Abstract: An intrinsically safe data network, such as one defining a system for acquiring and transferring data from inside a hazardous zone at an oil or gas well to outside the hazardous zone, includes a fixed number of at least one data signal conductor and a fixed number of at least one intrinsic safety barrier forming part of the overall network that allows for the use of more transducers than there are intrinsic safety barrier(s).

Abstract: Disclosed is a process for the purification of carboxyl streams such as product streams comprising one or more carboxyl compounds selected from carboxylic acids, carboxylic anhydrides and alkylidene dicarboxylates. The process provides a means for the reduction of the iodine content of carboxyl compound product streams which are contaminated with one or more iodine compounds.

Abstract: A capacitive differential pressure sensor comprises two end pieces and a central diaphragm all of the same type of electrically non-conductive material, such as quartz. As the central diaphragm moves relative to the end pieces in response to pressures applied through the end pieces, capacitance changes are sensed through one pair of facing electrodes on one end piece and the diaphragm and another pair of facing electrodes on the other end piece and the diaphragm. A method of measuring differential pressures at an oil or gas well with such a sensor is also disclosed.

Abstract: Apparatus and method for detecting the presence of extraneous magnetic fields having a predetermined weak magnitude include a transformer having an excitation winding, an output winding, and a saturable core which will saturate in a magnetic field of a predetermined saturation magnitude. The core is made of amorphous metal alloy and is shaped to cancel the electromagnetic effects of magnetic fields having flux lines which are substantially parallel with respect to the transformer. An excitation circuit is connected to the excitation winding for generating a magnetic field having an excitation magnitude of lesser magnitude than the saturation magnitude of the core. The excitation magnitude and the weak magnitude of the extraneous magnetic fields combine to create a magnetic field of greater magnitude than the saturation magnitude of the core. A detector circuit is connected to the output winding for detecting and indicating saturation of the core.

Abstract: Disclosed is a process for the recovery of a cyclohexanedicarboxylic acid from an aqueous solution of the cyclohexanedicarboxylic acid and sodium sulfate by contacting the solution with vinylpyridine/divinylbenzene ion exchange resins.

Abstract: Disclosed is a continuous method for refining acetic anhydride produced by the reaction of ketene and acetic acid by means of a vacuum distillation system to provide a refined material comprised of at least 99.5 weight percent acetic anhydride, not more than 0.5 weight percent acetic acid and not more than about 90 parts per million (ppm) diketene.

Abstract: Disclosed is an improved process for the removal of acetone from a production system wherein acetic anhydride is produced by contacting a mixture comprising methyl iodide and methyl acetate and/or dimethyl ether with carbon monoxide in the presence of a carbonylation catalyst or catalyst system. The process comprises two distillation steps wherein acetone is separated from a mixture of methyl acetate, methyl iodide and acetone.

Abstract: A process for preparation of 1,3- or 1,4-cyclohexanedicarboxylic acid comprising(A) preparing a solution comprised of the disodium salt of terephthalic acid or isophthalic acid and water,(B) continuously preparing the disodium salt of 1,3- or 1,4-cyclohexanedicarboxylic acid by continuously contacting the solution with hydrogen and the combination of ruthenium metal and a carbon support in a packed column,(C) preparing 1,3- or 1,4-cyclohexanedicarboxylic acid by contacting the disodium salt of 1,3- or 1,4-cyclohexanedicarboxylic acid with sulfuric acid or hydrochloric acid, and(D) recovering the 1,3- or 1,4-cyclohexanedicarboxylic acid by crystallization of the 1,3- or 1,4-cyclohexanedicarboxylic acid.

Abstract: A process for preparation of 1,3- or 1,4-cyclohexanedicarboxylic acid comprising(A) continuously preparing a solution comprised of the disodium salt of terephthalic acid or isophthalic acid and water,(B) continuously preparing the disodium salt of 1,3- or 1,4-cyclohexanedicarboxylic acid by continuous contacting the solution with hydrogen and the combination of ruthenium metal and a carbon support in a packed column,(C) continuously preparing 1,3- or 1,4-cyclohexanedicarboxylic acid by continuously contacting the disodium salt of 1,3- or 1,4-cyclohexanedicarboxylic acid with sulfuric acid or hydrochloric acid, and(D) continuously recovering the 1,3- or 1,4-cyclohexanedicarboxylic acid by continuous crystallization of the 1,3- or 1,4-cyclohexanedicarboxylic acid.

Abstract: Disclosed is an improved process for the removal of acetone from a production system wherein acetic anhydride is produced by contacting a mixture containing methyl iodide and methyl acetate and/or dimethyl ether with carbon monoxide in the presence of a carbonylation catalyst or catalyst system. The process involves a water-methyl iodide extraction step wherein acetone is separated from a mixture of methyl acetate, methyl iodide and acetone.

Abstract: Disclosed is a process for the preparation of aqueous solutions of acetoacetamide wherein diketene and aqueous ammonia having an ammonia concentration of about 6.0 to 9.0 weight percent are continuously fed to a reaction zone at rates which maintain in the reaction zone a pH of about 7.0 to 8.2 and a residence time of about 20 to 150 minutes while (i) maintaining the temperature of the reaction zone at about 40.degree. to 75.degree. C. and (ii) subjecting the contents of the reaction zone to vigorous agitation. An aqueous product solution having an acetoacetamide concentration of about 25 to 35 weight percent is continuously removed from the reaction zone.

Abstract: A process for the liquid-phase oxyiodination of naphthalene which comprises (1) preparing a liquid-phase feed mixture of iodine and naphthalene and/or iodine, naphthalene and iodonaphthalenes, and (2) contacting the feed mixture with a zeolite catalyst in the presence of a gaseous source of oxygen to produce an iodinated naphthalene mixture and water, and (3) removing water from the iodinated naphthalene mixture.

Abstract: Disclosed is a process and apparatus for the chlorination of diketene, by contacting the diketene in nebulized form with chlorine gas, which contacting can be in the absence of a solvent or diluent, in an essentially uncooled reaction zone of short residence time followed by a cooling zone wherein at least a portion of the heat of reaction is removed from the product without the need for refrigeration.

Abstract: Disclosed is a process for the recovery of catalyst values from a catalyst-tar solution derived from a production system in which acetic anhydride is prepared by carbonylating methyl acetate in the presence of rhodium, lithium and methyl iodide. The catalyst values are recovered by submitting the catalyst-tar solution to an extraction using methyl iodide and aqueous hydrogen iodide. The presence of hydrogen iodide in the aqueous phase stabilizes the rhodium in a water-soluble form and prevents rhodium losses due to the rhodium plating out on the process equipment.