Abstract: To heat the circulating reboiler streams of multiple distillation columns a fired reboiler is provided for a first column requiring the most heat. A portion of the bottoms from the first column is passed through the tubes of the heater in the fired reboiler and recycled to the first column as is normal. A slip stream is taken from the recycle after heating and passed on to provide heat by indirect heat exchange to a second reboiler and if desired other reboilers or heat exchangers. The slip stream may then be recycled to the bottoms of the first column directly or to the circulating steam of the first reboiler. A portion of the recycled slip stream can be taken as feed into the second column.

Abstract: A system and method for reducing hydrocarbons in wastewater includes an oil separator and a stripper tower. The tower has a housing that includes a stripper section and a condensation section. The stripper section includes a plurality of trays and steam inlet under the trays. The condensation section includes a plurality of trays and a pan tray having provisions to allow vapors to rise from the stripper section.

Abstract: Benzene and other aromatics are separated from a stream of mixed hydrocarbons containing both aromatics and non-aromatics by extractive distillation with a solvent system containing dimethyl sulfoxide and optionally a co-solvent, preferably water, followed by distillation stripping of the aromatics from the enriched solvent system, and recycle of the lean solvent system to the extractive distillation step.

Abstract: The invention relates to a distillation apparatus including a housing (1) a blower (2), preheat exchangers (7) and (8) and an evaporative condenser (25) comprising pairs (13) of membranes. One pair (13) of membranes at a time can be detached from the evaporative condenser (25) for replacement. The pairs (13) of membranes are preferably made of plastic or similar material and they hang down loosely in the evaporative condenser.

Abstract: A distillation system for recovery of volatile components of contaminated liquids used in an industrial process includes a tube assembly including outer tubes to which hot bottoms liquids are supplied and inner tubes to which process liquids are supplied for transfer of heat from the bottoms to the process liquids. From the tube assembly the two liquids are discharged into the still through separate, elongated, parallel discharge pipes. The process liquids discharge pipe is positioned above the bottoms liquids discharge pipe and an elongated, metal, angle plate is positioned as an inverted V between the two discharge pipes. Efficiency is improved over prior systems wherein process liquids are added to the still without being preheated by the bottoms fluids, and without the unique still intake manifold.

Abstract: A distillation system has a degassing tank, a distiller for generating vapor of raw water taken from the degassing tank, a heater for heating the vapor from the distiller to convert the vapor into a high temperature and pressure vapor, a hydrophobic porous membrane through which the vapor from the heater flows, and a heat transfer unit provided in the distiller for effecting heat exchange between the vapor from the membrane member and the raw water from the degassing tank. The structural elements such as the heat exchange unit, piping, etc., with which the vapor from the membrane or the condensate thereof is brought into contact are made of titanium or titanium alloy.

Abstract: In a plate heat exchanger for evaporation of a liquid by means of a heat emitting vapor every second plate interspace forms an evaporation passage (28) and the rest of the plate interspaces form condensation passages (30). Aligned openings (16) in the plates form an inlet channel through the plate heat exchanger for introduction of evaporation liquid into the evaporation passages (28). For enabling use of a large inlet area of each condensation passage (30) and a large outlet area of each evaporation passage (28) the plate heat exchanger is arranged in a container (1), the interior of which is divided in two chambers (6, 7) by the plate heat exchanger itself and a partition (5).

Abstract: A water distillation system and process capable of high efficiency operation used in combination with a heat pump system wherein the water distillation apparatus includes a water pre-heating device positioned within the feed water to heat the feed water to approximately 150 degrees Fahrenheit to facilitate operation of a water evaporator device which vaporizes the water by boiling thereof. Contaminants are removed from this pure water vapor which is at approximately 215 degrees Fahrenheit. The water vapor is passed to a water condenser to provide high purity water at approximately 180 degrees Fahrenheit. The heat pump system provides for refrigerant condensing at approximately 225 degrees Fahrenheit to facilitate boiling of the water in the adjacent water evaporator and includes refrigerant vaporization adjacent the water condenser to facilitate absorbing and reclaiming of the latent heat of the distillate.

