Abstract:
Disclosed are nylon salt solution preparation processes including a trim diamine feed. The nylon salt solution is prepared by feeding a dicarboxylic acid monomer and a diamine monomer to a single continuous stirred tank reactor. The dicarboxylic acid is metered, based on weight, from a loss-in-weight feeder to the reactor. The nylon salt solution is formed continuously and has low variability from a target pH and/or a target salt solution concentration. The nylon salt solution is transferred directly to a storage tank, without further monomer addition, pH adjustment, or salt solution adjustment after exiting the continuous stirred tank reactor.
Abstract:
Disclosed are process controls for controlling the continuous preparation of nylon salt solution. The process controls include feed forward controls. A model is generated to achieve a target pH and/or salt concentration. Feed rates are set for each of a dicarboxylic acid monomer, a diamine monomer, and/or water to a single continuous stirred tank reactor. The dicarboxylic acid is metered, based on weight, from a loss-in-weight feeder to the reactor. The nylon salt solution is formed continuously and has low variability from a target pH and/or a target salt solution concentration. The nylon salt solution is transferred directly to a storage tank, without further monomer addition, pH adjustment, or salt solution adjustment after exiting the continuous stirred tank reactor.
Abstract:
The present disclosure relates to systems and methods for manufacturing a polyamide. The method can include obtaining, from a reservoir, an aqueous solution comprising a dicarboxylic acid, a diamine, and water having a substantially liquid phase; concentrating the aqueous solution including transforming a portion of the water having a substantially liquid phase to water having a substantially gaseous phase; condensing the water having a substantially gaseous phase into condensed water having a substantially liquid phase; removing at least one impurity from at least one of the condensed water having a substantially liquid phase and the water having a substantially gaseous phase to produce cleaned water having a substantially liquid phase; and reusing the cleaned water having a substantially liquid phase. The system can include, among other things, a reservoir; an evaporator assembly, in fluid communication with the reservoir; a condensation assembly, in fluid communication with the evaporator assembly; a collection assembly; and a conduit network.
Abstract:
The present invention relates to methods, systems, and apparatus for making polyamides having at least two heat-transfer media. The method includes heating a first flowable heat-transfer medium, to provide a heated first flowable heat-transfer medium. The method includes transferring heat from the heated first flowable heat-transfer medium to a second flowable heat-transfer medium, to provide a heated second flowable heat-transfer medium. The method also includes transferring heat from the heated second flowable heat-transfer medium to at least one polyamide-containing component of a polyamide synthesis system.
Abstract:
The present invention relates to an improved process for producing hydrogen cyanide involving a heat exchanger comprising a plurality of tubes, wherein each of the plurality of tubes comprises a ceramic ferrule extending through the entrance of the tube, each ferrule comprising an insulation layer surrounding at least a portion of the ferrule, and one or more washers, wherein at least one of the one or more washers surrounds the ferrule above the entrance of the tube, wherein the ceramic ferrule is spaced apart from the tube. It further relates to a reaction apparatus for producing hydrogen cyanide involving a heat exchanger comprising a plurality of tubes, wherein each of the plurality of tubes comprises a ceramic ferrule extending through the entrance of the tube, each ferrule comprising an insulation layer surrounding at least a portion of the ferrule, and one or more washers, wherein at least one of the one or more washers surrounds the ferrule above the entrance of the tube, wherein the ceramic ferrule is spaced apart from the tube. It further relates to the heat exchanger for use in this improved process and reaction apparatus.
Abstract:
The present invention relates to a process for producing hydrogen cyanide and more particularly, to a process for economically producing hydrogen cyanide. More particularly, the present invention relates to the controlled use of a ternary gas mixture including a methane-containing gas comprising less than 1 vol. % C2+ hydrocarbons, such as, for example, less than 5,000 mpm C2+ hydrocarbons, an ammonia-containing gas, and an oxygen-containing gas for production of hydrogen cyanide at enhanced levels of productivity and yield.
Abstract:
Process for producing compounds comprising nitrile functionsThe present invention relates to a process for producing compounds comprising at least one nitrile function by hydrocyanation of a compound comprising at least one non-conjugated unsaturation.The invention proposes a process for producing compounds comprising at least one nitrile function by hydrocyanation of an organic compound comprising at least one non-conjugated unsaturation, comprising from 2 to 20 carbon atoms, by reaction with hydrogen cyanide in the presence of a catalytic system comprising a complex of nickel having the oxidation state of zero with at least one organophosphorus ligand chosen from the group comprising organophosphites, organophosphonites, organophosphinites and organosphosphines and a cocatalyst of the Lewis acid type.
Abstract:
The invention provides methods useful in the industrial scale process for hydrocyanation of butadiene to adiponitrile for recycle of unwanted byproduct 2-methyl-3-butenenitrile (2M3BN) by conversion to process intermediate pentenenitrile. The invention provides a process for generating catalysts useful for carrying out the hydrocyanation of butadiene to adiponitrile, the process comprising contacting the 2M3BN and a solution of a nickel-ligand catalyst in cis-2-pentenenitrile (cis-2PN), trans-2-pentenenitrile (trans-2PN), or a mixture thereof. The improved methods of the invention can provide improved catalyst solubility for bidentate ligands without a requirement for a Lewis acid catalyst promoter such as zinc chloride to be present.
Abstract:
Disclosed is a process for isomerizing cis-2-pentenenitrile to 3-pentenenitrile in the presence of a non-aluminium metal oxide catalyst, wherein: (a) the metal in the catalyst has an oxidation state in the range from +1 to +4; (b) the metal has a cation radius in the range from 0.35 to 1.0 Å; (c) the metal of the catalyst has a polarising power, C/r, is in the range from 2 to >8, wherein C is the charge of the metal and r is the ionic radius in Å; (d) the bond network of the catalyst has a % ionicity of >20; (e) the metal oxide has an acidity strength in the range from strong to very weak; and (f) the metal oxide has a basicity (nucleophilicity) strength of weak to strong.
Abstract:
The invention provides a method of forming a phosphonate diester compound from a ligand hydrolysis product (LHP) of a phosphite ligand used in a nickel-phosphite hydrocyanation catalyst, such as for conversion of 3-pentenenitrile to adiponitrile, which serves to climinate acidic LHP compound for a hydrocyanation reaction milieu where the acidic LHP can catalyze further catalyst ligand destruction. The invention further provides phosphonate disester compounds prepared by alkylation of diarylphosphite LHP in the presence of a nickel-phosphite catalyst comprising a bidentate ligand, and a continuous hydrocyanation process for production of adiponitrile wherein catalyst ligand breakdown is inhibited through inactivation of ligand hydrolysis products towards further breakdown. A method of stabilizing a hydrocyanation catalyst is provided.