Abstract: Crude ammonia is separated into a low boiler fraction, a high boiler fraction and an intermediate-boiling pure fraction by continuous fractional distillation in a distillation apparatus configured either as a dividing wall column or as a system of thermally coupled distillation columns. In the process of the present invention, the low boiler fraction is taken off at the top of the distillation apparatus. The intermediate-boiling pure fraction is obtained at a side offtake which is preferably provided with droplet precipitators. In addition, the gas loading of the distillation column is restricted so that the operating pressure is in the range from 2 to 30 bar and the F factor does not exceed 2.0 Pa0.5.

Abstract: Apparatus and process are disclosed for the distillation separation of styrene monomer from ethylbenzene utilizing a split feed to two distillation columns in conjunction with cascade reboiling utilizing thermal energy from the overhead of one column to supply heat to the second.

Abstract: A method and apparatus for recycling and recovering potentially explosive solvents includes providing a contaminated solvent to a distillation tank, vaporizing the solvent in the distillation tank, thereby producing solvent vapor, condensing the solvent vapor, and adding a free radical scavenger substance to the distillation tank during the heating step. The vapor is then condensed and collected in a clean solvent tank where additional free radical scavenger substance is added to the clean solvent tank. Preferably, contaminated solvent is introduced into the solvent recovery system by providing contaminated solvent into contaminated solvent tank which is connected to the distillation tank, and an oxygen displacer substance is provided to the contaminated solvent tank and the clean solvent tank so as to minimize the amount of free oxygen in the tanks.

Abstract: Process and apparatus for regenerating a contaminated solvent wherein said solvent is first separated from higher-boiling contaminants in an evaporator, and then contaminants having a lower boiling point than said solvent are separated out in a condenser in which the temperature of said lower-boiling contaminants coming out of said condenser and the temperature of said solvent coming out of said condenser are separately controlled.

Abstract: A water distillation apparatus includes a degasification chamber having a top and a bottom. A liquid inlet is positioned adjacent to the bottom. A gas outlet is positioned adjacent to the top. A liquid outlet is positioned intermediate the top and the bottom. A float/valve assembly is provided for controlling the level of liquid within the chamber. A boiling chamber is provided having a top and a bottom. A liquid inlet is positioned intermediate the top and the bottom connected by a first transfer conduit to the liquid outlet of the degasification chamber. A steam outlet is positioned adjacent the top. A heating element is disposed within the boiling chamber whereby liquids within the boiling chamber are heated to the boiling point with the resulting steam passing out through the steam outlet. A condensation chamber is provided having a steam inlet and a liquid outlet. The steam inlet is connected by a second transfer conduit to the steam outlet of the boiling chamber.

Abstract: The invention is based on the discovery that hyperbaric, hydrostatic pressure reversibly alters the partitioning of nucleic acids between certain adsorbed and solvated phases relative to partitioning at ambient pressure. The new methods and devices disclosed herein make use of this discovery for highly selective and efficient, low salt isolation and purification of nucleic acids from a broad range of sample types, including forensic samples, blood and other body fluids, and cultured cells.

Abstract: A method for operating a column having a region for reaction with distillation of fluid streams is provided with structures including catalyst-filled containers having liquid permeable upper surfaces which allow for the accumulation and flow of liquid from a liquid stream. The containers include catalyst beds positioned beneath the upper surface of the containers. A portion of the liquid on the containers is driven through the catalyst bed by the liquid head created by the accumulated liquid and is catalytically reacted. Another portion of the liquid may be directed through a downcomer which allows the accumulated liquid to leave the container without passing through the catalyst bed so that higher volumetric flow rates can be achieved.

Abstract: A movable water distiller capable of use in conjunction with a water heater includes a frame having a top which supports the water heater. The distiller components are supported on a tray having a guide assembly engaging a track assembly horizontally positioned in the bottom region of the frame. The guide assembly allows the distiller components to be inserted within, and extracted from, the frame interior while the track assembly maintains alignment of the tray. Alternatively, the guide assembly may be attached to the top surfaces of the track assembly. Paneling surrounds the sides and back of the frame, while a front cover is attached to the front of the tray. The front cover and the paneling enclose the interior of the frame and prevent access to the distiller components.

