PolyStyreneLoop is building the first demonstration plant worldwide to treat PS-foam demolition waste containing HBCD.
The innovative physical-chemical treatment technology on which PolyStyreneLoop is based allows the safe destruction of HBCD and the recovery of elemental bromine and polystyrene to keep these valuable resources in the loop.
Polystyrene (PS) foam insulation material ensures energy savings in the built environment through optimal climate control. Due to their outstanding properties, expanded polystyrene (EPS) and extruded polystyrene (XPS) are among the most widely used insulation materials.
To meet national fire regulations, Hexabromocyclode- cane (HBCD) has been used in many European countries since the 1960s as flame retardant in EPS and XPS construction products.
In 2013 HBCD was brought under the Stockholm Convention regime due to its persistent, bio-accumulative and toxic properties as well as its potential for long-range transport and listed as a Persistent Organic Pollutant (POP).
The provisions of the Stockholm Convention are in Europe implemented in Regulation (EC) No 850/2004 and its amendments.
Under the European REACH regulation, the putting on the market or use of HBCD was prohibited after 21 August 2015.
Today the new polymeric flame retardant (pFR) has mostly replaced HBCD. In the Basel Convention Tech- nical Guidelines, the prescribed treatment for PS foam waste with concentrations ≥ 1,000 mg/kg HBCD is either incineration or physical-chemical treatment, which was classified as Best Available Technology (BAT).
In Europe every year 1,600 kt of PS foam insulation products are installed while at the same time 98,6 kt PS-foam waste is generated during the demolition of buildings.
This is an urban mine containing resources that need to be treated in a way that allows keeping the value in the economic loop.
As the majority of the buildings demolished or refur- bished today were built before 2015, all the PS-foam demolition waste generated is likely to contain HBCD.
The innovative physical-chemical CreaSolv® Process on which PolyStyreneLoop (PSLoop) is based, allows the recovery of both polystyrene and elemental bromine as well as the safe destruction of HBCD:
- The PS-foam waste is dissolved in a tank that contain a PS-specific Solid impurities are separated using filtration and are subsequently incinerated.
- The introduction of a second solvent converts the PS into a gel, while the HBCD additive remains in the The PS gel is then separated from the liquid, dried and transferred into granulated polymer. The solvent in the remaining liquid is distilled and re-used in a closed loop. The HBCD additive remains as sludge.
- The HBCD additive in the sludge is destructed using high-temperature waste incineration. During the last step, a Bromine Recovery Unit (BRU) reco- vers the elemental.
The Process is not sensitive to impurities of incoming material. The impurity level of the incoming PS-foam demolition waste should however not exceed 7% by weight. Furthermore, water content is to be limited to a maximum 3% by weight and bituminous impurities excluded.
The innovation of PolyStyreneLoop does not only lie in the technology that is used but also on the organisation. PolyStyreneLoop is a cooperative with over 75 mem- bers and supporters of the entire PS-foam value chain spanning across 18 European countries.
Via the members the supply of feedstock for the plant as well as the off-take of the PS recyclate is secured, making this a robust business case that due to the vast amount of PS-foam demolition waste generated is also scalable.
The elemental bromine is used to produce new pFR and together with the PS, with the same properties as virgin material, new insulation material such as extru- ded EPS (X-EPS) and XPS are produced and thereby clo- sing the loops.
End 2019 the first spade went into the ground for the construction of the first PolyStyreneLoop demonstration plant in Terneuzen, the Netherlands.
The plant is located right next to the only BRU in Europe, owned by ICL-IP. The demonstration plant with an annual capacity of 3,300 t of PS-foam demolition waste will be built in the course of 2020 and be operational in Q1 2021.
NOTE: this article was written by: Ms. Alix Reichenecker
This article was featured in the 2020 edition of the publication. Access the full publication here:
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