Editorial PT 12

The Journey is the Reward – Power Plant Chemistry in Changing Times

Power plants are to be operated safely, in line with environmental regulations, trouble-free, and economically. These targets are to be achieved with the support of power plant chemistry that is highly committed to make its contribution towards meeting the requirements.
The history of power plant chemistry started in the twenties of the past century through the investigation of corrosion phenomena, i.e. the interaction between medium and material. Spectacular corrosion of steam generators led to the foundation of the “Feedwater committee” that later became the “VGB Technical Association of Steam Boiler Operators” and then the “VGB Technical Association of Large Power Plant Operators”, today’s “VGB PowerTech e.V.”
Providing extremely clean boiler feedwater has been among the first steps of power plant chemistry on the long journey through decades of technical development and progress.
The replacement of evaporators by ion exchange technology and the introduction of condensate polishing plants have been milestones in the development towards save power plant operation. Today, membrane techniques are pushed ahead aiming at zero-effluent power stations. The conditioning of water-steam cycles in order to create stable protection layers and to avoid corrosion has led from neutralisation via alkaline- to combined conditioning, including oxygen treatment, which was vigorously debated at the beginning and nearly considered a sacrilege.
As units became larger, chemical treatment and supervision of cooling water systems gained in importance.
Knowledge and experience have been concentrated and embraced by VGB´s Technical Guidelines and Rules. Today, it goes without saying that they are observed in existing plants and new constructions.
In the mid-seventies of last century it seemed as if the development had been completed. The tasks of power plant chemists were limited to issues of water chemistry, water balance and material science. Only some fuel chemistry of minor importance had to be dealt with. Normally coal was black and burning.
But roughly at the same time, conventionally-fired boilers were massively retrofitted with flue gas cleaning systems, and suddenly new and ambitious challenges emerged for power plant chemistry. Fossil-fired plants were equipped with “chemical factories” producing gypsum that did not amuse the mechanical engineer. These developments did not seem to be the original task of electrical utilities.
A few years later, reactors equipped with catalysts were also added to denitrify flue gases. The selective catalytic reduction is of course a chemical process, too.
The power plant chemist had to widen his knowledge to also become an expert in environmental-protection technologies, however, without neglecting his original tasks.
The increased application of hard coal originating from all over the world also made fuel analytics an important topic. The same applies to substitute fuels like biomass or sewage sludge that have been increasingly used in conventional power plants.
These new challenges could only be met successfully with the support of chemistry!
Against this background it is sometimes complained that the role of power plant chemistry is not fully appreciated, and that power plant chemists are suffering above average from restrictive measures of cost-cutting programmes. That might be true in single cases, but I cannot recognize a systematic approach apart from the fact that increasing cost pressure firstly leads to staff reductions. This simple but risky solution might lead to a lack and finally loss of know-how.
Recent complains from different industrial branches unfortunately confirm this assumption.
However, this applies to all professions. The power plant chemist should not lament but go ahead according to the motto: “act brilliantly and talk about it”.
In this context I would like to highlight the work of the Associations like VGB and BDEW and the still highly accepted willingness to co-operate in committees and to frankly exchange experience.
Power plant chemistry is not a university course. Being a power plant chemist is – based on the study of chemistry – the result of experience and transfer of know-how. According to my opinion it is absolutely necessary to pass on experience and knowledge to future generations for “technical survival”. Concerns about deregulated electricity markets do not really apply to power plant chemistry, because the experience exchanged on VGB-level and other activities is never a one-way but it rather can be described as a typical “win-win situation”.
Today, power plant chemistry is an integral part of a complex structure, comprising mechanical-, electrical-, process- and chemical engineering.
On the one hand the power plant chemist is an analyst who is expected to supply results quickly and reliably, and on the other he is an advisor who has to evaluate analytical results, to classify them, to draw the right conclusion and to offer solutions.
In this sense I would like to quote my highly appreciated colleague Professor Dr. Heinz Gutberlet “…he [the power plant chemist] keeps away chemistry from the engineers… “ but not as exclusion but as a consultant and multidisciplinary thinker.
The development of power plant technology is not yet terminated, new challenges for power plant chemistry are evident:
– carbon dioxide capture and storage (CCS),
– upcoming discussions about trace element emissions from fossil-fired plants,
– design of power stations with higher temperatures and pressures including the unavoidable questions related to the interaction between medium and material,
– and – at least outside of Germany – the development and design of nuclear facilities of new generations.
If and where all these technical developments end up is not yet foreseeable. We cannot look into the future.
But wasn’t it Confucius who said: The journey is the reward?