Abstract: A process for minimizing evaporator scaling during the recovery of liquids and solids from the aqueous effluent discharged during a partial oxidation gasification, wherein the aqueous effluent contains ammonium chloride (NH.sub.4 Cl). The aqueous effluent is evaporated to produce a distillate water and a brine having an NH.sub.4 Cl concentration of about 10 to 60 weight percent. The brine can be further concentrated and ammonium chloride crystals are recovered. The distillate water is recycled to the gasification reaction. No effluent discharges to the environment.

Abstract: The invention relates to a process for evaporating a liquid containing vaporizable oxidation-sensitive compounds in an evaporator in which the liquid is brought into contact with a heated solid surface for evaporation, by a process in which direct contact between the resulting vapor phase and the heated solid surface is substantially avoided. It also directed to an evaporator composed of a heatable solid surface (16), an apparatus (2, 3) for heating the solid surface and an apparatus (10) for feeding a liquid containing vaporizable compounds to the heatable solid surface, wherein the apparatus for feeding the liquid is designed and arranged in the evaporator in such a way (12, 14, 18) that direct contact between a resulting vapor phase and the heatable solid surface is substantially avoided.

Abstract: A process for extracting salt from brine contained in at least one open evaporation basin. At least part of the brine is heated in a heating unit located outside the evaporation basis and returned to the evaporation basin. The heating unit is driven by waste heat from a recooling industrial plant. According to this process, climatic values and the degree of recooling are measured and evaluated in a control unit. At least part of the heated brine and some non-heated brine are sprayed by a spraying device of the evaporation basin. The amount of sprayed brine is regulated by the control unit depending on the measured data.

Abstract: A method for purifying liquefied corrosive gases of metallic impurities is described. The principle for this purification method relies on vapor-phase transfilling the vapor phase from a source container into a receiving container. This method has been observed to decrease metal concentrations by a factor of at least 1000 and decreases the metallic impurity levels in the resulting condensate. The vapor transfer is accomplished by controlled differential pressure rather than mechanical pumping, thereby generating no particle or metal impurities.

Abstract: An installation for cleaning oil-polluted water, in particular at oil and gas production plants, is provided with a distillation column having a polluted water feed and at least one contact packing above which the outlet of the polluted water feed is located, a vapor discharge, a clean water outlet and a measuring device for the analysis of the water from the clean water outlet.

Abstract: A method and apparatus for separating components from a mixture includes a condensing surface located in a high vapor concentration region above the source of evaporated liquid. The evaporated liquid is condensed on the condensing surface. The condensed liquid is removed from the condensing surface while it remains liquid, using substantially capillary forces. A plurality of open grooves are formed on the condensing surface. The grooves channel the condensed liquid on the condensing surface away from the mixture. The grooves can be capillary grooves which satisfy the Concus-Finn Inequality.

Abstract: An improved process for preparing an aromatic dicarboxylic acid wherein the improvement resides in dehydrating and recovering solvent from a feed stream having from 20% to 40% by weight water via azeotropic distillation with organic phase reflux using an entrainer selected from isobutyl acetate, n-propyl acetate or an entrainer with a boiling point between isobutyl acetate and n-propyl acetate.

Abstract: Distillation system having an evaporator/condenser core with heat transfer plates welded together along their edges to form alternate boiling and condensing chambers. Feed liquid is supplied to the boiling chambers through a pair of heat exchangers which preheats the liquid and a steam stripper utilizing ceramic pieces to remove gasses from the liquid. Vapor from the boiling chambers is compressed and delivered to the condensing chambers where it is condensed and gives up its heat to the liquid in the boiling chambers. Pumps positioned between the two heat exchangers draw the condensed product and unvaporized feed liquid containing dissolved solids from the evaporator/condenser and circulate them through the heat exchangers to transfer heat to the feed liquid.

Abstract: A method and apparatus for forming an array of multiple parallel flow orifices, for example by holes drilled through a plate in a selected pattern and spacing and of selected sizes or flow diameters, and whereby these orifices are used to provide an approximately equal and adequate distribution of liquid flowing through them as parallel streams of liquid and into an evaporation zone or a parallel array of evaporation channels, and wherein the orifices can be adjusted in flow diameter to control the flowrate of liquid in generally parallel streams with an array of orifice adjusting apparatus, for example an adjacent sliding orifice plate which provides for orifice flow rate adjustment with orifices through this second plate corresponding in position to those of the first orifice plate, and the use of such dual orifice plates for supporting a pool of liquid there-above and for controlling the flowrate of liquid through the first array of orifices by reducing or enlarging their orifice flow diameters to control

Abstract: Process technology is described making possible substantial improvements in the separation and recovery of highly pure vinyl aromatic monomers, notably styrene. A number of design, construction and operational features are made available for selection and use both for new plant facilities and for upgrading existing plant facilities. One major aspect of the invention is reduction in retention or residence times in the distillation towers.

