11 black powder removal from transmission pipelines diagnostic & solutions lindsay mcrae –...
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11
Black Powder Removal from Transmission Pipelines Diagnostic & Solutions
Lindsay McRae – Pall Australia
Kaustubh P Chitale – Pall India
© Pall Corporation, 2003© Pall India Pvt Limited 20102
• 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
What is ‘Black Powder’?
© Pall Corporation, 2003© Pall India Pvt Limited 20103
• 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…
Consequences of presence of Black Powder
Erosion Damage on 12-Inch Control Valve Body (top) and Trim cage (bottom)(By Courtesy of a Middle East oil company)
© Pall Corporation, 2003© Pall India Pvt Limited 20104
• Possible approaches to overcome Black Powder issues:
• Elimination of root causes (moisture…)
• Internal pipeline coating
• Separation technologies
Solutions for removal of Black Powder
© Pall Corporation, 2003© Pall India Pvt Limited 20105
• 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
© Pall Corporation, 2003© Pall India Pvt Limited 20106
• Black Powder particles are very fine (typically <10-15µm)
Solutions for removal of Black Powder
5-10µm75%
10-15µm18%
(results from Pall site survey on condensate)
(results from Pall site survey on gas)
© Pall Corporation, 2003© Pall India Pvt Limited 20107
• 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
Solutions for removal of Black Powder
Source : “Principles of Filtration - Scientific & Technical Report WER 5300, Pall Corporation”
© Pall Corporation, 2003© Pall India Pvt Limited 20108
• 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
© Pall Corporation, 2003© Pall India Pvt Limited 20109
• Site survey capabilities:
Isokinetic sampling using portable membrane disc holder and isokinetic probe
collection of solid contamination
Diagnostic of Black Powder issues
© Pall Corporation, 2003© Pall India Pvt Limited 201010
• Site survey capabilities:
Laboratory means to exploit field samples
• Optical microscopy
• Scanning Electron Microscopy
• X-ray analysis
Diagnostic of Black Powder issues
© Pall Corporation, 2003© Pall India Pvt Limited 201011
• 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
Diagnostic of Black Powder issues
5-10µm75%
10-15µm18%
© Pall Corporation, 2003© Pall India Pvt Limited 201012
• 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
Case Study
© Pall Corporation, 2003© Pall India Pvt Limited 201013
• 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
Case Study
Non-Pall filter elements Dry black sludge - Stored in drums
© Pall Corporation, 2003© Pall India Pvt Limited 201014
• 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
Case Study
© Pall Corporation, 2003© Pall India Pvt Limited 201015
Case Study
Pall ‘Coreless’ filters
6’’
40’’
© Pall Corporation, 2003© Pall India Pvt Limited 201016
• 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
© Pall Corporation, 2003© Pall India Pvt Limited 201017
Upstream Pall Coreless
filter
DownstreamPall Coreless
filter
• After 6 months operation, client requested Pall to perform performance test
• On-line measurements carried out upstream & downstream Filter
Case Study
© Pall Corporation, 2003© Pall India Pvt Limited 201018
• 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
Conclusion
© Pall Corporation, 2003© Pall India Pvt Limited 201019
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.
Thank you for your attentionAny questions ?
How to contact Pall : www.pall.com