chemical process debottlenecking

CHEMICAL PROCESS DEBOTTLENECKINGAICHE PHILADELPHIA 14 NOVEMBER 2016

CONTENT REFLECTS MY OWN VIEWS, NOT THOSE OF MY EMPLOYER, ARKEMA

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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)

PROJECTSAICHE Phila, 14 November 2016. Content reflects author’s views, not those of Arkema Inc

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AICHE Phila, 14 November 2016. Content reflects author’s views, not those of Arkema Inc3

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

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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.

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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”

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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 Losses2. Process capacity

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AICHE Phila, 14 November 2016. Content reflects author’s views, not those of Arkema Inc

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

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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)

Can do with “pounds lost”, instead of ”time lost.”

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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

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Pareto your losses determine where improvements are needed

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OUTLINE

DEBOTTLENECK BACKGROUND ASSESSMENTS - where’s your problem?


TRICKS AND TRAPS SOLUTIONS – INCREASE EQUIPMENT

CAPACITY PROJECT MANAGEMENT FOR

DEBOTTLENECK (REVAMP) PROJECTS

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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

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MAP PROCESS UNITS TIMES (Petrides 2007)

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GANTT gives bottleneck critical path (Petrides 2007)

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EQUIPMENT UTILIZATION SHOWS BOTTLENECKS (Petrides 2007)

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ADD CRITICAL EQUIPMENT TO DEBOTTLENECK (Petrides 2007)

CycleTime Reduced13%

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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).

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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.

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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.

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

performance

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Gamma-ray scans of towers

Liquid level on trays

Distillation tower loading: Gamma-ray scans of towers are very helpful.

(Jaafar 2005)

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Gamma-ray scans of towersLiquid level on trays(Jaafar 2005)

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

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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

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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.

INCREASING VACUUM DISTILLATION TOWER CAPACITY (from Fair 1996)

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Stepwise debottlenecking of trays operating at low pressureAction Advantages DisadvantagesIncrease pressure More capacity

No column changesLower relative volatilityHigher temperatures

Decrease hole size More capacity New tray panelsChange style of tray (e.g., to Nye, MD=multiple downcomer)

More capacity New tray panelsPossible downcomer modificationsPossible increase in # of trays and support rings

Switch to structured packing

More capacity, if larger crimp heightLower pressure drop

Cost of packing and attendant hardwareCost of removing trays and tray rings

Install new high-capacity device(e.g., cocurrent tray)

More capacity Higher pressure dropCost of new deviceCost of removing old trays and possibly tray rings

INCREASING PRESSURE DISTILLATION TOWER CAPACITY (Fair 1996)

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Stepwise debottlenecking of trays operating at high pressureAction Advantages DisadvantagesEnlarge downcomers and increase open area

More capacity Loss of active areaCost of modifications

Change style of tray (e.g., to MD)and decrease tray spacing

More capacity Lower efficiency; need more traysCost of new traysCost of removing old trays and some tray rings

Switch to larger-size structured packing

More capacity Lower efficiencyCosts of removing and replacing packing

Install new high-capacity device

More capacity Higher pressure dropCost of new deviceCost of removing old device

IMPROVED PROCESS CONTROL

Shorten transitions Stabilize process & operate closer to our

capacity limits Operate closer to our quality limits

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Further equipment debottleneck modes (Rangaiah 2016)

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Equipment/System Debottleneck modePneumatic system -increase capacity

Change air velocity, air-to-solid ratio, blower speed, screw or rotary valve speed

Centrifugal compressors

Modify internals, including rotor; increase speed

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/replaceexisting tank mixers.

Vacuum systems Install pre-condensers cooled withcooling/chilled water. Use multi-stage steam ejectors arranged in series/series- parallel arrangement.

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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.

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Reactor 1Conversion

Monomer 2

Monomer 1

InitiatorContinuous

flow reactors in series

Reactor 2Residual scavenging

Radical Scavenger

Devolatilizer

Reactor 1

Monomer 1

Initiator + Scavenger

Reactor 2

Devolatilizer

Monomer 2

Continuous flow reactors

in parallel

Doubled Production byPutting 2PolymerReactors in Parallel Instead of Series

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INCREASING CAPACITY IIIa.- Feeds

BATCH POWDER BLENDER

Powder 1

Powder 2

Liquid ingredient

Batch feedSingle 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.

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INCREASING CAPACITY IIIb.- Feeds

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

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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)

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Laser scanning of piping (Smith 2015)

SCAN THE PLANT

CONVERT POINT CLOUD INTO 3D MODEL

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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.

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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

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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.

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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.

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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.

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DISCUSSION AND QUESTIONS

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REFERENCES and Further ReadingJoseph 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 1999L. J. Cabano, Retrofit projects: the ultimate management challenge, Chemical engineering progress, 1987, vol. 83, no 4, pp. 27-31Fair, 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, 2001Distillation-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, 2015Petrides et al, “OPTIMIZE MANUFACTURING OF PHARMACEUTICAL PRODUCTS WITH PROCESS SIMULATION AND PRODUCTION SCHEDULING TOOLS,” Chemical Engineering Research and Design Trans IChemE, Part A, July 2007Jaafar, HYDROCARBON ASIA, JAN/FEB 2005, “Gamma-ray scanning for troubleshooting,….”M. Smith, “Laser Scanning for Revamps” PTQ 2015

http://www.process-worldwide.com/debottlenecking-exploiting-opportunities-to-boost-performance-a-299052/index2.html

http://www.stratusengr.com/Articles/DebottleOptions.pdf