By Patrick Whiteway
I’m sure you’ve heard the saying that the solution to one problem is very often the cause of another. Well, in their day-to-day work mine engineers grapple with this concept all the time. However, they tend to think of it in terms of efficiency.
When I was the editor of Canadian Mining Journal in the late 1980s, I visited almost every significant mine in the country. One of the most impressive was a so-called “open cast” coal mine in southern
During a tour of that coal mine in 1993 I sat in a huge electric-powered machine called a dragline – a W-1800 Ransom-Rapier to be exact. One scoopful at a time, this humongous machine swings back and forth, moving thousands of tonnes of earth every day. It’s purpose is to remove the layer of soil that sits on top of the valuable seams of low-sulphur lignite coal beneath. Once this soil, or overburden as it is called, is safely out of the way and the black coal exposed to the open prairie air, the coal is then mined by more conventional methods using trucks and shovels. For a mine engineer, it was a beautiful sight to see because everything was deliberately arranged in such a way that the dragline dumped the overburden in a place where the coal had just been mined out, say, the week before. In this way, the flat prairie landscape could be restored for future agricultural uses.
Incidentally, all of the output of this mine – about four million tonnes a year -- is trucked just down the road to two near-by power plants where it is burned to generate electricity (to, among other things, power the lights for all you CFL fans at Mosaic Stadium in Regina where the Roughriders grind it out).
The funny thing about this whole set-up from an efficiency perspective, however, was that a surprisingly large percentage of the 300 megawatts of electricity generated by one of the coal-fired plants is actually needed to run the dragline; that exposed the coal seams; that supplied the plant with its fuel.
Now, consider the biggest issue facing the world today -- climate change. As the world begins to frantically de-carbonize the global economy over the next few decades, nickel is going to be in very high demand. Where we get that nickel will help determine how quickly we de-carbonize. In this posting, I will explain how this works.
But first, why should you care about nickel? Why should you care that nickel is going to be in high demand? Quite simply, nickel is important because its a major Canadian resource and its a big part of the solution to climate change.
Climate scientists tell us that if we limit global warming to just two degrees Celsius, that means we need to limit the concentration of carbon dioxide in the atmosphere to just 450 parts per million. When you consider that there’s already 380 parts per million of carbon dioxide equivalent in the Earth’s atmosphere and that this is increasing at a rate of three parts per million per year, you soon realize that we have to take this problem very seriously and do something serious and do it quickly.
The Intergovernmental Panel on Climate Change (IPCC) in their 2007 report, created a list of technical fixes that if pursued would help us to achieve this goal. It was a list of off-the-shelf technologies that the world’s major economies need to develop and encourage in order to meet the goal of maintaining carbon dioxide concentrates at 450 parts per million and to begin the process of de-carbonizing the global economy. Leading the IPCC’s list of technologies were ways of generating electricity that emit fewer greenhouse gases than is the case today. Next on their list were was to improve the efficiency of all forms of transportation.
The Copenhagen Treaty that is to be negotiated next month could set firm targets of a 40% reduction in emissions by 2030 for the world’s leading industrialized nations (the U.S., U.K., Germany and Japan) and softer targets for developing nations (such as China and India). As the advanced nations commit themselves to becoming extremely energy efficient and extremely energy independent over the next few years, the experts predict, they will set a shining example for the rest of the world. And by 2015 or 2016 the developing nations will join the club that will de-carbonize society globally.
As it turns out, the devil’s metal is a very important, dare I say an essential element in many of the proposed technical solutions to climate change. Let’s look first at sources of renewable energy.
In 2004, renewable sources provided just 13% of the world’s energy needs. However, non-carbon, renewable sources, such as wind energy is growing globally at a much higher rate of about 18% a year. So, renewable sources are becoming more and more important to our energy mix.
