Katie Heath, Consultant for Wardell Armstrong’s Regulatory Support Team, asks if there’s room for residual waste in a circular economy?
Circular economy has now become a familiar concept, encouraging innovation across the resources and waste sector as we look to embrace opportunities that deliver on this ambition. However, are we maximising those opportunities to tie in with addressing the climate emergency?
In a few short decades, we have seen global challenges become mainstream societal conversation. These include the ever-increasing urgency to tackle climate change, all while finding a sustainable way to manage Earth’s dwindling resources amongst continual population growth.
Though daunting, these challenges have given rise to opportunity and innovation in the resources and waste sector, especially through finding itself an intrinsic part of the circular economy. We find ourselves in a time of transition, where the boundaries between ‘waste’ and ‘resource’ are becoming less distinct, as we seek unlock the resource potential of even residual waste streams.
Efforts to move towards a more circular economy and to shift resources up the waste hierarchy continues to drive policy and yield new technological advances
The development of modern technology and infrastructure has allowed UK recycling rates to grow from 10% to 45% in the last two decades alone. Although this has stagnated in recent years, recycling targets set by the UK government’s Resources and Waste Strategy aim for 65% of all municipal solid waste to be recycled by 2035, with less than 10% going to landfill.
The strategy aims for every household to have a weekly separate food waste collection in place from 2023, as well as Defra seeking consistent collection of dry materials from all households and businesses.
Efforts to move towards a more circular economy and to shift resources up the waste hierarchy continues to drive policy and yield new technological advances. Plastic waste has become a particular material of interest, with concerns of plastic pollution resulting in bans on the sale of single use plastics, including that which will come into force in the UK in April 2020.
We have seen efforts by a number of companies increase recycling rates or reduce use of plastic overall. Recent examples include Müller’s recent partnership with Biffa to enable the dairy company’s 100% recyclable rHDPE milk bottles to comprise 40% recycled plastics, and Unilever’s partnership with Veolia, Viridor, Suez and TOMRA to develop a recyclable black plastic pigment, which could see an additional 2,500 tonnes of plastic bottles recycled in the UK each year.
There are also solutions being sought to divert low‑grade plastics from the residual waste stream, especially in the wake of the Chinese import ban. Emerging technologies include utilising pyrolysis to process low-grade plastics into a feedstock for the petroleum industry, with some industry experts even suggesting the controlled landfilling of this waste stream for later ‘mining’, when an appropriate technology develops.
There have also been significant developments in the energy recovery sector, allowing heat and power to be recovered from waste otherwise destined for landfill. Legislative targets to phase out biodegradable material going to landfill have resulted an increase in energy recovered at anaerobic digestion facilities; this coupled with recovery of landfill gas has resulted in significant saving of greenhouse gas emissions from the waste sector as a whole.
We now see more residual waste going to energy recovery facilities than being deposited in landfill, with bottom ash and air pollution control residues routinely recycled into secondary aggregates.
With the circular economy in mind, I wonder how far we can go to further reduce our emissions from what we currently consider to be residual waste – including municipal solid waste (MSW). Though preferable to landfill, energy recovery has the disadvantage of producing polluting emissions from the energy generation process.
With the circular economy in mind, I wonder how far we can go to further reduce our emissions from what we currently consider to be residual waste
These will continue to improve thanks to updated standards recently adopted across Europe but their cumulative impact across the globe will be significant.
Furthermore, when converted to electrical energy, there are energy efficiency losses through the transmission network.
In the near future, I hope to see considerable investment into solutions for residual waste to improve efficiency, such as through combined heat and power recovery from energy recovery facilities, or through advancements like the recent surge in gas to grid technology at AD facilities.
At least for the medium-term, I foresee that high efficiency energy recovery facilities have an important role in providing energy security in the face of a growing renewable energy infrastructure that is not yet mature.
Looking further to the future, if we are to succeed in closing the circle and achieving sustainable consumption, I believe we should work to make ‘residual waste’ an outdated concept. Indeed, the Resources and Waste Strategy aims to double resource productivity and eliminate avoidable waste of all kinds by 2050.
In an idealistic future we might even achieve a significant uptake in reuse and repair, leading to a decrease in certain materials available to recycle. Consumers and producers will also have a part to play, but it is evident the waste and resource sector must continue to be innovative, adaptable and responsible in an age of transition to a circular economy.