Chemical process debottlenecking

1. CHEMICAL PROCESS DEBOTTLENECKING AICHE PHILADELPHIA 14 NOVEMBER 2016 CONTENT REFLECTS MY OWN VIEWS, NOT THOSE OF MY EMPLOYER, ARKEMA

2. OUTLINE  DEBOTTLENECK BACKGROUND  ASSESSMENTS– where’s your problem?  CURRENT PRODUCTION LOSSES  CURRENT VS FUTURE UNIT CAPACITIES  CURRENT PROCESS CAN BE SIMPLIFIED?  DEBOTTLENECK TRICKS AND TRAPS  SOLUTIONS – INCREASE EQUIPMENT CAPACITY  INCREASE EQUIPMENT CAPACITY  PROCESS SIMPLIFICATION  Out of scope: intensification, new technologies, advanced control  PROJECT MANAGEMENT FOR DEBOTTLENECK (REVAMP) PROJECTS 2

3. OUTLINE  DEBOTTLENECK BACKGROUND  ASSESSMENTS - where’s your problem?  CURRENT PRODUCTION LOSSES  CURRENT VS FUTURE UNIT CAPACITIES  TRICKS AND TRAPS  SOLUTIONS  INCREASE EQUIPMENT CAPACITY  PROCESS SIMPLIFICATION  PROJECT MANAGEMENT FOR DEBOTTLENECK (REVAMP) PROJECTS 3

4. ECONOMIC AND BUSINESS CLIMATE SUPPORT DEBOTTLENECKING.  Plants are running maxed out  Business capacity demands can be incremental, uncertain or insufficient to justify new plant.  Increased competition and modest market growth.  Tight economic times, especially post- recession, make big spending difficult.  Smaller-capacity plants not economical. 4

5. 30-YEAR OLD WISDOM  “Get more from what we have,” by upgrading existing facilities instead of building new  Still true after 30 years! L. Cabano, ChemE Progress (1987)“Retrofit Projects – the ultimate management challenge” 5

6. Background debottleneck.  Debottleneck =improvements to specific parts of a plant to increase production by relieving limitations.  Debottlenecking is playing “Moneyball” – Get more production with smart data and experience, not necessarily by spending a lot or “buying a new one.”  Limitations to overcome. Define your problem. 1. Production Losses 2. Process capacity 6

8. Know your current production limitations?  Define your real problem. How can you really get more production?  Eliminate Losses (Opportunities)  Planned downtime  Reliability of units  Availability of resources – internal and external  Performance - how closely and frequently we run relative to the Instantaneous, sustainable process capacity  Quality losses  Transitions  Increase instantaneous capacity 8

9. OEE -operational equipment effectiveness (Williamson 2006)  A 6-Sigma and TPM (total productive maintenance) concept. Variants are TEEP (Total Effective Equipment Performance) OAU (operational asset utilization) 9 Can do with “pounds lost”, instead of ”time lost.”

10. OEE Definitions  OEE is a “batting average” comprised of component batting averages.  OEE % : Availability % x Performance efficiency % x Quality rate %  Availability: (Actual operating time ÷ Gross available time) x 100%  Performance efficiency: (Actual production rate ÷ Design production rate) x 100%  Quality rate: ((Total produced – Off-spec) ÷ Total produced)) x 100 %  Can add other “batting averages” for transitions 10

11. Pareto your losses determine where improvements are needed 11 16.0 5.0 3.0 1.0 0.0 5.0 4 3 1 1 0 2 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Equipment- Extruder/Drive System Equipment- Feeders Process Interuption Equipment- ScreenPack Equipment- Utilities Other LOSSES(hours) EXTRUSION LINE MAIN AVAILABILITY LOSSES Hours Incidents

12. OUTLINE  DEBOTTLENECK BACKGROUND  ASSESSMENTS - where’s your problem?  CURRENT PRODUCTION LOSSES  CURRENT VS FUTURE UNIT CAPACITIES  TRICKS AND TRAPS  SOLUTIONS – INCREASE EQUIPMENT CAPACITY  PROJECT MANAGEMENT FOR DEBOTTLENECK (REVAMP) PROJECTS 12

13. ASSESS CAPACITY BOTTLENECKS – BATCH PROCESSES  Talk to the operators for clues  Theory of Constraints (“The Goal,” by Goldratt.)  WIP (work in process) accumulates just ahead of the bottleneck unit.  WIP is scarce downstream of the bottleneck.  Time studies on existing process phases. Collect data on durations of phases of a batch process.  Gantt charts (MS project)to depict constraints for batch processes. (Critical path).  Software such as Intelligen, SchedulePro® batch software 13