Abstract: A system is disclosed for recovering and disposing of volatile organic contaminants, from water contaminated with organics, which system includes a pump to feed water from the body of contaminated water to the system, with indirect heat exchange and direct steam addition to raise the temperature of the water, a stripping vessel to strip the heated water with gas to strip the volatile contaminants from the water, gas supply to provide stripping gas to the vessel conduits to pass the removed volatile contaminants to a vessel containing a bed of adsorbent selective for the removal organics and regenerating the near-saturated bed by stripping with ambient air heated by heat exchange with the exhaust gas from a fuel-fired heater, passing the contaminant-containing regenerating gas from the regenerating bed to said fuel-fired heater, and combusting the contaminants in said fuel-fired heater.

Abstract: An apparatus and process for recovering a diesel-quality fuel from produced crude oil is described. The diesel-quality fuel is produced by flashing the crude feedstock at high temperatures and recovering the diesel quality fuel as a liquid from a refluxing exchanger. Process efficiency is enhanced by heat integration. The process is particularly applicable to remote locations, both onshore and offshore, where conventional fuel supplies are inadequate or not available.

Abstract: The disclosed invention is an apparatus and process for the distillation of liquids. The apparatus is comprised of a plurality of vertically stacked parallel disks which are rotated in a horizontal plane. The liquid to be distilled is introduced into the center of the disk stack and migrates by centrifugal force as a thin film across the top surface of each disk. During migration, the more volatile portion evaporates from the top surface and condenses on the bottom surface of a top, neighboring disk. The apparatus is multiple-effect in that the heat evolved from condensation is transferred through the thin, heat-conducting disks to provide the heat necessary for vaporization.

Abstract: A thermally-integrated extractive distillation process for recovering anhydrous ethanol from fermentation or synthetic feedstocks has a distillation train of four columns. Two columns are preconcentrators operated in parallel. The remaining columns are an extractive distillation dehydrating tower, and an entrainer-recovery column. The two preconcentrators and the dehydrating tower are operated at three successively increasing pressures so that the condensing vapors of the overhead product of the dehydrating tower supply the necessary heat to the reboiler of the intermediate-pressure preconcentrator. The overhead vapors of this preconcentrator are, in turn, used to supply the required heat to the reboiler of the lowest-pressure preconcentrator. The bottom product from each preconcentrator is used to preheat the dilute feed. Additional energy savings are accomplished by the appropriate heat exchange between the various feeds, overheads, and bottoms.

Abstract: The invention is a system for removing volatile hydrocarbon contaminates from both water and moisture-ladened air. In detail the invention comprises a steam stripping system for mixing the contaminated water with steam, at below atmospheric pressure, providing clean water for reuse and contaminated steam and vaporized hydrocarbon contaminates. A first condenser receives the contaminated steam and vaporized hydrocarbon contaminates and condenses, at below atmospheric pressure, a portion of the vaporized contaminates and a portion of the contaminated steam into contaminate water. A second condenser thereafter further condenses the steam and hydrocarbon vapor.

Abstract: Deodorizing and/or physical refining of relatively small, varying charges of high-boiling liquids, viz. fatty acids, edible oils, fats, glycerides and other high-boilding esters, is conducted continuously in a single-stage or multi-stage falling-film column (20) through the trickle passages (23) of which stripping steam is passed in counter-current flow. In the supply conduit (15, 15', 15", 15'") leading to the falling-film column and in the discharge conduit (30, 30', 30", 30'") leading away from the bottom (26) of the falling-film column a plug-flow of the liquid is maintained. Upon a change of charge the fresh liquid to be treated is normally introduced into the supply conduit--without any blank charge--directly following the liquid of the preceding charge. Charging of the liquid onto the deflector (22) in the head (21) of the falling-film column is interrupted for a short period of time when the front of the liquid of the fresh charge has reached a check valve (16) disposed adjacent said deflector.

