Process for producing caprolactam
AssigneeHillyard Chemical Company
InventorFrank C. Fowler
Life of this patent
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Abstract
A non-catalytic method is provided for depolymerizing nylon-6 to produce e-caprolactam. The nylon, as a melt is continuously fed to a reaction zone together with superheated steam and undecomposed polymer melt is continuously withdrawn from the reaction zone together with steam and polymer decomposition products. Caprolactam is recovered from the polymer decomposition products.
Claims8
A process for producing e-caprolactam from a polymer thereof which comprises continuously introducing into a reaction zone a melt of said polymer, continuously introducing high temperature steam into said reaction zone as the sole depolymerizing agent therein, continuously withdrawing from said reaction zone, steam, polymer degradation products and undecomposed polymer melt, maintaining said reaction zone at a temperature of at least about 600.degree.F. and recovering e-caprolactam from said polymer degradation products as a product of said process.
A process for producing e-caprolactam from a polymer thereof which comprises maintaining a melt of said polymer at a temperature between about 400.degree. and about 600.degree.F., continuously injecting a portion of said melt into a stream of steam heated to between about 750.degree. and about 1000.degree.F. in a weight ratio between about 1/10 to about 1/2 pounds of melt to one pound of steam to produce a combined stream of polymer melt and steam, continuously introducing said combined stream into an elongated reaction zone, said steam being the sole depolymerizing agent in said zone, maintaining said reaction zone at an average temperature between about 650.degree. and about 1250.degree.F., maintaining said polymer melt in said reaction zone for an average residence time between about 1/2 minute and about 10 minutes, continuously withdrawing from said reaction zone, steam, polymer degradation products and undecomposed polymer melt, recovering e-caprolactam from said polymer degradation products and recycling to said reaction zone at least a portion of said undecomposed polymer melt and at least a portion of said polymer degradation products from which said e-caprolactam has been removed.
Dependencies are inferred from the claim text.