Interviews
Engineering some answers to the world's demand for energy
02/09/2007
Greg Lewin, President, Shell Global Solutions International BV for World Energy, Q4 2007
In today's world, we are faced with some inescapable truths. One is that demand for energy is rising. It is forecast that global energy demand will rise by more than 50% by 2030, with much of this increase occurring in developing countries, such as India and China, as they expand their economies to Western levels.
Another truth is that fossil fuels account for 80 to 85% of the world’s energy supply. Even with strong international action, it seems unlikely that this share will drop below 77% by 2030. Commercial supplies of renewable energy represent only a small fraction of the total mix today – solar energy, wind energy and biofuels provide only 0.35% of commercial primary energy supply. This share will grow in the future, but it is predicted that renewables will supply only one quarter of the world’s total energy requirements by 2050.
A further truth is that production of light oil is approaching, or perhaps has even reached, its peak. This is not to say that we are running out of oil, far from it, but it is an indication that in the future there will be a shift in the balance of oil supplies, with more coming from heavier crudes, tar sands and other unconventional sources. Exploiting these different sources will present us with fresh challenges, to which we are responding with new and improved technology.
At the same time, the environmental impact of using fossil fuels is coming under increasing scrutiny. The most recent development in this sense has been the growth in concern about the human influence on climate, with its long-term consequences. This has been illustrated by the Intergovernmental Panel on Climate Change in its recent triplet of reports.
So life is not simple for those of us working in the energy industries. But who wants a quiet life? Meeting society’s needs for inexpensive and reliable energy supplies without damaging the environment is the sort of challenge that I relish. The power we can bring to bear, using modern technology, to solve these problems will, I am sure, enable us to meet this variety of needs. With the investment that industry has made in improved technology, we are working to provide solutions just as quickly as the problems are being enunciated at present. The task now facing us is to invest sufficiently for the future so that we can continue to deliver solutions in this way.
Some good examples of how this has been achieved can be seen in the new ways that have been developed for using coal. Coal is a major fuel for power generation around the world, as well as for other heavy industries such as iron and steel, and cement. More than half of the electricity generated in the USA comes from coal-fired power plants. In the EU, the corresponding figure is 36%. In China, 80% of electricity comes from coal-fired plants, and in India the situation is similar. China is building on average one new coal-fired power plant each week, adding as much generating capacity as exists in the whole of the EU every seven years. The reasons for this are well known – China has great economic ambitions, which will require a great deal of electricity. Coal is widely available at a relatively modest and stable cost and is therefore a sensible choice for generating electricity. At the same time, coal suffers the disadvantage of producing more pollutants than most other fuels – especially in terms of carbon dioxide (CO2) emissions.
So what can be done about this? Historically, emissions from coal-fired power plants were cleaned up by fitting filters on the back-end, first to remove particles, which cause smoke, then to remove sulfur and nitrogen oxides, which cause acid rain. The same could be done to remove CO2. But at some point in the evolution of any technology there comes a point when we say, “Perhaps there is a better way of doing this? Let’s go back to first principles and see if we can design a cleaner process from scratch.”
This is just what we have done in Shell, in order to continue to be able to use coal to generate electricity. Using experience gained in oil refineries for treating the more viscous and less useful components of the oil barrel, we have adapted and developed our gasification technology for use with coal. The first prototypes were demonstrated during the so-called energy crises of the 1970s. These provided the basis for a new type of power plant – the integrated gasification combined-cycle (IGCC) plant. Such plants emit fewer of the recognized pollutants than conventional pulverized coal-power plants, with virtually no emission of dust or other particulates, next to no releases of sulfur or organic compounds. We now have the potential for removing CO2 by adding some extra equipment.
