Author: anderthalbAdmin

Sodium Analyzers and Film-Forming Substances: Working Together?

Eric M. Etter and Harold Stansfield

The increasing application of film-forming substances (FFS) in power generation and process steam applications as a corrosion mitigation strategy has raised concerns regarding their impact on plant systems, particularly valves, piping, and instrumentation. This study focuses on the adverse effects reported by users of film-forming amine (FFA) products, including loss of instrumentation sensitivity, premature electrode failure, sensor fouling, and overall accuracy and reliability issues.

Experiments aimed at replicating field conditions have revealed rapid sensor fouling occurring well before standard maintenance cycles for electrode cleaning and replacement. The observed accelerated fouling necessitates frequent mechanical cleaning, posing risks of electrode damage, increased downtime, and additional labor for maintenance. Because the fouling does not result in calibration failures, this creates a situation where the analyzer appears to be functioning normally, but is no longer capable of responding to adverse events such as a condenser leak. These highly dampened responses will follow trends over time but are incapable of rapidly reflecting transient spikes or changes in values.

PPCHEM® 2023, 25(6), 296–299

Cooling Tower Operating and Water Treatment Fundamentals – Part 2

Brad Buecker

Cooling water systems are an integral component of many power plants and industrial facilities of all types. Performance degradation from microbiological fouling, scale formation, and corrosion can seriously impact plant operation and revenue. Severe cases may force unit process or plant shutdowns. The remainder of this series examines the most problematic fouling, scaling, and corrosion mechanisms, and it outlines modern control methods for all of them. This installment focuses on microbiological fouling, with much of the discussion extracted from Reference 1.

PPCHEM® 2023, 25(6), 310–318

Why Do Sample Coolers Fail?

Aditya Sanjay Kanetkar

In steam and water analysis systems (SWAS), the sample cooler is one of the most important components. The main function of the sample cooler is to reduce the temperature of high-temperature samples from elevated temperatures to the temperature required for analyser sensors. In the case of steam sampling, the steam samples are not just cooled, but are condensed to water (phase change).

PPCHEM® 2023, 25(6), 322–325

Additives from Natural Resources – The Way to the Future?!

Wolfgang Hater

Additives from natural resources have been known since the end of the 19th century and have had a renaissance in recent years due to the demand to replace mineral-oil-based chemistry with materials from nature. They are considered to be green and sustainable. In spite of their positive image and a huge number of research papers, hardly any new compounds from natural materials have successfully found their way onto the market.

The assumption that natural equals harmless, green, or sustainable is quite common but does not always hold. While the criteria for green and sustainable are not well defined, the European Community has developed a standardized risk-based approach for the evaluation of whether a chemical can be safely applied.

This paper describes the major advantages and drawbacks related to natural material or biobased material. On the one hand, the production process is generally more simple and raw materials are cheap, especially if waste/recycled materials or residues are processed. On the other hand, a serious obstacle is the high variability of their chemical composition as well as the presence of components with no function.

Selected examples of studies and the application of additives from natural resources for water treatment are briefly discussed which show the potential but also the roadblocks for market success. It can be expected that they will play an increasing role in the future. Legislation will also be a strong influencing factor.

PPCHEM® 2023, 25(6), 330–337

Review vgbe Chemistry Conference 2023 October 24 to 26, 2023 in Ingolstadt

Around 170 participants attended the 59th vgbe Chemistry Conference from October 24 to 26, 2023. The wide-ranging lecture programme was once again rounded off by an accompanying trade exhibition with 20 exhibitors who presented their products and services relating to power plant chemistry.

The vgbe conference team would like to thank all speakers, exhibitors and sponsors as well as the interested participants for their support and looks forward to the next vgbe Chemistry Conference, which will take place in Potsdam from October 22 to 24, 2024.

PPCHEM® 2023, 25(6), 338–339

ABHUG 2023 Highlights

The annual meeting of ABHUG held on the 14th–16th November 2023 in Brisbane, Australia was chaired by Barry Dooley of Structural Integrity Associates, UK and Bob Anderson, Competitive Power Resources, USA. This ABHUG conference included conventional fossil plant technology and issues closely related to those in HRSGs. ABHUG2023 attracted 100 participants from Australia, New Caledonia, New Zealand, Singapore, Switzerland, UK and USA. About 55 % of the participants were Users.

