Oil, Fuel Cells and Alternative Energy

Researchers in the Netherlands are developing an online computer-generated 'virtual counsellor', dubbed a 'chat-bot' to help smokers to kick the habit. Betsy van Dijk and her colleagues at the University of Twente, together with a Dutch anti-smoking organisation called Stivoro, hope that the anonymity of the web, together with twenty-four hour access to their virtual life coach, will help more smokers to quit. The team are planning a female chat-bot who will respond, with the same answers and facial expressions as those used by real-life counsellors at Stivoro, to questions and confessions tapped into a chat-box by nicotine-craving would-be quitters. But the idea isn't just a pipe-dream; indeed virtual life-coaches are developing something of a track record including pursuading elderly people to take more exercise, which was the achievement of "Laura", a chat-bot created by Boston-based researcher Timothy Bickmore. Meanwhile, if the quit-smoking programme is a success, the team are planning to wheel out a raft of counsellors tailored to help with other problems including phobias and alcoholism.

Our world is living under the threat of climate change and we're running out of fossil fuels fast. So how should we solve the coming energy crisis? 

At the moment, the UK government is deciding whether we should build new nuclear power stations to cope with our rising energy demands.

But there are many complex issues involved - including the environmental, political, economic and scientific aspects.

To help make sense of it all, the Institute of Physics has asked three writers - including our own Dr Kat - to look into the issues surrounding nuclear power and new power stations.

Over the next ten weeks, the team will be detailing their investigations on a blog entitled Potential Energy.

You can check out their thoughts, and add to the debate yourself at www.potentialenergy.iop.org

Phil - Now it's time to hop over the ocean for this week's science update, where Bob Hirshon and Chelsea Wald will be looking at an anti-theft mechanism in scrub jays and how camel can help calculate the amount of caffeine in your coffee.

Bob - This week for the Naked Scientists since the topic is energy, we'll discuss a newly developed test for that chemical that many of us use as our personal fuel: caffeine. But first, Chelsea has some news of some research from your neck of the woods. It involves some very energetic birds that will go to great lengths to protect what's theirs.

Chelsea - Burglary is rampant among western scrub jays. That's why these small woodland birds hide their food. Now researchers at Cambridge University have found that they also keep close tabs on each other. Psychologist Nicola Clayton says that if a scrub jay hides his food when another bird is watching, he'll go back to check on it later. If the coast is clear, he'll move the move the food once. And if the same observer is still there, he'll move it several times to confuse the would-be thief. If a new bird is there, he won't move it at all.

Nicola - To do so they must not only recognise different individuals but they must remember who was watching at a particular time. So the idea is that they're keeping an eye on the competition.

Chelsea - Which for a bird is a surprisingly sophisticated sort of paranoia.

Bob - Thanks Chelsea. And now to caffeine. If you sometimes worry that that cup of decaff you got is really decaff, you'll be happy to learn that a handy caffeine detector for beverages may soon be on the way courtesy of a llama. Why a llama? Well along with camels, llamas are among the few species that make antibodies to caffeine that can withstand high temperatures. Protein chemist Daniel Crimmins and his colleagues at Washington University in St. Louis Missouri were able to use those antibodies to detect the caffeine in a hot cup of coffee.

Daniel - And then you no longer have to schlup around your camel or your llama to your favourite coffee house to do the measurement. We cloned the antibody sequence by standard molecular biology techniques so we can make as much as we needed to.

Bob - A llama named Very Senorita had the toughest antibodies, so they're using hers to develop a commercial product for home use.

Chelsea - Next week we'll be talking about one of our favourite topics: bacteria. We never tire of the amazing things they can do like make the world's strongest super glue or survive Mars-like conditions. Until then, I'm Chelsea Wald.

Bob - And I'm Bob Hirshon, for AAAS the Science Society.

Chris - We've heard about the science and we all know where it ends up; that's in our cars. And it ultimately translates into a lot of carbon dioxide that we think is promoting a greenhouse effect which is warming our planet up and promoting climate change. Now one way we might be able to bypass this problem is to develop cleaner sources of energy. Someone who's here to talk to us about that is Lynne Macaskie from Birmingham University. Tell us about your work.

