Nanocatalysis: Particles for Peace (PfP)?
Photo courtesy of Mats Kockum
OPINION BY PETI VASARA
It is worth the effort to log onto www.googlism.com and ask Google to use the Internet to define nanotechnology for you. Among the many more or less correct definitions you will find “nanotechnology is Alberta’s new oil”. Actually, it is nanocatalysis that is the “new oil for anyone with coal reserves”. When you ask the same web page for the definition of nanocatalysis, the answer is “Sorry, Google doesn't know enough about nanocatalysis yet.”
Well, Google should. Everything to do with oil is as politically sensitive as anything on this Earth. We are dealing with the world’s largest market – energy – and one of the two substances with the greatest power to launch wars. The other, of course, is water. Nanotechnology is unique in that it has the potential to lessen the tension driving both oil and water wars.
Long, long ago… ….
there was catalysis, and still is. Catalysts are substances that speed up or slow down,a chemical reaction without undergoing any permanent change itself. Catalysts are as old as the chemical industry. As ancient is the (unwitting) use of nanoparticles. A Roman cup, called the Lycurgus Cup (http://www.thebritishmuseum.ac.uk/science/text/lycurgus/sr-lycurgus-p2-t.html), used nanosized gold clusters to create different colors depending on whether it was illuminated from the back or the front. Evidence indicates that Roman goldsmiths tried to duplicate this effect, without success.
The Lycurgus Cup on a NanoNetwork
One particular secret of nanoparticles lies in the mathematical relationship between surface area and volume. Surface area in a sphere, of course, is proportional to the square of the radius, with volume related to the cube of the radius. The smaller the particle, the greater the surface area in proportion to the mass . In reactions where the surface area is key, it is obvious that nanoscale particles have more potential than mere microscale particles. One key application of nanocatalysis is coal liquefaction.
Coal liquefaction involves converting coal to a liquid fuel such as diesel. Particularly clean diesel, in fact, with low nitrogen and sulfur content. The attraction of this process is that whereas many countries are not dependent on imported oil for power generation, they are highly dependent on it for transportation. Coal liquefaction offers the possibility of reducing this dependence for countries with significant oil reserves.
A major limitation of coal is that it is not well suited for powering transportation and it is here that liquefaction technologies look particularly interesting, this being the area where many countries are still heavily dependent on imports. Coal has a lower hydrogen content than that of transportation fuels, about 5% compared to 12 - 15% in refined fuels.
Significant coal liquefaction research and development was started up in the early 1970s, particularly in the US, the UK and Japan, in response to various oil price shocks. After the 1980s, though, developments were largely put on hold with the notable exception of those in South Africa. There, with large reserves of coal but no oil or gas, trade embargoes over three decades to the mid-1980s drove large-scale application with up to 60% of transportation fuel requirements being met by coal.
Economies of scale
Many countries have undertaken R&D into coal liquefaction, with direct processes attracting the most interest. The processes have names such as H-Coal, Exxon Donor Solvent, SRC-I & II and Catalytic Two-Stage Liquefaction (all US), Kohleoel and Pyrosol (Germany), NEDOL and Mitsubishi Solvolysis (Japan) and Liquid Solvent Extraction (UK). Many projects were put on hold after the collapse of oil prices in 1985, but several processes are claimed to be ready for commercialization. These include NEDOL and Kohleoel, both of which are direct processes.
A major project in China, worth $2 billion, was announced in the early 2000’s involving the US's Department of Energy, Hydrocarbon Technologies Inc. (a part of Headwaters Inc.) and Shenhua Group Corp., China 's largest coal company. The goal was producing (mainly) diesel and gasoline from local low-sulfur coal. The plant, to be located in Majata, Inner Mongolia, would have a capacity of 50,000 barrels per day of diesel and gasoline when fully completed in 2005. Shenhua Group, which owns a 15% interest in the technology, was also planning three more coal liquefaction facilities. Shenhua has coal reserves of more than 220 billion tonnes and an annual production capacity of nearly 60 million tonnes.
