Allied Chemical Corporation

Alliedsignal Inc.

Allied Corporation

Dsm N.v.

Koninklijke Dsm N.v.

Stylianos Sifniades

Alan Bart Levy

Allen A Tunick

Fred W Koff

William J Boyle, Jr

Theodore Largman

Josefina T Baker

Jan Agnes Hendrix

Jan F Van Peppen

Robert S Cooke

John Pisanchyn

Harry E Ulmer

John H Bonfield

Dominick Frollini, Jr

Robert Fuhrmann

Reed H Belden

Jan Agnes Jozef Hendrix

Lloyd C Kent

Herbert C Wohlers

Meir Lahav

The present invention provides an efficient process for the recovery of caprolactam from polycaprolactam-containing waste material. The present process for depolymerizing multi-component waste material comprising polycaprolactam and non-polycaprolactam components to form caprolactam comprises the step of: in the absence of added catalyst, contacting the multi-component waste material with superheated steam at a temperature of about 250&deg; C. to about 400&deg; C. and at a pressure within the range of about 1 atm to about 100 atm and substantially less than the saturated vapor pressure of water at the temperature wherein a caprolactam-containing vapor stream is formed.

Process for depolymerizing nylon-containing waste to form caprolactam

The present invention provides an improved process for the recovery of caprolactam from polycaprolactam processing waste. The present process for depolymerizing polycaprolactam waste to form caprolactam comprises the step of: in the absence of added catalyst, contacting the polycaprolactam waste with superheated steam at a temperature of about 250.degree. C. to about 400.degree. C. and at a pressure within the range of about 1.5 atm to about 100 atm and substantially less than the saturated vapor pressure of water at the temperature wherein a caprolactam-containing vapor stream is formed.

Process for depolymerizing polycaprolactam processing waste to form

The present invention provides an efficient process for the recovery of caprolactam from polycaprolactam-containing waste material. The present process for depolymerizing multi-component waste material comprising polycaprolactam and non-polycaprolactam components to form caprolactam comprises the step of: in the absence of added catalyst, contacting the multi-component waste material with superheated steam at a temperature of about 250.degree. C. to about 400.degree. C. and at a pressure within the range of about 1 atm to about 100 atm and substantially less than the saturated vapor pressure of water at the temperature wherein a caprolactam-containing vapor stream is formed. The formed caprolactam may then be used in the production of engineered resins and fibers.

Process for depolymerizing nylon-containing whole carpet to form

The present invention provides an improved process for the recovery of caprolactam from polycaprolactam processing waste. The present process for depolymerizing polycaprolactam waste to form caprolactam comprises the step of: in the absence of added catalyst, contacting the polycaprolactam waste with superheated steam at a temperature of about 250.degree. C. to about 400.degree. C. and at a pressure within the range of about 1.5 atm to about 100 atm and substantially less than the saturated vapor pressure of water at the temperature wherein a caprolactam-containing vapor stream is formed. The formed caprolactam may then be used in the production of engineered resins and fibers.

The present invention provides an efficient process for the recovery of caprolactam from polycaprolactam-containing waste material. The present process for depolymerizing multi-component waste material comprising polycaprolactam and non-polycaprolactam components to form caprolactam comprises the step of: in the absence of added catalyst, contacting the multi-component waste material with superheated steam at a temperature of about 250.degree. C. to about 400.degree. C. and at a pressure within the range of about 1 atm to about 100 atm and substantially less than the saturated vapor pressure of water at the temperature wherein a caprolactam- containing vapor stream is formed. The formed caprolactam may then be used in the production of engineered resins and fibers.

A process for recovering monomer from multi-component waste material that includes a hydrolyzable polymer, the process including contacting the multi-component waste material with water and subjecting the resulting mixture to heat and pressure to form a liquid aqueous portion which mainly includes depolymerization products of the hydrolyzable polymer and a water insoluble portion which mainly includes components other than the depolymerization products; separating the liquid aqueous portion and the water insoluble portion; subjecting the separated aqueous portion to a pressure that is lower than that of step (a) and heat to produce a residue and a distillate which contains monomer; and separating the monomer in the distillate from other components in the distillate. The process is particularly useful for recovering caprolactam from waste materials that include nylon 6.

Monomer recovery from multi-component materials

Monitoring acidity at the ppm level in phenol-acetone-cumene process streams on a continuous basis is accomplished with a standard hydrogen electrode and a double-junction reference electrode with an external body solution comprising phenol, acetone, water, and a tetraalkyl- or tetraarylammonium salt, which provide a time invariant voltage without the necessity of adding any external solvent to the process stream. Phenol/acetone ratios can be varied from 1:10 to 10:1 which encompass the 1:1 ratio produced by the phenol-acetone process. A direct correlation of the electrode potential with the acidity of the medium is obtained. With the aqueous mixture isolated by a low flow ceramic junction from the process stream, no contamination of the process stream occurs.

