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Energy and Fuels Do you wonder what kind of energy you'll be using in the future? Lots of researchers around the globe are looking in to this very question. Is nuclear energy the way of the future? Or is there an alternative energy that will provide the answers? Maybe we need new batteries? Or can we get the energy we need from chocolate? We don't have the answers... yet... But maybe you will be the one to find the ultimate energy source. Researchers are also considering how to tell future generations about the energy solutions we discover today. Background Notes A brief synopsis of each of the energy and fuel items in our shows and links to our references.
In May this year the Prime Minister of Australia, Mr John Howard, called for a full-blooded debate on nuclear energy in Australia. What is nuclear energy? Why is it relevant to Australians? What are the advantages and disadvantages of nuclear energy? And what research on a nuclear future is happening right now? Whether you think nuclear energy is the answer to the world’s energy needs, or another environmental disaster that we can’t afford, it’s important to stay informed with what’s going on, so you can have a say in Australia’s nuclear future. What is Nuclear Energy? In Australia we mainly use coal to produce our electricity. This involves burning coal to heat water to produce steam to turn turbines to produce electricity. In a nuclear power plant, there is no burning of coal, instead uranium is used to heat the water, but the rest of the process remains basically the same i.e. uranium is used to heat the water to produce steam to turn turbines to produce electricity. The reason uranium can be used to heat water is because it is radioactive. It decays naturally. As some radioactive atoms break down they release small particles called neutrons. If these strike other radioactive atoms they make them split, releasing more neutrons and a whole lot of energy. As of the 6th June 2006 there were 442 nuclear power plant units world wide providing about 11% of the world’s electricity. In France, up to 75% of electricity is derived from nuclear power. Why is it relevant to Australians? In Australia we have 3 active uranium mines: Ranger in the Northern Territory, and Beverly and Olympic Dam in South Australia. These 3 mines provide around 23% of the world’s uranium, making us the second largest exporter of uranium, second only to Canada. It seems Australian exports of uranium are only set to increase as mining of a 4th site at Honeymoon in South Australia has been given the go-ahead. Despite our huge contribution to nuclear energy on a global scale, Australia does not have, and has never had, a nuclear power plant. Lucas Heights in Sydney is home to Australia’s only nuclear reactor, known as HIFAR (High Flux Australian Reactor). This reactor has been operating safely since 1958, and is about to be replaced with a new unit. The reactor is used for nuclear research and for the production of radioactive materials for use in medicine and industry. Uranium is big business for Australia, and is only going to get bigger. Now the government has put nuclear energy on the agenda, it's important Australians take a close look at nuclear power to weigh up the advantages and disadvantages, and decide if they support a nuclear future for Australia. Advantages of Nuclear Energy. • Producing electricity using nuclear energy emits no greenhouse gases. Disadvantages of Nuclear Energy. • There is the potential for nuclear weapons to be fuelled with enriched uranium originally mined for energy production. Australia Leading the way in Enrichment Technology. Some people say that using uranium for energy production is cleaner than other fossil fuels like coal because there are no green house gas emissions. Other people claim that because of all the energy required to mine and process uranium, it really is no better than coal. But now some scientists from Sydney have developed a method of processing uranium that has halved the financial cost of the process. These Aussie scientists have succeeded in a venture where hundreds of scientists from all around the world have previously failed, and now they have made a deal with US giant General Electric to commercially use their technology. What they have achieved is the development of a new way to enrich uranium. Uranium enrichment refers to separating out the different types of uranium. There are 2 main types (or isotopes) of Uranium: • Uranium-238 makes up 99% of all uranium found in the earth, this is unsuitable for energy production. Uranium enrichment is the process that separates the 2 isotopes of uranium. This is a long repetitive process, conventionally achieved through the use of diffusion or centrifuges. Diffusion involves forcing uranium through filters. The uranium-235 is lighter and passes through more easily, and is separated from the uranium-238. The second method uses centrifuges to spin the heavier and lighter atoms apart. Enrichment is said to account for up to 30% of the energy consumption of the nuclear fuel cycle. This is what makes this Aussie achievement so astounding. During the 1980’s and 1990’s the US, France, Britain, Germany, South Africa and Japan attempted to develop laser enrichment, utilising hundreds of scientists and billions of dollars, but all failed. The Australian venture took 25 staff and $65 million. The details of the method are top secret but basically the lasers electrically charge the uranium-235 atoms, which become trapped in an electromagnetic field and are drawn to a metal plate for collection. The new technology saves a lot of energy and consequently a lot of money. Now that it has been picked up by General Electric it is soon to be adopted in nuclear power plants in the USA and around the world. The Promise of Thorium. What about nuclear energy without uranium? Lots of research is going in to another radioactive element, thorium, which has the potential to create nuclear energy without the drawbacks of uranium. Thorium has similar properties to uranium (they are close to each other on the