Abstract: In a process for the continuous distillation of thermolabile monomers under reduced pressure in the presence of formamide in a column,the thermolabile monomers are continuously fed in liquid form, separately from formamide, into the lower part of the column up to the middle of the column,Formamide is vaporized with a vaporizer at the bottom of the column and, together with constituents having higher boiling points than the thermolabile monomers, is discharged from the bottom of the column and replaced by addition of fresh formamide,the thermolabile monomers are taken off at a side offtake in the upper third of the column, with the distillation being controlled such that the monomers contain less than 5% by weight of formamide, anda product stream containing constituents which have a lower boiling point than the thermolabile monomers is taken off at the top of the column.

Abstract: A water distiller incorporates a removable vessel for containing water, a heat source disposed below the removable vessel for heating the water to produce steam, a condenser for condensing the steam into distilled water, and an outlet from the condenser for directing distilled water into a collection container.

Abstract: Distilling equipment including evaporation apparatus having a boiling chamber and equipment and conduits for supplying raw liquid to the boiling chamber, a plurality of cells with the first cell being connected to the top of the boiling chamber to receive gas therefrom and condense the gas by contact with cold recycled distillate from the first cell, with each stage having vertical vacuum producing bubble tubes through which distillate and gas bubbles pass downward to a collection chamber through the bubble tubes. Cell recycle conduits and pumps recycle fluid from collection chamber to condensing chamber. Distillate is drawn from the condensing chamber of the first cell only. Gas by-pass tubes connect the collecting chamber of a cell to the condensing chamber of the next cell and provide the only connection between the cells to sum the vacuum generated by each cell's bubble tubes.

Abstract: For production of mineralized drinking water, water is distilled and then passed through a layer of soil which is taken from an area adjoining the source of natural mineral water.

Abstract: To compensate the bypassing, at the edges, of the liquid flowing downward in a distillation column, in order to achieve optimum mass transfer with the ascending vapor, a specific nonuniform distribution of the liquid trickling density over the column cross-section is established including the steps of establishing a nonuniform distribution of the liquid trickling density over the column cross-section in the distillation column and adjusting the liquid trickling density in the wall regions, said nonuniform distribution being achieved bya) arranging a number of outlet orifices or the diameter of the outlet orifices of a liquid distributor orb) arranging baffles in the stripping sections at height intervals from 0.1 to 2 m, in the case of dumped packings with baffles which project into the column space from the wall by about from 0.

Abstract: The viscosity of quench oil circulated in a pyrolysis fractionation unit is controlled by contacting pyrolysis furnace effluent with a slip stream of 0.1-0.5 kg/kg of the quench oil, separating the resulting vapor-liquid mixture to remove tarry liquid, and feeding the remaining vapor to the fractionator. Removing the tarry liquid from the fractionator feed in this manner allows operation of the fractionator with less reflux, a higher bottoms temperature, and more heat recovery at a higher temperature.

Abstract: A solvent recovery system for an oil and grease test collects and condenses solvent vapors to recover solvent. A vessel having an inlet for sealingly receiving an outlet of a separatory funnel receives solvent from the separatory funnel. The solvent is filtered through a filter paper placed in a funnel integral with the vessel. The funnel has a lower tubular section protruding from the vessel. A vapor return tube, integral with the vessel, surrounds the tubular section providing an annular space between an inside wall of the vapor return tube and an outside wall of the tubular section. Filtrate flows downward through the funnel tubular section into an evaporation flask, where the solvent is heated and evaporated leaving an oil and grease residue. Solvent vapors flow upward through the annular space within the vapor return tube into the vessel. A condenser, integral with the vessel, receives and condenses the vapors forming a condensate that is collected in a solvent recovery flask.

Abstract: A device for drilling a layer of coke within a reactor to effect the decoking of the reactor includes a decoking tool arranged at one end of a hose for conveying a decoking fluid to the tool. The decoking tool has a first part and a second part coaxial with the first part. The second part has means for ejecting the decoking fluid against the coke layer, including a first ejection means for ejecting the fluid in a substantially axial direction downwardly to penetrate the coke layer, a second ejection means ejecting the fluid in a substantially lateral direction and a third ejection means for ejecting the fluid in a substantially upward direction to remove any coke accumulated above the tool.

