Black Powder Removal from Transmission Pipelines Diagnostic & Solutions Lindsay McRae – Pall Australia Kaustubh P Chitale – Pall India

What is ‘Black Powder’? Generic word designating typically various forms of iron sulfide, iron oxide, iron carbonate Contaminants like sand, pipeline debris, liquid HC… can also be present Global phenomenon, potentially any kind of transmission lines (gas, condensate, LPG…) Formation due to internal reactions with steel: Chemical: internal corrosion in presence of water, acidic compounds (CO2 / H2S), oxygen Biological Presence of water inside pipelines due to condensation of water vapor, or due to process upsets

Consequences of presence of Black Powder Erosion of control valves Erosion of gas meters Erosion of pipelines Deposits inside compressors Fouling of instrumentation Operating issues at end users Complaints from end users etc… Erosion Damage on 12-Inch Control Valve Body (top) and Trim cage (bottom) (By Courtesy of a Middle East oil company)

Solutions for removal of Black Powder Possible approaches to overcome Black Powder issues: Elimination of root causes (moisture…) Internal pipeline coating Separation technologies

Solutions for removal of Black Powder Various solid/gas or solid/liquid separation technologies available on the market Typically usage of filters or cyclone separators But removing Black Powder efficiently is difficult ! Reality: Black Powder particles are very fine (typically <10-15µm) Nominal rated filters are not effective enough Cyclonic separators have limited removal performances, and efficiency drops with changes in operating conditions

Solutions for removal of Black Powder Black Powder particles are very fine (typically <10-15µm) (results from Pall site survey on condensate) (results from Pall site survey on gas) 10-15µm 18% 5-10µm 75%

Solutions for removal of Black Powder Nominal rated filters are not effective enough In practice, particles larger than the pores pass through nominal filters Absolute rated filters are recommended for a reliable and reproducible quality Source : “Principles of Filtration - Scientific & Technical Report WER 5300, Pall Corporation”

Diagnostic of Black Powder issues Selection of suitable solution requires a good understanding of the problem Characteristics of Black Powder Total Suspended Solids content (TSS) Particle Size Distribution (PSD) Root causes Nature (chemical composition) Scrutiny of process data (high dew point,…) or pipeline history Site survey capabilities and technical expertise can be proposed if lack of data

Diagnostic of Black Powder issues Site survey capabilities: Isokinetic sampling using portable membrane disc holder and isokinetic probe  collection of solid contamination

Diagnostic of Black Powder issues Site survey capabilities: Laboratory means to exploit field samples Optical microscopy Scanning Electron Microscopy X-ray analysis

Diagnostic of Black Powder issues In addition to experience, results of site survey may be useful for: selection of suitable locations for implementation, technologies and sizing better understanding of root causes of particles 10-15µm 18% 5-10µm 75%

Case Study Middle East plant receives natural gas from network Gas used as feedstock, requires compression stage, and as fuel gas 167000 Nm3/h, 40 barg, 45 degC Compressor and turbines protected by filter equipped with non-Pall nominal glass fiber pleated cartridges Vessel diameter 800mm, with 27 off filter elements Problems: Filter elements replaced every 1-2 days to 2 weeks Filter not able to handle design flowrate as clean DP almost max allowable Heavy deposits on compressor

Dry black sludge - Stored in drums Case Study Replacement of filter elements lead to very heavy maintenance Due to pyrophoric property of this Black Powder, filter vessel was filled with water, sludge drained from vessel and disposed of in drums Non-Pall filter elements Dry black sludge - Stored in drums

Case Study Pall proposal: replacement of existing nominally rated filters High dirt removal capacity, absolute rated, depth filter media technology (Pall ‘Coreless’) Pall supply: 2 filters (1 duty / 1 stand-by), ID 1280mm, equipped with 30 off Pall ‘Coreless’ cartridges each for Black Powder removal 2 liquid/gas coalescers (customer request), ID 950mm, equipped with 12 off Seprasol™ Plus cartridges each, for liquid removal Plant also purchased cyclones as pre-treatment stage, to implement upstream of filters

Pall ‘Coreless’ filters Case Study 6’’ Pall ‘Coreless’ filters 40’’

Case Study Plant commissioned Pall Filters and Coalescers without the upstream cyclone To date after 15 months of operation, Cyclone not been installed yet Since start-up Pall Filter has been operating at low DP (now ~400 mbar), and no change-out of cartridges since then All downstream equipment are fully protected, plant fully satisfied

Case Study After 6 months operation, client requested Pall to perform performance test On-line measurements carried out upstream & downstream Filter Upstream Pall Coreless filter Downstream Pall Coreless filter

Conclusion Black Powder particles are very fine Black Powder is difficult to remove efficiently Fine separation technologies are required to protect downstream equipment reliably Site survey capabilities are useful to understand the situation and to address the problem correctly

Thank you for your attention Any questions ? How to contact Pall : www.pall.com Copyright 2008 Pall Corporation, , and all Pall product names included in this presentation are trademarks of Pall Corporation. ® indicates a Pall trademark registered in the USA. Filtration. Separation. Solution SM is a service mark of Pall Corporation.