For the engineers who design facilities that produce renewable energy, nickel alloys and nickel stainless steels have attributes that come in very handy. As editor of Nickel Magazine, over a 10-year period I commissioned hundreds of articles that described specific examples of how nickel-containing materials are used to make the key components of renewable energy projects worldwide. I soon discovered there’s no shortage of such projects. Here are a few examples:
Those huge wind turbines that dot the landscape and seascapes around the world today have huge metal components such as rotor hubs, gearbox housings, base plates, gears and shafts, that weigh several tens of tonnes each. These components are typically made of a cast ductile iron that has certain critical properties. Two such properties are good impact strength and toughness at low temperatures.
Conventional ductile iron contains 2 to 3% silicon, which strengthens the metal but has the drawback of making it brittle at low temperatures. Adding a small amount of nickel (0.5 to 1 percent by weight) reduces the need for silicon and enables the iron to meet the technical specification. That’s a small amount of nickel per component, but because they are so huge (totaling up to 45 tonnes per turbine) and there are so many of these things being erected worldwide, the amount of nickel required adds up to a fair amount of metal.
The American Wind Energy Association estimates that wind power generated 31 billion kilowatt-hours of electricity in the
Consider also the massive concentrated solar energy projects being built in the world’s sun belts (such as in
These facilities are so massive that a plant that generates 50 megawatts of electricity requires 550,000 square metres of mirror surface. It is estimated that such a plant avoids the production of 172,000 tonnes of carbon dioxide annually. At the present rate of construction, concentrated solar power plants could potentially generate 270,000 megawatts by 2040.
In order for this technology to provide a long-term source of dependable energy, the heat exchanger, the pipes and storage tanks for the heat transfer fluid and the molten salt needs to be made of corrosion-resistant materials to ensure low maintenance. The grades of stainless steel that best withstands these corrosive conditions are typically nickel-containing grades with about 10% nickel by weight.
Closer to home, Canadians may be more familiar with hydro-electricity whereby the hydrostatic head of the water behind a dam is used to rotate massive metal turbines to generate electricity. The Lower Churchill Falls, James Bay,
In the not-to-distant future, tidal power may also become an important source of non-carbon emitting, renewable electricity. In
Hidden away inside this demonstration plant where passing tourists can’t see it is a generator that includes a 150-tonne component called a runner assembly. For corrosion resistance and low maintenance (and therefore, long-term dependability), it is made of a cast alloy containing 5% nickel. That single demonstration plant generates 30 gigawatt-hours of electricity a year, enough to supply 4,500 homes with their electricity needs.
Elsewhere in the world, engineers are developing other types of electric generators to harness the perpetual power of oceanic tides. Some are devices that sit on the ocean floor and look and operate like underwater wind mills, thus capitalizing on tidal currents in narrow channels. Another, called a Sea Snail, looks like a formula one racing car that sits on the ocean floor to harness the flow of water over its foils to generate electricity, reversing direction as tidal currents flow in the opposite direction every 12 hours. Prototypes are being tested and full-scale commercial models would need to be made of corrosion-resistant materials such as nickel-containing stainless steels.
On the west coast of
Another renewable source of energy is geothermal energy. We don’t have much interest in this in
Nickel alloys and stainless steels are also very useful in making more efficient use of our more traditional non-renewable energy sources. I’m referring here to the many electric generating plants fueled by fossil fuels that globally account for something like 2.5 billion megawatt hours of electricity. The fuels they burn include the biggest carbon dioxide emitters in the world: coal, petroleum and natural gas.
Coal is by far the fuel that generates most of the world’s electricity and in the process emits close to two billion tonnes of carbon dioxide every year. In other words, coal fuels half of all electricity generated, but contributes more than two-thirds of all carbon dioxide emissions from the electric power sector. That makes it by far the biggest single culprit when it comes to adding carbon dioxide to the atmosphere.
What can be done to change this picture?
Well, research is progressing at a frantic clip to capture the energy contained in coal by burning pulverized coal in the presence of oxygen at high pressures in closed systems so as to also capture the carbon dioxide and other gases released in the combustion process. This technology, called ThermoEnergy Integrated Power System, or TIPS, is in the research and development stage at Canmet labs in
Once it is, it is very likely that the process plants that will be build will use materials that have the strength and the corrosion resistance needed to make these plants reliable suppliers of electricity. Those materials will very likely contain the devil’s metal because of the attributes it brings to these alloys.