Abstract: The water distiller 10 includes a plurality of housings 12, 14, 16 each mounted below a support plate 32. A voltage regulator 144 maintains a desired voltage potential between heating probes 34 and 36 within a heating bowl 46. An operator selector 142 automatically regulates the flow of water through inlet valve 70 to control the incoming water flow rate to the heating bowl. Area contact between water in the heating bowl and a substantially horizontal plate 42 at the lower end of each heating probe determines the electrical power used by the distiller, and maintains water in the heating bowl at substantially a constant level. An improved particle trap 80 and vent valve 100 provide reliable and safe operation of the distiller. Heating bowl 46 and a water inlet line 76 may be easily removed for cleaning the distiller.

Abstract: In the continuous purification of a propylene oxide feedstock contaminated with water, methanol and acetone wherein an acetone buffer is established in the column, normal distillation conditions are maintained or restored during or after an upset by continuously monitoring predetermined distillation conditions in the acetone buffer zone, and adding additional acetone to the extractive distillation column when the monitored distillation condition deviates from a predetermined value by a predetermined amount.

Abstract: An improved drinking water apparatus is provided which utilizes a microcomputer to detect water level to automatically control water intake and heating. The apparatus includes a heating tank having a heater at the bottom side, a first cooling pipe at the top of the heating tank, a distilled water tank, and a second cooling pipe located at the top of the distilled water tank and connected to the first cooling pipe. The cooling pipes are each provided with a cooling fan for cooking the steam generated by boiling water into distilled water. The temperature of the distilled water is lowered to a degree suitable for drinking purposes.

Abstract: A method for continuously extracting a solute from a carrier medium. A volatile solvent is placed in a lower distillation chamber of a vessel, the vessel including a convergent baffle disposed to separate the vessel into a lower distillation chamber and an upper extraction chamber. The convergent baffle is contoured to converge to define a conduit riser projecting upwardly into the extraction chamber and terminating in a vaporized solvent port placing the distillation chamber in fluid flow communication with the extraction chamber. A carrier medium containing a solute to be extracted is placed in the extraction chamber. The volatile solvent in the distillation chamber is then vaporized. The vaporized solvent flows upwardly and is converged through the convergent baffle and conduit riser. The converged vapor stream passes through the vaporized solvent port into the carrier medium, flowing through the carrier medium and inducing a linear-torroidal flow in the carrier medium.

Abstract: When waste liquid is concentrated using a radiant heat section and a heat absorbent section of a heat pump circuit, in the proper place of the heating region of the heat pump circuit, a detector for detecting the pressure and/or temperature of the heat transfer medium is provided, or a detector for detecting the value of an electric current flowing through or the amount of electric power consumed in a system which includes a compressor for the heat pump circuit, is provided, and by the provision of a control system which can halt the concentration operation when the detected value exceeds a set value, both with a liquid in which the concentration of the non-volatile component is low so that a comparatively long time is required for the concentration operation, and, conversely, with a liquid in which the concentration of the non-volatile component is high so that the concentration operation is completed in a comparatively short time, the concentration operation has good efficiency, and can always be halted at

Abstract: Method and apparatus for recycling a water-displacement process fluid that includes an organic liquid and a surfactant, the boiling point of which exceeds that of the organic liquid, maintains a sufficient quantity of organic liquid such that water displaced into the organic liquid is evaporated at least as fast as it is introduced. If the water and the organic liquid are immiscible and exhibit different densities, the resulting condensate can be separated into constituent phases by decanting. The condensed organic liquid and unevaporated surfactant are then available for recycling.

Abstract: A process and apparatus for the production of a beverage distills aqueous influent into a forerun overhead fraction that is the first result of a distillation operation, a distillate, and a bottom products fraction that is left over from the aqueous influent without being distilled. The forerun overhead fraction is removed, the distillate is sterilized and remineralized into the beverage, and the bottom products fraction is removed so the process can begin again with more aqueous influent.

