Provided is a method capable of manufacturing high-purity 1,3-butylene glycol having a high potassium permanganate test value, a very low content of low boiling point components, and a high initial boiling point with a high recovery rate.

A method for manufa.cturing 1,3-butylene glycol is a method for obtaining purified 1,3-butylene glycol from a crude reaction liquid containing 1,3-butylene glycol. In a dehydration column used in the dehydration step, a liquid feed containing 1,3-butylene glycol and water with an acetaldehyde content of 1000 ppm or lower and a crotonaldehyde content of 400 ppm or lower is distilled, and a liquid concentrated with a low boiling point component containing water is distilled off from above a feed plate; and in a product column used in the product distillation step, a 1,3-butylene glycol liquid feed having an acetaldehyde content of 500 ppm or lower and a crotonaldehyde content of 200 ppm or lower is distilled under a condition of a reflux ratio of higher than 0.1.

The present invention relates to evaporation apparatus (100) comprising manifolds provided with at least one nozzle (102), a tank unit (103) for a liquid, and a sample holder configured to be inserted into the tank unit. The sample holder is configured to hold at least one sample in a defined position relative the at least one nozzle a control unit (104) an inlet port (105) configured to be connected to a gas supply, a pressure regulator (106) arranged downstream the inlet port (105). A set value of the pressure regulator (106) is controlled by the control unit (104), a control valve (107) arranged downstream the pressure regulator (106), wherein each of the at least one manifold (101a-d) is connected to a corresponding output port of the control valve. The control valve is controlled by the control unit (104), and the control unit is configured to set the set value of the pressure regulator to a value that causes a predetermined gas flow from each of the at least one nozzle.

The present invention relates to evaporation apparatus (100) comprising manifolds provided with at least one nozzle (102), a tank unit (103) for a liquid, and a sample holder configured to be inserted into the tank unit. The sample holder is configured to hold at least one sample in a defined position relative the at least one nozzle a control unit (104) an inlet port (105) configured to be connected to a gas supply, a pressure regulator (106) arranged downstream the inlet port (105). A set value of the pressure regulator (106) is controlled by the control unit (104), a control valve (107) arranged downstream the pressure regulator (106), wherein each of the at least one manifold (101a-d) is connected to a corresponding output port of the control valve. The control valve is controlled by the control unit (104), and the control unit is configured to set the set value of the pressure regulator to a value that causes a predetermined gas flow from each of the at least one nozzle.

A method of cleaning a condensate thermosyphon reboiler including modifying a flow rate of a hot oil stream introduced into the tube-side of a first condensate thermosyphon reboiler, modifying a flow rate of a condensate hydrocarbon stream introduced into the shell-side of the first condensate thermosyphon reboiler, and maintaining an operation of the condensate stabilizer system until the value of an overhead temperature of the first condensate thermosyphon reboiler is detected to have been modified from the first overhead temperature to a second overhead temperature. The method further includes modifying the flow rate of the condensate hydrocarbon stream from the second condensate flow rate to the first condensate flow rate, and modifying the flow rate of the hot oil stream from the second hot oil flow rate to the first hot oil flow rate.

The present invention relates to a method for continuously operating a distillation column, which is designed to separate a mixture S, which contains essentially a substance A and a substance B, which boils significantly higher than substance A. In the method according to the invention, the reflux ratio is changed according to the feed flow and, at the same time, the energy input by means of the heat-transfer medium is changed proactively (so-called feed-forward control) by accounting for the feed flow by means of feed-forward control. At the same time, the bottom temperature is observed and the control structure is changed if the bottom temperature falls too far when the heat-transfer medium is reduced by means of the feed flow.

The present invention relates to a plant for removing C.sub.6-C.sub.11 hydrocarbons from methanol, comprising at least one reactor for the conversion of carbon monoxide and hydrogen to a crude methanol containing hydrocarbons, a distillation column with a head and a sump for the purification of the methanol, and at least one conduit for guiding the crude methanol from the at least one reactor into the distillation column. At its head, the distillation column includes a feed conduit for feeding in water.

