Pyrolysis of filled PMMA for monomer recovery

The pyrolysis of low filled poly(methylmethacrylate) (PMMA) waste is one of the few technical processes for feedstock recycling of plastics. Highly fi lled PMMA was pyrolyzed in an indirect heated fluidized bed for monomer rec overy and compared with experiments using pure PMMA pellets as feed. The ex periments were carried out in laboratory plants with throughputs of about 1 kg h(-1) and in a mini pilot plant with a throughput of 30 kg h(-1). At a temperature of 450 degreesC acrylic glass yielded 98 wt.% of methylmethacry late (MMA) while the amount decreased to 94% at 480 degreesC. PMMA containi ng over 60% of quartz sand was pyrolyzed to 91% MMA. Other compounds are ga s (2.0%), liquids (5.7%), and carbon black (1.2%). (C) 2001 Elsevier Scienc e B.V. All rights reserved.