14. MAP PROCESS UNITS TIMES (Petrides 2007) 14

15. GANTT gives bottleneck critical path (Petrides 2007) 15

16. EQUIPMENT UTILIZATION SHOWS BOTTLENECKS (Petrides 2007) 16

17. ADD CRITICAL EQUIPMENT TO DEBOTTLENECK (Petrides 2007) 17 Cycle Time Reduced 13%

18. ASSESS CAPACITY BOTTLENECKS – CONTINUOUS PROCESSES  Talk to the operators for clues  Aspen or other simulator- to check for bottlenecks when unit ops are well understood.  Certain things can’t be predicted by simulators, Fouling behavior. Catalyst activity.  FRI rating program for distillation towers  Well-designed test runs, under representative conditions. (Texas summer versus winter, for cooling). 18

19. Beware of tricks/traps in assessing bottlenecks I.  Hydraulics - Line sizes, Pumps and pump suction conditions (NPSH)  Powder handling systems, including pneumatic conveying systems  Bottlenecks can be right behind each other.  Story moment: Spray dry dryer was bottlenecked by performance of rotary atomizer. Replaced it and found that pneumatic conveying system downstream was limiting, right away. 19

20. Beware of tricks/traps in assessing bottlenecks II.  Assess your Quality – check the quality required by your customer . Sometimes relaxing quality can get more capacity.  Story moment: water level in a product.  Organic product was dried in process by molecular sieves which were a bottleneck. It had a very low water level specification, to avoid freezing problems in cold weather applications.  All customers had shifted to use in warm locations on US Gulf Coast.  Water level spec was then relaxed with customer approval, eliminating process bottleneck. 20

21. Beware of tricks/traps in assessing bottlenecks III. (Jaafar 2005)  Use Gamma ray scans to assess distillation tower performance 21

22. Gamma-ray scans of towers 22 Liquid level on trays Distillation tower loading: Gamma-ray scans of towers are very helpful. (Jaafar 2005)

23. Gamma-ray scans of towers 23 Liquid level on traysJaafar 2005)

24. Summarize unit capacities – where are the bottlenecks? (Litzen, Bravo 1999) 24

26. INCREASING CAPACITY I. - EQUIPMENT  Pumps – sometimes one can replace an impeller in centrifugal pumps. Trap: Check motor hP and NPSH first!!!  Heat exchangers - Larger, more plates, corrugated tubes, twisted tubes Trap: If upsizing diameter to get more A, we can reduce shell side velocity and U.  Powder processing – vibrating bottom bins. Steeper bin walls, larger vessels, mass Flow screws. Story moment: powder feed system for extrusion was under producing. Cohesive powder being fed through 2” bin outlet, 60º angle walls. Increased to 6” with 70º angle, solved problems 26

27. INCREASING CAPACITY II. - REACTIONS  Catalyst modification in catalytic reactors for improved yield, or selectivity (check tosca)  Increasing active concentration in batch reactions. Story moment: emulsion polymerizations, story time, increase capacity 60% by increasing emulsion activity from 25% to 40%.  Use a separate post treatment vessel, for example to scavenge residual reactant or to wash out impurities. 27

28. INCREASING VACUUM DISTILLATION TOWER CAPACITY (from Fair 1996) 28 Stepwise debottlenecking of trays operating at low pressure Action Advantages Disadvantages Increase pressure More capacity No column changes Lower relative volatility Higher temperatures Decrease hole size More capacity New tray panels Change style of tray (e.g., to Nye, MD=multiple downcomer) More capacity New tray panels Possible downcomer modifications Possible increase in # of trays and support rings Switch to structured packing More capacity, if larger height Lower pressure drop Cost of packing and attendant hardware Cost of removing trays and tray rings Install new high-capacity device (e.g., cocurrent tray) More capacity Higher pressure drop Cost of new device Cost of removing old trays and possibly tray rings

29. INCREASING PRESSURE DISTILLATION TOWER CAPACITY (Fair 1996) 29 Stepwise debottlenecking of trays operating at high pressure Action Advantages Disadvantages Enlarge downcomers and increase open area More capacity Loss of active area Cost of modifications Change style of tray (e.g., to MD) and decrease tray More capacity Lower efficiency; need more Cost of new trays Cost of removing old trays and some tray rings Switch to larger-size structured packing More capacity Lower efficiency Costs of removing and replacing packing Install new high-capacity device More capacity Higher pressure drop Cost of new device Cost of removing old device