Lynne - We were looking at alternative ways of making energy using bacteria which are very small organisms found in the soil and found in water and found in loads of places. On eof the clever things that bacteria can do is that they can make hydrogen. You can make hydrogen from the petrochemicals industry but as we've just heard, the lifetime of that industry may be finite. So it's high time we started looking at other ways of making hydrogen as a potential fuel because when it's burned, it just leaves water.

Chris - So it's a lot cleaner.

Lynne - It's a lot cleaner and the water is clean. So if we also look to a potential water crisis through global warming, we have a way of making clean water as well.

Chris - Presumably, if we take water out of the ground and turn that into carbon dioxide, Nicky, that's not carbon neutral because you're taking away a stable source of carbon that's been locked away and releasing it into the air. Whereas what Lynne is suggesting is using energy that is already available from various sources and it's not liberating new carbon dioxide. Would you say that that was a fair comment?

Nicky - That's correct, but the oil industry is looking at ways of sequestering or burying the carbon dioxide that's produced during the burning of hydrocarbons as well.

Chris - So then how does your technique actually work?

Lynne - Well bacteria can eat sugars and for this we were looking at sugars that would otherwise go to waste and may be buried and end up back in the environment. This is an awful waste of sugar and a waste of energy. Since bacteria love to eat sugars, what we decided to do was to see if we could make them make hydrogen. Now when we eat, we breathe out and the bacteria do the same thing: they eat bacteria, breathe out and they breathe out hydrogen. In Birmingham we've actually got the Cadbury plant not very far away, so we had a little project with Cadbury's to see if we could take some of the waste from confectionery and feed it to bacteria and see if we could make the bacteria make hydrogen.

Chris - How much do they chuck away that you could potentially be using? What's the energy value going down the drain each day just because there's no way to use it at the moment?

Lynne - It's very high in sugar and if it was reusable then I'm sure they'd reuse it. I don't have the figures to hand as to how much is actually thrown away. It might actually be recycled into animal feed; I don't know that information. But to be able to reuse the waste on site may have the potential to generate energy and offset some of their own fuel demands, while at the same time reduce the pressure on the National Grid.

Chris - How much energy can you generate and how do you actually do it? Talk us through the nuts and bolts of how bacteria ultimately culminate in the production of energy.

Lynne - It's a bit too premature to say how much could actually be done in the future. We can calculate that to run a house at a base level without cookers or heating, you could make a drum of perhaps one or two cubic metres of bacteria, so that's the sort of level one would be looking at. The way they do this is they make the hydrogen, and you pass the hydrogen into a machine called a fuel cell. What the fuel cell does is it splits the hydrogen and the electrons go off into the circuit and run a load, for example, an electric fan. Then at the other end, the electrons recombine with the protons from the hydrogen and the oxygen from the air to make water. So actually it's possible to couple the bacterial vats into a fuel cell and couple that into an electrical device.

Chris - How much space would this take up? Is it feasible at the moment? The beauty of what Nicky is talking about, oil, is the energy locked away in a tiny amount of oil is huge. In order to produce a viable amount of hydrogen how many barrels of bacteria would you need?

Lynne - It's a bit too soon to say that. We did a basic calculation where we calculated that you could probably run the background energy demands of a house on something that was about the size of a fridge-freezer.

Phil - How much fuel do you need to put into something like that? How much chocolate or sugar would you need to run a household or something domestic?

Lynne - You're looking at quite a lot really. You're looking at bagfuls. So it's quite unlikely that the average house would generate that much sugar. I think at the moment that we'd be looking at factories that produce very concentrated wastes and lost of it. But the next stage of the work would be to look at domestic waste and to see if in an ideal world if one could recycle one's composting material into making hydrogen, which you could then use for the fuel supply of the house.

Chris - Do you have to genetically modify the bacteria to make them more efficient at doing this, or can you find these bugs living naturally in the environment?