Abstract: A water distilling apparatus includes a preheat tank having an inlet and an outlet for storing water from a water source via the inlet, a boiling tank formed of a conductive casing connected to a ground potential and having an inlet in connection with the outlet of the preheat tank, a heater located within the boiling tank to boil water thereby generating steam, and an outlet flue extending from the boiling tank through the preheat tank as to condense the steam and preheat the water within the preheat tank, a heat dissipation coil connected with the outlet flue out of the preheat tank, a fan blowing air against the heat dissipation coil, a cool water tank connected with the heat dissipation coil for storing condensed water therefrom, an electrode vertically extending into the boiling tank, electrically isolated from the case of the boiling tank and connected to a positive voltage source, a control circuit electrically connected to each of the electrode, the fan, and the heater for disconnecting the fan and th

Abstract: A process for preparing essentially pure 3-chlorophthalic anhydride from a mixture in which 3-chlorophthalic anhydride is present in addition to 4,5-dichlorophthalic anhydride, which involves first distilling off a mixture of 3-chlorophthalic anhydride and 4,5-dichlorophthalic anhydride, so that the obtained bottoms is essentially free of 4,5-dichlorophthalic anhydride, and then by distillation of the obtained bottoms, recovering 3-chlorophthalic anhydride in a second distillation step. The starting mixture is preferably prepared without solvent in a melt by incomplete chlorination of phthalic anhydride using FeCl.sub.3 as a catalyst.

Abstract: A distilling apparatus which includes a water chamber to receive cold water from an external water supply source, a heating chamber having an electric heater controlled to heat water to the boiling point, a guide pipe connected between the bottom side of the water chamber and the bottom end of the heat chamber to guide water from the water chamber to the heating chamber, a radiating coil pipe connected to a distilled water drain pipe outside the apparatus, and a steam pipe connected between the steam chamber and the radiating coil pipe and passing through the water chamber to guide steam from the heating chamber to the radiating coil pipe, permitting steam to be condensed into distilled water and heat to be absorbed by water in the water chamber.

Abstract: A water purification apparatus positionable on an existing dispenser has a valve control member positionable in the water plenum of the dispenser to control release of purified water from the apparatus to the dispenser. A feedwater tank receives supply water which is fed to a water level control tank to maintain the water level in the boiler of the apparatus above the heating element. The control tank includes a partition separating a main reservoir from a de-foamer control chamber within which anti-foaming agent may be added. A condenser is coiled into a number of convolutions about a central opening and has external heat exchanger fins. An end cap assembly closes the central opening except for a small portion through which air is blown by a fan so that substantially all of the air flows over the fins. The boiler is a cylindrical container having a peripheral lip about an open end on which a lid having a steam outlet tube is positioned.

Abstract: The invention relates to an improved distillation method wherein hexamethylcyclotrisiloxane is isolated from a crude blend thereof by mixing the crude blend with a hydrocarbon co-solvent having a normal boiling point of 125.degree. C. to 150.degree. C. and distilling the resulting mixture in an apparatus having a reboiler, a fractionating column and a condenser, whereby deposition of solid hexamethylcyclotrisiloxane in the condenser is eliminated.

Abstract: A system for decontaminating and separating individual refrigerants from a mixture of refrigerants contaminated with solids, liquids and non-condensible gasses, includes three stages. In the first stage, solid and liquid contaminants are removed. In the second stage, the mixture of refrigerants passes through a condensation column where successive condensation stages remove individual refrigerants from the mixture of refrigerants. The remaining mixture of refrigerants passes through a third stage where non-condensible gas contaminants are removed.

Abstract: A method of evaporating liquid from a liquid and solid solution in a container within a chamber involves moving the container in an orbital motion such that the solution forms a vortex configuration within the container and also involves directing gas into the container. The gas is directed into the container from a point source above the liquid in the container to decrease the partial pressure on the solution thereby increasing the evaporation rate of the liquid from the solution. To further increase evaporation of the liquid, heat may be applied to the container. The temperature within the chamber may be regulated by sensing the temperature within the chamber and controlling the application of heat to the container in response to the temperature sensed within the chamber.

Abstract: An apparatus for converting seawater or other contaminated water into pure water for reuse including: a source of the contaminated water; a first horizontal housing connected to the source of contaminated water and having a heat exchanger therein for vaporizing the contaminated water therein; a vertical housing connected to the distal end of the first horizontal housing for fluid communication therebetween; a second horizontal housing connected at its proximate end to the vertical housing for fluid communication therebetween, the second horizontal housing having a heat exchanger therein for condensing vapor therein; a weir vertically mounted in the first housing for retaining a portion of the contaminated water in the first housing and allowing the other portion of the contaminated water to pass through the heat exchange evaporator from the proximate to distal end of the first housing.