Abstract: In the purification of ethylene oxide from an ethylene oxide-containing reaction formation gas produced by catalytic gas-phase oxidation of ethylene with a molecular oxygen containing gas, external thermal energy required for heating an ethylene oxide refiner is economized by a method which utilizes the diffusate obtained from the top of an ethylene oxide stripper as a heat source for the refiner. Further, the bottom liquid of the stripper can be used as a heat source for ethylene oxide refiner and/or a light ends stripper.

Abstract: A steam generator, especially a pure steam generator, having a feed line for conducting feed water to the same, an electrode system for heating the feed water, a steam outlet for removing generated steam, and a separating space in a lower part of the generator 10, along with a droplet separator through which the steam that has been generated is disposed to flow from the separating space to the steam outlet. Electrodes have been placed in small tubular spaces in a water space (i.e. a space receiving incoming feed water). The steam generator may be used in a multi-stage distilling apparatus by conducting the steam that has been formed to a second column or stage of the distilling apparatus, to constitute feed steam therefor.

Abstract: A heat exchange device which is employed for separating components of different volatility from a solution containing the components and which has particular application as a heat exchanger/rectifier/generator in an absorption cycle refrigeration system. The device comprises a plurality of heat conductive plates which are stacked as laminations in face-to-face heat conductive relationship and a chamber is formed in the plates, the chamber defining a zone into which fluid is directed and in which liquid and vapor phases of the fluid can separate. First, second, third and fourth fluid flow channel regions are formed within the plates.

Abstract: The invention pertains to a method for processing of organic materials containing nitrogen compounds, where the organic material undergoes an anaerobic digestion with simultaneous liberation of biogas which contains methane and carbon dioxide. The liquid product obtained after anaerobic digestion is, according to the invention, heated to boiling temperature, ammonia bonded as carbonate which is distilled off, and the tail product from distillation is further processed to the valuable product and clear water or is discharged as prepurified waste water. During the processing to the valuable product in the form of organo-phophate-lime concentrate, the tail product of distillation is alkalized by lime and carbonized with carbon dioxide. Biogas or carbon dioxide obtained by distillation may be used in carbonation.

Abstract: This document describes an improved method and apparatus for recycling energy in counterflow heat exchange and distillation. The basis of the invention is transferring heat with thin sheets of material having extensive surface area relative to the flow rate through the system. A distillation apparatus (11 and 12), a counterflow heat exchanger (11), a clothes dryer (FIG. 9), a power generator (FIG. 12), and other embodiments of the invention are described.

Abstract: A process for the separation of water from a water-containing mixture of azeotrope, with an extractant which removes water from the mixture or azeotrope, recovery of the non aqueous portion of the mixture or azeotrope as a product, and regeneration of the extractant for reuse by the removal of water therefrom. A feature thereof is that residual water can be removed from the extractant, and the extractant regenerated for reuse by contacting the heated extractant with a portion of the same product from which the water has been removed; or, the extractant can be regenerated in the process by contact with an inert gas which has been dried in the process. The water-containing mixture or azeotrope is preferably contacted with a portion of the vaporous product to recover the heat of condensation for use in the process.

Abstract: A water purification and hot water supply apparatus is provided including a feed water intake providing water in excess of the distilled water output, a heater controlling the quantity of water boiled, a waste water exit port to remove accumulated water above a certain level, a distilled water exit port in the vapor space, a condensing device to transfer the heat of condensation to a hot water tank and a waste water heat exchange device to transfer heat from the waste water to the hot water tank. A volatile organic compound removing tank to heat and vent off the contaminants is positioned to receive heat from the water in the still section of the apparatus which then feeds water to the feed water intake.

