The present invention relates to a toluene diisocyanate purification method enabling acquisition of a product having a small amount of dimers in a final product by means of using a reactive dividing wall column during toluene diisocyanate preparation. More particularly, according to the present invention, in order to obtain a product having a small amount of dimers in accordance with a reversible reaction of a monomer and a dimer, a purification procedure is designed by means of applying the temperature, pressure, time of stay and the like of a reactive dividing wall column as appropriate particular conditions, a reboiler having short time of stay and high heat transfer rate is used, and thus a dimerization reaction is inhibited and the purity and yield of the product are enhanced. Therefore, high-purity toluene diisocyanate can be purified and obtained.

The present invention provides to a process for recovery of an organic compound (i.e. Ethanol, propanol, butanol, Acetone, iso-propyl alcohol) from a fermented broth which is produced from different fermentation technologies. The present invention particularly relates to an integrated process for ethanol separation from the fermentation broth using integrated vapor compressing unit (turbofans), evaporator (falling film) and a broth stripper column (vacuum distillation system). The process is operated under low temperature for the separation and recovery of the organic compound (particularly ethanol) from the fermented broth containing live microbes typically below or at 50 C. to ensure the activity of the microbes in the broth recycle. Again, the activity of the microbes is further ensured by maintaining the residence time of the microbe containing broth outside the Fermentor is less than or equal to 10 minutes.

Regenerative vapor energy recovery system and method for use with an ethanol plant. Regenerative vapors are partially condensed in a regenerative precondenser using a warm water stream. The warm water stream is fed to the regenerative precondenser and the partially condensed regenerative vapor stream is sent back to the ethanol plant where the stream is fully condensed using an existing condenser. The ethanol plant is thus operated at greater energy efficiency with lower operating costs than would be achieved with conventional systems.

A method for separating a mixture of materials A and B by extractive distillation, using an extraction medium having a higher affinity to B than to A, collecting a liquid fraction on a collecting tray and heated and partially evaporated in a first indirect heat exchanger, collecting the resultant vapor is released into the column and a non-evaporated proportion of the liquid fraction in the sump of the column, and a series of heating, separation and cooling where partially cooled extraction medium fraction is used as heating medium for a heat exchanger.

The present invention relates to a method for treating a pyrolysis gasoline C5.sup.+ containing monoolefinic, diolefinic and sulfur hydrocarbons, comprising at least, and in any order: a) a step of hydrotreating the pyrolysis gasoline or a hydrocarbon fraction C6.sup.+ originating from the pyrolysis gasoline, in the presence of hydrogen and at least one hydrotreatment catalyst at a temperature ranging between 220 and 380 C. so as to produce a hydrotreated effluent; b) a step of separating the pyrolysis gasoline or the hydrotreated effluent originating from step a) when said step is completed before step b), into a separation column for separating into a top hydrocarbon fraction C5.sup. and a bottom hydrocarbon fraction C6.sup.+, said separation column comprising a reboiling section including two heat exchangers, at least one of the two exchangers being configured to perform a heat exchange with a portion of the bottom fraction that is recycled in the column via the reboiling section. According to the invention, one of the two heat exchangers of the reboiling section is supplied with at least one portion of the hydrotreated effluent so as to supply part of the heat required to operate the reboiling section.

A process of the type for producing chlorinated propanes by reacting carbon tetrachloride with ethylene within a tank reactor that includes a liquid reaction mixture and a headspace above the reaction mixture wherein ethylene gas diffuses from the liquid reaction mixture into the headspace while agitating the reaction mixture, the improvement comprising transferring ethylene within the headspace back into the reaction mixture through a conduit within the mixing device that agitates the reaction mixture.

The invention relates to a distillation unit (100 000) which is designed for a continuous distillation process and to a method for a continuous operation for separating a liquid substance mixture (10) into two to six liquid product flows (201, 202, . . . ) with different compositions and into a gaseous product flow (300). For this purpose, an evaporation unit (10 000) is provided consisting of multiple evaporation devices (10 000-1, 10 000-2, . . . ), wherein each evaporation device has a circuit device (1 200-1, 1 200-2, . . . ) for recirculating a sub-quantity of each of the liquid sump flows (22, 21, . . . ) of an evaporation device into the respective evaporation device, and each of the circuit devices additionally has a discharge device (1 300-1, 1 300-2, . . . ) for providing one of the liquid product flows (201, 202, . . . ).

The present application relates to a selective distillation apparatus and a distillation method, which provides a distillation apparatus capable of switching between a serial connection mode and a parallel connection mode on the situation, thereby enabling selective operation of high-efficiency operation and high-capacity operation.

A process and apparatus for hydrocracking a hydrocarbon stream and with heat integration between two stripping columns. Both stripping columns use a reboiler for heat input to avoid steam recovery and dew point issues in the overhead. A hot stripped stream can provide heat to the cold stripping column by heat exchange. Additionally, as few as two heaters that rely on external utilities may be required for reboiling fractionator column bottoms.

A system and method for producing substantially anhydrous ethanol, methanol or other volatile chemicals includes: (a) a first distillation stripping column or column set with overhead vapors compressed using mechanical vapor recompression to strip off a weak ethanol overheads; (b) a second distillation rectifying column having a higher operating temperature than the stripping column; (c) a dehydration means in fluid communication with the rectifying column; (d) reboiler for the stripping column which partially condenses the vapor from the mechanical vapor recompression, (e) a trim condenser which completes the condensing of the vapor/liquid mix of the reboiler, (f) a heat recovery circuit which condenses the rectifying column overheads and molecular sieve dry ethanol condenser and (g) a heat exchange to transfer the recovered heat of (f) to the first distillation stripping column reboiler feed.