Visbreaking waste

Gebauer et al. [38] suggest visbreaking of waste plastics with vacuum residue. This is a thermal process, applied in refineries in order to convert partially atmospheric vacuum residue and decrease viscosity and melting temperature. According to the authors, addition of 5% of waste plastics in laboratory tests does not influence noticeably the process parameters and final products properties. As in the case of LCO and VGO fractions the application of vacuum residue and mixture of waste plastics is applicable in refineries. 

This chapter presents the industrial applications and validations of certain detailed models which refer to the kinetics analysed earlier. The steam cracking process will be analysed first followed by visbreaking and delayed coking processes. Last of all, the method will be applied to the thermal degradation of plastic waste. 

Figure 1.13 Processing of plastic wastes in refinery units.19 VVA pre-treated mixed plastic scrap AR residue from the atmospheric distillation process VR vacuum distillation residue VisR visbreaker residue VVR vacuum visbreaker residue.

To feed the reactor, the plastics waste has previously undergone visbreaking alone or in the mixture with heavy petroleum derived vacuum residues [390-392]. 

Thermochemical processes used to recycle the feedstock from plastic waste are usually those used in the petrochemical industry. These include visbreaking (viscosity reduction or breaking), steam cracking. 

Used in Germany during World War II. A version developed by Veba Oel EntwicklungsgeseUschaft mbH was operated in Bottrop, Germany, from 1988 to 1994, using vacuum residues from crude oil distillation and visbreaking operations, with plastics from municipal wastes, and with chlorinated organic compounds. 

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