Abstract: A fractionation method is disclosed for the recovery of product alkylaromatic hydrocarbons produced by the alkylation of aromatic hydrocarbons. Three fractionation columns are employed in series. Aromatic feed hydrocarbons are recycled from the overhead of the first column, which is reboiled by the overhead vapor of the second column. The product alkylaromatic is recovered from the condensate produced in using the second column overhead as a heat source. The product alkylaromatic is also present in the bottoms of the second column which flows into a low pressure stripping column. The entire overhead vapor of the stripping column is compressed and passed into the lower portion of the second column.

Abstract: Demineralized crude water is distilled during flow along a first path which is defined by stationary parts. Such water is evaporated and thereafter cooled and condensed by a heat transfer medium which is circulated along an endless second path. Evaporation of crude water results in condensation of the medium, and condensation of resulting water vapors into distillate results in evaporation of the medium. The medium is caused to pass through a heat pump which raises its pressure and temperature before the thus heated medium exchanges heat with and evaporates crude water in the first path. The medium and/or the distillate can be used for preheating crude water upstream of the evaporating station, and the vapors are preferably purified by one or more cyclones, by an electrostatic filter and/or by ultrasonic waves intermediate the evaporating and condensing stations.

Abstract: A system for the distillation of sea water comprising a sea water input conduit, an evaporator, a work extractor, a float, a condenser, a distilled water output conduit, and a brine solution output conduit. The evaporator is connected to the input conduit. The work extractor comprises a cylinder, a piston slideably engaging the interior of the cylinder, and a piston rod extending from the piston. The piston rod is pivotally coupled to the float. The cylinder is pivotally attached to a second float. The second float is connected to the first float. A conduit connects the piston-and-cylinder arrangement with the condenser. The condenser communicates with the distilled water output conduit. The evaporator communicates with the brine solution output conduit. The energy for this system is provided by the wave motion of a body of water.

Abstract: In a combination alkylation-methyltertiary butyl ether (MTBE) operation, isobutane vapor side-draw and bottoms product yield from the alkylation fractionation, respectively, are used to indirectly heat the mid-section and reboil section of the methyltertiary butyl ether fractionator for heat conservation, beneficiating both the alkylation operation and the MTBE operation.

Abstract: A vapor compression distillation system for distillation of any two-component liquid mixture where separation of the more volatile from the less volatile component is required. This system achieves a very high efficiency through the use of vapor compression in conjunction with three heat exchangers: a reboiler which condenses the hot vapors compressed by a vapor pump and uses the heat given up by the condensing vapor to boil bottoms liquid to produce vapor within the stripper, a distillate heat exchanger which recovers heat from the distillate stream, and a bottoms heat exchanger which recovers heat from the outgoing bottoms effluent. This particular component configuration and process results in an exceptionally stable and reliable operation requiring the continuous control of only one parameter, reboiler temperature, while fixing all other process variables.

Abstract: The invention pertains to improvements in a fluid handling system in which a working fluid passes through a rotor while undergoing a pressure change. A shaft extends longitudinally from and rotates with the rotor. A first seal surrounds the shaft in axially spaced relation to the rotor, and a lubricant having a minimum boiling point is injected into the first seal adjacent the shaft at a pressure sufficient to cause the lubricant to flow axially toward the rotor. A housing surrounds the rotor and shaft and defines a contact zone between the rotor and the first seal for receiving both lubricant and a contact fluid such as the working fluid or a seal buffer gas used to isolate the working fluid from the lubricant. The contact fluid has a maximum boiling point substantially less than the minimum boiling point of the lubricant.

Abstract: Solar distillation apparatus is disclosed in which the released heat of condensation of the condensing liquid is recovered in a transparent conduit disposed over the liquid to be distilled. Solar energy passes through the transparent conduit and is received on an undulated plate system over which the liquid to be distilled is conducted. A cooling fluid is circulated through the conduit to absorb heat released by the condensing liquid. In one embodiment, the conduit does not concentrate the solar energy. The conduit is preferably disposed at an angle of up to about 25.degree. with the horizontal so that the system is subjected to minimal pressure. In another embodiment the conduit defines a fluid lens system which concentrates the solar energy on the plate system. Provision is also made to recover heat from the condensate and a concentrate of the liquid to be distilled.

