Solutions to Amine Headaches #7
Cyanide Control - Cyntrol™
“Cyanide Corrosion Causes Costly Upsets!”
Refinery cyanides cause considerable corrosion,
hydrogen blistering and waste water treatment
problems. The majority of refinery cyanides are
formed in the reactor of fluid catalytic cracking
(FCC) units. All of the gas from the reactor,
including the cyanide, is carried overhead into
the distillation column, where water is injected
into the overhead stream to control corrosion
problems.
“Expected Operations”
The resulting sour water is separated from the hydrocarbon products at various stages in the system. At this point free
cyanide can contribute to 3 possible scenarios:
(1) Free cyanide may be deposited in the wet gas stream as corrosion products. The formation of these corrosion products
may also destabilize the iron sulphide layer causing it to flake off as free iron sulphide.
(2) Some free cyanide may be removed from the wet gas stream with the condensing water or water wash. Once in the
water phase, the cyanide is transported with the water stream causing many forms of corrosion.
(3) If the free cyanide is not removed, it will be collected by the amine system and form heat stable salts. These heat
stable salts will affect the efficiency of the amine system and cause corrosion and amine issues.
Currently, the selection of the crude charge is driven primarily by cost and opportunity. As a result, there is an increase of
refinery sour crudes containing higher amounts of nitrogen, at larger throughputs, and more severe processing conditions.
This increases cyanide corrosion and hydrogen blistering. In addition, significant concentrations of cyanides are also found
TM
in the waste water from coker units of the refinery. With our Cyntrol program you can effectively address all of this!
Cyntrol™ - The most effective cyanide control
A known method of controlling cyanide concentration in sour water streams involves injecting sulphur-containing
compounds, i.e. ammonium polysulphides (APS), into the sour water system. The polysulphides convert the cyanide into
non-corrosive, biodegradable thiocyanate before complexes of cyanide/metal are formed.
MPR's Ammonium Polysulphide (APS) Cyntrol™ Program reduces the potential for cyanide assisted corrosion while
practically eliminating the potential for free cyanide in refinery waste water effluent. Our formula of ammonium
polysulphide provides the most active sulphur for this process. If excess cyanides have been found, our goal is to prevent
cyanide corrosion through our cyanide control program. The items reviewed will include the efficiency of your current
wash water system and/or current scavenger program including application methodology, separation limitations and foul
water handling limitations.
MPR Services will help you optimize and monitor the operation of your amine/glycol treating units!
Contact us today
MPR Services, Inc, a member of Tessenderlo Group
1201 FM 646, Dickinson, TX 77539-3014 USA
Telephone 281-337-7424 Fax 281-337-6534
E-mail: [email protected] [email protected] [email protected]
www.mprservices.com