Air Products and Chemicals, Inc.

Augustine I Dalton, Jr

Ronald W Skinner

Shivaji Sircar

David Anthony Zagnoli

Eugene J Greskovich

John J Sheridan, Iii

Edward F Kiczek

Henry J Doran

Jeffery Van Bauer

Robert D Murray

A process for producing microcellular foamed articles wherein a low pressure compressible, inert gas such as nitrogen is used as a foaming agent. The process comprises introducing a thermoplastic material into an inlet of an extruder having a length to diameter ratio of at least 30:1, said extruder comprising a screw having at least one stage; heating the thermoplastic material in a melt zone to a temperature sufficient to melt or soften the thermoplastic material to form a melted thermoplastic material; injecting an insoluble compressible, inert gas into the melted thermoplastic material at a position approximately 1 to 2 screw diameters downstream of the melt zone; mixing the molten thermoplastic material and the inert, compressible gas to form a homogeneous dispersion of insoluble bubbles within the material; reducing the pressure of the molten thermoplastic material causing the homogeneously dispersed bubbles to expand within the melted thermoplastic material to form a foamed article and cooling the foamed article to a temperature below the melting or softening point of the foamed article.

Process for extruding thermoplastic materials using low pressure inert

An adiabatic pressure swing absorption process is disclosed for the removal of essentially all oxygen contained in an inert gas stream in minor amounts. The oxygen is absorbed and desorbed adiabatically from a dioxygen sorbent. Optionally, an inert purge gas can be utilized to improve the desorption of oxygen from the dioxygen sorbent. The process utilizes at least two switching beds of the dioxygen sorbent in which one bed is in an absorbing mode while the other bed is in a desorbing mode.

Adiabatic pressure swing absorption process for removing low

An adiabatic-isothermal swing absorption process is disclosed for the removal of essentially all oxygen contained in an inert gas stream. The oxygen is absorbed from an inert gas stream adiabatically on to a dioxygen absorbent and then desorbed from the absorbent isothermally by the use of external heat. The process method utilizes at least two switching beds of the dioxygen absorbent in which one bed is in an absorbing mode while the other bed is in a desorbing mode.

Process for removing oxygen from mixed gas streams using a swing

An improvement in a process for producing hydrogen peroxide by contacting a mixture of hydrogen and oxygen with a palladium on carbon catalyst in the presence of an acidic liquid capable of inhibiting decomposition of thus-produced hydrogen peroxide comprises prolonging the useful life of the catalyst by continuous removal of palladium salts produced by solubilization of the catalyst from the acidic liquid, preferably by employing high surface activated carbon as the catalyst support and adsorbent for palladium salts.

Process for producing hydrogen peroxide

This invention relates to improvements in palladium-carbon catalysts for the production of hydrogen peroxide from a mixture of hydrogen and oxygen in the presence of an aqueous liquid capable of inhibiting the decomposition of hydrogen peroxide. The improvement comprises pretreating the catalyst with an aldehyde or ketone, and, preferably, also pretreating the catalyst with a dilute solution of hydrochloric acid. Improved catalysts are obtained by reducing a soluble palladium compound deposited on a high surface area non-graphitic carbon base, in the form of a dried powder, with hydrogen at 27.degree.-200.degree. C.

Hydrogen peroxide synthesis

PdCl.sub.2 /C catalyst which has been deactivated in the oxidation of an olefinic halide or olefinic hydrocarbon present as contaminant in air or other inert oxygen-containing gas stream, is regenerated by prolonged exposure to air or other oxygen-containing gas stream at temperatures below 70.degree. C. and preferably below 60.degree. C.

Stabilization and regeneration of activated carbon supported palladium

An improvement in a process for producing hydrogen peroxide by contacting a mixture of hydrogen and oxygen with a palladium on carbon catalyst in the presence of an acidic aqueous liquid capable of inhibiting decomposition of hydrogen peroxide comprises prolonging the useful life of the catalyst by continuous removal of palladium salts produced by solubilization of the catalyst from the acidic aqueous liquid.

This invention relates to an improvement in hydrogen peroxide synthesis from hydrogen and oxygen, in an acidic medium containing an oxygenated or nitrogenous organic compound using a supported Group VIII noble metal catalyst. The improvement comprises using an oxygen/hydrogen ratio higher than about 3.4 and a catalyst level above 30 mg. per 100 ml. of medium.

Synthesis of hydrogen peroxide

Hydrogen peroxide is synthesized by contacting hydrogen and oxygen with a supported palladium catalyst in the presence of methanol. Preferably, the methanol contains up to 1.0% by weight of formaldehyde and is at least 0.0001 N in hydrochloric acid.

Salts of Group VIII noble metals are recovered from neutral or acidic solutions by admixing with the solution up to 10% by weight of hydrogen peroxide, adsorbing the salt of the Group VIII noble metal from the peroxide-containing solution on activated carbon and separating activated carbon containing the adsorbed Group VIII noble metal salts from solution diminished in concentration thereof.

Method for the recovery of salts of group VIII noble metals from

A method of stabilizing aqueous hydrogen peroxide solutions against decomposition catalyzed by a combination of iron and copper consists of adding to the solution an amount of alkali metal meta- and pyrophosphates effective to prevent decomposition and adjusting the pH of the solution to 2-4.

Method of stabilizing hydrogen peroxide solutions

Dissolution of Group VIII supported metal catalysts from semi-conductive or conductive carriers in liquid media containing a strong inorganic acid is stopped by making the Group VIII noble metal cathodic with respect to an anode placed in the reactor. A representative embodiment is in processes for synthesis of hydrogen peroxide from its elements.

Cathodic protection of catalysts in a corrosive environment

Primary and secondary unsaturated alcohols are converted to their corresponding aldehydes and/or carboxylic acids and ketones respectively with alkali metal (per) halate, preferably sodium periodate, in the presence of ruthenium catalyst. The process is particularly useful in the oxidation of chrysanthemyl alcohol. Any unconverted intermediate aldehyde formed may be converted to the acid by recycling or by a separate oxidation step.

Selective catalytic oxidation of unsaturated alcohols to carbonyl

Chrysanthemyl alcohol is selectively oxidized to the corresponding aldehyde by contact with oxygen-containing gas in the presence of supported noble metal catalyst composed of platinum on carbon. The obtained aldehyde may be further converted to chrysanthemic acid by oxidation with a solid inorganic oxidizing agent such as silver oxide in excess of stoichiometric quantity, or by reaction with a catalytic amount of oxidation promoting catalyst such as silver oxide in the presence of cupric oxide and molecular oxygen.

Selective oxidation of chrysanthemyl alcohol

A method for removing low concentrations of oxidizable organic contaminants from an oxygen containing inert gas comprises: (1) adsorbing the contaminants on a sorptive media which contains an oxidation catalyst in a reaction zone; (2) interrupting the flow of the gas through said sorptive media; (3) thermally desorbing the adsorbed contaminants; (4) oxidizing the desorbed contaminants to innocuous reaction products; and (5) venting and purging the reaction products from the reaction zone.

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Allentown, PA, United States of America

Augustine I Dalton, Jr