Carbon capture and sequestration, or CCS, is another technology under development that will require nickel-containing materials in order to succeed. Several demonstration systems are presently operating at various locations around the world to prove the viability of this technology but there are some serious doubts that it will become a commercially viable means of storing carbon. The cost of separating dilute carbon dioxide from flue gases and condensing it and delivering it by pipeline to a deep earth injection site may simply be too daunting.
The producers of crude oil from
Besides trying to make coal burning more carbon neutral by reducing emissions, we could simply use a fuel that emits less carbon dioxide per megawatt of electricity produced. One such fuel is natural gas. The utilization of this fuel is surging around the world. In fact, the switch to natural gas to generate electricity is the main reason the United Kingdom has been able to live up to it’s commitment under the Kyoto agreement.
Since geological reservoirs of natural gas are rarely found close to where the gas is needed by society, the gas has to be transported. In the case of natural gas, the best way to move it to where it can be burned to generate electricity is by ocean-going vessels. And the most economical way to move a gas is to reduce its volume by condensing it to liquid form. For natural gas this is done at a temperature of minus 162 degrees Celsius which reduces its volume by a factor of six hundred.
To contain a liquid at that temperature inside of an ocean-going vessel a specially designed container is needed that maintains its strength at low, cryogenic temperatures. An ingenious low-expansion nickel alloy known as Invar fits the bill perfectly. It is in high demand for liquefied natural gas (LNG) vessels that are being built at an amazing pace to move the world’s natural gas around the world to where it can be used to satisfy electricity demand.
Once ocean-going LNG vessels arrive at their destination, the LNG must of course be off-loaded and stored in tanks on shore. A type of low-carbon alloy steel, which contains 9% nickel, is the material of choice in the construction of these facilities.
In the very near future, Canadians should become more familiar with this type of fuel handling facility as more LNG terminals are constructed. One such facility was recently commissioned by Canaport near
Another technology that advanced nations are using to de-carbonize their economies and to become more energy independent is ethanol production. This transportation fuel is produced by converting plant matter into the so-called biofuel. It is produced in small-scale processing plants constructed largely of nickel-containing stainless steels, again for its corrosion resistance.
Many countries such as the
Other forms of biomass are also being used to generate electricity. Microbes naturally break organic matter (such as moo poo) down into its component parts, emitting methane and carbon dioxide in the process. By harnessing these greenhouse gases to generate electricity, we can utilize these gases and reduce the demand for fossil fuels.
The advent of reliable, long-lasting micro-turbines – small scale natural gas turbines that produce 30 to 200 kilowatts each – means small scale farmers can generate their own electricity. USAID reports that in 2003 biogas projects worldwide helped prevent the production of 11.3 million tons of carbon dioxide. Micro-turbines use nickel alloys and stainless steels in components such as the combustion chamber, spinning turbine, main rotor shaft and recuperator housing, all of which run continuously with minimal maintenance required.
One fuel source that has been talked about for a very long time as a replacement for fossil fuels is hydrogen. To make the hydrogen dream a reality in the transportation sector, however, requires a clever way to economically separate hydrogen from water and to store hydrogen safely on board a moving vehicle. If this can be accomplished, this technical marvel would vault fuel cells into the leading power source of our future fleet of personal vehicles. Some nickel compounds have unique catalytic characteristics that make them leading candidates as a means of both generating hydrogen and storing it. These are being tested on a laboratory scale.
Fuel cells are electrochemical devices that convert the energy produced by a reaction between a fuel such as hydrogen and an oxidant such as oxygen, directly and continuously into electrical energy.
