Sulfur corrosion

Carbonyl sulfide reacts with chlorine forming phosgene (qv) and sulfur dichloride [10545-99-0] and with ammonia forming urea and ammonium sulfide [12135-76-1]. Carbonyl sulfide attacks metals, eg, copper, ia the presence of moisture and is thought to be iavolved ia atmospheric sulfur corrosion (27,28). Its presence ia propane gas at levels above a few ppm may cause the gas to fail the copper-corrosion test. 

Carbonyl sulfide is overall the most abundant sulfur-beating compound ia the earth s atmosphere 430—570 parts per trillion (10 ), although it is exceeded by H2S and SO2 ia some iadustrial urban atmospheres (27). Carbonyl sulfide is beheved to origiaate from microbes, volcanoes, and the burning of vegetation, as well as from iadustrial processes. It may be the main cause of atmospheric sulfur corrosion (28). 

Sulfur Corrosion Chromium is the most important material in imparting resistance to sulfidation (formation of smfidic scales similar to oxide scales). The austenitic alloys are generally used because of their superior mechanical properties and fabrication qualities, despite the fact that nickel in the alloy tends to lessen resistance to sulfidation somewhat. 

Carbon steel, where not limited by sulfur corrosion or hydrogen attack, can be the most economical material... 

Steverding, B., Intergranular Sulfur Corrosion in Missile Thrust Chamber Nickel Tubes , Corrosion, 18, 433t (1%2)... 

The presence of asphaltenes, originating in the fuel, acts as a trap for vanadium, nickel, and sodium (which promote slagging and sulfur corrosion)-, these asphalthenes often contain sulfur compounds, which simply add to the contaminant load. Additionally, asphaltenes act as precursors to spherical stack solids (cenospheres), which are exhausted with the flue gases as stack emissions. 

Average corrosion rates — high-temperature sulfur corrosion in hydrogen-free environment. 21... 

Figure 1.11 Average corrosion rates of high temperature sulfur corrosion in a hydrogen free environment as compiled from 1961 A.P.I. questionnaire data from industry-desulfurizing processes and published or reported data—npndesulfurizing processes,9...

In petroleum refineries, process streams containing hydrogen also frequently contain hydrogen sulfide. This causes sulfidic corrosion. You know from experience that increasing the chromium content of a steel increases its resistance to corrosion by high-sulfur crudes. However, do not jump to the conclusion that chromium alloying always improves resistance to sulfidic corrosion. It does so if the operation is dirty, as it usually is in crude streams, or if the corrodents are elemental sulfur or sulfur compounds that do not decompose to release hydrogen sulfide. This increased resistance to sulfur corrosion depends on formation of a protective scale. With such scales, the corrosion rate is parabolic — it decreases with exposure time. 

Dowling [53] proposed a mechanism for corrosion of structural steel exposed to wet soKd elemental sulfur (Fig. 8). Freestanding moisture and steel/sulfur contact are requisites for corrosion of structural steel by solid elemental sulfur. The principal form of attack in S/H2O media is not due to secondary acid generation resulting from hydrolysis of the sulfur. Instead, the author demonstrated that steel oxidation was coupled to sulfur reduction through an electron conductive iron sulfide layer. Evidence is also presented for the direct electrochemical reduction of solid elemental sulfur in the presence of FeS, supporting the role of this process as the partial cathodic step in the mechanism of the sulfur corrosion reaction. 

Sulfide stress cracking (SSCC) has special importance in the gas and oil industry, as the materials being processed there (natural gas and crude oil) often contain a considerable amount of hydrogen sulfide. SSCC is a low-temperature effect of H2S in an aqueous environment, and sulfidation is the term used for high-temperature (>250°C) sulfur corrosion. In gas pipelines, if the gas is sweet... 

Llewelyn, G., Protection of Nickel-Base Alloys Against Sulfur Corrosion by Pack Aluminizing, Hot Corrosion Problems Associated with Gas Turbines, ASTM STP 421, ASTM International, West Conshohocken, PA, 1967, p. 3. 

Influence of Ion Sputtering on the S2p Photoelectron Peak for Zinc-Sulfur Corrosion Products... 

The total global emissions of H2S are estimated to be 70-80 Gg-S-yr (S stands for sulfur). Corrosion induced by H2S is a major risk in oil field equipment. The adsorption of HiS on a metallic surface is shown in Fig. 10.5. 

Uses Fuel oil additive (vanadium scavenger, sulfuric acid neutralizer, sludge suspending agent, water dispersant) for steam boilers and gas turbines rust inhibitor, scale inhibitor in storage tanks corrosion inhibitor for vanadium and sulfur corrosion control... 

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