A method for separating a hydrocarbon mixture, which is obtained at least in part by steam cracking and which contains at least hydrocarbons having one, two and three carbon atoms, including ethane and ethylene, a first fraction initially being obtained from the hydrocarbon mixture by separating off other components at least in part, said fraction containing the predominant part of the hydrocarbons having two or more carbon atoms previously contained in the hydrocarbon mixture or the predominant part of the hydrocarbons having two or fewer carbon atoms previously contained in the hydrocarbon mixture, further fractions subsequently being obtained from the first fraction. A fraction containing ethane is separated off in an amount which reduces the ethane content in the first fraction to less than 25%, the fraction containing ethane being low in or free from other hydrocarbons having two carbon atoms.

A contact tray for use in a mass transfer or heat exchange column and having multiple baffles walls that cause the liquid flowing on an upper surface of a tray deck tray to change its direction of flow and narrow its flow path width and extend the length of the flow path when the liquid flows from an inlet area to an outlet on the tray deck. By narrowing the flow path, the volumetric flow rate of the liquid at any portion of the deck increases and reduces the opportunity for vapor entrainment of the liquid at low liquid flow rates. A downcomer extends downwardly from the outlet to receive liquid when it enters the outlet and then convey it downwardly to a discharge outlet located at a lower end of the downcomer. The downcomer includes an inclined or horizontal portion that causes the discharge outlet to be positioned beneath and in vertical alignment with the inlet area on the tray deck.

A fluid contact tray (10) for a fractionation column (1), in particular a vapor-liquid contact tray suitable for the use in an offshore fractionation column, comprises: a tray deck (12) comprising an active mass transfer surface (20) suitable for contacting two fluids (l, g) of different densities, wherein the active mass transfer surface (20) comprises one or more orifices (18) for the passage of a fluid/gas (g), and wherein at least two at least partially radially extending separation walls (22-1, 22-2, 22-3, 22-4) and/or at least one separation weir (42) are arranged on the active mass transfer surface (20), which divides the active mass transfer surface (20) into at least two sections (24-1, 24-2, 24-3, 24-4), an annular channel (26) suitable for collecting fluids/liquids (l), which is arranged at the peripheral area of the active mass transfer surface (20) and at least partially embraces the mass transfer surface (20), a central downcomer (34) for collecting and discharging a fluid/liquid (l) from the annular channel (26), wherein the central downcomer (34) has the form of a hollow body with an opening (36) in the bottom section thereof being suitable for the distribution of liquid vertically downwardly, and wherein the central downcomer (34) is non-rotatably fixed at the fluid contact tray (10), and at least one conducting means (40) for transferring fluid collected in the annular channel (26) from the annular channel (26) to the central downcomer (34). This fluid contact tray (10) is in particular useable for offshore applications, such as for a fractionation column located on a FLNG or FPSO vessel.

A process for the distillation of an aldehyde mixture comprising a straight-chain aldehyde and a branched-chain aldehyde is described in which the process comprises: supplying a feed comprising the aldehyde mixture to a first separation vessel; operating said first separation vessel at a first temperature and a first pressure such that separation occurs; recovering a first stream comprising the straight-chain aldehyde from said first separation vessel and supplying said first stream to a second separation vessel; operating said second separation vessel at a second temperature and a second pressure such that separation occurs; recovering a product stream comprising the straight-chain aldehyde and a second stream comprising high-boiling components from said second separation vessel, and supplying said second stream to a third separation vessel; operating said third separation vessel at a third temperature and a third pressure such that separation occurs; and recovering a third stream comprising the aldehyde mixture from said third separation vessel and reintroducing said third stream to the first separation vessel.

An apparatus and process doubles the number of trays in a single fractionation column. A dividing wall is used to isolate a first side from a second side and fractionation on trays on each side is independent of the other. A transition vapor stream is ducted from a top of a first side to the bottom of the second side, and a transition liquid stream is ducted from a bottom of the second side to the top of the first side.

A high capacity and high efficiency co-current and cross-flow vapor-liquid contacting apparatus and process is useful in distillation columns and other vapor-liquid contacting processes. The apparatus is characterized by an arrangement of offset contacting modules in horizontal stages. The modules define a co-current contacting volume and in an exemplary configuration the modules include a liquid distributor and a demister. Half modules comprise downcomers against the shell of the vessel for transporting liquid to the subjacent stage.

An apparatus and process doubles the number of trays in a single fractionation column. A dividing wall is used to isolate a first side from a second side and fractionation on trays on each side is independent of the other. A transition vapor stream is ducted from a top of a first side to the bottom of the second side, and a transition liquid stream is ducted from a bottom of the second side to the top of the first side.

A high capacity and high efficiency vapor-liquid contacting apparatus and process is useful in distillation columns and other vapor-liquid contacting processes. The apparatus is characterized by a half module comprising a downcomer against a shell of a vessel for transporting liquid to a subjacent stage which utilizes a demister to effect vapor-liquid separation at the downcomer outlet.

A high capacity and high efficiency co-current and cross-flow vapor-liquid contacting apparatus and process is useful in distillation columns and other vapor-liquid contacting processes. The apparatus is characterized by an arrangement of contacting modules and perforated receiving pans in horizontal stages. The modules define a co-current contacting volume and in an exemplary configuration the modules include a liquid distributor and a demister. Liquid dispensed from the modules on a perforated receiving pan are contacted with upflowing vapor through perforations therein.

The present invention relates to a column (1) for thermal treatment of fluid mixtures, having a cylindrical, vertical column body (2) which forms a column cavity (3), a plurality of trays (8) mounted with vertical spacing in the column cavity (3), and a support construction (9) which supports at least one of the trays (8) in vertical direction. It is a characteristic feature of the inventive column (1) that the support construction (9) has a plurality of orifices (12) which allow horizontal mass transfer through the support construction (9). The invention further relates to a tray device for such a column and to a thermal separation process between at least one gas ascending within such a column (1) and at least one liquid descending within the column (1).