Abstract: A method of operating an evaporator is described. In evaporator feed water, a Taylor bubble is developed which has an outer surface including a thin film in contact with an inner surface of an outer wall of an evaporator tube. The Taylor bubble is heated as it rises within the evaporator tube so that liquid in the thin film transitions into vapor within the bubble.

Abstract: The present disclosure teaches a method and apparatus to gel a dopant material, which may be a low viscosity liquid, and apply it towards beneficially coating dopant liquid in the manufacture of a three-dimensional thin-film solar cell substrate. As an alternate to using high viscosity dopants, a dopant coating liquid, which is typically distributed in low viscosity alcohol based liquid forms, may instead be utilized as a dopant material in a gelatinous state towards the manufacture of a three-dimensional thin-film solar cell substrate. The methods and devices disclosed herein provide for enhancing the high viscosity characteristics of a dopant material. The present disclosure teaches the use of the dopant material in its gelatinous state towards an exemplary cavity filling method.

Abstract: A modular construction micro-reactor with parallel microchannels on fluid guide plates for chemical reactions, but not for evaporation purposes is known. A modular construction falling film evaporator is disclosed, comprising a stack of alternate gap-like evaporation chambers and sheet-like evaporator modules with an assembly of parallel microchannels, whereby the evaporation chambers are open above and/or below across the whole width of the module and the stack is arranged in a container. The falling film evaporator is used in a method for obtaining a gaseous phase from a liquid medium on a technical scale and is suitable for the concentration of thermolabile solutions and rapidly adjustable production of a gas stream.

Abstract: A one step method and system for producing nanofluids by a particle-source evaporation and deposition of the evaporant into a base fluid. The base fluid such (i.e. ethylene glycol) is placed in a rotating cylindrical drum having an adjustable heater-boat-evaporator and heat exchanger-cooler apparatus. As the drum rotates, a thin liquid layer is formed on the inside surface of the drum. A heater-boat-evaporator having an evaporant material (particle-source) placed within its boat evaporator is adjustably positioned near a portion of the rotating thin liquid layer, the evaporant material being heated thereby evaporating a portion of the evaporant material, the evaporated material absorbed by the liquid film to form nanofluid.

Abstract: In a multi-effect falling-film evaporator, purified water for special purposes is produced. In each effect, a steam phase and a water phase is produced from the feed water. The steam phase is used for heating in the subsequent effect, whereby it condenses to product water, and the water phase becomes the feed stream for the subsequent effect. A reject stream is removed from the process to carry off impurities separated from the water. According to the invention, a reject stream is removed from each effect. Preferably, each reject stream is a condensed fraction of the steam generated in the respective effect.

Abstract: Purified water for special purposes is produced using a falling-film multieffect evaporator. From the feed water, each effect produces a steam phase and a water phase. The steam phase is used for heating in the subsequent evaporating step, whereby the steam phase condenses to product water, and the water phase becomes feed water for the subsequent evaporation step. According to the invention, the product water may be wholly or partly recycled to the initial feed water, allowing process startup and sterilisation of the plant without conducting hot product water to the drain.

Abstract: The invention relates to a method and a device for the production of pure steam. A falling-film evaporator is used. Of the water-steam mixture leaving the evaporator unit, part of the water is collected at the bottom of the device, and a fraction mainly consisting of steam enters a rising spiral channel for the separation of impurities. In the periphery of the spiral channel apertures are provided for separating impurity-containing droplets, which condense on a surface outside the apertures. The liquid formed is removed from the device. The water phase collected at the bottom enters a recycle line connected to the feed end of the evaporator unit. Feed water is supplied to the recycle line to compensate for pure steam consumption.

Abstract: Device for distillation, for example extraction of fresh water from sea water, including a number of chambers (3) at least in one row, an inlet (10) for distillation fluid, an outlet (11) for the distillation residue, an outlet (5) for the distillate, and a gas compressor (13). Further, the device includes two pipe systems (1,2), where the first pipe system (1) has an inlet (10) for the distillation fluid and an outlet (11) for the distillation residue, together with an outlet (12) for damp. The second pipe system (2) has a number of chambers (3) in a row, each row (3) having an upper inlet (4) for damp and a lower outlet (5) for distillate. The inlets (4) are connected in parallel, and the outlets (5) are connected in parallel.

