Titanium was first used in chemical plant in the mid-1960's. Its outstanding resistance to corrosion in oxidising chloride environments, sea water and other aggressive media were rapidly established. In several processes titanium is the first and only choice for effective plant performance and acceptable levels of life cycle cost.
Today as shown below titanium is more widely used. Costs of material and fabrication have both stabilised and titanium equipment, properly designed can compete with most of the more common but usually less effective corrosion resistant alloys.
PROCESS MEDIA WHERE TITANIUM'S OXIDE FILM IS STABLE
(within wide operating boundaries) |
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|
1. Chlorine and chlorine compounds
a. Moist chlorine gas
b. Water solutions of chlorites, hypochlorites, perchlorates and chlorine dioxide
c. Chlorinated hydrocarbons and oxychloro compounds
2. Other halogens
a. Bromine; moist gases, aqueous solutions and compounds
b. Iodine; moist gases and compounds
3. Water
a. Fresh water, steam
b. River water
c. Seawater
d. Water containing organisms that cause biofouling
e. Water containing microorganisms that would typically cause microbiologically influenced corrosion in other materials of construction
4. Oxidizing mineral acids
a. Nitric
b. Chromic
c. Perchloric
d. Hypochlorous (wet chlorine gas)
5. Inorganic salt solutions
a. Chlorides of such minerals as sodium, potassium, magnesium, calcium, copper, manganese, nickel
b. Bromide salts
c. Sulfides, sulfates, carbonates, nitrates, chlorates, hypochlorites |
6. Organic acids
a. Acetic
b. Terephtalic
c. Adipic
d. Citric (aerated)
e. Formic (aerated)
f. Lactic
g. Stearic
h. Tartaric
i. Tannic
7 Organic chemicals (with moisture or oxygen)
a. Alcohols
b. Aldehydes
c. Esters
d. Ketones
e. Hydrocarbons
8. Gases
a. Sulphur dioxide
b. Ammonium
c. Carbon dioxide
d. Carbon monoxide
e. Hydrogen sulfide
f. Nitrogen
9. Alkaline media
a. Sodium hydroxide
b. Potassium hydroxide
c. Calcium hydroxide
d. Magnesium hydroxide
e. Ammonium hydroxide |
Fabrication costs for titanium pressure vessels are surprisingly lower than for some other widely used corrosion resistant alloys.
The above table and graph were first published in Chemical Engineering Magazine, and we are indebted to the publishers and the authors for permission to reproduce this information.