Abstract: The horizontal distance traveled by droplets of starting solution sprayed into a gaseous medium above a catch basin, where the gaseous medium has a horizontal velocity component is controlled by controlling the size of the droplets as a function of the horizontal velocity component.

Abstract: A water distillation apparatus and method include an improved control system for operation and maintenance, condensers with plastic to metal seals between a plastic condenser manifold and metallic cooling tubes, and a filter with steam bypass to allow for easy sterilization of the filter and remaining distillation system. The control system includes a three pronged probe assembly for monitoring conditions within an evaporation chamber. One of the three probes monitors steam conductivity and provides a steam fault signal to indicate an upper level of contaminants in the steam. A purge pump is responsive to fault signals, including the steam fault signal, to pump water from the evaporation chamber. Improved techniques are also provided for periodically dumping a portion or all of the water in the heating pan to reduce contamination of the system.

Abstract: A compact, transportable and self-contained apparatus for treating wastewater containing as impurities and pollutants various non-volatile (at water boiling points) fluids such as greases, oils and soaps, having a vessel/evaporator for receiving the wastewater, a heater below the evaporator to heat the wastewater admixture and boil off the water, a collector to draw off the non-volatile fluids from substantially the entire height of the water evaporator, and automatic refill/shutdown control devices for the apparatus.

Abstract: A distilled water supply device including a stand, a condensing unit mounted on the stand and separated by a partition wall into an upper chamber, which receives water from an external water source, and a bottom chamber, which condenses steam into distilled water, a heating unit detachably mounted inside the stand below the condensing unit and controlled to heat water from the upper chamber into steam, permitting steam to be guided into the bottom chamber for condensing, a vertical guide pipe for guiding water from the upper chamber to the heating unit, a vertical steam pipe for guiding steam from the heating unit to the bottom chamber for condensing.

Abstract: A regenerating system, for the removal of water and potentially harmful organic constituents from a hydration fluid used to dehydrate natural gas. The system includes a device to assure positive flow of the water and organic constituent vapor out of the regenerator, to, in turn, control back pressure associated with the regenerator during the distillation process.

Abstract: A method and apparatus for removing water from a solution of water and glycol solution. The apparatus finds application in recycling of glycol wherein a water and glycol solution having as much as a 95% water content when introduced to the apparatus leaves the apparatus with a water content in the order of 40% to 60%. The glycol concentrator has a packing medium made from glass shards that provide a labyrinth through which air is circulated in one direction and thin streams of glycol are circulated in generally the opposite direction. It is believed that mixing of the thin streams of solution and air flow steams in the labyrinth results in a thin film evaporation process. The glycol concentrator apparatus has reduced energy requirements when compared with a distilling process.

Abstract: A regenerating system, for the removal of water and potentially harmful organic constituents from a dehydration fluid used to dehydrate natural gas. The system includes a device to assure positive flow of the water and organic constituent vapor out of the regenerator, to, in turn, control back pressure associated with the regenerator during the distillation process.

Abstract: A process and device for purifying organically polluted waste water utilizing a primary system and a closed secondary system. The primary system includes a first heat exchanger, a second heat exchanger and a cyclone located between the two heat exchangers. The first heat exchanger evaporates the waste water into a waste water vapor and a waste water sump solution. The heat for evaporating the waste water in the first heat exchanger is obtained primarily from raw water in the secondary system. A second heat exchanger in the primary system condenses the waste water vapor and in the process causes evaporation of raw water in the secondary system. The level of waste water in the primary system is monitored as is an operational parameter in the secondary system. With the data obtained from this monitoring, the drawing off of the waste water sump solution is controlled.

Abstract: An apparatus and method for treating chemical production plant process condensate such that a contaminant-rich stream and a relatively pure aqueous stream is separately recoverable from the condensate, wherein the contaminants are substantially removed from the condensate by steam stripping and subsequent rectification in a relatively low pressure stripping/rectification tower. The tower overhead is then condensed with a portion of the condensed overhead being returned to the top of the rectification section of the tower as reflux and the balance being withdrawn as a concentrated stream for reuse in the plant. In a second embodiment, separate stripping and rectification towers operate in series whereby the overhead of the stripping tower is delivered to the lower section of the rectification tower and the rectification bottoms are returned to the top of the stripping tower.