Science Interviews


Sun, 26th Jul 2009

Rubbish Power

Richard Kirkman, Veolia Environmental Services

Listen Now    Download as mp3 from the show The Science of Rubbish

Kat -   Turning waste into fuel rather than just recycling it would also be an ideal way to kill two birds with one stone, reducing the rubbish we send to landfill and also cutting our reliance on fossil fuels, which as we all know, seem to be running out apace. Now, we’re going to talk to Richard Kirkman. He’s from Veolia Environmental Services where they’re finding different ways to get power from rubbish. Hi, Richard.

Richard -   Hi.

Kat -   So, tell us about what you’re doing about trying to make recovered fuel from rubbish, how does it work?

rubbishRichard -   Well, it’s all about turning waste into the most useful resource we can.  So for liquid wastes, we turn them into liquid fuels, and for solid waste, we turn them into solid fuels.  What we do; we set up facilities that take in the rubbish and we extract all the recyclable components that we can and then the residual parts, which are not easily recyclable, are made into fuels which can go into cement kilns or power stations.

Kat -   And what sort of, what sort of waste are we talking about?  Is everything equally, useful for fuel?  What sort of things makes the best fuels?

Richard -   Well, any waste that has an energy content, a calorific value that can be used in a process to recover that energy into electricity or heat.  So, municipal waste can be used, commercial waste can be used or industrial wastes, and depending on what type of waste we have as an input, we can produce different types of fuels to different specifications to meet the industrial needs.

Kat -   Now, what can we actually use these fuels for?  We’re going to be hearing in a little while from Peter Jones who’s going to be talking about making a syngas liquid – making gases that we can use as fuels.  But what about your solid and liquid fuels?  Could we stick them in the car?

Richard -  They tend to be rather complex mixtures and therefore they’re replacing oil, for example, in a cement kiln or a lime kiln if it’s a liquid waste, or through replacing coal with a solid waste in a power station for example. So, a typical power station with the steam cycle which will recover energy, we can replace that coal with a fuel made from solid waste, such as municipal waste. We can also have put it into industrial processes or as you said in gasification or pyrolysis processes if we produce a very specific waste stream. So, if we were to recover non-recyclable plastics that would be easily gasified into a gas that could be cleaned sufficiently to use it in a turbine to produce energy, which is a very efficient way to recover energy.

Kat -   Oh. It sounds like you know - it sounds fantastic. We can make all these fuel from basically rubbish, but how much energy does it actually take to make it? Because I know, for example, for recycling, you need to put quite a lot of energy into the process to get recyclable glass and plastics out. Is it really going to be energy efficient to do this?

Richard -   No, that’s right. There is a percentage of the energy recover used in the process to make the fuel, but we know from the way the waste hierarchy has been formed, we must always go above landfill as a final option.  So energy recovery, by making fuels is always going to be of net benefit.  Typically, if we had a hundred thousand tons of municipal waste, we could send that to a facility where we might recover another 10% for recycling and then the residual 90% would go into a fuel. This is going to be a much energy efficient than putting it into a landfill.

Kat -   You can almost imagine a sort of an apocalyptic vision where people are stealing other people’s rubbish to sell for fuel, right? Is this somewhere we can actually co-modify this and encourage people to maybe, separate their waste or really, you know, stop just chucking stuff out the window?  Do you think this has potential?

Richard -   Well, there are – it does have potential and there are a lot of schemes springing out now where people are actually incentivised to recycle their rubbish, put it in a recycling bin, put it in the right container, and they receive a credit which they can then go and use in shops and to, you know, incentivise them to do it further.

Sizewell BKat -   How scalable is the fuel generation process?  I mean, could you imagine some kind of generator in each house or in a village where people just chuck their rubbish in and it comes out with petrol the other end?

Richard -   Well, if you think back many years ago, some people still called their refuse container dust bins and were called dust bins because people used to burn all their refuse at home, and they would just put the ash in the bins.  This is not really a very efficient way to do it because it means the emissions are uncontrolled from that burning of waste.  So, it’s better to centralise the facilities then you can produce fuels that have a tight specification that can be used in industrial processes where the emissions are controlled, and we have a net environmental benefit from that.

Kat -   It sounds absolutely brilliant.  So, when are we going to start being able to have these fuels?  Are they available already, or is this something that is coming in the near future?

Richard -   We’re moving very quickly along the road in U.K. now.  I mean, around 10 years ago, we were only sort of 8 to 10% materials recycled, the rest was landfilled.  Today, we’re recycling around 30-40% and a large proportion of the materials also being made into fuels.  If you look across Europe, there’s probably about 5 million tons of solid recovered fuel produced from waste, and we’re heading very quickly in that direction now.

Kat -   It sounds like the kind of thing that will make my dad very happy.  That’s Richard Kirkman and he’s the head of technology at Veolia Environmental Services, explaining to us how rubbish could be used as a source of energy.


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