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Separation and valorisation of carbon black from the pyrolytic char

Periodic Reporting for period 1 - ReTyre (Separation and valorisation of carbon black from the pyrolytic char)

Reporting period: 2017-06-01 to 2017-08-31

PROBLEM: More than 13.5m tonnes (~1bn tyres) of End of Life Tyres (ELT) are discarded annually throughout the world , of which Europe contributes 24% . By the year 2030, this number is forecast to reach up to ~5bn tyres (including stock piled) to be discarded globally on a regular basis . Disposal of these ELTs presents serious environmental and commercial challenges. Europe produces 3.3m tonnes of ELT every year and spends €600m annually on its management. In 2014, 37% of the collected ELTs were used in the energy recovery, 35% used in for granulation and 27% utilised for re-treading & reuse .
Several ELT management routes have been tried in the past such as;
• Land Filling- used prior to 2006. Due to heavy metals and other pollutants found in tyres there is a potential for leaching of toxins in to the water table. This is dangerous to human health and other organisms. Since 2006, ELT, Landfill is no longer an option as EU legislations (1999/31/EC) and (2000/53/EC) prohibit the disposal to landfill of the whole or partly shredded tyres
• Shredding- The rubber (SBR/NR) can be used to make floor surfaces, such as children’s playgrounds or carpet underlay. Very niche market with low margins and not big enough market to consume the tyres waste generated globally. UK alone generates 480,000t tyres per annum.
• Burning Tyres as fuel- At least two-thirds of tyres collected today are incinerated to produce energy in cement kilns and paper factories etc. due to their high calorific value (CV). Along with having a negative effect on the ‘circular economy’ and EU’s Waste Hierarchy by losing valuable materials, this causes emissions of harmful pollutants such as carbon and sulphur compound.
The only method to drive ELT management towards the Circular Economy & EU’s Waste Hierarchy is ‘Pyrolysis’ which has the potential to convert tyres into its constituent fractions which can then be recycled. Pyrolysis is thermal decomposition of the ELT in the absence of oxygen to produce steel, char, liquid oil and gas . Pyrolytic oils (mixture of paraffins, olefins & aromatic compounds) have a high heat value (CV~44MJ/kg), can be combusted directly or with petroleum products . The gas fraction contains CH4, CO, CO2, N2, H2 & O2 and is usually burnt to fuel the pyrolysis process. However, at present pyrolytic char is too contaminated and non-functional to have much commercial value. Pyrolytic char consists of carbon black(CB) and a mixture of carbonised rubber polymer, non-volatile hydrocarbons and ash containing tyre rubber additives such as ZnO, Sulphur compounds, Clays, and Silica . Although char makes up to 40%wt of the output in a pyrolysis process, there is a very limited market for the char due to these ash contaminants and its low surface area which has a range of 40-60 m2/g. Therefore, pyrolytic char obtained from conventional pyrolysis cannot be reused in high end applications such as road tyres and conveyor belt manufacturing, therefore limiting its market to low grade applications eg manufacturing of cheap thermoplastics and low cost absorbents for the treatment of industrial effluents.
Our market research suggests that while there are over 20 R&D pyrolysis plants in the EU, most are university based) and there are no commercially successful ones. One of the major factors of the commercial non-viability of these plants and the pyrolysis process is their inability to fully extract the carbon char produced Its inferior quality to virgin Carbon Black (CB), due to the impurities present and loss of functional groups due to the pyrolysis, gives it limited end use applications. It is widely believed that reprocessing of waste tyres into value-added products would improve the economic leverage of ELT pyrolysis. Recovered CB (rCB) is under constant review by tyre manufacturers (an industry which uses about 75% of all carbon black produced worldwide) however there has been little success to date. Our initial ma
Within this feasibility study, our overall aim is to conduct the activities necessary to strengthen the ReTyre business case. The effort and resource investedenabled us to reach an advanced level of development of the technology, however the market readiness level (MRL) requires acceleration. The output of this feasibility study has helped us strengthen our MRL to mirror our technological achievement. Phase 1 feasibility study was split into discrete tasks to deliver the necessary output required to deliver a strong business case – alongside completing necessary tasks to enable swift commercialisation of ReTyre:

TASK 1 Validation of the customer demand – VoC surveys determined the dynamics of the anticipated initial markets. The survey determineed the acceptable terms of sale; ReTyre configuration and willingness to pay. Relevant market reports were used to understand the market size and trends to develop a market report detailing the market potential.
TASK 2 Technical Analysis- Technological solution was further evaluated in the light of customer feedback and upscale requirements. All technical risks along with their mitigations and contingencies were captured.
TASK 3 IPR Strategy –We have confirmed our freedom to operate, identified new routes of IP protection, extension of the existing patents and new avenues of IP generation through new designs and functionality. Commercialisation strategy was finalised using output of the task 1.
TASK 4 Supply Chain Development – A partner engagement activity was undertaken to identify relevant supply chain partners for Phase 2 to build a robust supply chain for the upscale manufacture and commercialisation of ReTyre. We also developed a set criteria to evaluate the recruitment of supply chain partners. Appropriate route to market was sought by analysing different licensing models
TASK 5 Project Planning – Based on the customer needs identified in Task 1, a future Phase 2 project plan was developed to deliver a commercial scale demonstrator for ReTyre
TASK 6 Business Planning – Based on the output of Tasks 1–5, a comprehensive business plan was developed
All nearest state of the art coating methods are batch, filler/coating specific & fail to provide the monolayer coverage necessary to give optimised end use performance. They involve extra heat treatment to cure the surface coating & cost ~EUR 200/ton of the filler. We build upon batch SoA coating methods by providing a continuous coating method which involves no further treatments & involves additional costs of only £30/t. We believe that there is no competitive method which can bring about 33% improvements in the specific surface area & impart bespoke surface functionality in a continuous milling process without the need for further curing treatments. Our surface functionalisation innovation lies in the application of existing continuous jet milling processes with a modification to allow the application of liquid coating agent via peristaltic pump through which a known quantity (determined through physical analysis to provide mono layer coverage) of the coating agent sprayed on rCB
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