Abstract: The present water reclamation system comprises a series of concentric thin shells. The shells mount within a housing that can be maintained under vacuum or low pressure. The shells rotate at high velocity. Contaminated liquid from outside the housing is injected into the space between half the shells. The centrifugal force causes the liquid to form a thin film along the inward facing surface of the shell. A compressor lowers the pressure adjacent the thin film causing the liquid to boil. The compressor carries the vapor to the other side of those shells at a slightly higher temperature. There the vapor encounters the wall, which is cooler and its heat is transferred to boil the contaminated liquid. The vapor condenses, and rotation throws the condensate against the adjacent wall where it is collected. When condensing, the heat of condensation transfers to the shell for boiling the incoming contaminated liquid.

Abstract: An evaporator is provided for evaporation of liquid from a solution or liquid mixtures, together with methods of operation of the evaporator. The evaporator comprises a chamber (1); a liquid reservoir (3) for holding a heat transfer liquid exposed to the interior of the chamber; a support (6) for supporting a container (8) in the chamber, such that the liquid sample in the container is exposed to a fluid path (15) for connection to a condenser (16), the fluid path being separated from the chamber interior, and at least a portion of the container is closely thermally coupled to the chamber interior; and means (4) for heating the heat transfer liquid in the reservoir to create heat transfer liquid vapour, which in use condenses and releases latent heat of vaporisation to the liquid sample in the container. As the temperature of the sample is dependent on the saturated vapour temperature of the liquid in the reservoir, the temperature of the samples is reliably limited, thereby avoiding overheating.

Abstract: A total evaporator for fluids, including a cold chamber to prevent pre-evaporation, an evaporation region connected thereto having narrow flow cross-section for fast evaporation of the fluid, and a subsequent vapor chamber for pulsation damping and the controlled superheating of the vapor, the evaporation region being formed by a gap between concentrically nested cylindrical and/or conical tube sections and heat required for the evaporation and superheating processes is supplied by electric heating and/or by hot fluid and/or by catalytic or homogeneous combustion via the wall of the concentric tubes.

Abstract: An apparatus for concentrating solutions in a vaporising receptacle (1) is provided wherein the receptacle (1) has a mouth (3), and the axis of the receptacle is perpendicular to the mouth.

Abstract: The invention relates to a falling film evaporator, which is fitted with a liquid distributor which is divided into segments, such that it is possible to charge only a limited number of evaporator tubes with liquid and the evaporator can be operated in an optimum manner even with a partial load. The invention also relates to a method for operating said falling film evaporator, the aim of which is to transfer heat, which is released when a gas-vapor mixture is condensed, to a liquid which is to be evaporated at least partially. It would be useful to use said falling film evaporator thus fitted in heat recuperation systems such as those used in the production of 1,2 dichloroethane.

Abstract: The invention relates to a method and a device for the purification of an aqueous solution of an organic acid having a boiling point at atmospheric pressure of less than 450° C., which further has approximately 275 g carboxylate ions/1 or less, preferably 250 g carboxylate ions/1 or less, and preferably less than 1% by weight ionic impurities, calculated on the basis of the total solution. In particular, the invention relates to a method and a device for the continuous purification and concentration, on an industrial scale, of an aqueous solution of an organic acid having a boiling point at atmospheric pressure of less than 450° C. According to the method, this solution is subjected to two or more distillation steps, the first distillation step being carried out at a temperature of from 80° to 150° C. and a pressure of from 50 to 250 mbar, and the second distillation step being carried out at a temperature of from 80° to 200° C. and a pressure of from 0.01 to 50 mbar.

Abstract: An evaporating device including: a material retaining part for being filled with an evaporating material and heating the evaporating material; an opening for dispersing the evaporating material vaporized from the material retaining part toward an evaporated member; and a high-temperature body disposed between the material retaining part and the opening, the high-temperature body being heated to a temperature higher than a temperature of the evaporating material heated in the material retaining part.

Abstract: The present invention relates to a method for the purification of an ?-hydroxy acid on an industrial scale, in which the method involves: (a) subjecting an aqueous stream containing mainly ?-hydroxy (1) to an extraction step, with the formation of an aqueous place containing mainly ?-hydroxy acid (2), (b) concentrating the aqueous phase containing mainly ?-hydroxy acid (2) by means of evaporation of water under reduced pressure, with the formation of a concentrated ?-hydroxy acid solution in water (3), and (c) subjecting the concentrated ?-hydroxy acid solution (3) to a crystallization, with formation of pure ?-hydroxy acid (4), where (i) the concentrated ?-hydroxy acid solution (3) is directly cooled in a melting crystallization device, and/or (ii) the concentrated ?-hydroxy acid solution (3) is diluted with water and crystallization is brought about in one or more cooling crystallization devices and/or evaporative crystallization devices, and/or (iii) crystallization is brought about in one or more adiabati

Abstract: Pseudo-distillation, steady-state method for purifying dry cleaning solvents containing laundry soils and other contaminants.

