hydrocarbons, separating from the obtained reaction product, by fractionation, at least the major part of the unconverted C.sub.4 hydrocarbons, and discharging them, and fractionating the remaining product in two fractions, one of which contains an azeotrope of methanol with the C.sub.5 and/or C.sub.6 hydrocarbons and is recycled, the other fraction containing the purified MTBE.

Abstract: Process for separating benzene and/or toluene from mixtures thereof with saturated hydrocarbons, by extractive distillation using an aliphatic N-alkylamide as extraction solvent, comprising introducing in the distillation column, above the level of introduction of the extraction solvent, liquid water in an amount and under such conditions that said water is completely vaporized without substantially diluting the solvent, condensing the vapors discharged from the top of the column and dividing the resulting condensate into a phase of liquid saturated hydrocarbons, and a phase of water.

Abstract: Process for producing aromatic hydrocarbons, particularly benzene and/or toluene from a feed charge containing saturated and unsaturated hydrocarbons, by catalytic treatment of said charge with hydrogen, fractionation of the resulting product to separate a fraction containing benzene and/or toluene, extractive distillation of at least one aromatic hydrocarbon in a column, by means of an extraction solvent from which said hydrocarbon is subsequently separated, and recycling to the reaction zone of at least one portion of the products recovered at the top of said extractive distillation column and containing essentially C.sub.6 and C.sub.7 saturated hydrocarbons.