An interview with Prof. Emeritus Rosemary Falcon
The recent Russia/Ukraine war has forced Europe and the UK to reexamine their plans for coal, at least in the short term. Coal is suddenly being seen as essential for providing energy security for the European winter, especially with Russia lessening or cutting off supplies of natural gas to Europe. This has led to more countries turning to South African coal, especially to replace Russian coal which will no longer be imported because of sanctions.
Chris Meyer, on behalf of Energize, spoke to Prof. Emeritus Rosemary Falcon, about the value and use of coal in South Africa.
Prof. Falcon retired recently after serving as SARChI Chair of Clean Coal Technology at the University of the Witwatersrand, following a career in coal and related matters of over 43 years.
One of the problems facing Europe, particularly Germany, is the presence of huge high-pressure systems in winter, with very little wind in the weak winter sun. How important will coal-generated power be in Europe (particularly Germany) during the coming winter?
Coal-fired power will be important in Germany for quite some time to come for these very climatic reasons, and this will not be the only country in Europe and around the world where this is so: e.g., California, Australia, and elsewhere. First, the amount of energy required to replace coal-fired power is enormous because renewable energy (wind and solar) has very low capacity. This means that for each unit of electricity supplied by coal, extremely high quantities of wind turbines and solar panels (up to ten times more) are needed to provide the same unit of electricity. In the case of Germany, when the sun is weak or does not shine or the wind does not blow, Germany is fortunate in having access to power from its neighbours – nuclear from France and coal-fired power from Poland as well as gas from Russia – or at least it did have until the Russian-Ukraine war. This is not the case for Australia or California, both proudly renewable-promoting countries, as both have suffered severe rolling blackouts in recent times. In fact, as recently as a month or so ago, eight million Australians were asked to 'switch off their lights'. In Germany, the cost of replacing or substituting failed renewable power by bringing in nuclear or coal-fired power has led to the highest cost for electricity in the world. This, in turn, has led to more energy poverty (i.e., homeowners being unable to pay their power costs and the closure of many smaller industrial firms).
Furthermore, the intermittency of supply and the nature of renewable energy is known to damage the grid, thereby requiring different forms of electricity transmittance which itself is costly. Such transmission lines must be installed and replaced. Furthermore, electricity storage is limited and will always be limited on any meaningful scale, given the limited quantities available of the minerals that will be needed to manufacture the batteries required by the world soon, should most countries follow the renewables-only energy path. In terms of cost, what is also little-known is that for every unit of power provided by renewables, an equal source of reliable and secure power is required (by coal or nuclear) to stabilise the national power requirements which, in turn, results in double the price of 'renewable' energy. An integrated (mixed) and well-balanced energy plan should be the future for any country, at least until a long-term development such as fusion energy (nuclear) or something better takes over.
How long can South Africa expect to benefit from the current European need to replace imported Russian coal? Just for the European winter or possibly longer?
Initially, I believe South Africa and other coal (and gas) exporting countries will benefit from the current Russia/Ukraine situation for as long as the war continues, and perhaps also in the longer term due to the recognition of the need to supplement renewables with ‘clean’ coal or other fossil fuels and/or nuclear. Surely policymakers in Europe and the USA will shortly see the limitations of a ‘total renewables’ or ‘renewables only’ policy. Certainly, countries in the Far East have already done so, and have gone for clean coal options along with renewables in their energy mixes.
How competitive is South African coal compared to other countries the European Union could import from?
South Africa has already mined most of its high-grade, highly reactive, good steam coal in currently mined coalfields. Coal that remains in those coalfields requires considerable beneficiation in order to meet the high-grade steam coal qualities required by coal-fired power stations in western Europe, although Turkey and India use lower grades of coal and can accept South African coal more easily. The beneficiation required to produce high-grade products leaves a considerable amount of so-called ‘middlings’ and ‘discards’ for local use (at a lower price), and this adds to the cost of preparing export coal.
For western Europe, South Africa is competing with the USA and Colombia on the Atlantic seaboard side, and coal from both of those sources is generally higher in quality (grades and reactivity) than many of the products that South Africa can now produce in bulk. The question then arises as to the role that price plays. Interestingly, in the past, South African high-grade coal was sold at a marginally lower price than internationally traded high-grade coals, helping South African coals gain market share, despite the difference in quality or grade. It, therefore, remains to be seen what will transpire in this regard going forward, and how desperate for coal-fired power the countries in Europe will be. The decision will then need to be made – ‘quality versus price’ when it comes to South African coal vs. the competitors.