30. IMPROVED PROCESS CONTROL  Shorten transitions  Stabilize process & operate closer to our capacity limits  Operate closer to our quality limits 30

31. Further equipment debottleneck modes (Rangaiah 2016) 31 Equipment/System Debottleneck mode Pneumatic system - increase capacity Change air velocity, air-to-solid ratio, blower speed, screw or rotary valve speed Centrifugal compressors Modify internals, including rotor; increase Conveying fans Install bigger impeller and/or additional fans in parallel. Reduce pipe/duct pressure losses Fin-Fan coolers Increase fan pitch angle and/or fan speed, reduce tip clearances, install inlet bells, fan seal disk and/or high Mixers Use static mixers or high-shear rotary disperser to retrofit/replace existing tank mixers. Vacuum systems Install pre-condensers cooled with cooling/chilled water. Use multi-stage steam ejectors arranged in series/series- parallel arrangement.

33. Process Simplification  Ways to simplify process, using ingenuity with minimal technology risk?  Can challenge the accepted norms?  Parallel reactor usage, instead of series. Story moment: Two reactors in series for polymer line converted to parallel, doubled plant capacity for very low investment. 33

34. 34 Reactor 1 Conversion Monomer 2 Monomer 1 Initiator Continuous flow reactors in series Reactor 2 Residual scavenging Radical Scavenger Devolatilizer Reactor 1 Monomer 1 Initiator + Scavenger Reactor 2 Devolatilizer Monomer 2 Continuous flow reactors in parallel Doubled Production by Putting 2 Polymer Reactors in Parallel Instead of Series

35. INCREASING CAPACITY IIIa.- Feeds 35 BATCH POWDER BLENDER Powder 1 Powder 2 Liquid ingredient Batch feed Single Screw Extruder Manual loading to powder blender Pharmaceutical dispersion made from single screw extrusion, melting down and making micro droplets out of a powder blend. Team replaced the 2 step operation by a single-step compounding and meltdown in a twin screw extruder.

36. INCREASING CAPACITY IIIb.- Feeds 36 Twin Screw Extruder Continuous feed to extruder Mass flow powder feed Powder 1 Mass flow powder feed Powder 2 Liquid pump Liquid Ingredient Eliminate powder blender. Use Twin-screw, doubled capacity and improved quality & ergonomics

38. What’s different about debottleneck projects? I.  Debottleneck projects build onto/into all the sins of the past.  Heavy dependence on accurate facility data for existing plant.  Requires extensive field verifications of what’s in the plant (drawings, manuals, specifications and performance histories). But! Sometimes our surveys can’t access easily what’s already there, OR it’s under insulation.  Need to have good drawings, PIDs, ISO drawings. Most plants don’t have them up to date. Need a budget for this prework!  Laser scans of piping can be useful. (Image from PTQ) 38

39. Laser scanning of piping (Smith 2015) 39 SCAN THE PLANT CONVERT POINT CLOUD INTO 3D MODEL

40. What’s different about debottleneck projects? II.  The existing plant is a stakeholder. Heavy dependency on cooperation with existing plant leadership, and their production plan.  Usually the work is constrained to a short period. If performing work during an overall plant shutdown, integrate the work into an overall project plan for the plant’s work.  Budget for plant staff time in the project – it’s extensive.  Budget for staff, time, budget and responsibilities for pre-cleaning the equipment. Account for any waste disposal.  Budget & plan for inclusion of the modifications into existing plant’s IT systems and databases, such as maintenance and mechanical integrity. 40

41. Debottleneck Project Traps I.  Be sure to define a good owner scope agreement, detailing what plant problems WILL be fixed and what WON’T.  If adding a new unit, will you fix the problems with the old one?  Will you demolish or mothball in place?  Constructibility studies are key. Piping, utilities conflicts, safety (working near other work), available space, laydown areas, use of existing foundations.  3D CAD models are indispensable for revamp projects 41

42. Debottleneck Project Traps II.  Be wary of condition od existing, mothballed equipment. Plant may say “we have another one available.”  Cleaning, MI inspection  Check last performance.  Budget for the above  Lots of carbon steel out there; modification can be difficult.  Story moment: Carbon steel, versus stainless steel in new lines. Carbon steel was cheaper, but with the pre and post-weld heat treatment needed, it cost more in these services and delays waiting.  Pipe replacements go flange to flange when possible. Modification of vessels can take time:  Rerating vessels for new conditions takes time.  Code approvals for modifications also require time. 42