The next meeting of ABHUG will be in Brisbane around early December 2024.

PPCHEM® 2023, 25(6), 340–341

A Specialty Ion Exchange Resin for Deoxygenation Treatment of
Boiler Makeup Water

Zhendong Liu, Amy Peddie, and Juan Carlos Pinilla

Oxygen level control can be very important in the cycle chemistry of power plants. Sometimes a higher oxygen level is desired for all-ferrous materials due to its creation of the more corrosion-resistant ferric oxide hydrate layer in the natural magnetite. This is practiced as either all-volatile treatment under oxidizing conditions (AVT(O)), or oxygenated treatment (OT). However, for some alloy materials (e.g., copper alloys and nickel alloys) used in the steam generation/recirculation systems, a reducing environment and very low oxygen levels are favored to avoid corrosion. This paper reports on a specialty ion exchange resin and its use in treating the makeup water for a pressurized water reactor (PWR) nuclear power plant. The resin is coated with a precious metal as catalyst for the oxygen-hydrogen reaction to generate water. It requires minimum maintenance (only annual backwashes), and has fast reaction kinetics, a small footprint, and a long operating life (> 20 years). The case study shows the resin can achieve < 10 μg ⋅ L–1 oxygen consistently from a makeup water with 1–10 mg ⋅ L–1 oxygen at a 189–1 514 L ⋅ min–1 flow rate. The catalyst doping, reaction mechanism, and some operational details are discussed.

PPCHEM® 2023, 25(5), 240–244

Press Release – IAPWS Annual Meeting 2023

Between September 3rd – 8th, 2023, 62 scientists, engineers and guests representing 20 countries converged in Turin, Italy at the Star Hotel Majestic for the annual meetings of the IAPWS Executive Committee and Working Groups. This continues a series of meetings that began in 1929 in London, UK with the purpose to connect scientists and researchers with the industry operators, engineers and managers who use their work. Collaboration and engagement across these varied groups provides guidance to the researchers on topical problems within industry and provides the engineers with the latest research results for direct application in their facilities.

The main meetings included discussions around power cycle chemistry, high temperature aqueous technologies applicable to steam cycles and hydrogen generation, oceanography and global climate modelling, geothermal steam, electrode boilers, power cycles with CO2 capture and storage systems and combined heat and power systems.

PPCHEM® 2023, 25(5), 250–251

The Role of Organics in Relation to Corrosion in Steam-Water Systems

Yu Xue, Karlien Dejaeger, Ben Bischoff Tulleken, Duygu Disci, Peter Janssen, Andrea M.Brunner, David Moed, Wolfgang Hater, Emile R. Cornelissen, and Marjolein Vanoppen

A sampling campaign was conducted in a film-forming amine product (FFAP) treated highpressure steam-water system of an ammonia producing plant to optimize the cycle chemistry. Cycle chemistry guidelines were assessed to be applicable with modifications fitting the local situation according to the pH and conductivity. Methanol, a main organic compound originating from the production process, entered the steam-water system with the process condensate and was tested possible to degrade. Furthermore, organic compounds from cation exchange resin were found in blowdown streams, suspected to originate from resin carryover. No operational and corrosion issues were observed.

Lab-scale first condensate experiments confirmed that a lower pH was present in the first condensate compared with the bulk steam, however, it was still partially buffered by ammonia. Via corrosion tests it was observed that oleyl propylenediamine (OLDA), in addition to ammonia, formed a smoother and more uniform magnetite layer. Moreover, magnetite layers formed under OLDA added to ammonia were more resistant against acidic conditions (pertinent to condensate return systems) than layers formed under the ammonia only chemistry and blank chemistry (without a chemical additive), with less reduction of the magnetite layer thickness.

These studies in combination with the plant experiences confirm that the steam-water system can be safely run with the selected FFAP treatment concept even with organics from the production process.

PPCHEM® 2023, 25(5), 256–275