Abstract: A method for removing vinyl chloride monomer rapidly from a large amount of slurry of vinyl chloride resin to give waste water separated from said slurry, exhaust gas used in the drying of separated resin and resin product which are not objectionable from the environmental sanitation or to produce such a treated slurry which can give waste water separated from said slurry, exhaust gas used in the drying of separated resin and resin product which are not objectionable from the environmental sanitation by the repetition of said method. In said method a slurry of vinyl chloride resin is caused to flow down a plate column in which flow of slurry on the trays in each step of plates is treated with steam in a combination of specified plates and specified conditions of treatment.

Abstract: An improved distillation method and apparatus are provided for recovering anhydrous ethanol from fermentation or synthetic feedstocks. The system includes at least one stripper-rectifier tower, a dehydrating tower, and an azeotropic agent stripping tower. Substantial energy savings are realized by operating the dehydrating tower, and preferably also the azeotropic agent stripping tower, at a higher pressure than the stripper-rectifier tower and by condensing the overhead vapors from the dehydrating tower (or dehydrating tower and azeotropic agent stripping tower) to provide the heat required in the stripper-rectifier tower. In a preferred embodiment, two stripper-rectifier towers are used, one operating at a higher pressure than the other, in which case the higher pressure tower is heated as just described and the overhead vapors from the higher pressure tower are condensed to supply the heat required in the lower pressure tower.

Abstract: Substantially anhydrous, i.e., absolute, ethanol is distilled at high thermal efficiency from a dilute feedstock such as a fermentate ("beer") containing one or more low boiling components whose removal at least in part prior to anhydrous distillation is necessary in order to achieve an acceptable degree of phase separation in a decanter. Most of the low boiling component(s) are removed from the feed in a rectifying column with the balance of the low boiling component(s), insufficient in amount to seriously interfere with proper operation of the decanter, being removed from the system employing a light-ends column. Both the anhydrous column and the light-ends column are operated at substantially superatmospheric pressure with thermal values recovered from these columns being used in the operation of the rectifying column.

Abstract: A process and apparatus for the separation of components from a mixture which forms an azeotrope is disclosed by subjecting the mixture to extractive distillation to remove one of the components and regeneration to separate another component from the extracting agent added to the extractive distillation column. According to the invention, a first side stream is withdrawn from the extractive distillation column, passed in heat exchange with the bottoms from the extractive distillation column en route to the regeneration column and returned to the extractive distillation column at a point below the point at which it is withdrawn. A second side stream from the extractive distillation column is withdrawn, passed in heat exchange with the bottoms of the regeneration zone and returned to the extractive distillation column. For this purpose, separate heat exchangers are used for the respective side streams.

Abstract: Reconcentration of moist glycol, which has been used to dry natural gas, by heating the moist glycol with flue gas from a reboiler and by thereafter stripping water from the moist glycol with the dried flue gas or with a hydrocarbon gas by-product of the natural gas being dried.

Abstract: A process and system for obtaining fresh water from salt water such as sea water, by direct contact heat transfer using staged evaporator-condenser units operating with a low boiling water-immiscible liquid hydrocarbon. Each stage comprises a closed vessel divided into two compartments, an evaporator and a condenser, by a bubble cap tray similar in construction to those used in distillation. Relatively hot fresh water is introduced into the liquid hydrocarbon contained in the lower compartment of each stage, causing boiling of the hydrocarbon at a temperature differnce of 2.degree.-4.degree. F. Hydrocarbon vapors pass from the evaporator compartment through the bubble caps to the upper condenser compartment where they are condensed in contact with a colder saline stream, and the condensed hydrocarbon is returned to the lower compartment.

Abstract: A method and apparatus for distillation wherein the heat of partial condensation and the heat of evaporation are incrementally utilized as produced thus guiding the gaseous phase of the distillation along the dew-point line of the enthalpy-concentration diagram and guiding the fluid phase along the bubble-point line of the enthalpy-concentration diagram of the mixture to be rectified.

