The following report is provided by Paul Frith of Frith Resource Management.
The summit included speakers covering the following technology types:-
* Energy from waste (Sita)
* Gas Plasma (Advanced Plasma Power)
* Anaerobic Digestion (Hot Rot Solutions)
* Mechanical Heat Treatment (EVRS)
* Pyrolysis (Enval)
* Gasification (Waste2tricity)
* Incinerator Bottom Ash treatment and recovery (Rock Solid BV)
* Processes for Deriving Chemicals from Waste (Solvert), and
* Processes for Recycling Plastics Waste Into Food Grade Bottles (Nextek Ltd)
The diversity of technical solutions to waste management challenges appear broad, and one aspect that was made clear from the presentations is substantial innovation and ambition in evidence to both help meet our waste management challenges and provide resources back into the UK economy.
It is also clear however that there remain major challenges to delivery of waste technology ranging from the planning risks of Energy from Waste plant through to bankability risks and blockages for various new technology solutions. In some regards it was ever thus, but at present there are more recent (and ongoing) nuances, notably relating to the uncertainty of the Localism agenda and the risk aversion of banks.
It is a far more complex picture than this however, and some of the key messages from day 1 of the conference are included here.
Sita
Stuart Hayward Highman explained the openness with which they were exploring and partnering for the development of new technologies, in addition to their existing Energy from Waste (EfW) infrastructure. This was tempered by a caution over risk and finance, however Sita are actively involved in expanding the use of landfill gas in vehicles (including deals with Tesco and Sainsbury’s for their vehicle fleets) for which a limiting factor is the effectiveness of the Renewable Transport Fuel Obligation (RTFO) subsidy, which delivers less income than the equivalent Government support mechanism for electricity generation, the Renewables Obligation.
Furthermore, it involves greater effort to deliver a fuel that meets the RTFO than convert energy to electricity and meet the RO through waste treatment technologies. In this context, and it was a message reiterated during his talk, the UK Government incentives for renewable energy do not adequately promote the ‘most sustainable’ option, but rather seem to bias towards electricity generation (which often yields a lower efficiency environmental return). This was a concern for Sita, which sees new technologies as offering a better environmental solution when waste is used as a feedstock for liquid and gaseous fuels rather than burned for electricity generation.
In this context, Mr Hayward Highman explained their new developments with end of life plastics at Avonmouth, which converts the waste stream through an advanced thermal treatment process into diesel, and recent developments in Anaerobic Digestion at Sita.
He also outlined future planned developments including the hope of testing a static hydrogen fuel cell technology. Where technology risk is a factor in financing Sita has used its balance sheet to facilitate investment in new technologies where appropriate, and sees a range of technical solutions available in the market for managing waste.
Advanced Plasma Power (APP)
Rolf Stein delivered a presentation on the activities of APP, utilising their plasma gasification process. This technology initially prepares the waste through mechanical separation of non-combustibles from the input waste stream and gasifies the resultant (prepared) fuel feedstock using a conventional gasification process. The output syngas and ash is then passed to a second chamber containing the plasma process. The high temperature / UV light cracks the syngas to generate a cleaner gas suitable (after acid gas scrubbing) for combustion in a gas engine (without he informa us, the inherent fouling problems associated with conventional gasification). Furthermore, the ash is vitrified into a glassy residue with the trade name ‘Plasmarok’, which may have value as an inert ‘product’. Mr Stein also cited the potential innovation of spinning the vitrified residue into ‘Rockwool’ type insulation applications.
APP are also processing the excavations from a Belgian landfill (containing auto-shredder residues and Commercial / Industrial wastes) through the Plasma Gasification process. A typical scale proposed for an APP Plasma Power plant for mixed wastes would be ~150ktpa input for mechanical sorting and preparation, in order to deliver ~90ktpa of fuel for the thermal process. This scale of plant would cover a footprint of ~10,000m2.
EVRS (Mechanical Heat Treatment)
Martin Osment explained the EVRS process for utilising mechanical heat treatment technology to derive usable materials from a mixed waste stream. This process mechanically sorts out the glass / aggregate, metals and plastics fractions from the waste stream leaving a predominantly cellulose based feedstock for the autoclave vessel.
The EVRS was described as unique in adding additives and catalysts to the input waste to homogenise the waste and tailor it to an appropriate output specification. This can include dyeing the waste in order to deliver an output of appropriate colour for a particular user. The process is claimed to deliver 99.99% pure cellulose fibre (known as Zystur© fibre), and the technology is marketed towards, commercial and municipal waste streams. The usage of the fibre (which is a pale straw colour) is cited as an insulation material or for use in ‘soft landing’ applications, there was also the potential for use in paper making.
The technology has been demonstrated at lab scale and at a small demonstration plant and it was stated that the process had no emissions to land, air or water. It is a scalable technology with commercial sized facilities beginning at ~6ktpa upwards, with standard vessels of 50ktpa, allowing multiples to be placed on one site in order to deliver larger scale facilities.
Nextek (Waste Polymer Sorting)
Ed Kosior delivered a fascinating talk around the issues with sorting / reprocessing the more ‘difficult’ plastic polymers. He focussed particularly on the black plastics (e.g. some food trays), seeking to attain food grade polypropylene and the recycling of plastic films.
As regards black plastics it was evident that optical sorters used in materials recycling facilities (MRFs) or plastics sorting facilities, could not differentiate the plastic polymers of these materials because the carbon black within the plastic absorbed the near infra red (NIR) light that is used to bounce off of plastics to determine their composition. In tests, Nextek changed the dye within the black plastic to an organic black dye, which did not absorb the light rays. After a re-program of the optical sorting software, the equipment was able to both see and sort the black plastic, enabling effective separation for recycling.
Delivering food grade polypropylene (PP) was considered a major challenge for the industry. One reason for this is the tendency for PP bottles to be used for bleach, detergents, shampoos and other non foodstuff with potentially toxic contents. However, using a dedicated hand-picking / sorting line, it was possible to deliver a food grade PP recyclate stream with around 50% of the mixed PP considered appropriate for this application. This approach has yet to reach commercialisation.
Mr Kosior also explained that laboratory tests have shown that it is possible to deliver 100% recycled plastic film, although in the current market much lower levels of recycled content are usually used because of issues with organics contaminating the recyclate stream. This is another area that is progressing in terms of commercialisation.
In questions and answers, Mr Kosior discussed how many times PET and HDPE bottles could be recycled ‘though the loop’ before degrading. For PET bottles the main issue, he stated, is discolouration after one recycling stage. It is possible to add brighteners to the plastic, in which case they could potentially be recycled ~5 times.
For HDPE bottles, the limiting factor was the amount of antioxidant within the plastic, again around 5 times recycling was possible if more antioxidant was available. He speculated that if more antioxidant were added to the material at the start of its life then the ‘recycling life’ could be extended.
Conclusion
The 1st EyeforEnergy Waste Technology Summit was notable for the high quality of the speakers from Waste Technology Companies, and it was your reviewer's view that this conference was unique in attracting industry speakers not seen at other recent events, each of which came with with new and promising marketable technologies which commissioning clients in the public and commercial sectors will be very interested in.
Find out more about Frith Resource Management at www.frithrm.com .
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