Application and performance of titanium linings in FGD ductwork and stacks

Abstract

Wet scrubbing of fluc gas to rcinovc wlphtir dioxide generates highly corro.;ivc conditions i n the operating plant. Conditions in the mixing zone arc discussed in detail. Titmiiuin has bccn evaluated and has bcen installed ;IS ;I corrosion resistant liner in several major US plants. Competitive. cost effective installation has been achieved using Rcsista-Clad Plate. Installalion and seal welding techniques arc dctailcd and discussed. Cost comparisons with other lining materials arc given.Using five case studies the performance of titanium is considcrcd in rcl ;I t ion to ope r;i t i ng c nv iro n mc n ts B nd extraneous factors. Specific failures are commented upon in detail. The corrosion resistance of titanium t o FGD cnvironmcnts. fluorides, and hot concentrated reducing acids is discussed. Plant monitoring is Conclusions point t o the overall satisfactory performance of titanium. despite the specific and localised failures experienced in service.cnco LIrngcd.

Corrosion Behavior of a Ni–Cr–Mo Alloy Coating Fabricated by Laser Cladding in a Simulated Sulfuric Acid Dew Point Corrosion Environment

“…Anti-corrosion materials widely employed in the low-temperature surface of boilers mainly include austenite and duplex stainless steels, titanium, and nickel-based alloys [28][29][30][31][32][33]. High performance nickel-based alloys have been utilized in preheater, FGD systems, backend ductworks, etc., to extend the service life to several decades.…”

Electrochemical Behavior and Passive Film Properties of Hastelloy C22 Alloy, Laser-Cladding C22 Coating, and Ti–6Al–4V Alloy in Sulfuric Acid Dew-Point Corrosion Environment

“…The use of alloys with high resistance to dew-point acid corrosion, like titanium alloys and Ni-Cr-Mo alloys, is an efficient method to overcome the corrosion failure of these facilities and has been utilized for decades in the most corrosive environments of FGD systems [5,6] and other low-temperature equipment in the United States and Europe [7,8]. Titanium alloys are used as lining materials for chimneys for FGD systems in China.…”

“…It is widely agreed that the Ni-Cr-Mo alloys, just like C276 and C22, are the best candidates for construction or lining materials of facilities suffering the sulfuric acid dewpoint corrosion. [5,8]. However, the extensive application of Ni-Cr-Mo alloys in FGD systems and other facilities is restricted because of the high construction cost resulting from the persistently high price of nickel and molybdenum raw materials.…”

The impedance method of monitoring the degradation of rubber linings in applications where progressive deterioration is the predominant failure mechanism

“…The absorber jacket made of carbon steel can be protected from corrosion by steel alloy or nickel alloy linings (wallpapering) Krakowiak, 1999, 1997a;Francis et al, 1998;Plant, 1998;Miszczyk et al, 1997). Alternatively special organic coatings can be used to protect absorbers from corrosion (Miszczyk and Darowicki, 1998a;Noshir, 1976;Cerny and Peacock, 1992;Goy and Kaepffer, 1992). Rubber linings are used for anticorrosion protection in Germany and Poland (Fenner, 1999;Cassiday and Aminabhavi, 1983).…”