Sep 2, 2007 - a Venn diagram (Figure 1), in which meeting needs ... great fusion reactor in the sky (the sun). ... wind power, nuclear fission and a lot of other ...
the chemical engineer www.tcetoday.com september 2007
y lit bi ue na ss ai l i st cia Su pe S
save the planet measure sustainability biofuels potential and pitfalls process intensification micro delays
contents
The Chemical Engineer September 2007 Issue 795
features cover story
Sustainability 1
26
Richard Darton discusses measurement, development and change
Sustainability 2
30
Green possibilities for business with Colin Chambers
Sustainability 3
32
Boosting butadiene capacity with Bernd Heida
Sustainability 4
36
Lu Feng talks Chinese emissions
Sustainability 5
38
Gordon Weiss and Linda Funnell-Milnar investigate the Global Reporting Initiative
Renewables 1
40
Biofuel considerations with Keith Stewart and Phil Webster
Renewables 2
42
Wendy Laursen reports on the progress of the palm oil industry
Engineering for a better world – p26
guest author
Renewables 3
46
Biomass and refining with Martha Simpson-Holley, Adrian Higson, and Geraint Evans
Renewables 4
50
Sean Milmo peers into the biofuel future
Green chemistry 1
52
Roundtable round-up with Berkeley Cue and Julie Manley
Green chemistry 2
56
Karen Peabody O’Brien makes the case for business
Process intensification
58
Sean Milmo takes a look at the microreactor situation
Plant efficiency
60
Improving fuel efficiency with Barry Singh
Awards profiles
62
regulars Whole system engineering: money matters – p24
Catalyst
2
Malcolm Wilkinson views the road ahead for sustainability and chemengers
Analysis
Chinese safety standards; Toshiba uranium mine; Pharma cuts; New bubble theory
Australia
10
Japanese battery warning; Kazakh pipe to China; Indonesian paper cuts
UK
Intensification: microreactors – tiny steps forward – p58
New capacity construction; CBI’s STEM recommendation; Drigg decision made; Independent monitoring too pricey
Americas
Fluoridated water worries; Brazil looks global; $33b education pledge
Contracts
Issues at Ignalina; HPPO exported to Thailand; Areva pushes back Olkiluoto
Renewables: biofuel concerns – p42 2
september 2007
12
14 15
Innovations
16
Process news
18
Interview
20
Useful finger juice; Chilling chips; Paper batteries; Switching glue on and off
22
Guest author
24
Day in the life
61
Member networks
64
People
65
University update
66
Campus
67
Reactions Diary of events Appointments Residue
70 72 74 76
Jon Close directs us through the implications of the modified 1996 Construction Act Whole-system engineering with Imran Sheikh and Amory Lovins
9
Parliament sees carbon trading proposal; ITER involvement; precarious pulp mill
Asia
4
Legalwatch
Misplaced energy metric; Novel casting grant; Getting rid of chicken litter; Plastic scrubber
Peter Davidson tells Adam Duckett about his hopes for the fuel-crop Jatropha
David Brown tells Rob Crossley about his journey from Cambridge University to IChemE
Get Chartered update; Popular subject group seminar; Sustainability SG sets up in Australasia Brown and the BBC; Clive Pratt obituary; Water winner Sydney extracts mining money; Notingham carbon centre; New Queensland VC Judy Scully tells Adam Duckett about tempting SMEs back to university
Foot in mouth; carbon crazy; animal magic
in the October issue
energy special and awards supplement
sustainability 1
Measuring sustainability Richard Darton highlights the need for development, and change “Sustainable development is development that meets the needs of the present, without compromising the ability of future generations to meet their own needs.” Source: Our Common Future, World Commission on Environment and Development, 1987, OUP THE statement above is a carefullycrafted short definition of sustainable development from the Brundtland Report, which is deceptively simple in its language, but includes the two essential ideas. First that development is necessary to meet the needs of people now living, and second, that we must not make it more difficult for future generations to meet their needs. This concern for future generations is termed “inter-generational equity” – being fair to those who will come after us. The Brundtland Report recognises that much material development is not only not meeting the current needs of large numbers of people, it is leaving a legacy of consumed resources and scattered pollution that will be a burden on future generations. Partly, this is a question of scale. With a human population of around 6b, perhaps rising to 10b later this century, the very small quantity of consumption and pollution that we are each individually responsible for soon adds up. The Brundtland report was published in 1987, and its appearance was a
Sustainable development is the route towards complete sustainability of all human activity
Environment Economics
Society Environment Economics
Society
Figure 1: The route to sustainability 26
september 2007
Environment Economics
Society
