摘要:
A process comprising contacting a liquid polyester stream with hydrogen in the presence of a hydrogenation catalyst comprising a metal supported on the surface of silicon carbide at a metal dispersion of at least 0.5% or graphite at a metal dispersion of at least 10% to produce a treated liquid polyester stream. The treated stream may be polycondensed in the presence of a polycondensation catalyst to produce a polyester polymer having an It.V. of at least 0.55 dL/g. The liquid polyester stream desirably has a composition comprising: a) terephthalic acid residues, isophthalic acid residues, and/or naphthalenedicarboxylic acid residues and b) an average degree of polymerization of 0.5 to 20 and c) an acid number ranging from 5 to 600.
摘要:
Disclosed is a process for the isomerization of 2,2,4,4-tetraalkylcyclobutane-1,3-diols, such as 2,2,4,4-tetramethylcyclobutane-1,3-diol, by contacting the diol with a supported ruthenium catalyst in the presence of hydrogen at elevated pressures and temperatures. The process is carried under conditions in which there is no net production of 2,2,4,4-tetraalkylcyclobutane-1,3-diol. The process may be carried out in the presence or absence of a solvent and in the liquid or vapor phase.
摘要:
Disclosed is a process for the isomerization of 2,2,4,4-tetraalkylcyclobutane-1,3-diols, such as 2,2,4,4-tetramethylcyclobutane-1,3-diol, by contacting the diol with a supported ruthenium catalyst in the presence of hydrogen at elevated pressures and temperatures. The process is carried under conditions in which there is no net production of 2,2,4,4-tetraalkylcyclobutane-1,3-diol. The process may be carried out in the presence or absence of a solvent and in the liquid or vapor phase.
摘要:
A process for removing metal species from a composition comprising contacting: a. an oligomer mixture stream comprising the monomers of a partially aromatic polyester polymer and at least one metal species, or b. a molten polyester polymer stream comprising partially aromatic polyester polymers and at least one metal species, with a non-catalytic porous material in the presence of hydrogen to produce a treated stream containing a reduced amount of at least one metal species. There are provided compositions comprising a partially aromatic polyester polymer having an It.V. of at least 0.50 produced in a direct esterification melt phase process, from greater than 0 to less than 50 ppm antimony, and less than 40 ppm cobalt, or produced in an ester exchange melt phase process, having from greater than zero to less than 5 ppm titanium and less than 10 ppm manganese.
摘要:
Provided is a composition with partially aromatic polyester polymers having an It.V. of at least 0.50 dL/g, produced in an ester exchange melt phase process, having from zero or greater than zero to less than 5 ppm titanium, from zero or greater than zero to less then 10 ppm germanium, and from zero or greater than zero to less than 20 ppm manganese.
摘要:
A process for removing metal species from a composition comprising contacting: a. an oligomer mixture stream comprising the monomers of a partially aromatic polyester polymer and at least one metal species, or b. a molten polyester polymer stream comprising partially aromatic polyester polymers and at least one metal species, with a non-catalytic porous material in the presence of hydrogen to produce a treated stream containing a reduced amount of at least one metal species. There is also provided a composition comprising a partially aromatic polyester polymer having an It.V. of at least 0.50 produced in a direct esterification melt phase process, from greater than 0 to less than 50 ppm antimony, and less than 40 ppm cobalt. There is also provided a composition comprising partially aromatic polyester polymers having an It.V. of at least 0.50 produced in an ester exchange melt phase process, from greater than zero to less than 5 ppm titanium, and less than 10 ppm manganese.
摘要:
A process for removing metal species from a composition comprising contacting: a. an oligomer mixture stream comprising the monomers of a partially aromatic polyester polymer and at least one metal species, or b. a molten polyester polymer stream comprising partially aromatic polyester polymers and at least one metal species, with a non-catalytic porous material in the presence of hydrogen to produce a treated stream containing a reduced amount of at least one metal species. There is also provided a composition comprising a partially aromatic polyester polymer having an It.V. of at least 0.50 produced in a direct esterification melt phase process, from greater than 0 to less than 50 ppm antimony, and less than 40 ppm cobalt. There is also provided a composition comprising partially aromatic polyester polymers having an It.V. of at least 0.50 produced in an ester exchange melt phase process, from greater than zero to less than 5 ppm titanium, and less than 10 ppm manganese.
摘要:
Disclosed is a process for the preparation of dimethyl cyclohexanedicarboxylates by the hydrogenation of the corresponding dimethyl benzenedicarboxylate ester in the presence of supported catalysts comprising (i) a Group VIII metal and (ii) a catalyst support material selected from graphite and silicon carbide.
摘要:
A catalyst for the preparation of ketones from carboxylic acids is described. The catalyst comprises a mixture of zirconium dioxide, titanium dioxide, and one or more metal oxides from Group 1 or 2 of the Periodic Table of Elements. The catalyst can operate at a lower temperature, reduce coke formation, and provide longer lifetime.
摘要:
Disclosed are catalysts comprising copper chromite, palladium and lanthanum having hydrogenation activity. The combination of copper chromite with palladium and lanthanum enhances catalyst activity more than the presence of either palladium alone or palladium in combination with alkali or alkaline earth metals. The catalysts are useful for the preparation of methanol from carbon monoxide and hydrogen and for the hydrogenation of carbonyl compounds such as, for example, aldehydes, ketones, and esters, to their corresponding alcohols. The catalysts may be used for the preparation of cyclohexanedimethanols from dialkyl cyclohexanedicarboxylates or of ethylene glycol from alkyl glycolates.