periodic table), so it can also be used to produce nuclear power. But unlike uranium, thorium can not undergo a reaction all by itself – it needs a catalyst. This means that a nuclear reactor fuelled by thorium has zero chance of a meltdown. Thorium is also a lighter element than uranium, which means it does not produce as many radioactive waste products, and the waste it does produce does not stay radioactive for as long. Additionally the waste produced in a thorium reactor would not be useful in the construction of nuclear weapons. In these ways, thorium combats three of the greatest issues surrounding nuclear energy – meltdown, waste and weapons. It may seem to be too good to be true, and at this point it is. The question of how to provide the catalyst (a stream of neutrons) to keep the reaction going has scientists puzzled, but new solutions are popping up all over the world. Thorium Power, based outside of Washington DC in the USA, use thorium in conjunction with uranium (uranium is the catalyst). While a project in Italy is attempting to make a reactor that requires no uranium at all- but at this point have been unable to do this on a commercial scale. A nuclear future involving thorium, no meltdowns, no weapons and no waste may be a while a way, but in the mean time people are working all over the world to make nuclear energy cleaner and safer. For more information: On Nuclear Energy:
On Laser Enrichment:
On Thorium
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According to calculations done by ecologist Jeff Dukes, one litre of petrol is made from about 11/2 football fields' worth of prehistoric plants. That's a lot! And the process of breaking down the plants into oil is really slow and quite inefficient. Each year we burn lots of fossil fuel (about 2.5 km3 per year). All the plant matter produced all over the world in one year would only make enough fuel to power us for one day (and then only after waiting hundreds of thousands of years for it to turn into fuel)! This means we need to start thinking about (and using) more sustainable fuels. Already there are quite a few of them about, things like: Biodiesel Take old fish and chip oil, filter it, take out the glycerine (which can be used to make detergent) and you get a fuel that can be used in any diesel engine. The cool thing is that not only is it made from a waste product, but it causes less pollution than regular diesel and your exhaust smells like fish and chips! UP-DATE- October 2005 A German researcher, Dr Christian Koch, has created a new procedure for turning our household garbage into biodiesel. Christian has created a system that involves burning garbage at 300 oC and putting one of the by-products (hydrocarbons) through a catalytic converter. At the moment he has a patent on his method and has proven that he can make efficient biodiesel out of all sorts of household garbage - including tyres, paper, motor oil, plastic and maybe even dead cats. He believes that one day we will be able to produce fuel in our own backyards using his system. What a great way to recycle our rubbish and make our cars more sustainable. Ethanol Made from biomass (rotting plants) and produces less pollution than petrol. Even as little as 10% ethanol in petrol makes a big difference to the environment. The problem is that ethanol is more corrosive than petrol, so some modification of current car engines and petrol pumps is needed. However, it does work, and it works well, as Ventura bus lines from Melbourne will testify - they've been running specially designed buses on 100% ethanol for years now. Solar Power from the Sun. Unfortunately, although there are cars that run on solar power, you and I can't drive them! Solar cars are basically electric cars, with rechargeable batteries (also charged by the Sun) for cloudy days and for going uphill. Current solar cars are specially designed for racing, and as a result they're hard to see, can't be driven on the road without an escort team, can't be driven at night, and have room for only one person (the driver). However, these cars can travel a long way without 'refueling', and the Sun certainly isn't going to run out too soon. Fuel Cells Add oxygen to hydrogen and what do you get? Water and electricity! And this electricity can be used to run cars. Contrary to popular belief, a lot of research is going into fuel cells, with many car companies checking them out. Fuel cell powered cars are expected to cost about the same as current petrol cars but be way better for the environment. And because they're electric, fuel cell cars have no engine noise, so the radio won't need to be so loud. The problem with fuel cell cars is getting the hydrogen - at the moment hydrogen is made from water, natural gas, coal or petrol (remember our lack of fossil fuel problem) and because hydrogen needs to be stored under pressure, the storage tank will need to be really strong and crash proof (in case of accidents). Abattoir Waste It sounds a little crazy, but the team at the Environmental Biotechnology CRC believe that little bugs will be able to turn bits of animals into fuel. Currently, when sheep and cows are processed at an abattoir, only half of it goes to the butcher, the rest of it is just disposed of. But using a complex system of bacteria, this waste may be able to be broken down into fuel, which could then be used to run cars. This would not only help with our fossil fuel problem, but would also mean we were using our livestock more efficiently (for food and fuel). References
