It's becoming increasingly apparent that our current social behaviours are having a negative impact on the environment, whether it's due to persistent product waste or greenhouse gas emissions. As such, many experts are calling for countries to move towards circular economies, where resource waste, depletion and loss are minimised through regenerative practices like recycling. Here, Dean Hislop, managing director of carbon-neutral fuel producer Renovare Fuels, explains where perishables fit into the concept.

In recent years, we've seen many countries state their interest in moving towards adopting circular economies. In 2012, the European Commission's Manifesto for a Resource Efficient Europe declared this in no uncertain terms, stating that "in a world with growing pressures on resources and the environment, the EU has no choice but to go for the transition to a resource-efficient and ultimately regenerative circular economy".

This goal has been largely adopted by EU member states, which is reflected in the total amount of non-hazardous waste recycled each year. EU statistics agency Eurostat estimated that EU states recycled a total of 847 million tonnes of non-hazardous waste in 2016, with France, Germany, Italy and the UK leading the way.

Despite its subsequent plans to depart the EU, the UK remains set on establishing a circular economy. In December 2018, the UK Government published its Waste and Resources strategy, with a foreword from Michael Gove, the Secretary of State for Environment, Food and Rural Affairs, outlining the UK's goal of moving "to a more circular economy which keeps resources in use for longer".

While the circular economy is primarily focussed on improving a country's resource management and reducing environmental impact and pollution, it does offer benefits to many businesses as well. Reusing or recycling products reduces the requirement for new resources and allows businesses to draw the most value from existing assets. This is especially useful for agricultural, food production and waste processing businesses.

In its strategy, the UK Government draws attention to a handful of ways that the circular economy feeds into the push for more renewable, green forms of energy. In particular, it mentions biogas from incinerating bio-waste and anaerobic digestion (AD) as an effective means of generating energy in a circular economy.

AD has been supported by UK Government for the past few years, with feed-in tariffs and incentives for AD facilities in place since the country's Anaerobic Digestion Strategy was published in 2011. Currently, AD contributes to the circular economy by recycling waste streams into low-carbon energy and producing a biofertiliser which provides vital nutrients to the soil used for food crops.

Whilst AD does produce low-carbon energy, the conversion process, such as generating electricity through a Combined Heat & Power engine, is inefficient with a considerable amount of the energy created lost or emitted as heat. The UK Waste and Resources Strategy document focusses solely in terms of the biogas produced during the process but AD can also be used to produce a drop-in liquid fuel from biodegradable waste through a more efficient conversion process — ideal for agricultural or food production businesses that can use liquid fuel in their equipment without having to modify it.

The trouble with this is that the Fischer-Tropsch (F-T) process used to turn AD biogas into a liquid fuel is energy intensive. Fortunately, a recent breakthrough in the underlying technology has changed this, making the process self-sustaining and carbon neutral. This new process, developed by Renovare Fuels, makes the production of liquid biofuel from waste a much more viable option for the circular economy and does not require a subsidy to be economically viable.

Renovare Fuels' process embodies the concept of the circular economy. Waste products act as feedstock to the AD process, which produces a biogas that Renovare's unique process turns into a liquid fuel that is chemically similar to its fossil fuel counterparts, allowing it to be dropped into systems as a direct replacement for diesel, petrol and jet fuel. The process requires no external energy, with the water and heat produced during the F-T process being recycled to power the system and utilises within the process the carbon dioxide that exits in the biogas without the need to emit it to the atmosphere. This makes it entirely carbon-neutral.

As more countries look to become circular economies where resources are reused and recycled until they are completely depleted, technology like Renovare's will be increasingly important. Ensuring that the process of producing energy from waste is carbon-neutral is key to realising a brighter, greener and more efficient future.