Lynne - You can usually find these bugs living in the environment if you go looking for them. Obviously genetic engineering will help you to make better ones but it's probably best to go with what nature has provided. Sometimes you can make bacteria breed if you put them together and you end up with better strains by selective breeding rather than genetic modification.

Chris - And very briefly Lynne, what's the time scale on the roll out on this kind of thing. At the moment this is sitting in your laboratory. When could we expect, reasonably, to see the first commercial and viable uses of this technology?

Lynne - Well the technology is likely to be installed in individual companies within five or ten years. For the hydrogen economy to take off in a real way, I think we're realistically looking at 15 years, if not 20 years.

Chris - Now tell us a bit about the science of oil because it's something we all take for granted. We just go to the filling station and just fill up. How much oil is being burnt off every second around the world? Do you know?

Nicky - That's not a question that's easy to answer. What I can say is how much oil we use annually. We use 30 billion barrels of oil world wide.

Chris - And how much is that in a barrel?

Nicky - There are six barrels of oil in a cubic metre, so a cubic metre is a large box; a metre by a metre by a metre.

Chris - So how much space underground is this that was oil and is now empty?

Nicky - Well that's a complicated question. The best way to answer it is to look att he North Sea. Most people probably know that the North Sea is an important oil province. If you go out into the middle of the North Sea there's about 200 metres of water and underneath that water there are about ten or fifteen kilometres of layered sediment; so dirt basically. If you go down about four kilometres into that dirt, what you find is oil. But it doesn't occur in caverns, it occurs within the pore spaces of sandy rock. A sandy rock would have a porosity of about 30% or so, which isn't very much. Those pore spaces would be filled with oil.

Chris - So how do we know where to go looking?

Nicky - Yes that's the hard bit for the oil industry. The easy picking were all on shore. The main way in which they were found was through oil seeps which occur at the surface. So that makes it very easy indeed. So the classic oil fields in places like Texas, Louisiana and indeed the Middle East were all found in that sort of easy way. And you can drill relatively cheap holes down to the oil.

Chris - And they must have some sort of cap over the top of where the oil is, to stop the oil floating up the surface, in other words trapping it.

Nicky - Yes. There are several ingredients to all this. You need something to make the oil in the first place but you certainly need something to trap it at depth. These sandy horizons which have the oil trapped in their pores usually have an impermeable layer, like an area of limestone or salt for example on top, which stops the oil coming out.

Chris - So what's the difference between oil and coal? They contain many of the same types of chemicals don't they?

Nicky - They do indeed. They're both basically decayed organic matter. So if you decay organic matter in the absence of oxygen, you'll get things like coal and oil. So why are they different? The main difference is that oil is formed from decaying algal matter primarily. This is rather surprising I suppose. Whereas coal is mostly due to the decay of things like trees and organic matter.

Chris - Why should there be that distinction? Is it obvious?

Nicky - The main reason is that when you decay organic matter, depending on whether it's trees, algae or indeed sheep, it'll have a different composition in an organic chemical sense. So when you cook it, which is the primary thing you need to do to release oil or gas, what you produce in the cooking depends on the ingredient you start with to some degree.

Chris - So we've got to the stage where we've produced the oil. I assume that most oil in this world is millions of millions of years old.

Nicky - Yes, so if we take the North Sea, the oil there was made between 60 and 30 million years ago.

Chris - So the end of the dinosaurs to fairly recently really.

Nicky - Yes.

Chris - And why is that the cut off? Was there not enough biomass, plants and living things on Earth to make things like that?

Nicky - It's a little bit of both, but it's primarily because of the cooking time. The layer in the North Sea which is the best source rock, which is the layer of organic matter, is a layer that occurred in Jurassic times. That's about 150 million years ago. That layer got progressively buried by later sediment pouring in on top of it, which made in sink down. As it did so it cooked up. It took all that time to cook and was basically ready between 60 and 30 million years ago.

Chris - So we have a porous sponge of rock which has this stuff stuck in it. How do you get it out? Most of us have this idea that someone sticks a drill bit down and then you see the old Wild West picture where loads of stuff comes gushing out the top of your derrick. How is it achieved?