Abstract: Liquid organic material is controllably delivered to a receptacle located in the center of a heated surface capable of horizontally rotating about its central axis. As the heated surface rotates, material deposited within the central receptacle is forced outwardly and across the rotating surface. As the material moves radially, it evaporates into a vapor which is then transported to one or more nozzles. From the nozzles, the vapor is applied to a substrate and condensed. The spinning disk evaporator enables the evaporation of a wider variety of organic liquids greater reliability in continuous operation, a decrease in maintenance, and a larger and more constant material flow rate.

Abstract: A tert-C4–C8-alkyl (meth)acrylate is prepared by reacting (meth)acrylic acid with an olefin of the formula where R1 and R2, which may be identical or different, are methyl or ethyl and R3 is H, methyl or ethyl, in homogeneous phase in the presence of an acidic catalyst and isolating the tert-C4–C8-alkyl (meth)acrylate from the reaction mixture, by a process in which the catalyst is separated off as residue by a two-stage distillation of the reaction mixture and the tert-C4–C8-alkyl (meth)acrylate is isolated from the distillates. The novel process makes it possible to use acetic acid-containing (meth)acrylic acid. The danger of cleavage of the ester and of polymerization of (meth)acrylic compounds is reduced.

Abstract: The present application is directed to a continuous contacting apparatus for separating a liquid component from a liquid mixture.

Abstract: Liquid organic material is controllably delivered to a receptacle located in the center of a heated surface capable of horizontally rotating about its central axis. As the heated surface rotates, material deposited within the central receptacle is forced outwardly and across the rotating surface. As the material moves radially, it evaporates into a vapor which is then transported to one or more nozzles. From the nozzles, the vapor is applied to a substrate and condensed. Relative to existing devices and methods, the present invention enables the evaporation of a wider variety of organic liquids, greater reliability in continuous operation, a decrease in maintenance, and a larger and more constant material flow rate.

Abstract: The present invention relates to a process and a device for evaporating liquids, for example black liquor from cellulose cooking, which contain solid and dissolved substances which are to be concentrated. The liquid is heated to close to boiling temperature in a heat exchanger (1) of the falling-film type. The process is characterized in that the pressure on the liquid side in the falling-film heat exchanger (1) is kept so high that boiling does not take place in this heat exchanger and in that the evaporation takes place, by means of flashing, in a separate expansion tank (7) that has a lower steam.

Abstract: A method of removing substantially all solvent from a solution containing a polyphenylene ether polymer resin with little by-product formation (less than 250 ppm) is provided. The method employs a wiped thin film evaporator with a cylindrical heating chamber operating under conditions that satisfy the relationships defined by Equations I and II. 5.3*1024RL? exp(?24123/T)/m<C??I 100?(4960AP/Tm)<C??II; Yields are maximized wherein values for feed rate (m) and percent solids (C) are selected to provide a maximum value for the output, Q, determined from the equation m*C=Q and the melt viscosity of the polyphenylene ether product is less than 50,000 centipoise at the operating temperature of the cylindrical heating chamber.

Abstract: A method for the concentration of liquid mixtures includes the step of causing a continuous stream of the liquid mixtures to flow in the form of a turbulent thin layer in contact with a heated wall; for that purpose, a continuous stream of liquid mixture is fed into a turbo-concentrator including a cylindrical tubular body (1), a heating jacket (4) and a bladed rotor (8) rotatably supported in the cylindrical tubular body (1), and is centrifuged to form a dynamic and tubular thin layer, the thin layer advancing inside the cylindrical tubular body (1) then being discharged continuously in the form of a stream of concentrated liquid mixture.

Abstract: In the production of water vapor, particularly in the production of especially clean water vapor, dissolved gases, mainly atmospheric gases, are removed from feed water (2). The feed water is sprayed by a spray nozzle (3) mounted in a hemispherical chamber (1) in a spray pattern which matches an area of an upper end (4) of an arrangement of vertical feed tubes of a falling film evaporator. The dissolved gases are liberated quickly from the sprayed droplets and removed through outlets (5) in the hemispherical chamber. The sprayed droplets collect at the upper ends of the vertical evaporation channels and are distributed evenly thereamong before atmospheric gases can be redissolved.