watershed, for the approach that it advocated had a huge influence on the UN Conference on Environment and Development in 1992 (the Rio summit), and on much that has happened since then. Note that sustainable development does not mean no development: the report itself made it clear that much of the world’s population lives with an unacceptably poor quality of life, and this has to change. The average income of the world’s richest billion people is about 50 times that of the poorest billion. The poorest billion live on an income of around $1/d, and whilst the World Bank tells us that the number living at this level has halved since 1981, this still represents grinding poverty for a billion people. The urgent need for economic development that enables people to break out of the bleakness of poverty has to be balanced with the need for social development and social justice. And satisfying both these basic human needs has to be balanced with the finite resources of the environment, which must supply our wants and absorb our waste products. This balance is conveniently illustrated as a Venn diagram (Figure 1), in which meeting needs in economics, society and environment are shown as adjacent circles. That zone represented in the diagram by the area of overlap marks human activity which is fully sustainable. This “sustainable” zone does not represent stasis, nor does it require some reversion to a primitive lifestyle. The objective is to develop a sustainable world in which human needs are met, not in the same way for everybody, because, as Brundtland was careful to point out, there will always be cultural diversity; but in this idealised sustainable state, human society is in equilibrium with a natural
world that is passed, undamaged, from one generation to the next. We cannot be sure that this idealised state is obtainable, but we can be sure that our present situation can, and must, be significantly improved. To illustrate the potential for more sustainable living, consider the current debate about energy and global warming. We are concerned both that our supplies of fossil fuel, particularly oil, may become in short supply in the next few decades, and that the carbon dioxide we are putting into the atmosphere will cause global temperatures to rise by several degrees this century. And yet we rely on fossil fuel to drive the economy and create the wealth that is so desperately needed. What is to be done? Well, we should note that the current world primary energy demand of about 13 TW is tiny compared with the 120,000 TW of radiation energy reaching the Earth’s surface from the great fusion reactor in the sky (the sun). If we converted solar radiation to electricity at 15% efficiency, we would still only need to cover 0.4% of the Earth’s land area with photovoltaic cells to supply all our present energy needs. I am not at all suggesting that we should do this! I am only pointing out that we have not been set a question to which there is no conceivable answer. There are many answers, probably involving wind power, nuclear fission and a lot of other options that produce much less carbon dioxide. It is a question of developing new technology and different ways of living: there is no energy shortage, just an energy distribution problem, and a failure as yet, in imagination – the world can, and will, be different, when fossil fuels no longer dominate the energy supply scene.
the need for measurement It must be admitted that sustainable
sustainability 1
example of indicators – human development Since 1975 the United Nations Development Programme (UNDP) has published metrics that indicate the state of development of each country: the Human Development Index (HDI), of which some examples are shown in Figure 2. This index is an average of three normalised indices covering life expectancy at birth, education (adult literacy and school enrolment), and gross domestic product (GDP) per head, on a purchasing power parity basis. These three components have been carefully chosen by the UNDP as main indicators of human development. Interestingly, the calculation of the GDP indicator involves taking the logarithm of GDP per head, because “a respectable level of human development does not require unlimited income”. This feature of the method assigns greater importance to changes at the poorest end of the economy. Movements in the HDI record events and trends, the triumphs
1
UK
0.9
Russia
0.8
China
0.7
Niger
0.6 HDI
overall performance can most usefully be presented in terms of a few key indicators like yield of gasoline per ton of feedstock, or the profit ($/day). Depending on the purpose therefore, we choose either a hundred metrics (for process control), or a few important metrics (to monitor overall performance). In both cases detailed knowledge of the process together with experience and judgement are needed to make a good choice. The requirements for selecting sustainability metrics are: 1. Clear definition of what is to be assessed, and why. 2. Available data – quantifiable empirical data, not qualitative judgements. 3. Coverage – key aspects must be included. 4. Avoid duplication and needless complexity. 5. Use composites if appropriate (recognise weighting problem). Defining the purpose and choosing the metrics with care is essential. If this is not done, we simply have a collection of statistics. Composite indicators that combine two or more aspects can be very powerful. They do introduce the problem of weighting the different aspects, though this can sometimes be overcome if a common measure is available, such as monetary value, or an environmental impact like global warming potential.