For the record, Indonesia and Australia have abundant coals and their export qualities are generally good and high-grade. [NB: I am not including the lower grades being sold to India, where much of South Africa’s moderate to lower grade coals are shipped to]. Distance to Europe and the costs attendant to the transport of coals from the East would add to the costs paid in Europe. Such coal from the East is sold primarily to China, India, Japan, and other Far Eastern countries.
How does South African export coal differ, if at all, from the coal produced by competing countries?
Of the better-quality bituminous coal for export (6000 kcal/kg), South Africa has a limited amount for the reasons given above. The bulk of the coal exported from South Africa is in the lower calorific value ranges (5500, 5000, and 4500). Countries competing to export coal generally produce and aim for markets requiring higher quality coal (6000).
Key problems with Medupi and Kusile are that the boilers used were designed for coal that burns far more quickly than the South African coal used and that the tube mills originally specified were replaced by the contractors with vertical mills, which did not mill the coal fine enough to compensate for the slower burn rate.
This is all true! A similar situation almost took place with Lethabo Power station where specifically difficult-to-ignite and long-burning coal is used. In this case, the design of the power station was rectified before the final agreement was reached and construction began. Prior testing established the nature of combustion early in the process. The need to test all Southern African coals destined for coal combustion and power generation is paramount before further mistakes are made. All coals can be burnt successfully and cleanly, irrespective of their nature, but the relevant power-generating equipment needs to be designed specifically for the coals concerned.
Could power stations in Europe have similar problems with coal imported from South Africa? Put another way, would German power stations be able to use coal from South Africa?
Coal destined for Europe needs to meet the designs of the boilers operating there. The highest grades and qualities of South African coal can meet the specifications for Europe, but only after considerable beneficiation. Moderately lower grades can be used but boiler efficiencies and burnout of the coal particles may be lower than expected when using our coal relative to European, USA and Colombian coal.
And what of German power stations designed to burn lignite?
South African coal and German lignite are unlikely to co-combust efficiently! Lignites have high moisture content and once heated, the particles would dry out to form ‘chars’ which would be highly porous and burn out rapidly. Such chars are likely to operate at lower temperatures (ignition and combustion) than bituminous coal and may well be incompatible. This is specifically so with South African bituminous coal which contains organic materials that require specific ignition requirements and longer burnout times.
Much has been said about the so-called 'coal supply cliff' for power stations. But would a similar 'coal supply cliff'also be looming for the synthetic fuels produced locally? Is Sasol also going to run out of coal at some stage?
I am told that Sasol has coal resources for the next 100 years, should they require it. So, any ‘cliff’ would not be coal related.
For some time now, much has been said about replacing coal-fired power stations (which currently supply more than 80% of South Africa’s electricity generation) with renewable energy (particularly that generated by sunlight). How practical do you think this is?
Replacing South Africa’s old coal-fired power stations should be considered far more practically than currently appears to be the case. Of course, the first plan of action should have been to replace the old boiler and ancillary parts with new ones, or better still to re-furbish them with different new, more efficient, practical, and clean operating equipment − as is happening widely in China, India and elsewhere in the Far East. There are now boiler designs that can clean the flue gas emissions to 99% while also producing valuable byproducts from the greenhouse gas emissions captured in them (SOx produces sulfuric acid, NOx produces fertilisers via ammonia, fly ash particulates contain valuable trace elements that can be extracted, and CO2 can be captured and the carbon extracted for valuable carbon products). It is unbelievably sad that Eskom lost out on the opportunity to build such high-tech clean power-generating plants at Medupi and Kusile when they had the opportunity, instead of the incorrect and ill-conceived boiler designs and ancillary plant currently operating there. Such high-tech clean coal-fired power stations are currently being built by the hundred at present in India and the Far East.
Replacing the 80% coal-fired power generation with non-coal-fired technology will be difficult. As explained earlier, the quantity of renewables that will be required to do so is beyond comprehension – I refer to the mismatch in energy capacity between renewables and coal in terms of electricity production. Wind is only significant and feasible in a belt 3 km wide around the entire South African coastline, and at times when gusting too hard, wind turbines (particularly in the vicinity of Port Elizabeth/Gqeberha) must be closed down lest they break. Solar is only feasible as a bulk source of energy in the western sector (Northern Cape) of this country. Transmission lines will be hard-pressed to bring such wind and sun-sourced intermittent power to the industrial hubs in Gauteng. Gas has been claimed to be another alternative to coal, but methane is ten times more harmful to the environment (with a more significant impact on climate change than CO2). And South Africa would have to depend on gas from its neighbours due to the paucity of such resources in this country. Hydrogen – now being considered for a ‘hydrogen economy’ – requires considerable quantities of water for its manufacture, and South Africa is a water-impoverished country.