Abstract: The present invention discloses an improved evaporation method compressing an evaporation material from power into compressed particles or tablets at a predetermined pressure, temperature, and time; since the compressed evaporation material being consistent in crystallization property is more even and denser than powder, therefore the efficiency of the thermal conductivity becomes higher and the efficiency of heating more stable.

Abstract: A method for processing a vitamin E acetate-containing product stream, which comprises

Abstract: Process for the manufacture of a concentrated solution, like a concentrated aqueous hydrogen peroxide solution, by distillation and evaporation of a dilute solution, in which the distillation and the evaporation are carried out in two distinct pieces of equipment which are easy to dismantle and to transport. Aqueous hydrogen peroxide solutions having a concentration of at least 90% are obtainable.

Abstract: A film or tape has one of its major surfaces defined by microstructured features including a plurality of channels defined by spaced apart protrusions. The microstructured film is able to acquire liquids and to control the directional transport of such liquids for subsequent removal therefrom. The transport can be passive or active (i.e., caused or enhanced by an applied potential). The inventive microstructured films and tapes have applications in laminate floor assemblies (for spill removal) and industrial articles such as computer keyboards and other devices and assemblies that benefit from fluid removal. The invention also has application in evaporative and condensation applications. In one embodiment, at least one cross-channel is formed on the microstructured surface to join adjacent channels for liquid flow therebetween.

Abstract: The invention concerns appliances, one of which uses solar energy as sole source of power. It comprises an accumulation solar water heater (222) and quasi-reversible liquid/vapour heat exchanging alveolar elements, provided with hydrophilic coatings. Elements of types E and C, respectively assigned to water evaporation (224a, b, c) and to vapour condensation (226a-b) are interposed, with narrow free spaces, in a heat-insulated treatment chamber (223), arranged above the boiler (222). Hot water coming from the heater (222) flows in closed circuit, by thermosiphon, from the top downwards of elements E and from the bottom upwards of elements C. A slightly cooling member (242) is interposed between the bottom collectors (240-244) of elements E and C. Hot water spills over slowly from the top of the hydrophilic coatings of elements E and the vapour produced is condensed opposite, on the walls of elements C.

Abstract: An evaporation product discharged from a lower end a falling-film evaporator enters a downpipe (7), makes a 180° turn at a bottom of the downpipe, and moves upward through an annular rising channel (9) defined between the downpipe and an intermediate housing (10). As the evaporation product moves along a spiral path (12) defined by the spiral fins, centrifugal forces urges water droplets and impurities to a radial outward periphery where they pass through openings (13) in the intermediate shell as pure steam continues through the spiral path and out a pure steam outlet (21). A cooling jacket (15) chills a peripheral wall of an outer shell (14) adjacent the holes such that the discharged water droplets condense on the outer shell and flow down a reject water return path to a reject water reservoir at the bottom of the outer shell.

Abstract: A method including evaporating aqueous solutions containing ammonia, adding an acid to the evaporated vapor flow to form an ammonium salt, and condensing the vapor flow to form a liquid containing the salt. By this method the ammonia formed into a salt is not present as an inert gas layer which would impede condensation on the condenser surfaces.

Abstract: A method for distilling a fluid which is useful, for instance, in eliminating salt from brackish and/or sea water includes percolating films on plates with multiple effects having several evaporating zones and condensation zones. The evaporation zones (EVAP) and the condensation zones (COND) are vertically arranged. The liquid to be distilled emerges in the top part of the evaporation zone (EVAP). The vapors produced in the evaporation zone (EVAP) are horizontally transferred into the condensation zone (COND) through a communicating connection. The condensed liquid percolates vertically along the walls of the condensation zone and is evacuated from the lower part of the condensation zone. A distilling plant is also provided for implementing the distilling method, and includes plural cascades made up of elementary cells alternatingly assembled in thermal series.

Abstract: A method is provided for preventing an easily polymerizable substance from being polymerized in a thin-film type evaporating device by supplying a solution of the substance to the evaporating heating surface of the device by the centrifugal force of a stirring rotary shaft, characterized by mixing a distilled vapor of the substance with a molecular oxygen-containing gas and supplying the extracted liquid or a solution having lower viscosity than the extracted liquid to a feed raw material inlet thereby adjusting the quantity of a wetting liquid per unit length of the surface in the range of 0.02-2 m3/mHr. In the evaporation of the substance by the use of the device, a method for preventing the substance from polymerization is provided.

