Analytical Case Study on a Dedicated Pigment in Recycling Processes of Polyethylene

The ability to track & trace materials is a key feature in the entire chain, and it ensures circularity principles. Examples from plastic recycling show the enormous added value that analytical technology can have for the circular economy. During polymer production and recycling processes, pigments can be added for different purposes;e.g. as colouring agent of the polymeric product but also as tracer for tracking process development and control in the final recycle products versus possible by-products. An analytical method for tracking the pigment Solvent Blue 15 in input materials, in intermediates as well as in recyclates was developed by tracing and quantifying an indicator metal which is copper (Cu). Therefore, suitable digestion procedures and a quantification method by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) were developed and used for measuring the polymeric digests. The method was tested on relevant samples from chemical recycling processes. The background concentrations in base/raw material are in the range of 0.05 - 0.1 mg·kg-1 Cu. The processing concentrations are in the range of 4.2 to 28 mg·kg-1 Cu, while the pigment starting material (polyethylene, PE) has a concentration of around 50 mg·kg-1 Cu.

Beyond cost reduction:improving the value of energy storage in electricity systems

From a macro-energy system perspective,an energy storage is valuable if it contributes to meeting system objectives,including increasing economic value,reliability and sustainability.In most energy systems models,reliability and sustainability are forced by constraints,and if energy demand is exogenous,this leaves cost as the main metric for economic value.Traditional ways to improve storage technologies are to reduce their costs;however,the cheapest energy storage is not always the most valuable in energy systems.Modern techno-economical evaluation methods try to address the cost and value situation but do not judge the competitiveness of multiple technologies simultaneously.This paper introduces the‘market potential method’as a new complementary valuation method guiding innovation of multiple energy storage.The market potential method derives the value of technologies by examining common deployment signals from energy system model outputs in a structured way.We apply and compare this method to cost evaluation approaches in a renewables-based European power system model,covering diverse energy storage technologies.We find that characteristics of high-cost hydrogen storage can be more valuable than low-cost hydrogen storage.Additionally,we show that modifying the freedom of storage sizing and component interactions can make the energy system 10% cheaper and impact the value of technologies.The results suggest looking beyond the pure cost reduction paradigm and focus on developing technologies with suitable value approaches that can lead to cheaper electricity systems in future.