Nicky - In places like Texas in the old days that was all you had to do, and people drilled more or less at random until they found something, which can be expensive even on shore. The trouble these days is that most oil is found off shore and it's rather hard to find. Drilling holes off shore is extremely expensive. So if you drill a hole in three kilometres of water off West Africa you could pay up to 60 million dollars per hole, so you kind of need to know it's there before you drill the hole. So what do you do? To find out what's down there you have to drill a hole. Well the major technique that is used by the oil industry to locate favourable structures and indeed favourable rocks is called echo-sounding. Ina way we think of it as a downward-looking Hubble, so it's a way in which we can produce spectacular 3D images of the sub-surface from the sea bed or the land surface down to about twenty kilometres depth. We can see that hidden world in fully three dimensions and identify structures. So it's still a risky business, but you can basically reduce the risk quite a bit by collecting all this echo-sounding data first.

Chris - So say you have ticks in all the right boxes and you drill a hole, how do you actually get the stuff out?

Nicky - The oil that occurs in the pore spaces of the buried sandy rocks is under quite a lot of pressure, so in fact it pretty much comes out of its own accord, at least to start with. In the lifetime of producing an oil field, that pressure starts to drop. One of the things you then need to do is encourage the pressure back up. The main way in which you can do that is put explosives down the bore hoels and break up the rocks, which encourages better flow. Or you can drill holes which are called water injectors. You drill extra holes around the side of the oil field and you pump down seawater. It's like pushing oil on a pan-full of water. You can push the oil towards the producing gaps.

Chris - So how much oil in the reserve can we actually get at? When you say that this field is spent, roughly how mush oil is actually left in there?

Nicky - Unfortunately most of the oil is left behind. We can produce between 30 and 40% economically.

Chris - That's terrible.

Nicky - It's appalling. We're getting a bit better at inching those numbers up but it's a great technological feat.

Chris - So how much oil is left in the world? Because when I was at school just over ten years ago, people were saying that by the millennium we'll be really worried about how much oil there is. Now people are saying figures like 300 years of coal, 50 years at least of oil. How much is actually out there still?

Nicky - There's a lot of doom and gloom. The pessimistic line is that if you take liquid hydrocarbons, so oil only and not coal or tar sands or gas, liquid hydrocarbon production will peak at about 30 billion barrels a year in something like 10 to 15 years time and then decrease rapidly over the next 100 years. However there are optimists who believe that even that scenario is too pessimistic.

A rocket works by throwing something out of the back so the rocket goes forward. So the action and reaction are actually inside the spacecraft. The fuel pushes outwards and pushes the spacecraft forwards. So in space what we actually use is a fuel called hydrazine and we burn this out of the back of the spacecraft through little thrusters. This is how we manoeuvre the spacecraft and push it around. There are some other ways we do it as well. We're looking at things such as ion drives. That takes individual atoms, ionises them so that they've got an electric charge, and then uses electric fields to throw these gas molecules out f the back of the spacecraft. We've used that sort of application to send a spacecraft to the moon. It took a long time to get there but was moving very fast by the time it got there. So that could be a possibility for long range spacecraft. The bottom line is that if you want to slow something down you have to apply force in the opposite direction to which you're travelling. So you have these retro-rockets which fire against the direction in which you're travelling. So the rocket has a certain momentum moving in one direction and you want to give it momentum in the other direction so they cancel each other out. So the rocket is pushing against itself.

First of all, when the oil is extracted, it's coming out of the pores in the sandy rocks and in most places the framework of that rock remains reasonably intact. You do in the long term get some subsidence. Perhaps the most notorious example is in the Netherlands where they don't really want anymore sinking but there's a very large gas field in the middle of the Netherlands called the Groningen gas field. There's a lot of subsidence associated with that. There's also a lot of subsidence associated with coal fields but that's a little bit different because you're excavating underground. When the oil comes out it's seeping out of the pores, so you're not actually making a big hole down there.