Abstract: The invention relates to a rectifying column for extractive distillation, comprising a column main section (204) and a raffinate section (205) above said main section, an evaporator (208) situated on the lower end of the column, an inlet (214) disposed between the main section of the column and the raffinate section and a solvent inlet (215) arranged on the top side of the raffinate section (205) for feeding an extracting agent. According to the invention, the main section (204) has two chambers (216, 217) connected in parallel. A stripping section (222) is disposed between the bottom of the column (221) and the main section (204), in which concentration of the extracting agent occurs from the top down. The bottom (221) is connected to the solvent inflow (215) by a device (223) for recycling the extracting agent.

Abstract: The invention relates to a process and a facility for the production of ultra-pure aromatics with 6 to 8 carbon atoms from a hydrocarbon mixture which consists of at least one aromatic compound, an olefinic compound, a paraffinic compound or a mixture thereof and which contains impurities consisting of water-soluble organic and/or inorganic substances. An extremely high degree of purity of the product obtained by said process can be achieved with regard to impurities in the form of organic or inorganic compounds of the elements sulphur, nitrogen, oxygen and chlorine.

Abstract: The invention relates to a process for purifying hydrocarbon vapor consisting of at least one aromatic or one olefinic or one paraffinic compound or of a mixture thereof, this hydrocarbon vapor entraining impurities of acid or alkaline nature which consist of at least one water-soluble organic and/or inorganic substance and it also relates to a facility for performing such a process.

Abstract: In the production of aromatic hydrocarbon from coking crude by-product benzene after a vaporization stage in which the crude benzene is evaporated to leave a residue, the crude benzene is subjected to pressure refining in the presence of hydrogen. The residue is distilled to form high and low boiling fractions and at least the gas pressure and temperature of the distillation stage is controlled so that the sump product apart from styrene is substantially free from aromatic hydrocarbons with less than 9 carbon atoms. The rate of withdrawal of the vaporization residue from the vaporizing column is controlled, depending upon the concentration of polymer formers in the crude benzene to be in the range of 6 to 40% of the rate of feed of the coking by-product benzene to the vaporizing column.

Abstract: The production of high purity benzene and high purity toluene is obtained by utilizing the initial gas separating column for the treatment of the aromatic containing starting material as a separating column for separating a benzene rich from a toluene rich component. The benzene rich component is subject directly to distillation while the toluene is subject to predistillation to separate high boiling components and only then to extractive distillation is distilled to separate the high purity benzene from the high purity toluene.