The present invention relates to a process for purifying a wastewater stream WW1 contaminated with nitrobenzene, comprising (I) stripping of the wastewater stream WW1 with a stripping gas SG1 in a continuously operated stripping column to obtain a wastewater stream WW2 which contains nitrobenzene in a concentration reduced relative to WW1 (c.sub.NB,WW2), (II) further purification of the wastewater stream WW2 in a wastewater treatment plant, wherein a target value (c.sub.NB,WW2,TARGET) is specified for the concentration of nitrobenzene in the wastewater stream WW2, which is greater than zero but takes into account the requirements of the wastewater treatment plant for the maximum content of nitrobenzene in the wastewater streams supplied thereto, wherein, for at least one combination of specified boundary conditions of (a) nitrobenzene concentration in WW1, (b) the temperature of WW1, and (c) the temperature of SG1, a set of linear mathematical relationships of the type m.sub.SG1=x.Math.m.sub.WW1 is stored in a database, which linear mathematical relationships define a range of concentrations of nitrobenzene in WW2, wherein the set comprises, in addition to a mathematical relationship (0) which corresponds to the target value c.sub.NB,WW2,TARGET, at least a first mathematical relationship (1) for a first value of c.sub.NB,WW2, which corresponds to 98% of the target value c.sub.NB,WW2,TARGET, and a second linear mathematical relationship (2) for a second value of c.sub.NB,WW2, which corresponds to 102% of the target value c.sub.NB,WW2,TARGET, and wherein the flow rate of the stripping gas is adapted to the flow rate of the wastewater WW1 such that the flow rate of WW1 is within a range of values (AB) that is generated by the first mathematical relationship (1) and the second mathematical relationship (2) at the respective flow rate of WW1, and controlling the concentration of nitrobenzene in WW2 (c.sub.NB,WW2) by adjusting the flow rate of stripping gas SG1 accordingly in the event of a measured actual value of this concentration which is outside a window of >98% to <102% of the target value.

The present invention relates to a process for purifying a wastewater stream WW1 contaminated with nitrobenzene, comprising (I) stripping of the wastewater stream WW1 with a stripping gas SG1 in a continuously operated stripping column to obtain a wastewater stream WW2 which contains nitrobenzene in a concentration reduced relative to WW1 (c.sub.NB,WW2), (II) further purification of the wastewater stream WW2 in a wastewater treatment plant, wherein a target value (c.sub.NB,WW2,TARGET) is specified for the concentration of nitrobenzene in the wastewater stream WW2, which is greater than zero but takes into account the requirements of the wastewater treatment plant for the maximum content of nitrobenzene in the wastewater streams supplied thereto, wherein, for at least one combination of specified boundary conditions of (a) nitrobenzene concentration in WW1, (b) the temperature of WW1, and (c) the temperature of SG1, a set of linear mathematical relationships of the type m.sub.SG1=x.Math.m.sub.WW1 is stored in a database, which linear mathematical relationships define a range of concentrations of nitrobenzene in WW2, wherein the set comprises, in addition to a mathematical relationship (0) which corresponds to the target value c.sub.NB,WW2,TARGET, at least a first mathematical relationship (1) for a first value of c.sub.NB,WW2, which corresponds to 98% of the target value c.sub.NB,WW2,TARGET, and a second linear mathematical relationship (2) for a second value of c.sub.NB,WW2, which corresponds to 102% of the target value c.sub.NB,WW2,TARGET, and wherein the flow rate of the stripping gas is adapted to the flow rate of the wastewater WW1 such that the flow rate of WW1 is within a range of values (AB) that is generated by the first mathematical relationship (1) and the second mathematical relationship (2) at the respective flow rate of WW1, and controlling the concentration of nitrobenzene in WW2 (c.sub.NB,WW2) by adjusting the flow rate of stripping gas SG1 accordingly in the event of a measured actual value of this concentration which is outside a window of >98% to <102% of the target value.

A sewage treatment machine comprising: a closed container inside which the liquid to be treated is brought to boil; a vacuum-generating apparatus, which is adapted to maintain the inside of the closed container at a given pressure having a value lower than the environmental/external pressure; a heat-pump assembly which is associated to the closed container so as to be able to transfer heat to the liquid present on the bottom of the closed container, thus to bring said liquid to boil, and simultaneously remove heat from the vapours that reach the top of the closed container, thus to condense the vapour and obtain a distilled liquid, and which contains a refrigerant fluid comprising one or more gases of the family of the hydrofluoroolefins in a percentage greater than 3%.

A sewage treatment machine comprising: a closed container inside which the liquid to be treated is brought to boil; a vacuum-generating apparatus, which is adapted to maintain the inside of the closed container at a given pressure having a value lower than the environmental/external pressure; a heat-pump assembly which is associated to the closed container so as to be able to transfer heat to the liquid present on the bottom of the closed container, thus to bring said liquid to boil, and simultaneously remove heat from the vapours that reach the top of the closed container, thus to condense the vapour and obtain a distilled liquid, and which contains a refrigerant fluid comprising one or more gases of the family of the hydrofluoroolefins in a percentage greater than 3%.