Coal liquefaction, by whichever route, is capital intensive and therefore benefits substantially from economies of scale. Most studies on process economics have assumed that a full-scale commercial plant would produce 50,000 - 100,000 bbl/day of liquid products. Such a plant would process 15,000 - 35,000 tonnes/day of bituminous coal or up to double that amount of sub-bituminous coal or lignite. Such output is still small relative to that from a typical modern crude oil refinery, where a throughput in excess of 200,000 bbl/day is common.
The economics of liquefaction depend strongly on coal costs and this coal must be delivered to the plant at a low price. Since coal is more difficult to transport than oil, it would, as a general principle, be better for liquefaction to be carried out in the country of origin and preferably at the point of origin. The transport issue is one of the potential benefits of coal liquefaction. Depending on the geography and infrastructure, it may be sensible to transport the product of liquefaction, rather than coal, to other regions for generation of electricity, especially when one considers reduced emissions of sulfur- and nitrogen-based pollutants.
The Shenhua project is expected to produce diesel for $20 - $22 per barrel crude oil equivalent (add around $6 dollars for conversion to diesel), which is a remarkable improvement over the last couple of decades—prices were around $60 - $70 a barrel in the 1980s. The nanocatalytic technology involved in the project has improved the economics of the process by $5 to $10 a barrel according to HTI. This makes direct coal liquefaction now economically attractive in China at an international crude price of around $28. The Chinese situation is somewhat unique, however. Demand for power and transportation fuel in the country is increasing rapidly, and crude production there cannot keep up, despite extensive drilling. The country also has huge coal deposits, and large areas that are geographically quite isolated.
The economic and political impact of nanocatalysis is obvious. The major environmental impact looks likely to come from increased use of coal to produce transportation fuels given that coal liquefaction technologies are now, through the application of nanocatalysts, economically feasible for some countries and soon to be feasible for others. Political will to reduce dependence on oil imports increases the likelihood of adoption of such technologies even where they are not economically competitive with oil (assuming they are at least close). Additionally, new power station technologies such as integrated gasification combined cycle (IGCC) approaches are promising to make coal use for power generation more competitive.
The use of coal in energy production is, from the environmental point of view, intrinsically the least favorable option for the following reasons:
• high particulate emissions, especially when using lower grade coals; these are controlled well in developed countries, but are still a major environmental problem in many developing countries
• high carbon dioxide (CO2) emissions, contributing to global warming; CO2 emissions per energy unit produced are 20 - 25 % higher with coal than with oil (and normally at least 40 % higher than with gas)
• often high sulfur dioxide (SO2) emissions, and relatively high nitrogen oxide (NOx) emissions, resulting in problems with human health, and acid rain
• emissions of heavy metals, e.g. mercury
Linking this in greater detail to global warming, the Kyoto Protocol and emission trading is a story for another space. Especially as the battle around these issues is as hot as any environmental issue in Europe can be, at the moment.
Particles for Peace (PfP)
China recently gained the dubious distinction of being the second largest consumer of oil in the world, passing Japan. At the same time, its own oil reserves are nowhere near sufficient. What can be deduced? That the oilfields of the Middle East are being eyed from East and West. Not for the first time; during the First Gulf War, Mongolia proudly pointed out that Baghdad had been sacked by its ancestors in 1258 A.D. Environmentally, much remains to be done to improve the impacts of nanocatalysis in coal liquefaction. However: all things considered, nanocatalysis helping China to produce oil from domestic coal through liquefaction is more than industrial activity. It may be, for a poor nanoparticle, the closest thing to earning the Nobel Peace Prize.
Petri Vasara Dr. Tech is Principal, New Technologies at Jaako Pöyry Consulting.
For further information about nanocatalysis, see "Nanocatalysis and Fossil Fules" By Cientifica and Jaakko Pöyry Consulting.
OPINIONS EXPRESSED IN THE ARTICLE ABOVE ARE SOLELY THE OPINIONS OF THE AUTHOR
Read more about Dr. Petri Vasara at NanoNordic.com
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