They are not presently used in commercial vehicles, however, the large, stationary types of fuel cells are being used to generate power close to where it is needed. Since they can produce several megawatts at a reasonable cost, they are being used in hospitals, prisons, waste water treatment plants and some manufacturing facilities in
Sticking with the non-renewable sources of energy, let’s look for a moment at nuclear energy. When viewed as a possible solution to climate change, most people’s perception of nuclear power changes significantly from the perception that was molded by
As the leading supplier of uranium to the world,
One of the engineering lessons learned from the earlier operation of nuclear power plants is that to improve their reliability and to lower maintenance requirements, a lot of the hardware needs to be made of corrosion resistant nickel alloys and nickel-containing grades of stainless steel. These materials perform best under high operating temperatures. Major components that use nickel materials include reactor vessel internals, control element drive mechanisms, steam generator tubing and supply water piping.
South Korea and China are leaders in the construction of new nuclear power plants with five under consgtruction in China and six other planned for the near future. In
Nickel alloys are also being considered for use in the very long-term storage of spent nuclear fuel. Many years of study have been devoted to the design of spent fuel canisters that can withstand the corrosive conditions inside of the proposed deep burial sites such as
It’s interesting to note that the tailings ponds of the uranium mining and concentrating operations in northern
The nuclear fission revival is perceived by many non-governmental organizations as an intermediate step to the eventual commercialization of nuclear fusion. That work is being spearheaded by a joint effort of scientists and engineers from seven countries (the
International Thermonuclear Experimental Reactor
The key to this project is selecting combinations of materials that are suitable for plasma facing, heat sink and support structures. Nickel-containing materials have been selected for many major structural components such as the main vacuum vessel and ports and for neutron shielding. They have also been selected for other critical internal functional components such as fasteners and attachments.
Besides the generation of energy, the IPCC also recommended in 2007 that advanced nations concentrate their considerable efforts on becoming extremely efficient in the use of the energy that they already generate. In northern climates the largest single use of energy is in heating buildings during the winter and cooling them in the summer. Therefore easy “wins” can be gained by making buildings more energy efficient.
Nickel stainless steels, it turns out, have a role to play here as well. There are two ways that stainless steel roofs can reflect sunshine during summer months and help to absorb the sun’s energy during the winter months when the sun is at a much shallower angle in the sky.
One is to design the slope of the roof in such a manner so as to achieve this and the second is to select an appropriate surface finish for the stainless steel. A non-directional matte surface finish, for example, can lower the amount of energy a surface reflects. This property is known as the solar reflectance index or SRI of the material. This, along with the fact that stainless steel is a poor thermal conductor helps to deduce air conditioning requirements in the summer and heating requirements in the winter. These attributes are gaining acceptance under the international architectural certification system known as Leadership in Energy and Environmental Design, or LEED.
After buildings, the second largest user of energy is transportation (accounting for about 20% of global carbon dioxide emissions). Whether its cars and trucks, trains or planes, much can be done to improve energy efficiency and thus reduce emissions and the devil’s metal plays an important enabling role here too.
Some of the coolest emission-reducing innovations involving nickel are taking place in the automotive sector. A neat material called nickel foam is being used to make diesel cars and trucks less polluting and thin gauge (therefore lightweight) structural stainless steel is being used to manufacture long-lasting car frames that will make vehicles more fuel efficient.
A consortium of six European automakers and three stainless steel producers, called Next Generation Vehicle, has demonstrated that austenitic stainless steel components in car frames can reduce vehicle weight significantly. By replacing carbon steel frames with thin gauge stainless steel that gains strength as it is formed, vehicles would be lighter and therefore more fuel efficient. The consortium expects to have a complete car frame on display at the Detroit Motor Show in early 2010.
When it comes to the black smoke emitted by diesel engines, a high-temperature, corrosion-resistant nickel alloy foam is being touted as a more efficient way to capture nanometer-sized particles of carbon soot. Exhaust systems designed using this foam can be smaller, require less platinum catalyst and can be designed into any shape. The result could be a reduction in overall vehicle fuel consumption and fewer diesel emissions.
