General Waste Recovery: Why the Best Solution Might Be the Simplest
The ‘holy grail’ of waste management in a circular economy is the biorefinery approach: a process where heterogeneous waste enters an advanced, almost magical black box, and out comes high-value chemicals, oils, fuels, paraffins, phenols, organic acids and even precious metals. The idea is that anything, from residual municipal waste to historical landfill material, could be fed into this machine, which would then extract valuable compounds, transforming waste into wealth. It is the ultimate vision of waste valorisation.
This is the dream, the solution that might finally boost the UK’s stagnant recycling rate and usher in a golden age of resource recovery. It sounds almost too good to be true, like alchemy.
But is it that simple?
The Promise of Resource Innovation
Resource innovation – recovering component parts from waste streams – does offer real benefits. Whether it’s critical raw materials from mineral industries, proteins and flavonoids from food production waste, or phosphates from wastewater, such practices improve how we use finite resources.
This principle already works well in specific contexts, especially with organic byproducts. These can be processed using nanofiltration, microwaves or solvents to extract high-value compounds with antioxidant or anti-inflammatory properties; flavourings, pigments and more. But in these cases, the input material is clean and consistent: orange peels from juice production, or apple pomace, for example. Similarly, fish skins can yield Omega-3-rich oils instead of becoming fishmeal, compost or fuel for anaerobic digestion.
But municipal waste? That’s a whole other beast.
The Value Imperative in Waste Recovery
So, the question is: what exactly are we hoping to extract from a municipal waste stream that includes crisp packets, used nappies and half-eaten sandwiches? And let us not overlook the obvious fact that the general waste stream includes innumerable plastic bin bags!
The principle of a biorefinery is only viable – and appropriate – when the end product holds sufficient value. This is why biorefining works well with single-stream organic byproducts: the outputs are typically high-value compounds like flavonoids or proteins that command strong market prices. For instance, catechins extracted from citrus waste are highly valued in the food and skincare industries due to their proven health benefits, including cancer-preventive properties.
However, when it comes to general waste, the same economic logic does not hold. Such waste streams are complex and diffuse, making the recovery of specific compounds costly and inefficient. The more mixed the feedstock, the more energy and resources are required for extraction, efforts that often are not justifiable economically.
This becomes particularly evident when examining the two main technological hopes for non-recyclable waste: Sustainable Aviation Fuel (SAF) and chemical recycling of plastics. While these processes offer a theoretical route to circularity, they are inherently expensive. SAF, for instance, is essentially synthetic kerosene – valuable in context, but not remotely as valuable per gram as rare plant-derived compounds used in pharmaceuticals or cosmetics. Worse still, the alternative to waste-derived kerosene is simply … regular kerosene.
The same applies to plastics. Chemical recycling can indeed break down and rebuild polymers, but the economic incentive is weak. Virgin plastic, made directly from oil, is cheap and readily available, making it difficult for recycled alternatives to compete on price. Closing material loops may be principled, but without high-value outputs, it isn’t necessarily practical.
None of this is to downplay the remarkable innovation behind these technologies. But in economic terms, SAF and chemically recycled plastics are likely to remain uncompetitive with their mass-produced counterparts for the foreseeable future.
Sometimes, the Simplest Answer Is the Right One
Yes, we should absolutely recycle everything we can through upstream segregation, or sorting technologies in the waste management sector. But for the contaminated, non-recyclable fraction of waste that is too complex or dirty to process, the most effective solution might just be the simplest one: energy recovery through incineration.
Not fancy gasification. Not experimental processes. Just straightforward, proven incineration, ideally with heat utilisation as well as electricity generation to maximise the yield.
In some cases, this means creating Refuse Derived Fuel (RDF) for use overseas. And that is OK. It is a reliable way to extract energy from waste that would otherwise sit in landfills.
Conclusion
Maybe one day, technology will advance far enough that we really can extract gold from garbage. Until then, we need to be realistic. Let’s invest where it makes sense, recycle what we can, and, for the rest, recover energy in a way that’s affordable, reliable and actually works.
Sometimes, simplicity is the smartest strategy of all.