While the conversion of coal into electricity is about to be phased out a considerable byeffect has to be considered: gypsum is an important byproduct of coal power plants that is extracted by flue-gas desulfurization (FGD). Experts caution about a foreseeable lack of gypsum which is widely used in construction, writes WELT:
There is broad social and political consensus on phasing out coal-fired power generation. Hopefully, we will still find out where the electricity will come from on windless winter nights. But another substance will also become scarce when the coal-fired power plants go out of operation: gypsum.
So far largely overlooked by the general public, it is becoming clear that the white universal building material will slip into a supply gap by the 1930s at the latest. Because today more than half of the material - exactly 55 percent in Germany - comes from flue gas desulphurisation plants (FGD). These amounts will no longer apply in the future.
It will be difficult to do without, because gypsum is almost a kind of miracle material: it can be shaped in any way, moisture-regulating, non-flammable, infinitely recyclable, mineral. It's found in countless uses. Only rarely in medicine, where for bone fractures instead of the legendary plaster leg, other solutions with plastic splints are often used.
On the other hand, it is all the more common in construction, either clearly visible as stucco, modern molding and painting, more often still hidden behind wallpaper or wall coverings as lightweight construction panels or gypsum plaster. Around ten million tons are consumed annually, according to the Federal Association of Building Materials, Stones, Earths (BBS). Trend: rising - if only because of the ongoing construction boom.
People have been using the easily accessible material for literally thousands of years. In the palace of Knossos, built 4,000 years ago, many of the walls were made of gypsum, as archaeologists discovered.
A few decades after the turn of the century, when the Romans dominated the then known world, Pliny the Elder reported on techniques for making death masks. In the Middle Ages, builders used plaster of paris as a binding agent for mortar or to fill the compartments in half-timbered houses, often reinforced with horse hair.
But where will the material come from in the future? The coal-fired power plant park is already shrinking incessantly. The most important gypsum supplier will no longer apply if the desulphurisation systems are completely shut down. The pace of development is already considerable.
"The coal phase-out is progressing steadily," said Jochen Homann, President of the Federal Network Agency, recently. The authority expects that by 2023 only coal-fired power plants with a capacity of 13,300 megawatts will be available for feeding into the grid.
The operators have applied for a decommissioning permit for numerous plants. For comparison: Hard coal and lignite power plants with an output of more than 43,000 megawatts were still on the grid in 2019.
More than five million tons of gypsum a year will soon have to be procured in another way. The boom for FGD gypsum began four decades ago when acid rain and forest death were major environmental issues.
At that time, power plant engineers flanged flue gas desulphurisation systems on a large scale to the huge exhaust chimneys. The principle of operation is simple. The sulfur dioxide in the flue gas reacts with a solution of water and finely ground limestone.
The end result is gypsum - millions of tons for which a channel has been sought. Above all, drywall construction with plasterboard was found - a method that has now become so established that many builders can hardly imagine interior construction without it.
But opinions on how to fill the gypsum gap vary widely. It is a very common mineral in the earth's crust that is often stored in layers close to the ground.
According to the BBS, the resources in Germany would be sufficient to cover the demand for several hundred years. But the mining does not leave nature untouched. Environmentalists are therefore not only calling for an exit from coal, but also from natural gypsum.
In a joint position paper, the Nature Conservation Association (NABU), the Association for the Environment and Nature Conservation Germany (BUND), the Association of German Karst and Cave Researchers (VdHK) and some other eco-organizations spoke out in favor of no more mining areas with immediate effect to approve and to completely end the extraction of natural gypsum in Germany by 2045.
"Gypsum is a finite raw material that we cannot take indiscriminately from nature," said BUND managing director Antje von Broock. Half of the natural gypsum is extracted in the southern Harz, which is one of the most biodiverse landscapes in Germany.
Instead, the conservationists are calling for recycling instead of dredging. “The gypsum industry also needs a functioning circular economy,” Brook demands.
Currently, the lion's share of gypsum products in building rubble ends up in landfills. Although it is technically relatively easy to recycle, recycling is the exception. According to the industry, the proportion of recycled gypsum does not exceed a single-digit percentage.
An estimated three to four million tons of scrap material is generated annually. In most cases, however, the gypsum is then intimately mixed with other building materials, while large-scale separation processes are largely absent.
An alternative would be to replace the plasterboard with other building materials such as wood or clay. The Ministry of Economics in Thuringia had announced that it wanted to set up its own “Competence Center for Gypsum Substitutes” in the country, as reported by the specialist journal “Trockenbau aktuell”.
It is probably an attempt to keep the added value and jobs related to gypsum extraction in the structurally weak region of the southern Harz. But recently it has become quiet about the plans. The Federal Association of Gypsum Industry points to an annual value creation of almost 320 million euros and around 4,600 jobs, which, according to a DIW study presented in November, would be secured by them. In any case, natural gypsum is "not substitutable".
Therefore, in parallel to an increase in the recycling rate, the breakdown of natural gypsum must even be intensified. What is required is "a doubling of the areas usable for mining for natural gypsum in Germany," it said last year in a strategy paper by the association. By 2035, the amount must increase to nine million tons annually, which means that today's market supply would remain more or less stable.
Burkhard Vogel, head of the BUND Thuringia, then spoke of "excessive overexploitation", while the industry promises "resource-saving mining". The roughly 70 active or disused gypsum quarries in Germany showed themselves "with often uninviting, rugged surfaces", even the gypsum lobby admits. Even more: the mining sites appeared to be hostile to life to the human eye.
"But as varied habitats they accommodate rich plant communities and specialized animal worlds," says the lobbyists' self-portrayal. The nature conservation organizations are apparently not convinced by the argument. There will probably continue to be a struggle to get out of the plaster of paris.
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