Feedstock Recycling of MPW with Low PVC Content

The following technologies have been reported as most promising options for feedstock recycling of MPW [9]. 

In the liquefaction step the plastic waste is cracked nnder relatively mild thermal conditions. This depolymerization results in a synthetic heavy oil and a gas fraction, which in part is condensable. The noncondensable fraction is nsed as a fuel in the process. The process is very comparable to the cracking of vacnnm residues that originate from oil recycling process. 

2 Polymer Cracking Process (Consortium Project, Pilot) 

This is a fluid-bed cracking process. It was first tested in 1990s. This pilot plant has a 400 tonne per year feed capacity, but runs continuously on a 50 Kg/h scale as it has limited product storage. The next steps in the development process to follow are optimization and scale-up. 

The decomposition of PVC leads to the formation of HCl, which is neutralized by bringing the hot gases into contact with a solid absorbent. This results in a CaCl2-fraction that has to be landfilled. The purified gas is cooled, most of the hydrocarbon condensed as distillate feedstock. The remaining light hydrocarbon gas is compressed, reheated and returned to the reactor as fluidizing gas. Part of the stream could be used as fuel gas for heating the reactor, but as it is olefin-rich, recovery options are underway. 

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