0.5 0.4 0.3 0.2 0.1 0 1970
1975
1980
1985
1990
1995
2000
2005
2010
Year
and tragedies of human experience on a large scale over many years, for example the rise of China, whose HDI is now approaching that of Russia, and the march of HIV-AIDS through subSaharan Africa, where life expectancy in some countries is now less than 40 years and falling. HDI can’t represent the entire state of development in a particular country, and various other indicators are also reported by the UNDP, such as the Human Poverty Index, and the Gender Empowerment Measure. These illustrate particular aspects of development in more detail. All these indicators are used by international bodies such as the UNDP and the World Bank to guide development advice and aid.
Figure 2: Typical trends in the human development index (hdr.undp.org/ hdr2006/statistics)
example of indicators – sustainable development The HDI is a composite indicator for human development, but it is not Figure 3: River health index for the Lower Yellow River (Source: Is the Lower Yellow River Sustainable? Ni, Borthwick, Oian, Li Zhao)
2.0
Integrated index of river health
development has its critics. Disagreements about definitions and the difficulty of understanding the implications of sustainability, and its occasional hijacking for commercial purposes, lead some to question whether the term “sustainable development” has any real meaning. To counter such criticisms it has been pointed out that many concepts such as “justice” also defy precise definition; but should we therefore consider justice to be pointless and allow criminals to go free? Neither should we accept the lazy conclusion that because it is difficult to understand, we should not be bothered with it. Of course the concept and terminology of sustainable development will be misused, as an advertising gimmick, as a political slogan, and for much else. Its real meaning is not made less relevant and important by this misuse. A crucial aspect of sustainability is whether it can be measured. This is an example of a point made neatly by Lord Kelvin in a lecture to the Institution of Civil Engineers in 1883: “I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind.” The quantitative measurement of sustainability is crucial, since it focuses attention on the precise issues. In particular, we really need to be aware of how sustainability is changing at all levels – local, national and global – and for this, measurement is essential. If we can measure it, we can take planned and coherent action to change it in a desired direction. The measures of sustainability that provide this guidance are called “metrics” or “indicators”. Since sustainability has many aspects, its measurement will involve the gathering together of many individual measurements. Choosing a group of metrics for a complex situation is not straightforward. It is rather like arranging the control of an industrial process such as a catalytic cracker. Thousands of different measurements are possible, but a safe and efficient process control scheme can be designed with around a hundred separate instruments (measuring temperature, pressure, flowrate etc). Each of these hundred measurements is important in determining how the process is working, and in supporting the control system. On the other hand,
1.5
1.0
0.5
0.0 1965
1970
1975
1980
1985
1990
1995
2000
Year
In 1997, China’s Yellow River ran dry for 226 days, though the situation has improved since; Photo courtesy of Yellow River Conservation Press september 2007
27
sustainability 1
Sustainability indicators for industry (Institution of Chemical Engineers, www.icheme.org/ sustainability) Environmental indicators Resource usage Emissions, effluents and waste Economic indicators Profit, value and tax Investments Social indicators Workplace Society 50 indicators in total, but under each heading there is scope for additional items. Example: R&D expenditure as % sales – an economic indicator for investment
Richard Darton (richard. darton@eng. ox.ac.uk) is senior research fellow and tutor in chemical engineering at Oxford University, UK 28
in itself a measure of sustainable development, because it does not account for changes in the environment. A composite indicator that does not include economic, societal and environmental aspects may be measuring something, but it is not sustainability. An example of how indicators can be used in the context of sustainable development is provided by a case study developed by Alistair Borthwick, professor of engineering science at the University of Oxford, and Ni Jin-Ren, professor of environmental engineering at Peking University. This study relates to the Yellow River in China, vitally important to about 100m people who depend on the river’s resources for agriculture, industry and domestic water supply. The river transports an astonishing 1.6b t of yellow sediment every year, which not only gives it its name, but also causes silting up and severe flooding when the river bursts its banks. At the same time, a variety of factors including increased rates of extraction for human usage and climate change, are causing flowrates in the river to decline, sometimes to zero – in other words, the river dries up. This is a familiar story in many parts of the world where scarcity of water resources is a real problem. To date, the worst year for no-flow events was 1997, during which no water flowed into the sea for 226 days. It is important for the state of the river to be monitored and assessed, and for this purpose Borthwick and Ni have defined a River Health Index (RHI; Figure 3), which takes into account the length of river over which there
september 2007
is no-flow, the amount of sediment, the severity of no-flow events which upset the river’s ecosystem, and the availability of water for socio-economic development. The trend of this index between 1964 and 2001 shows that in this period the Lower Yellow River was in decline. That is the strength of the composite indicator – the key data are monitored and the situation is presented clearly and understandably. To meet the challenge, the Chinese government has decided to divert 55m m3/y of water from South China to the Yellow River by constructing three canals. By these means it is hoped to return the river to better health.
