Exxon Research and Engineering Company

Other

Kobe Steel, Ltd.

Robert P Cahn

Norman N Li

Adam L Shrier

Edward W Nicholson

Boyd E Hurst

John P Longwell

Michael Siskin

John M Longo

Frederic Leder

Paul R Geissler

Jeffrey H Siegell

Taras Hucal

Stephen L Wythe

Murray Nadler

The instant invention is an improvement in the method of producing optically pure sterioisomers from a racemic mixture. The method is based on the well-known fact that a supersaturated solution or melt of the racemic mixture can be seeded with just the crystals of the desired stereoisomer, which will then crystallize out selectively, leaving the undesired stereoisomer behind in the liquid mother liquor. The desired isomer, in crystaline form, can then be separated by simple liquid/solid separation from the undesired isomer remaining behind in the mother liquor. In the conventional method, supersaturation is achieved by careful cooling of a saturated solution or melt. In the present invention, supersaturation is achieved by increasing the ambient pressure over the saturated solution or melt of the racemic mixture, and relying on the fact that the melting temperature of a substance increases with increasing pressure, provided there is an increase in molar volume when the substance melts.

Separation of pure optical stereoisomers by pressure crystallization

A gas desulfurization process is provided in which a gaseous mixture comprising sulfur oxides is contacted in an absorption zone, at absorption conditions, with an aqueous composition comprising ammonium carbonate, or ammonium bicarbonate or mixtures thereof, in an amount such that the product of the partial pressures of the sulfur oxides and ammonia over said aqueous composition is below a specified limit, to produce a gaseous product having a decreased content of sulfur oxides and a decreased appearance of blue haze. A combination nitrogen oxides removal (deNO.sub.x) and desulfurization (deSO.sub.x) process is also provided.

Process for removing SO from a gaseous mixture (OP-3409)

A combination gas denitrogenation and desulfurization process is provided in which a gaseous mixture comprising NO.sub.x, SO.sub.x and O.sub.2 is reacted with excess NH.sub.3 to reduce the NO.sub.x to N.sub.2 and the resulting gaseous effluent comprising the unreacted ammonia and SO.sub.x is passed to a gas desulfurization zone to form an ammonium salt of an acid of sulfur which can be recovered and used as such or converted to elemental sulfur.

Process for removing NO.sub.x and SO.sub.x from a gaseous mixture

A process for removing and recovering a dissolved substance, either acid or a base, from an aqueous feedstream. The feedstream is contacted with an aqueous dispersed phase containing liquid membrane emulsion which removes the dissolved substance to the degree desired from the feedstream and absorbs it into the liquid membrane emulsion. The aqueous dispersed phase of the emulsion comprises a reagent which reacts with the dissolved substance by neutralization, allowing the dissolved substance to accumulate to a significant concentration in the emulsion before the spent emulsion is separated from the treated feed and coalesced into a membrane and a spent aqueous internal reagent phases. The spent aqueous internal reagent phase is subjected to electrolysis in a bipolar membrane cell which regenerates the dispersed reagent loaded internal aqueous phase in a composition suitable for recycle to emulsification and further feedstream treatment. The bipolar cell also generates an aqueous stream rich in dissolved substance from which the extracted dissolved substance can easily be recovered in pure form by conventional separation means.

Recovery and concentration of aqueous acids and bases

The instant invention is a major energy saver in the form of a blanket which allows personal heat control, particularly cooling. More specifically, the blanket is provided with internal ducts through which a stable foam is circulated as a cooling fluid in such a way that the inside of the blanket facing the person being cooled is maintained at a temperature slightly below body temperature, while the outside of the blanket is insulated to minimize heat exchange with the environment. Compared to the use of a liquid as the circulating cooling fluid, foam is very light and thus minimizes the weight of the blanket, but it has better heat transfer properties and heat capacity than a gas. Cooling of the recirculating cooling fluid is done separate from the blanket in a refrigeration unit connected to the blanket by a feed and return duct. The refrigeration unit can operate by means of a heat pump, or use a stored refrigerant such as ice, or employ a continuous coolant, such as tap water. The integrity of the circulating foam is maintained by passing a certain fraction of the circulating fluid through a foam regeneration unit which both reconstitutes foam which has started to collapse and agglomerate, and regenerates foam which has completely broken when the unit is out of service for extended periods.

