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: A method for transferring a fluid sample from a first chamber to a second chamber separated from the first chamber involves opening a closed cavity defined between the end portions of two coaxially arranged cylindrical rods while in the first chamber, then closing the open cavity in the first chamber to enclose the fluid sample, transferring the closed cavity from the first chamber to the second chamber by effecting axial movement of the rods relative to the chambers, then opening the closed cavity in the second chamber to allow the fluid sample to enter the second chamber. A device for carrying out this method is provided with first and second rods arranged to move along a common axis, the device including an arrangement for effecting displacement of the rods relative to each other and relative to the chambers or displacement of the rods together while the end portions of the rods are in contact to effect transfer of the fluid sample from one chamber to the other.

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 and apparatus for the treatment of a gas containing methane, water, at least one hydrocarbon other than methane, as well as at least one acid gas.