The value of waste

Devin Walker explains why landfills are not the end of the line for biodegradable waste and how instead it could be used to reduce the UK’s dependence on foreign energy supplies

There is no such thing as ‘away’. When we throw anything away, it must go somewhere.” These are the wise words of Annie Leonard, executive director of Greenpeace, and they touch on one of the biggest issues of our time. The disposal of waste has huge environmental impacts and involves a myriad of processes.

It’s estimated that up to 80 per cent of the contents of our bins could be recycled or composted. Currently, around 1.2 kilograms of municipal solid waste (MSW) is generated by each person every day. That’s the equivalent weight of 384 teabags and, what’s worse, reports published by the World Bank suggest that this figure is only set to increase. Forecasts predict that by 2025, each person will be accountable for 1.5 kilograms of waste per day.

Many waste disposal and management facilities have a myopic approach to developing effective recycling and waste reduction programmes. In the UK, most food waste is still being buried in landfill sites, where it rots and releases the harmful greenhouse gas methane.

While countries like Switzerland and The Netherlands are renowned for their recycling strategies, in the UK, Wales has been piloting recycling programmes for several years and the results are beginning to pay off. To date, figures show that 66 per cent of the country’s residents recycle their food waste.

Now, we are seeing world leaders prioritising strategies to reduce waste and increase recycling targets. Countries in the EU, for example, are required to recycle at least 55 per cent of their MSW by 2025, with plans to increase this by at least five per cent every five years following this.

The legislation surrounding this, which was published in the official journal of the EU in June 2018, was welcomed by many. Among those welcoming the legislation was Piotr Barczak, waste policy officer at the European Environmental Bureau, who stated that: “After years of discussions, it is now time for EU countries to walk the talk on waste reduction. These laws are necessary to tackle some of the world’s most pressing issues such as pollution in our cities and environment.”

In addition to the heaps of harmful waste mounting every day, the UK has become heavily dependent on imports of energy since the decline in the North Sea oil and gas production. In 2017 alone, the UK imported 47 million metric tons of crude oil and natural gas from countries like Algeria and Nigeria. Not only does this contribute to harmful emissions, but this also costs the country millions in transportation and contributes to harmful emissions.

Innovative process
To meet energy demands, countries need to lower their dependence on imported fossil fuels but doing so also has its economic advantages. For example, by reducing dependency on fossil fuels, governments can safeguard their country against uncertain political climates and mitigate the chances of energy being used as a weapon in international conflicts.

Slowly, we are seeing an increase in the percentage of energy coming from local renewable sources like wind and solar. However, locally-sourced energy still only accounts for nine per cent of the UK’s annual energy consumption. At Renovare Fuels, we believe more can be done with the waste that is currently being produced, which is not only friendlier to the environment but also offers economic value.

Technology that can convert waste into liquid biofuel has existed for some years now, but is off-putting to many businesses. This is because the Fischer–Tropsch (F-T) process is often found to be energy intensive, which means it must be done on a large scale to be considered commercially viable.

What we have created at Renovare is a process that can operate on the biogas created from waste, anaerobic digesters and sewage treatment facilities. This is because the technology efficiently recycles both mass and heat flows in a way that balances exothermic and endothermic reactions. By balancing these reactions, Renovare’s process requires no external energy input to function.

This technology is incredibly valuable for businesses in the agricultural and wastewater sector. Here, the biodegradable by-products of other operations can be converted to, and used on site as, a source of energy for future processes. With no external energy input required, the process remains carbon neutral.

Utilising resources
The technology operates by combining the biogas, which incorporates both the methane and carbon dioxide elements, with a contaminant remover. The biogas is then cleaned and purified, before transferring to a reformer reactor where synthesis gas is produced. Finally, the substance is put through a F-T reactor to create clean liquid fuel, water and fuel gas.

The use of alternative fuels considerably decreases harmful exhaust emissions like carbon dioxide, carbon monoxide and ozone-producing emissions. The benefit of the fuel produced by Renovare’s technology is that it can be used as a direct replacement for traditional fossil fuel derived petrol, diesel and jet fuel, without the need for blending. It is also fully compliant with the EU’s renewable energy directive sustainability criteria.

In fact, the department for environment, food and rural affairs (DEFRA) reported that 31.8 million metric tons of biodegradable waste was produced in 2016. Based on this figure, at Renovare Fuels we believe our technology and the fuel it creates could displace over two billion litres of fossil fuels annually. This is 42 times more fuel than is currently being imported into the UK, and would equate to a reduction in greenhouse gas emissions of around five million tons per year.

Biofuels like Renovare’s bring a new meaning to the old belief that one man’s rubbish is another person’s treasure. In this instance, it can not only fuel a car or an aeroplane, but because it can be created domestically, businesses can use their own resources instead of relying on imports. This can strengthen the local economy and reduce the number of harmful emissions in the atmosphere as a result.

Renovare Fuels
Devin Walker is chief technical officer of Renovare Fuels. Renovare Fuels designs, manufactures and markets a new technology for converting biogas into liquid fuel. The chemical and physical properties of Renovare’s fuels are virtually identical to their fossil fuel derived analogues, allowing the biofuel to be used as a direct replacement for diesel without the need for engine design modifications. Renovare’s process can operate on biogas that is produced from landfills, anaerobic digesters and sewage treatment facilities.

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