Abstract: An externally cooled, absorption engine apparatus and method, the apparatus including a closed cycle system having a first fluid and a second fluid, the first fluid constituting a working fluid and having a relatively lower boiling point while the second fluid constitutes a solvent for the first fluid and has a relatively higher boiling point and a relatively high degree of absorptivity for the first fluid. The apparatus further includes a distillation column, a superheater, a mechanical expansion engine, an externally cooled absorption column, and heat exchange apparatus. The distillation column separates the first fluid or working fluid from the solvent with heat energy supplied by an external combustion source and the superheater increases the thermal energy thereof prior to passing the working fluid through the mechanical expansion engine. The mechanical expansion engine converts thermal engine in the working fluid vapor to mechanical energy.

Abstract: An improved distillation method and apparatus are provided for recovering hydrous ethanol from fermentation or synthetic feedstocks. Substantial energy savings are realized by utilizing a pair of stripper-rectifier towers in which overhead vapors from one tower operating at a higher pressure supply the heat required for the other tower operating at a lower pressure and by preheating the feedstock in multiple heat exchange steps. The feedstock is split into two portions of unequal size, the larger portion being supplied to the higher pressure tower and the smaller portion to the lower pressure tower.

Abstract: The recovery of alcohol from fermentation liquors is accomplished by the evaporation of the liquor feed and simultaneous rectification of the volatile component. Evaporation of the liquor feed can be accomplished by a single flash evaporation or multiple effect evaporation combined with the flash evaporation in which the flash evaporator is one effect of the multiple effect evaporator. A concentrated alcohol component is recovered along with a concentrated residue useful as a fertilizer or animal feed supplement.

Abstract: In a distillation process, the heats of distillates and bottom product are recovered to preheat the feed and to generate the steam of higher than 5 kg/cm.sup.2 G which in turn may be utilized to improve the distillation efficiency.

Abstract: A process for the separation of isobutane from an alkylation reaction zone hydrocarbon effluent stream comprising isobutane, n-butane, propane and alkylate is disclosed. The hydrocarbon effluent stream is charged to an isostripper column. An isobutane vapor stream from the column is condensed in indirect heat exchange with the lower liquid stream from said column comprising n-butane. The lower liquid stream is flashed in indirect heat exchange with said vapor stream at conditions to provide a vapor phase, said vapor phase being compressed and recycled to said column at a temperature to promote vapor formation therein.

Abstract: Reconcentration of moist glycol, which has been used to dry natural gas, by heating the moist glycol with flue gas from a reboiler and by thereafter stripping water from the moist glycol with the dried flue gas or with a hydrocarbon gas by-product of the natural gas being dried.

Abstract: Water containing dissolved compounds is preheated, and is then pressurized in stages of water pressure, while receiving a quantum of steam. Scale-forming compounds in the water are thermally precipitated, and clarified post-thermal water is formed. This is flash vaporized in stages corresponding to the stages of water pressure, and the flashed vapors are compressed to form each said quantum of steam. Alternately, the flashed vapors themselves comprise each said quantum of steam, by being induced into the water as it flows through an eductor means. Flash-cooled, post-thermal water, substantially devoid of scale-forming compounds, is employed as such, or more generally is evaporated to form fresh water and an end concentrate of dissolved compounds.

Abstract: A process and system for obtaining fresh water from salt water such as sea water, by direct contact heat transfer using staged evaporator-condenser units operating with a low boiling water-immiscible liquid hydrocarbon. Each stage comprises a closed vessel divided into two compartments, an evaporator and a condenser, by a bubble cap tray similar in construction to those used in distillation. Relatively hot fresh water is introduced into the liquid hydrocarbon contained in the lower compartment of each stage, causing boiling of the hydrocarbon at a temperature difference of 2.degree.-4.degree. F. Hydrocarbon vapors pass from the evaporator compartment through the bubble caps to the upper condenser compartment where they are condensed in contact with a colder saline stream, and the condensed hydrocarbon is returned to the lower compartment.