Monitoring pH in phenol acetone

Uranium is extracted from phosphoric acid with organophosphorus extractants supported or impregnated on polymeric resins, and especially macroreticular resins. Suitable extractants include mono and dialkylphenyl esters of phosphoric acid. Uranium may be stripped from the supported or impregnated resins with hotter or more concentrated phosphoric acid, optionally with oxidation to hexavalent form, or with aqueous fluoride solutions.

Extraction of uranium from phosphoric acid using supported extractants

A cumene oxidation product containing cumene hydroperoxide (CHP) and dimethylphenylcarbinol (DMPC) is decomposed with acid catalyst in a first step at mild temperatures that lowers the CHP concentration to about 0.5-5% and converts most of the DMPC to dicumylperoxide (DCP). In a second step at mild temperatures the CHP concentration is lowered below 0.4%. In a third step the DCP is decomposed at a higher temperature for a short time to alpha-methylstyrene (AMS), phenol and acetone, with any remaining DMPC also converted to AMS. The DCP concentration is monitored during the third step, and the reaction is stopped by cooling when about 0.5-5% of the DCP remains undecomposed so as to maximize AMS yield.

Decomposition of cumene oxidation product

A mixture of ketoxime such as methyl ethyl ketone oxime (MEKO), an inorganic acid such as sulfuric acid and optionally water is fed to an intermediate point of a fractional distillation column. Steam is fed to the base of the column and operating conditions are sufficient to produce the corresponding ketone (e.g. methyl ethyl ketone) or its water azeotrope as the overhead product and the corresponding hydroxylammonium salt (e.g. the sulfate) as the bottoms. Crystallization of the salt from the bottoms leaves a mother liquor which may be recycled to a reboiler from which the steam is generated.

Continuous hydrolysis of ketoxime

Aqueous phosphoric acid solutions containing uranium values are contacted with an organic solution of a mixture of organophosphorus compounds produced from a carboxylic acid and PCl.sub.3 in the presence of water or from corresponding acid halides or anhydrides and phosphorous acid to extract the uranium values. The organophorus compounds generally include an alkane-1,1,2-triphosphonic acid or a 1-hydroxy-1,1-alkanediphosphonic acid or both, which differ from common organophosphorus extractants in having a carbon-phosphorus bond. The extraction has high distribution coefficients even when the phosphoric acid solution is 10 molar or more and even when the extraction is conducted at elevated temperatures such as 60.degree. C. While distribution coefficients in the presence of iron are higher for tetravalent uranium, efficient extraction can be conducted of hexavalent uranium as well. Uranium values are recovered from the organic solution by contacting it with about 40-70 weight percent aqueous HF and separating a uranium-rich precipitate from the solution.

Extraction of uranium values from phosphoric acid

A racemic mixture of D- and L- forms of alpha-aminocaprolactam ('ACL') dissolved in e.g. ethanol is resolved, and preferably the undesired form remaining is solution is simultaneously racemized, by forming a supersaturated solution of the D,L-(ACL).sub.3 NiCl.sub.2. EtOH complex; providing an optically active form of lysine (e.g. L-lysine) as crystallization inhibitor of the undesired enantiomer of said complex (e.g. the D-form), and crystallizing a portion of the desired form of the complex from the solution. The undesired form remaining in solution can be simultaneously racemized by providing a strong base and an excess of ACL over the stoichiometric proportion required to form the complex. The recovered crystals of the desired form of the complex can be processed to afford the desired form of ACL, and to recover the nickel reagent. The ACL can be converted to the desired form of lysine, a nutritionally valuable amino acid.

Resolution of enantiomeric complexes of nickelous chloride and

Poly(ester/carbonates) are produced by adding phosgene to a reaction mixture of bisphenol A and terephthalic acid as ester-forming reactants, at mole ratios in the range between 2.0:0.8 and 2.0:1.3, in which the reaction medium consists essentially of pyridine, the concentration of bisphenol A plus terephthalic acid is in the range between 5 and 50 grams per 100 ml of pyridine; and the phosgene is added under agitation at a rate of at least 0.07 gm-mmole/liter.sec. The process is carried out at temperature in the range between 50.degree. C. and 115.degree. C. and not below the temperature given by the Arrhenius equation:

Process for poly (bisphenol A/terephthalate/carbonate) using pyridine

A process for separating hydroxylamine from an aqueous solution containing hydroxylammonium salts in mixture with salts of predominantly monovalent cations whose corresponding free bases have base dissociation constants greater than 10.sup.-7. Said solution is passed through a bed of cation exchange resin loaded predominantly with monovalent cations whereby hydroxylammonium and the other cations in solution substantially displace said cations from the resin. A second aqueous solution containing a monovalent amine or hydroxide base of at least 0.5 molar concentration having a dissociation constant greater than 10.sup.-7 is passed through the resin bed whereby hydroxylamine is preferentially released to the solution and the resin is correspondingly loaded with the cation of said base. Hydroxylammonium salts can be crystallized from the solution after addition of a stoichiometric amount of an appropriate acid.

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Madison, NJ, United States of America

Stylianos Sifniades