Individual comfort control device

Solids comprising a magnetically stabilized fluidized bed are transported in a direction transverse to the flow of the fluidizing fluid exiting the bed by contacting at least a portion of said solids with fluidizing fluid which enters the bed with a velocity component in the direction of solids flow; i.e. the transverse flow direction. In a preferred embodiment, the fluidizing fluid entering the bed is passed through a distribution means containing propulsion passages slanted in the desired direction of solids flow which serve to orient the fluidizing fluid in the transverse flow direction. Use of this invention eliminates the need for the costly and inconvenient pneumatic, hydraulic and mechanical transport devices employed in the prior art. Solids attrition and elutriation are also reduced.

Fluid induced transverse flow magnetically stabilized fluidized bed

This invention relates to a process for the removal of dissolved species from aqueous solutions, which comprises contacting said aqueous solution with an emulsion, said emulsion comprising an exterior phase which is characterized as being immiscible with said aqueous solution and yet permeable to said dissolved species, and an interior phase which contains a reactant capable of converting said dissolved species to a nonpermeable form. The dissolved species permeate the exterior phase, into the interior phase where they are converted into nonpermeable forms and thus retained in the interior phase of said emulsion. The aqueous solution, depleted in said dissolved species, is separated from said emulsion and the emulsion cycled for reuse. In one preferred embodiment said dissolved species are ions, and an ion exchange compound is incorporated in the exterior phase of the emulsion, to promote the permeation of said ions through the exterior phase.

Water in oil emulsions useful in liquid membrane

A gas containing oxygen, H.sub.2 S and sulfur oxides is desulfurized by contacting same with cerium oxide at a temperature of from about 350.degree.-600.degree. C. This invention is particularly useful for desulfurizing tail gas from a Claus plant. In a preferred embodiment the cerium oxide is supported on alumina and oxygen is present in the gas in an amount more than that stoichiometrically required to convert the H.sub.2 S and SO.sub.2 to cerium oxysulfate.

Desulfurization of hot gas with cerium oxide

In a liquid membrane process for removing ions from solution which comprises contacting a feed solution containing a first ion with an emulsion, said emulsion comprising an external phase which is immiscible with said solution and contains a complexing agent, said complexing agent being capable of forming a first complex with said first ion, which is soluble in said external phase, and an internal phase, the improvement which comprises providing a second ion, in the internal phase, of the emulsion, said second ion being capable of converting said first complex to a second complex by replacing said first ion in said first complex, said second complex being also soluble in said external phase, whereby the first ion diffuses from said solution into said internal phase, and said second ion diffuses from said internal phase into said solution. More particularly, the instant invention comprises maintaining the concentration of the second ion, in the feed solution, at a sufficiently low level to allow formation of the first complex at the interface of the external phase of the emulsion and the solution, and maintaining the concentration of the second ion, in the internal phase of the emulsion at a concentration, sufficiently high, to convert said first complex into a second complex. Preferably, the first ion is a metal ion--for example, copper, or a complex ion, such as H.sub.g Cl.sub.4 =comprising a metal constituent and said second ion is either hydrogen or hydroxyl ion.

Use of liquid membrane systems for selective ion transfer

A method for producing sulfur from sulfur dioxide. In the broadest embodiment, sulfur is produced by reducing the sulfur dioxide with a reducing gas comprising one or more lower, monohydric alcohols. The reduction may be accomplished either thermally or catalytically and the principal products obtained will be elemental sulfur and/or hydrogen sulfide, depending principally upon the particular conditions and relative reactive concentrations actually employed and in some cases, at least, some carbon oxysulfide will be produced. In the broadest embodiment, the reduction, and hence, the sulfur production will be accomplished in a single stage. In the more preferred embodiments, however, the production will be accomplished in a plurality of stages and, in a most preferred embodiment, the sulfur dioxide is first contacted with methanol under conditions such that the molar ratio of the hydrogen sulfide and carbon oxysulfide actually produced to the unconverted sulfur dioxide is within the range from about 1.8:1 to about 2.2:1. The H.sub.2 S, COS and SO.sub.2 will then be further reacted in one or more catalytic converters so as to increase the sulfur yield. Conventional Claus plant equipment can be used to effect this further conversion.