For all the above reasons, no complete replacement of coal by renewable energy can be considered for South Africa. However, the possibility of an integrated plan using all resources would seem to be the answer, as has been proposed in the Integrated Resource Plan put forward by the Department of Minerals and Energy Resources in 2019. In this plan, coal does have a place, even if somewhat reduced, with wind, solar, and gas taking prime spots. It is to be hoped that sense prevails and that such a plan continues to be implemented with minor adjustments as and when necessary.
Please outline how using clean coal technology could improve the coal supplied to and utilised by our power stations, and possibly the performance of those power stations. What techniques are possible, and which would be practical for use in South Africa?
There are major new developments in power generation designs that permit high-efficiency and low-emissions (HELE) operations. It is these plants that are being built across the Far East. These are supercritical (SC), ultra-supercritical (USC), and advanced ultra-supercritical (AUSC) boiler designs.
Of specific relevance to Southern African coal would be the circulating fluidised bed form of boilers. These boilers circulate tiny coal particles (not the powdered coal dust as in pulverised coal boilers) until the particles have fully combusted and in so doing, they ensure efficient burnouts. They can accept low-grade coal which precludes the need for beneficiation, they operate at low temperatures which prevent the production of NOx, they can absorb SOx in the combusting bed by the inclusion of limestone, and they can operate at high efficiencies which reduces the CO2 produced considerably. By these means, the boilers do not require expensive capture mechanisms for SOx and NOx after the boiler, and CO2 can be considerably reduced (see Figure 1 below).
With highly efficient boilers, CO2 is reduced significantly and what is emitted can be captured and used in the manufacture of a host of carbon-based products. Research work conducted in our DSI-NRF SARChI Clean Coal Research group proved that valuable carbon nanotubes can be produced from the 12% CO2 emitted from Eskom flue gases, and this is only the start of what can be done with such carbon materials.
Concluding comments
I just wonder how many people realise what coal provides this country in terms of generating income from export and sales locally. Just think of the jobs involved (the Fossil Fuel Foundation (FFF) estimates that almost one million people are involved directly or indirectly) and the products coal provides – 33% of the country’s petrol and diesel and 100% of the metallurgical carbon for iron and steel making. People forget that iron and steel cannot be made without carbon, for extracting metal elements out of the rock to providing the carbon in the furnaces for making the iron and steel − and coal is the only source available for that purpose! Also 70% of cement production (some cement factories are trying to use old tyres now but that provides many more environmental hazards). And coal is the source of the hundreds of products provided by Sasol, AECI, and many other industrial companies. About 4000 small-scale industrial, agricultural and mining-related companies use coal.
Recently, my colleagues at Wits University (under Prof. Samson Bada) produced astonishing products simply from coal discards (coal not exported or used by industry, of which we now have about 2 billion tonnes). For example, an incredible variety of building materials (tiles, boards, etc.), activated carbon, carbon fibre, and a host of other materials. They have also identified and extracted an amazing array of rare earth elements (REEs) in certain coals which are extremely valuable (China currently produces 80% of the world’s REEs). REEs are used in all telecommunications, IT, space travel, etc.
The high ash content and elements within coal discards appear to provide the catalytic reactions for some of the processes used to make the products. The coal material contained in the discards provides the carbon suitable for carbon-based products.
Some of these products could become extremely important in future (including for the manufacture of batteries, electric cars, etc.). This includes products such as highly porous activated carbon - these coal-based forms can store up to six times more LNG gas than is currently in use, this includes the storage of hydrogen which could be used in H2-gas-run cars because this activated carbon is so light in weight! Then there are vital products such as capacitors, carbon fibres, carbon nanotubes and graphene (the latter products are extremely strong, lightweight materials for vehicles, planes, spacecraft, etc.). These developments are at fully proven ‘proof of concept’ stage and only need further funding to go to pilot if not directly to commercial scale, so the potential is huge.
To demonstrate the relevance of such developmental matters, the USA is spending millions in a specifically appointed new research centre looking into such coal-carbon-based developments (including the source and extraction of REEs from coal). Sadly, this country has not seen fit to consider the same yet, probably because the exorbitantly high price of export coal is dominating the minds of the coal industry at the moment.
Coal is not just a fuel to be burnt in power stations, it is a valuable resource that could be used by many existing industries and could also be a resource for new industries. New uses for coal (including coal discards) could supply jobs when coal-fired power stations are shut down, and possibly even before they are shut down. Such points are seldom advertised or appreciated. Coal is seriously the most valuable mineral commodity in this country. We should not forget that.
Chris Meyer is an independent consultant.
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