Pipeline Contamination

PIPELINE CONTAMINATION & BLACK POWDER FORMATION

One of the biggest and most prevalent problems affecting the efficient operation of pipelines is commonly known as black powder. In simple terms, it is an accumulation of corrosion which typically forms in gas, oil, petrochemical and aviation fuel pipelines. The resultant financial costs across worldwide industry are enormous. It can form at throughout most stages of the process in either a powder, liquid or a black sludge substance built up from very fine often sub-micron particles.

A combination of the presence of water, oxygen, hydrogen sulfide and carbon dioxide acts as a catalyst for corrosion of ferrous steel pipe. Ultimately this produces black pyrrhotite, more commonly known as black powder. Whilst the formation is gradual black powder can accumulate to several thousand kg in untreated pipelines. Natural erosion from contact from the substance in the pipe with the pipe wall can further add to the accumulation.

WHY IS PIPELINE CONTAMINATION A PROBLEM?
Each year black powder formation costs pipeline industries several million dollars in direct costs alone. There are several reasons why companies should invest in equipment which optimizes the management of black powder.
FILTER COSTS
Pipelines traditionally use disposable barrier or cartridge filters to address the problem. These require regular changes as they become blocked or in effective. This results in excessive replacement consumable filter costs, maintenance/labour costs and waste disposal costs.
PIPELINE EFFICIENCY
Black powder formation reduces the usable diameter of the pipeline thereby reducing flow and pressure. Expensive pipeline scraping is often required to address the problem.
ABRASIVE DAMAGE
Black powder is harder than typical carbon steel used to make pipelines and other components. This can mean it’s presence accelerates further erosion of the pipe wall. In addition, components such as compressors, meters, valves furnace nozzles etc can be damaged by abrasive wear or blocked by accumulation. This can result in inefficient operation, labour intensive cleaning or expensive parts replacement. For example something like an orifice meter may give inaccurate readings.
HEALTH & SAFETY
Black powder can be prone to combustion when in the powdered form. This means disposal of black powder contamination or contaminated filters is a long and costly process which requires specialist equipment and procedures.
Collected Contamination
Image courtesy of Air BP
Used Cartidges
CONTROLLING BLACK POWDER

There are many ways of trying to control black powder accumulation, traditionally membrane or barrier filters such as cyclones, separators, cone or basket strainers are used. However, they are generally limited in terms of particle size they can collect and are prone to reducing flow. They also use consumable filters which can be costly and incur expensive waste disposal costs. Disposing of consumable filters also has an environmental impact adding to pollution and landfill.

More recently, advances in in magnetic technology and enhanced understating of fluid flow dynamics have given rise to the development of high performance magnetic filters such as Ultrafiltrex, which extract sub-micron sized particles and do not rely on consumable components. 

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