Final report: Material and Energy Valorisation of Waste in a Circular Economy

Apr 2022

Final report: Material and Energy Valorisation of Waste in a Circular Economy

Waste-to-energy, commonly via a combustion-based process, is an effective component of a modern waste management strategy, whereby landfill-bound waste streams are converted to heat and power. The technologies supporting these pathways are mature and well-developed and have for many years contributed positively to sustainable waste management processes. In more recent times there has been the emergence of principles associated with the ‘circular economy’, an economy-wide concept moving from a make–use–dispose model to one where reuse, remaking, and recycling underpin a move away from reliance on resource extraction. Circular economy principles are embedded in business models, in consumer behaviours, and government policy, and have implications for the waste management sector.

These circular economy principles demand more from inherently linear combustion-based waste to energy processes. In response to this, there has been technology development and deployment that supports additional resource recovery: recovery of nutrients from composting, digestion, and combustion process; extraction of useful metals and salts from combustion residues; and the beneficial re-use of ash from incineration plants to further reduce the volume of material sent to landfill.

Increasingly-stringent regulations, however, are driving the need for new technology pathways to be deployed—ones that support the use of waste as a feedstock for new recycling pathways, new manufacturing processes, and a more diverse suite of energy products. These pathways are not based on established combustion processes, but on ones that produce useful intermediates (e.g. gasification for syngas production) that can in turn be used as industrial feedstocks for a range of applications. As well as an energy-recovery pathway, this supports the notion of ‘keeping molecules in use for longer’ and allows the waste management sector to play an important role in a broader transition towards a circular economy.

Transitioning to new technologies, however, is not without challenges. Any adoption of new technology comes at a cost, and we have seen that play out in some early demonstrations of some of these at scale. This highlights the role of supportive policies and regulations that incentivize and encourage pathways that are more sustainable over the long term, which support ongoing deployment which, in turn, drives down costs.

The challenges are not all technical, however. Community acceptance is an ongoing challenge for almost any waste-to-energy project, and this process can be further complicated if the technology suite in question is less mature or the public have less experience with their operation. Information is important, but by no means the most important factor at play here—with significant effort needed for communication, engagement, and an appreciation of the different factors that are important for developed vs the less-developed countries.

The planned work of the task for the next triennium will seek to understand these emerging pathways in more detail, with a focus on sustainability, and the role of advanced sorting technologies and the emergence of new waste streams and product opportunities (such as clean hydrogen)—all with the goal of supporting the transition of the waste sector towards more circular principles.

Link to the reports below:

Final Report

Final Report 2 Pager