43. Debottleneck Project Traps III.  Harder to estimate cost.  No simple costing “rules of thumb,” such as 4x to 8x major equipment cost  More contingency.  More engineering, per $ of capital cost.  Add productivity allowances for labor, in such projects.  Add allowances (in cost and schedule) for field adjustments and fit-up.  Check everything and communicate the scope well to your EPC. 43

44. Scope must include OSBL and HES  Utilities - water, air, steam, and probably most important electrical power.  Include logistics and packaging, storage, filling systems.  Check your environmental permitting implications for the new capacity! Incorporate into the project plan.  Enviro abatement systems need to be checked.  Safety systems need to be checked. Reliefs need to be checked. Watch you’re not operating too closely to relief points and rupture discs burst points. (Rupture pin, instead of disc, can be useful)  Facility siting (safety) studies, if adding new storage.  Story moment: OSHA auditee was required to show all past capacity increases and show verifications that the relief valves were checked each time. 44

45. DISCUSSION AND QUESTIONS 45

46. REFERENCES and Further Reading Joseph C. Gentry, Succeed at Plant Debottlenecking, Chemical Processing, Mar 10, 2004. A basic introduction with specific examples. S. Ottewell, Debottlenecking Takes A Broader View, Chemical Processing, April 18, 2011. Treats use of simulation. Hans-Jürgen Bittermann, Dr. Jörg Kempf, Debottlenecking: Exploiting Opportunities to Boost Performance, Process Worldwide.com, 10/17/2014, downloaded 24 Sept 2016. D .F. Schneider, Debottlenecking Options and Optimization, white paper of 1997, downloaded 24 Sept 2016. Manganaro, J. L. Estimate the Capacity of Simple Batch Processes. Chemical Engineering Progress, 98(8): 70-75, August 2002. GP. Rangaiah, Chemical Process Retrofitting and Revamping, Wiley, 2016. N. P. Lieberman, Process Engineering for a Small Planet, Wiley 2010. Litzen and Bravo, “Uncover low-cost debottlenecking opportunities,” CHEMICAL ENGINEERING PROGRESS • MARCH 1999 L. J. Cabano, Retrofit projects: the ultimate management challenge, Chemical engineering progress, 1987, vol. 83, no 4, pp. 27-31 Fair, J. R., and A. F. Seibert, “Understand Distillation-Column Debottlenecking Options,” Chemical Engineering Progress, 92, (6), p. 42 (June 1996). Seiichi Nakajima, “Introduction to TPM and TPM Development Program,” Japan Institute for Plant Maintenance 1988. Translated into English, Productivity Press, ShopFloor Series, called “OEE for Operators.” Pablo F. Navarrete, William C. Cole, Planning, Estimating, and Control of Chemical Construction Projects, Second Edition, CRC press, 2001 Distillation-How to Push a Tower to Its Maximum Capacity: Proper analysis and operating adjustments help boost separation capacity without increasing flooding, Simon X. Xu, Charles Winfield, John D. Bowman Tru-Tec Services, Inc.; Shelley, Suzanne. Chemical Engineering105.8 (August, 1998): 100. G. Towler, R. Sinnott, Chemical engineering design : principles, practice, and economics of plant and process design, 2nd ed., Elsevier (2013) D. H. Stamatis, “The OEE Primer: Understanding Overall Equipment Effectiveness, Reliability, and maintainability” CRC Press, 2010. R. Ogle and A. Carpenter, Chemical Engineering Progress August 2014, Calculating the capacity of chemical plants. Al-Zahrani; Bright, S; Roy, E; S.. Debottleneck crude-unit preheat exchanger network inefficiencies.Hydrocarbon Processing (Feb 2012). M. Smith, Laser scanning for revamps, PTQ, 39-43, 2015 Petrides et al, “OPTIMIZE MANUFACTURING OF PHARMACEUTICAL PRODUCTS WITH PROCESS SIMULATION AND PRODUCTION SCHEDULING TOOLS,” Chemical Engineering Research and Design Trans IChemE, Part A, July 2007 Jaafar, HYDROCARBON ASIA, JAN/FEB 2005, “Gamma-ray scanning for troubleshooting,….” M. Smith, “Laser Scanning for Revamps” PTQ 2015 46

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