Abstract: According to the invention, the vapor is taken from the condensation chamber of the dehydrator and, prior to being compressed and at a temperature substantially equal to 100° C., it is caused to pass in succession through a series of purifiers, and in each of the purifiers it is forced through rain containing a purifying solution, at least one of the rain solutions being water, another containing an acid, and another containing a base. The invention is applicable to treating the vapor that results from dehydrating a variety of kinds of matter, such as farmyard manure, in particular.

Abstract: A process vessel containing both an evaporation zone for evaporating a liquid feed and a treatment zone for treating the resulting vapor comprises an injector having an orifice, the orifice being in the evaporation zone, at least one evaporation surface for evaporating feed and generating vapor, the evaporation surface being located in the evaporation zone, wherein the injector orifice and the evaporation surface are positioned to prevent the formation of a drop at the orifice, a treatment zone for treating the vapor and at least one heater associated with at least a portion of the process vessel.

Abstract: A description is given of a process and an apparatus for the removal of volatile constituents, in particular solvents, monomers or oligomers, from polymer compositions or polymer solutions by evaporating the volatile components from the preheated polymer compositions in the form off free-falling films, strands (4) or foaming liquids in an evaporator system (1). In the process, following partial or complete degassing of the volatile components in the degassing space (9) of the evaporator system (1), the degassed polymer composition (4) is received at the lower end of the evaporator system (1) directly by a discharge delivery device (5) and is discharged, thereby avoiding contact of the polymer with the inside wall of the evaporator system (1).

Abstract: An arrangement for a falling film type reactor uses corrugated plates to improve the distribution and dispersion of the gaseous reactant into the liquid. Corrugated plates introduce increased turbulence for promoting better distribution and dispersion of the gas. Corrugation angles can be varied to suit the fluid flow properties of the liquid reactant. The reactor arrangement can also include heat transfer channels defined by the corrugated plates in an alternate arrangement of heat transfer channels and gas liquid contacting channels. The corrugations may also be varied to suit the particular heat transfer requirements of the reactions. The corrugated plates are spaced apart in the contacting channels to prevent localized film contact and placed in contact in the heat exchange portion to stabilize the plate elements defining the corrugations.

Abstract: A tert-C4-C8-alkyl (meth)acrylate is prepared by reacting (meth)acrylic acid with an olefin of the formula 1

Abstract: A method of removing substantially all solvent from a solution containing a polyphenylene ether polymer resin with little by-product formation (less than 250 ppm) is provided. The method employs a wiped thin film evaporator with a cylindrical heating chamber operating under conditions that satisfy the relationships defined by Equations I and II.

Abstract: A process of evaporating a viscous polymer solution is described. The process includes: (a) providing a viscous polymer solution including at least 30 wt. % of solvents and monomers; (b) introducing the viscous polymer solution into a heated helix (5), the heated helix having a vapor exit velocity of 200 to 300 m/s, (a film flow including a two-phase mixture of polymer melt, and solvent vapors and monomer vapors being formed within the helix); (c) forwarding the film flow from helix (5) into a heated vapor separator (6); (d) expanding the two-phase mixture of polymer melt, and solvent vapors and monomer vapors of the film flow within vapor separator (6) at an absolute pressure of 10 mbar to 800 mbar, (a bottom product including a concentrated melt of the polymer is formed within the vapor separator); and (e) withdrawing the bottom product from vapor separator (6).

Abstract: In a rotary evaporator, the rotating speed of the rotating flask is automatically controlled or regulated dependent upon a detected process value, particularly the vibration behavior or the mass moment of inertia of the rotating flask.

Abstract: Volatile siloxane oligomers are removed from an emulsion containing siloxane polymers and volatile siloxane oligomers prepared by emulsion polymerization of volatile siloxane oligomers by continuously feeding the emulsion to a continuous flow device for vaporizing liquids, continuously feeding a stripping gas to the continuous flow device, continuously removing an overhead fraction of volatile siloxane oligomers from the continuous flow device, and continuously removing an unvaporized bottom fraction from the continuous flow device of an emulsion containing siloxane polymers which is substantially free of residual volatile siloxane oligomers used to prepare the emulsion. A benefit of the method is that the viscosity of the siloxane polymer in the emulsion before the emulsion is fed to the continuous flow device is substantially the same as the viscosity of the siloxane polymer in the emulsion after the emulsion is removed from the continuous flow device.