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Batteries are portable energy sources that we all use. Think about all the things you use batteries for – CD & mp3 players, mobile phones, etc. Although batteries are really useful, we don't dispose of them very well with them when they run out. Batteries are usually made out of metals (like zinc, lead, and cadmium) with acidic or alkaline mixtures used as electrolytes. Some of these components of batteries are toxic. Every year lots of batteries go to landfill and they can then leach toxins into the soil or groundwater. All over the world people are trying to make better batteries. We can already buy all sorts of rechargables – NiCd, nickel metal hydride, lithium ion, etc. However, the race is on to make smaller, lighter, cheaper and more environmentally friendly sources of energy. Some of the interesting research that is going on at the moment are to do with batteries and fuel cells that run on food scraps, ethanol, or people (biobatteries). Food scrap powered fuel cells As big as a walkman and use E.coli bacteria mixed in with some chemicals to produce electricity. The bacteria produce enzymes which break down carbohydrates from the food and release hydrogen atoms. The resulting redox reactions create a voltage potential that can be used to a power a circuit. Ethanol batteries These also use enzymes, but these ones are immobilised by a membrane. The enzymes act as a catalyst for getting electrons from alcohol. The prototype of the ethanol fuel cell is as big as a postage stamp (500 mm2) and has been tested using all sorts of alcohol. The best fuels are flat beer, gin, white wine, and vodka. These batteries can 'refueled' quickly and easily and are biodegradable. Biobatteries and biofuel cells These are not new – the first enzyme-based battery was produced in 1964. However, it's only recently that chemists have managed to miniaturise the system. The biobattery consists of two carbon fibre electrodes with enzymes 'wired' on to them. The electrodes are tiny – each thinner than a piece of hair, and only 20 mm long. One electrode takes electrons from glucose. The other electrode adds electrons to dissolved oxygen and creates water. Glucose, oxygen and water are all things that are in our bodies all the time. Unlike conventional batteries, there's no need for a separator or salt bridge between the electrodes because the enzymes are very selective. This means that the battery can be much smaller than conventional ones – in fact, these biofuel cells are smaller by a factor of 100 than the smallest battery on the market! And that's great for what they want to use the biobatteries for - medical sensors. In the future, you may get a miniature autonomous implant after an operation. It could send information back to your doctor about your blood pressure, or your glucose levels, or whatever they needed to know about. The whole system would be powered by a biobattery and would be smaller than 2 mm3. There's still a lot of work to be done before they get to this though – when they trialled the biobatteries in simple body fluids, one of the electrodes didn't work so well. However, they trialled the biobattery in a grape and discovered that one grape can generate enough power to run a wristwatch. Overall There's still a lot of work to do before any of these new kinds of batteries make it to the market. However, one day we may be feeding our CD players, giving our mobile phones a quick drink and plugging our watches into our skin! References
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Making Electricity From Chocolate Chocolate is yummy. It tastes great and it provides us with heaps of energy, although too much might not be great for our health. It seems we’re not the only ones who love chocolate. The bacteria Escherichia coli also love eating chocolate, and what’s interesting is after they eat the chocolate, they produce hydrogen (under the right conditions of course). Some researchers from the University of Birmingham noticed this and decided to try to use the hydrogen to make electricity. They collected some bacteria, fed them chocolate, collected the hydrogen, converted it to electricity and tried to run a small fan. And guess what?! It worked! In other words, they made a battery out of chocolate and bacteria. This may sound a bit weird, but in the future instead of buying new batteries or charging your old ones, you may simply need to feed your battery some chocolate. For those chocoholics out there who have trouble giving up their chocolate, never fear - the researchers have done the same thing with caramel and nougat as well, and it worked. The bacteria will eat anything with sugar in it. Whatever we end up using, it seems the future's looking sweet. References
Return to top. Sending a message to the future Imagine a group of people carving things onto a giant rock. Now imagine that it is 10,000 years later and you’re standing in front of that rock, looking at the symbols. What would you make of it? Is it a piece of art work? Is it a message? Is it a warning? It would be pretty hard to work out what it was if you didn't understand what you were seeing. A group of people are considering this problem right now as they are trying to send a message to the people of the future. Historians, futurists, and scientists want to design a sign that will last at least 10,000 years. This sign will be placed in the Waste Isolation Pilot Project (WWIP) located in New Mexico. The sign will warn people of the future about the dangers of nuclear waste. Today, we know that nuclear waste is dangerous, but humans who roam the earth in the future may not. If you think about it, the language may be different, there will be new technology, different cultures and the symbols we know instinctively today may not make sense in the future. Nuclear waste can remain radioactive for billions of years (uranium waste lasts for over 4 billion years), so how do we tell the people in 2 millions years that nuclear waste is dangerous and they shouldn’t dig it out. The tools we use today, like shovels, might be in museums in the future and people might ponder for hours to try and figure out what they are for? Are they back scratchers? Decorations? Weapons? If they don’t know what a shovel is in 2 million years, we can’t just have a picture of a shovel with a big red cross on it. A big red cross might mean something else in 2 thousand years, and change to something else in 2 million years. So this is the problem that these historians, scientists and futurists need to solve: how would we communicate to the people in 2 billion years time? Let's hope they come up with a good solution. References
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