English to Portuguese Tech/Engineering Engineering (general) petróleo e gás

Black Powder is a common corrosion related contamination found in pipelines transporting LPG, LNG and hydrocarbon condensates. Studies1 of particle size distribution have shown that a majority of the contaminant is very fine and sub-micron in size. Previous studies2 have shown that they consist primarily of iron oxides. The presence of sour gas accelerates the formation of mixtures of iron sulfide and iron oxides. Black Powder is a global phenomenon and occurs in pipelines. Elevated temperatures appear to increase the formation of these solids. Additional non-corrosion related solids such as sand or silt may also be present in the gas stream. Characteristics of black powder solids are: • Very fine contaminants, forming agglomerates in micron size range – typically 1-10 micron • Easy to transport, difficult to capture • May be pyrophoric • Need for appropriate handling and disposal procedures “Pipeline rouge” is another term commonly used to describe corrosion products retrieved from pipelines, but the composition is similar to black powder, only the color is red instead of black. The predominant compound in pipeline samples is typically magnetite, which is black in color. Minor components such as greigite (Fe3S4), siderite (FeCO3), or hematite (Fe2O3) probably give pipeline rouge its color. In addition to these solids, the gases may pick up hydrocarbon and aqueous contamination from storage in the pipelines. They are present as fine droplets or aerosols in the gas phase. The presence of water in liquid phase promotes corrosion reactions. The presence of oxygen, hydrogen sulfide and carbon dioxide accelerate the corrosion reactions in the steel pipelines. Pigging operations have resulted in enormous amounts of black powder (500-5000 kg) being removed from scraped pipelines.