Abstract: An evaporation product discharged from a lower end a falling-film evaporator (1, 2) enters a downpipe (7), makes a 180° turn at a bottom of the downpipe, and moves upward through an annular rising channel (9) defined between the downpipe and an intermediate housing (10). As the evaporation product moves along a spiral path (12) defined by the spiral fins, centrifugal forces urges water droplets and impurities to a radial outward periphery where they pass through openings (13) in the intermediate shell as pure steam continues through the spiral path and out a pure steam outlet (21). A cooling jacket (15) chills a peripheral wall of an outer shell (14) adjacent the holes such that the discharged water droplets condense on the outer shell and flow down a reject water return path to a reject water reservoir at the bottom of the outer shell.

Abstract: Process for the recovery of fluorinated sulphonic acid including the step of subjecting the spent acid to heat treatment with stepwise or continuously increasing temperature, withdrawing at least two fractions during the heat treatment; and recovering the fluorinated sulphonic acid from each fraction.

Abstract: A heat-deteriorative compound contained in a liquid mixture is refined by a distillation procedure using a distillation column in which a vapor fraction and a liquid fraction containing the heat-deteriorative compound are generated from the liquid mixture, and a liquid film-falling reboiler in which the liquid fraction falls in the form of liquid films along inner surfaces of a plurality of vertical heat-conductive pipes at a Reynolds number (Re) of 700 to 10,000 and heated to a temperature lower than the heat-deterioration temperature of the heat deteriorative compound to such an extent that 1 to 15% by weight of the liquid fraction is evaporated per pass through the reboiler, the heated liquid fraction being returned into the distillation column to generate the vapor fraction from the liquid mixture fed into the distillation column.

Abstract: Liquid organic material is controllably delivered to a receptacle located in the center of a heated surface capable of horizontally rotating about its central axis. As the heated surface rotates, material deposited within the central receptacle is forced outwardly and across the rotating surface. As the material moves radially, it evaporates into a vapor which is then transported to one or more nozzles. From the nozzles, the vapor is applied to a substrate and condensed. Relative to existing devices and methods, the present invention enables the evaporation of a wider variety of organic liquids, greater reliability in continuous operation, a decrease in maintenance, and a larger and more constant material flow rate.

Abstract: A process for evaporating spent liquor or other waste liquids from cellulose cooking, The evaporation is performed in a multiplicity of evaporators which are coupled in series and in which the evaporation is driven using the liquor steam. The condensates from the steam are divided, in one of more effects, into at least two fractions with respect to purity. The parer fraction from one effect is conveyed, at a high level, into a subsequent effect in the direction of movement of the liquor, while the dirtier fraction is conveyed, at a high level or at the very top, into a preceding effect in the direction of movement of the liquor.

Abstract: A process is described for producing ester quats of the formula (I) ##STR1## where X.sup.- is an anion of an inorganic or organic acid, R.sub.a is a C.sub.1 to C.sub.4 alkyl group, R.sub.b and R.sub.c are each, independently of one another, a C.sub.1 to C.sub.3 alkylene group, and R.sub.d is a C.sub.1 to C.sub.22 fragment of a saturated and/or unsaturated aliphatic carboxylic acid, m, n, p, and q are integers, m has a value from 1 to 3, n a value from 0 to 3, p a value from 0 to 1, m+n+p=4, and q has the value 1 or, if m=3, n=0, and p=1, the value 2, in which process a quaternary compound of the formula (II) ##STR2## where X.sup.-, R.sub.a, R.sub.b, R.sub.c, m, n, p, and q have the above meanings, is esterified, in the presence of an oxo acid of phosphorus and/or one of its alkali or alkaline-earth salts as a catalyst, with a saturated and/or unsaturated C.sub.1 to C.sub.22 carboxylic acid, alone or in a mixture, while withdrawing water.

Abstract: This invention concerns a process to provide high purity alkylene carbonate though use of multiple distillations wherein the unused fractions are recycled to the reactor.

Abstract: A method for the treatment of cerebrovascular contraction in mammals involving administration of a pharmaceutical composition containing as an effective ingredient a p-guanidinobenzoic acid derivative represented by the formula ##STR1## wherein R denotes a group represented by the formula ##STR2## or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.