Method for continuous hydrolysis of polyurethane foam in restricted tubular reaction zone and recovery

• Main Author: JOHNSON; OLIN B
• Format: Patent
• Language: English
• Published: 24.05.1977
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATERTREATMENT OR WASTE MANAGEMENT; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; MAKING GRANULES OR PREFORMS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A continuous method for converting particulate polyurethane foam to diamines and liquid polymeric hydrolysis product of the polyurethane (polyethers or polyesters) and simultaneously separating diamines from the liquid polymeric product comprises propelling a stream of particulate polyurethane foam into a first end of an enclosed tubular reaction zone, introducing steam into said first end of said tubular reaction zone under sufficient pressure to pass through said tubular reaction zone and exit from the opposite end thereof into an enclosed separation zone of greater cross sectional area than said tubular reaction zone while carrying with it the liquid and gaseous hydrolysis products of the particulate polyurethane, recovering liquid hydrolysate from the lower half of the enclosed separation zone, and recovering gaseous effluent from the upper half of the enclosed separation zone, said particulate polyurethane in passing from the first end of said tubular reaction zone toward the opposite end thereof being obstructed by two or more grids with apertures of cross sectional area which vary inversely with their distance from said first end of said tubular reaction zone.