And, of course, there are the more familiar gasoline/electric hybrid cars that have been on the market for several years now and are being replaced by a new generation of plug-in electric vehicles. The batteries in about two-thirds of these vehicles are nickel metal hydride batteries and the others are lithium ion batteries (which also contain a small amount of nickel).
What could make personalized ground transportation extremely low-carbon emitting is fuel cell technology. Nickel materials play an enabling role here in the cathodes, anodes and catalytic materials in the fuel cells themselves and nickel materials would also be used in the hydrogen fuel delivery and storage systems.
One of the very first articles I published when I became editor of Nickel magazine was a story about magnetically levitated, or maglev trains. That was in 1997. Today, maglev trains are in commercial operation in
Trains that travel at more conventional speeds are much more fuel efficient (and crash resistant) when the body of the carriages are made of nickel stainless steels.
The really sexy nickel alloys, or super alloys, are those that are used in jet engines that power our commercial and military aircraft. The evolution of this glamorous form of transportation follows exactly the development of nickel base super alloys that can withstand high and higher temperatures.
Today, commercial air travel has evolved to the point where the use of lightweight carbon composite materials in the fuselage and wing components have enabled aircraft manufacturers to develop new, fuel efficient double-decker airplanes. This reduces the amount of fuel consumed per passenger kilometer and reduces local pollution at airports. How does nickel figure in this development? Well, as it turns out, nickel alloys enable manufacturers to make these composite components without them cracking.
Invar, a low-expansion nickel alloy is essential for the molds inwhich the composite components are formed. Due to the low coefficient of thermal expansion of the Invar mold, the composite components don’t crack or deform as they are heated and then cooled during the curing process. So, nickel plays a double, enabling role in today’s most advanced aircraft -- Boeing’s Dreamliner and the Airbus A380.
Hopefully, in this posting I have demonstrated that, as the rate at which we de-carbonize the global economy accelerates, nickel demand is going to accelerate. I’ve given examples of existing, so-called off-the-shelf technology that will keep atmospheric concentrations of carbon dioxide below the target of 450 parts per million.
But there are many technologies involving nickel materials that are presently being developed.
Interestingly, a good percentage of all engineering patents registered in the
In 2008, demand for nickel for use in nickel alloys amounted to about 133,000 tonnes. This year, due to the global economic crisis, demand is expected to be about 110,000 tonnes, according to Markus A. Moll, senior market analyst for Steel & Metals Research who spoke at a recent meeting for the International Nickel Study Group in Lisbon, Portugal on October 7, 2009. He predicts that demand for nickel (used in nickel alloys) will increase to 165,000 tonnes by 2015. Sectors with the highest growth rates are the chemical process industries (+24%) and aerospace (+20%). Power generation is not far behind with a +12% projected growth rate.
Where, over the next 5, 10, 15 years, we source that nickel will determine how quickly we can, and therefore how successfully we are, at reducing the level of greenhouse gases in the atmosphere.
Mining, concentrating, smelting, refining and shipping nickel is a very energy-intensive process that generates significant amounts of greenhouse gases.
There’s no point in trying to solve the problem of climate change with materials that, during their recovery and processing, emit more greenhouse gases than they prevent once employed. That would be just spinning our wheels. Or thinking back to the coal mine example with which we began this chapter, it would be like generating just enough electricity to run the dragline.
The nickel we use must come from sources that result in the release a minimum amount as possible of carbon dioxide, nitrous oxides and methane. In other words, we need to tap the lowest carbon sources of nickel in the world.
We could recycle more nickel from all those non-essential applications that we’ve encouraged over the past 85 years and re-use it in more essential applications that help us to de-carbonize the economy. There are several thousands of tonnes of nickel in the stainless steel cooking utensils in our parent’s kitchens, for example. And there are a few tonnes of nickel in golf clubs in garages all across
And if the amount of nickel in these non-essential applications is not enough to meet demand, then we need to get “virgin” nickel from the lowest-carbon natural sources available to us.
That’s where Canadian sulphide nickel resources come in which is the subject of a future posting.
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Patrick Whiteway is based in Toronto.