example of indicators – industrial operations Several years ago, IChemE published a set of 50 metrics for assessing the sustainability of process plant operations (see Figure 4). They present a balanced coverage of environmental, economic and social aspects of sustainable of chemical manufacturing operations, and with some adjustments they could be used as a model for other industries. These metrics were intended for industrial use, but have also proved helpful in guiding student design work. We can normalise the metrics by comparing them with company targets or industry best practice, which will yield a “footprint” of plant behaviour. Alternatively, the metrics could be combined in one or more composites, for specific purposes. Whilst an ad hoc list of metrics is a useful tool, to be sure that we are making a comprehensive assessment of the sustainability of an industrial operation, we have to examine the effects of that operation in more detail. This is the method we have been developing at Oxford (Aidil Chee Tahir: DPhil Thesis 2006, A systematic approach to sustainability metrics: palm oil production as a case study). The thesis analyses the interactions of the business processes with the domains of economics, society and environment, identifies issues arising through these interactions, and characterises them through appropriate indicators and metrics. The result is not only a comprehensive set of metrics for the specific case, but also a route tracing each metric back to a business process, which is a useful management tool.
metrics and targets The HDI, and the RHI are examples of how indicators can be used to
monitor the progress of quite complex things, such as the state of human development in a country. Methods are also being developed to generate indicators to assess the sustainability of industrial operations. Metrics that give a quantitative measure can then be used in a “control loop” which enables action to be taken to improve sustainability. It is worth noting however that in the field of human endeavour, “when a measure becomes a target, it ceases to be a good measure”. This is a statement of Goodhart’s law, which was formulated by the London School of Economics’ economy professor Charles Goodhart. It is a natural consequence of human ingenuity: for example, when waiting times for operations became a publicised target in UK hospitals, they did indeed become shorter, but it is suspected that this involved the diversion of resources from other (necessary) medical procedures, and perhaps administrative action to keep patients off the waiting lists. Improving performance according to the stated target can have less than benign side-effects on equally important but non-targeted areas. For sustainability, there is a similar danger: it is a holistic concept, and concentrating on one or two particular aspects may distort the drivers for corrective action in other areas. Thus, important though the potential for global warming undoubtedly is, it is only one aspect of the challenges arising from the massive utilisation of resources for wealth creation. Thought must also be given to the large-scale and long-term use of land and water resources, as we cope with global development. Aligning decisions about development with the priorities of sustainability, or at least encouraging this alignment, will take us towards a more sustainable world. Not doing so will store up more difficulties for future generations to sort out. Sustainability metrics will present the information we need to monitor our progress, and help us to maintain a consistent approach over long periods of time. Our future will then be a highly sustainable one, we have every reason to hope.
acknowledgement This paper is based on the Hartley lecture of November 2005. I would like to record my thanks for helpful discussions to Aidil Chee Tahir, Al Borthwick and Roger Booth of the University of Oxford, and Roland Clift of the University of Surrey.
