Abstract: Disclosed is an improvement in the process for making an aromatic carboxylic acid or its methyl ester from an aromatic compound having at least one methyl or formyl group bonded directly to a nuclear carbon atom of the aromatic ring. The process comprises effecting oxidation of said compound in the liquid phase with molecular oxygen or a gas containing the same with a catalyst comprising a heavy metal compound, and in the substantial absence of an aliphatic carboxylic acid as a solvent, whereby a reaction mixture comprising the acid is formed. If the ester is desired, the acid then is esterified with methanol. The improvement comprises carrying out the oxidation in the co-presence of a lithium compound at a concentration of 0.1-10 moles per mole of heavy metal compound. The lithium compound is at least partly soluble in the reaction mixture or reacts with an acid component of the reaction mixture to form a lithium compound soluble in the reaction mixture.

Abstract: Disclosed is partially hydrolyzed, DMT process residue. Also disclosed is the reaction product of propylene oxide and the partially hydrolyzed, DMT process residue. The reaction product is useful as a polyol reactant in the preparation of urethane foams.

Abstract: Disclosed is an improvement in a method for the recovery for recycle to the cooxidation-coesterification process for the production of dimethyl terephthalate from p-xylene, air and methanol of oxidation catalyst by aqueous extraction of a distillation residue containing the same. To minimize recycle of any iron present in the residue, iron oxidant material (for example, hydrogen peroxide) is admixed in one embodiment with the residue and water in the aqueous extraction procedure, and in a second embodiment with the resulting aqueous extract. In both embodiments, if any iron is present, it is precipitated. In the first embodiment the precipitate stays with the residue. In the second embodiment the aqueous extract is separated from the precipitate.

Abstract: Disclosed is a process for the recovery of aromatic carboxylic acid or ester thereof from the residue fraction of the oxidation or esterification reaction mixture resulting from the oxidation or oxidation and esterification of an aromatic compound having at least one methyl or formyl group directly bonded to a ring carbon atom. The process comprises treating the residue fraction with hydrogen and a hydrogenation catalyst.

Abstract: Disclosed is a process for producing styrene-soluble unsaturated polyester resins from DMT process residue. In a preferred embodiment of the process, DMT process residue is transesterified with propylene glycol until a hydroxyl-terminated ester product having a methoxyl content within a specified range is formed and then the resulting ester product is esterified with maleic anhydride.

Abstract: Disclosed is a process for recovering dimethyl terephthalate and intermediate products from the tarry fraction of the residue generated in the production of dimethyl terephthalate from p-xylene and methanol by the cooxidation procedure. In the process the tarry fraction is established in admixture with a catalytic quantity of alkali metal material, examples of which are sodium and potassium carbonate, at about 200.degree.-350.degree. C., and the resulting reaction mixture is maintained in this temperature range until at least a substantial quantity of dimethyl terephthalate has formed. Generally, dimethyl terephthalate and intermediate products are separated from the reaction mixture. The separation in preferred embodiments is by distillation.

Abstract: Disclosed is an apparatus for exchanging heat with liquid material and particularly liquid material under superatmospheric pressure. A preferred embodiment of the apparatus comprises a pressure vessel for holding a body of the liquid material, and having an inlet and an outlet for the liquid material. Inside the vessel is an integral tube assembly for conducting heat exchange fluid into, through and out of a body of the liquid material in the vessel. The tube assembly comprises a heat exchange fluid feed header, a heat exchange fluid discharge header, and a plurality of heat transfer tubes from the feed header to the discharge header. In a preferred embodiment of the apparatus, the headers are coaxially aligned with a normally vertical axis, and are vertically spaced apart. The headers are joined to conduits passing through the top and bottom of the vessel. These conduits in combination with the vessel support the tube assembly.

Abstract: Disclosed is the stabilization of thermally unstable, fresh dimethyl terephthalate of at least 99.8 weight % purity, free of alkali metal compound material, and produced by the cooxidation-esterification process. Stabilization is effected by incorporating therein a stabilizing quantity of alkali metal acetate material having no significant concentration of either phosphonic acid moiety or phosphite moiety.

Abstract: Disclosed is a process for the catalytic hydrogenation of the aldehyde content of molten aldehydic dimethyl terephthalate (DMT). The process comprises first dissolving in the molten aldehydic DMT a quantity of molecular hydrogen sufficient to hydrogenate at least a substantial portion of the aldehydic content, and then contacting the molten aldehydic DMT with its dissolved hydrogen content with a hydrogenation catalyst for a period of time sufficient for reaction of the dissolved hydrogen with the aldehydic content to take place, but insufficient for substantial ring hydrogenation to occur.