At the heart of an IGCC plant is the gasifier. The Shell gasifier takes in dry fuel, which facilitates the use of a wider range of coals than some other types of gasifier; even biomass can be gasified along with the coal. Any inorganic materials in the feed that cannot be gasified are removed as inert slag, which can then be used for construction purposes. Sulfur is produced in elemental form, again as a saleable product. Even waste water can be reused after treatment. The gasifier produces a clean mixture of hydrogen and carbon monoxide gases, which makes an excellent fuel for the gas turbine used to generate electricity. Further heat is then collected from the gas turbine exhaust to drive steam turbines to make more electricity. If appropriate, the carbon monoxide can be converted into CO2 and more hydrogen by addition of a shift reactor. The CO2 can then be separated and piped away for storage. |
Energy efficiency is an essential element of all of our operations – this helps reduce CO2 emissions. But if we want to go further, we can make a simple modification to the IGCC design that allows us to capture most of the carbon in the fuel as CO2. Using technology established in the oil industry and employed by Shell for several decades, CO2 would then be piped away for storage underground. My upstream colleagues are also interested in using CO2 to improve the recovery of crude oil from certain reservoirs. Shell is participating in initial projects in Australia, Norway and elsewhere, in which CO2 captured from power stations will be used to enhance oil recovery, and subsequently be stored underground.
Another approach to reducing greenhouse gas emissions using the IGCC process may be to supply it with biomass, thereby reducing the use of coal even further. This is something that will be examined at a new IGCC plant in the Netherlands, a country that is also home to the first European commercial-scale plant of this type. The Buggenum IGCC plant, now owned by Nuon, has been operating on a commercial basis since 1998. Each of these plants uses a Shell gasifier.
An IGCC plant can also use biomass wastes that do not have another use – avoiding competition with resources needed for biofuel or food production. This has been demonstrated at Buggenum by co-firing waste biomass such as chicken manure, sewage sludge and wood with coal.
| Another growing application of gasification is in the production of liquid fuels from coal. In countries with large reserves of coal, such as China and the USA, there is much interest in making transport fuels from coal, not least because this would provide a domestic source of fuel, giving greater feeling of security of supply. These plants will be very large indeed, with 10 or more gasifiers each converting 3000 tonnes per day of coal, and producing over 70,000 barrels of product daily. It is notable that the Chinese government has expressed its preference for such large units rather than smaller scale projects in order to minimize pollution and the impact on water supply. A similar technical approach has been pioneered on a commercial scale by Shell for making liquid fuel from natural gas, which was recently used in the first diesel car to win the 24-hour race at Le Mans. |
So the IGCC process can be adapted to capture CO2, and it can also use alternative fuels. This means we potentially have a range of answers to the latest problems, using a solution we started to develop 30 years ago for another reason. It is not just a matter of chance that we are in a position from which we can adapt technology in this way. I use the term “we” because this is very much a team activity – a cadre of skilled people who embody the experience that Shell has built up in gasification over many years.
The same can, of course, be said about many other areas of technology. Shell Global Solutions has over 5000 staff working in 100 different areas of technology and service. They address problems that face the oil and gas industry and society today and prepare solutions for use tomorrow. The fact that they know there will be problems to be solved and are confident that they can find solutions should be encouraging. But is this sufficient to attract good recruits into the profession.
My colleagues and I know how exciting and rewarding a profession in engineering can be. I suspect many young people in China and India know this too. There are excellent engineers coming out of the universities in those countries and elsewhere. In the West, jobs in the media, finance and even IT can seem very attractive. Do we make engineering exciting enough to attract the best of today’s young people in the West? Are we doing enough to stimulate interest in the profession? During my recent presidency of the Institution of Chemical Engineers, I called on the profession to rise to this challenge. I would like to encourage engineers in all parts of the world to consider what they can do in this respect.
The pipeline of skilled people begins in the early years at school. Once young people make their choice of university course, the future pool of recruits has been determined. According to the American Petroleum Institute, there were 1500 petroleum-engineering students enrolled on US courses in 2003. In contrast, the upstream industry is expected to need more than 5000 engineers over the next five years. Sources of the extra recruits may be countries such as India, Russia and China where many more engineers are being trained.
Once people join the engineering profession, it becomes a joint responsibility for them and their employers to maintain and develop their skills. It is no longer sufficient for an engineer just to achieve professional status and then never work on developing his/her skills further. Professional bodies, such as the Institution of Chemical Engineers, encourage lifelong personal development, as well as improvement of practices and project performance. The Institution works inside companies and across the industry, as well as building links between different disciplines and sectors. By encouraging chemical engineers to continue their personal development throughout their careers, vitality is injected into the profession. This should encourage students to see engineering as the basis for a fulfilling career. In this way we will maintain a cadre of skilled and enthusiastic men and women who will meet the challenges of the 21st century, just as their parents addressed the needs of the past.