Reverse osmosis (RO) has become a common method to demineralize water. A successful RO system requires not only a good design but also appropriate pretreatment to minimize fouling of the membranes with suspended solids. We investigated using high-efficiency filters as pretreatment to RO systems to remove suspended solids and minimize fouling of the RO membranes. These filters have the ability to remove particles down to 0.25 µm in size. This report describes various aspects and specific applications of this technology.

In the May 2007 PowerPlant Chemistry issue, the paper VGB Primary and Secondary Side Water Chemistry Guidelines for PWR Plants authored by Harry Neder, Michael Jürgensen, Dieter Wolter, Ulrich Staudt, Suat Odar, and Volker Schneider appeared. In this paper in the subsection Secondary side Systems, three tables (Tables 11–13) were presented that have been the subject of several e-mails with requests for more information regarding the cation conductivity values. PowerPlant Chemistry has passed on your questions to the authors of this paper. The authors' response is presented.

Feedwater heater shells are frequently left unprotected during unit shutdowns and outages. Even though means are generally available during outages to protect these critical areas, many plants either fail to protect the heater shells or, in some cases, opt to leave the shells exposed to damaging environments. Failure to protect heater shells, even during short outages, can exacerbate problems with metal oxide transport when returning the heaters to service – particularly if the heaters contain copper-bearing tubes. This paper investigates a novel approach used by one utility to circumvent problems with oxide transport due to inadequate heater shell storage. It discusses structural modifications incorporated by the plant to improve the storage process. It also details the proper chemistry and testing procedures necessary for shell protection under various conditions. Equally important, this paper outlines critical controls for minimizing copper oxide transport during subsequent unit startup.

In the October 2007 issue of our journal, the paper Is Cation Conductivity Monitoring Relevant For Today's Combined Cycle Power Plant? – Yet Another Case Study Says It Is Not, authored by Luis Carvalho, Thomas James, and William E. Hunter, appeared. As a response, the first Letter to the Editor, authored by Eric Maughan was published in the November 2077 issue. In this issue, as a continuation of our discussion, two further replies are presented.

The power plant chemistry department of Alstom in Mannheim was founded in 1967. The presentation summarizes our contributions to the development of new power plant technologies over the past four decades. In addition, an overview of the future activities of our department is presented. In the retrospective the following examples are mentioned: nuclear power, combined cycles, supercritical steam generators and the contributions of Alstom's power plant chemistry department to, for example, the VGB guidelines. The outlook includes the expected contribution of power plant chemistry to solving challenges in connection with 700 °C technology steam power plants, oxyfuel processes and carbon capture.

A survey of the topics addressed at three major European power plant chemistry conferences has revealed that fossil cycle chemistry, like the neglected stepsister Cinderella, is not getting the attention it deserves. Boiler tube failures are the leading cause of forced outages in the conventional fossil plant utility industry, and heat recovery steam generator tube failures are the major cause of damage in the multiple-pressure combined-cycle plants. While other topics are surely important, more honest and open discussion of chemistry-related problems in fossil cycles is imperative to achieving operational benefits like higher reliability, availability, and efficiency.

Starting with the February 2008 issue, you will find at the end of the respective journal issue this new column. Our PPChem 101 program does not require enrollment, as is the case with typical university 101 courses – you can simply take part in this program by reading the individual articles, your "lessons." The major task of the program is to help all non-chemists responsible for chemistry-related tasks, all power industry newcomers, and all engineers, whether chemists or non-chemists, to learn the fossil cycle chemistry basics.

As every year, the January issue closes with abstracts of all the articles published in this journal in the previous year. I would like to remind you that back issues of our journal are – with few exceptions – still available and that you can receive PDF files of all articles by e-mail. The order forms may be downloaded from our homepage.