Dichlorination of Waste Plastics

Social Impact

Dichlorination is a major issue in the treatment of waste plastics.

The global push toward carbon neutrality is driving a circular economy. In Japan, the demand for plastic recycling is rapidly increasing. The Plastic Resource Circulation Act which came into effect in April 2022 is an example of such trend.

In reality, however, many plastics sent for recycling are mixed with PVC, which will deteriorate equipment if recycled as is. Therefore, plastic must undergo a dichlorination pre-treatment process to remove any existing chlorine.

Results of Screening Tests

Screening tests were conducted on the dehalogenation of waste plastic composed primarily of PS and 2% each chlorine and bromine by irradiating it with microwaves.

仕込み [g]	Weight after processing [g]	Weight loss [g]	pH after trapping
0.4994g	0.4412g	0.0582g	pH2
0.5041g	0.4647g	0.0394g	pH2

• Extracted halogens were collected as hydrogen halogenide in a trap.

• No significant change in sample shape before and after the test

Significance of Using Microwaves

Selectively heating the PVC resulted in less time and lower energy consumption in the dichlorination process.

Future Prospects

Our aim is to drive the entire chemical recycling process.

The results obtained from this study have confirmed the feasibility of using microwaves to efficiently dechlorinate mixed resins. We believe that this technology can also be used in combination with chemical recycling and material recycling. Furthermore, microwave irradiation can be designed to meet specific needs, so please do not hesitate to contact us regarding your specific situation