Method of producing sulfur from sulfur dioxide

The instant invention relates to a process for separating components from liquid mixtures which comprises emulsifying said liquid mixture in an immiscible liquid which is characterized as a solvent for the components. The emulsion is then contacted with an inert gas whereby the components of the mixture which, because of their solubility, permeate into said immiscible liquid, and are stripped therefrom by the inert gas. The components may then be separated from said inert gas stream by condensation and subsequent phase separation or fractionation, by absorption, distillation or by adsorption. In a preferred embodiment of the instant invention the liquid mixture comprises a hydrocarbon which is emulsified in an aqueous surfactant containing liquid. The hydrocarbon mixture contains hydrocarbons of different types, as well as hydrocarbons mixed with oxygenated compounds, i.e. alcohols, ketones, acids, and mixtures thereof. In a particular embodiment the hydrocarbon mixture contains toluene and heptane. In this embodiment the toluene preferentially permeates into said aqueous surfactant containing liquid and is removed therefrom by a stream of stripping steam.

Separation process

An improved process for storing the off-peak electrical output of an electricity generating plant in the form of heat by using said off-peak electrical output to raise the temperature level of a quantity of stored low vapor pressure thermal energy retention material and recalling said stored heat during periods of peak power demand in the form of electrical power, or industrial process heat wherein the excess electrical power, running a compressor (i.e. heat pump), compresses low grade heat containing vapor thereby raising the temperature and said compressed high heat is transferred to a LVP thermal energy retention material, the improvement comprising using as a source of low grade heat the waste heat generated by industrial and/or municipal installation such as refineries, steel mills, incinerators, etc. The process utilizes hot low vapor pressure (LVP) thermal energy retention material and appropriate storage means and cold LVP thermal energy retention material and appropriate storage means, low level, low grade waste heat either alone or in combination with stored hot water, most preferably alone, heat exchanger means, heat pumping means, turbine means, electric motor means and generator means and/or industrial process heat utilization means.

Thermal energy storage by means of reversible heat pumping utilizing

The excess power from a power station, whether nuclear, fossil fuel, geothermal, solar, etc. is stored in the form of heat in a low vapor pressure thermal energy retention material which is selected from the group consisting of petroleum hydrocarbon distillates having a boiling range of between 500.degree. to 1300.degree. F with a vapor pressure in the temperature range of 500.degree.-650.degree. F not exceeding 1 atm. Low vapor pressure thermal energy retention materials may be heated in any number of ways, for example, directly by turbine extraction steam and primary high pressure steam, or by means of excess volumes of boiler feed water heated by turbine extraction steam and primary high pressure steam, or by direct solar energy or by means of the excess electricity generated by any form of power station. The hot LVP thermal energy retention materials are stored in hot storage location means and used during peak demand periods to supply extra power when needed either by the transfer of heat to boiler feed water, the generation of intermediate pressure steam (to run turbines) thereby effecting the conversion of stored thermal energy into additional power. After use they are kept in cold storage location means.

Low vapor pressure organic heat retention materials kept at atmospheric

A method is described for storing the offpeak electrical output of an electricity generating plant in the form of heat by using it to raise the temperature level of a quantity of stored heat retention material and recalling said stored heat during periods of peak power demand in the form of electrical power. During low power demand periods hot water is drawn from a hot water storage means and cooled by flashing it at successively lower pressures. The cold condensate is sent to a cold water storage means while the various flash vapors are fed to appropriate stages of a steam compressor driven by excess power drawn from the electricity generating station. The steam which has been compressed by means of the excess electrical power is directed to heat exchanger means where it is used to heat a low vapor pressure (LVP) thermal energy retention material flowing from cold to hot storage means through the heat exchanger means. By the practice of this invention, heat is transferred, by means of the steam compressor powered by excess electrical power, from hot water (.about. 210.degree. F) to the LVP material raising its temperature from a cold storage temperature of about 190.degree.-300.degree. F to a hot storage temperature of about 450.degree.-600.degree. F. The hot LVP material is stored at atmospheric pressure preferably under an inert gas atmosphere. During peak energy demand periods, the process is reversed and the hot LVP material is used to generate steam which runs a turbine thereby producing electrical power from a generator.

Thermal energy storage by means of reversible heat pumping

A process for removing a dissolved component from a feedstream. The feedstream is contacted with a liquid membrane emulsion which removes a portion of the dissolved component. After separation of the emulsion from the feedstream, a substantial portion of the remaining dissolved component is removed by solvent extraction.

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Millburn, NJ, United States of America

Robert P Cahn