Abstract: An improved solvent recovery process comprising distilling soiled solvent in a main still and conducting hot solvent vapor through a heat exchanger associated with a tank in which an azeotropic mixture of water and soiled solvent is maintained, which mixture boils at a temperature lower than the boiling point of the solvent alone. A series of tanks feed soiled solvent to the azeotropic mixture tank and then to the main still, and heat exchangers fed by the vapor from the main still and the vapor from the azeotropic mixture tank pre-heat the soiled solvent. Automatic control of water injection into the azeotropic mixture tank in dependence upon the temperature of conductivity of the tank contents maintains the composition of the azeotropic mixture, the injected water being taken from separators which separate water from condensate of the main still and azeotropic mixture tank vapors.

Abstract: A method for separating two liquid components from a mixture by distilling the mixture in the presence of a third liquid which is immiscible at least with the component having the higher boiling point with the third liquid having a boiling range from at least the boiling point of the lower boiling component up to the boiling point of the higher boiling component. In a preferred embodiment the liquid mixture components are glycol and water and the third liquid is a naphtha fraction having a boiling range from about 212.degree. F. (100.degree. C.) to about 410.degree. F. (210.degree. C.).

Abstract: A process for separating, by means of a selective solvent, a mixture of C.sub.

Abstract: Impurities such as hydrogen sulfide and carbon dioxide are removed from fluids such as natural gas, synthesis gas or liquid or gaseous hydrocarbons by contact with an aqueous alkanolamine solution which absorbs said impurities from the fluid. The resultant spent impurity-enriched absorbent amine stream containing the absorbed impurities is split into two streams; one stream being routed directly to the top of an amine regenerator column and the second stream being routed to a heat exchanger where it is heated en route to an intermediate point of the regenerator column by heat exchange with the hot regenerated solution coming from the bottom of the regenerator column. The spent amine stream which is passed without prior heating directly to the top of the regenerator column is heated by condensing steam in the column which would normally escape therefrom, thereby reducing the amount of "saturation" steam which is lost from the system.

Abstract: Desalination apparatus using solar energy comprises a main insulated container with a subsidiary preheating container next to it; the main container is covered with a transparent cover serving as a selective filter to provide "the greenhouse effect" and also as a condensation surface for water vapor, and this transparent cover incorporates a hollow space, for example by making the cover double skinned. The hollow space forms part of a syphon which automatically regulates the water levels, transferring salt water from a preheating container to the main container as the level in the main container falls due to loss by evaporation leading to condensation and withdrawal of the desalinated water. The hollow part of the transparent cover thus serves also to preheat the incoming salt water with the heat lost upon condensation by the vapor within the main container.

Abstract: A hydrocarbon stream comprising C.sub.2 to C.sub.8 hydrocarbons is stripped at a high temperature to allow passage of the stripper bottoms stream into a reaction zone without further heating, and the effluent of the reaction zone is then heat exchanged against the feed stream to the stripper column to recover heat. Operation of the reaction zone at the desired temperature is achieved by adjusting the amount of the stripper bottoms stream which is split off for cooling by heat exchange against the feed to the stripper column. The cooled split-off portion is then admixed with the remaining high temperature portion. Adjusting the flow rate of the portion of hot reaction zone effluent which is heat exchanged against the stripper feed stream is performed to control either the temperature of the stripper feed stream or the temperature of the reaction zone effluent as it is passed to a downstream operation.

Abstract: In an alkylation process, the separation of the hydrocarbon effluent is accomplished by modifying the depropanizer tower to provide a lower bottom temperature. The depropanizer bottoms is flash separated to release an isobutane rich recycle stream with higher boiling alkylate being passed to an isostripper for separation with alkylation hydrocarbon effluent not passing through the above sequence. The use of low pressure steam for heat duty in the above sequence reduces energy requirements of the processing combination.