CORROSION GUIDE 181108_new table content format ... - Reichhold

Selected Application Recommendations
Desalination Applications
Droughts, demographic changes, and ever-increasing
need for fresh water are spurring needs to desalinate
brackish water and sea water to meet demand. There
is already one major project in progress in the City of
Tampa, and others are being considered on the east
coast as well as developing countries.
Reverse osmosis (RO) is a mature process, yet has
become more cost effective and energy effi cient in
recent years due primarily to advances in membrane
technology. Although RO is regarded as the baseline
technology, there are other desalination processes
under development, many of which are a tribute to
ingenuity. These include processes such as vapor
recompression, electrodialysis, and gas hydrate
processes which entail crystalline aggregation of
hydrogen-bonded water around a central gas molecule
(for example propane), such that the hydrate can be
physically separated upon freezing, which takes less
energy than evaporation.
Electroplating and other Electrochemical
Processes
Electroplating is used to electrolytically deposit specifi c
metals onto conductive substrates for anodizing or
other functional or decorative purposes. Most plating
solutions are acidic and thus reinforced composites as
well as polymer concrete vessels that have been used
extensively. Some plating solutions, such as those
associated with chrome, are aggressive due to the
oxidation potential as well as the presence of fl uorides.
Synthetic surfacing veils are commonly used. Good
curing is also necessary, especially if there are concerns
about solution contamination.
Apart from plating there can be growing applications
in electrolysis processes which might be practical
for hydrogen fuel production. The same applies to
accommodation of electrolytes (such as phosphoric
acid or potassium carbonate) associated with fuel cells.
Vinyl esters are already being used in fuel cell plate and
electrode applications.
Very often, most of the expense in these processes is
associated with water pretreatment, but nevertheless
there is overall a great deal of equipment involved, such
as storage tanks, piping, and reaction vessels.
Upon desalination, some saline solutions must be
disposed. Chlorides and other constituents can greatly
limit the use of stainless steel, and often it is necessary
to consider titanium or high nickel content alloys, all
of which are expensive. Hence corrosion resistant
composites can offer signifi cant cost and technical
advantages.
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