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Plant Operation. Christian Ziegler Olefin Academy 2010, Munich. Content. Definition of tasks and terms Precommissioning Commissioning Start-Up - Concepts - Special Equipments Operation Summary. Definition of tasks and terms. Commissioning
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Plant Operation Christian Ziegler Olefin Academy 2010, Munich
Content • Definition of tasks and terms • Precommissioning • Commissioning • Start-Up - Concepts - Special Equipments • Operation • Summary
Definition of tasks and terms Commissioning Operation of permanent equipment at conditions similar or equal to normal service (before start-up of the entire plant) Operation • Operations are those ongoing recurring activities involved in the running of a plant for the purpose of producing product Start-up Ready for Commissioning “ON-SPEC” Product Plant Acceptance Commissioning Start-up Operation Construction Time Line Trouble Shooting Precommissioning Mechanical Completion Left Open Work Design Rate Performance Test
Definition of tasks and terms Mechanical Completion (MC) Defined status of the plant or a part of it which implies and confirms readiness for commissioning activities or use (in case no commissioning activities are required). Mechanical Completion requires completion of construction and pre-commissioning activities for all disciplines. Handover System (HOS) Interconnected utility or process system which will be handed over to the commissioning after mechanical completion and pre-commissioning.
Content • Definition of tasks and terms • Precommissioning • Commissioning • Start-Up - Concepts - Special Equipments • Operation • Summary
Precommissioning Concept • Precom. schedule will be planed backwards from RFC (ready for commissioning) • Bring systems to RFC, commission and use them for other precom. activities • In close contact with construction • Based on HOS • Manpower planning
Precommissioning Main Activity Blowing and drying of cold section with CGC (Cracked Gas Compressor) Instrument Air Regeneration etc. PRECOMMISSIONING COMMISSIONING Fuel Gas CGC BFW Boiler COLD SECTION AIR BLOWING Steam System DRYING Seal Gas Lube Oil Cooling Water
Precommissioning Main Activity Drying of furnace refractory • Fuel Gas • MP-Steam (Process Steam) • Instrument Air • BFW (Demin Water)
Precommissioning Cupper target with and without hits from VHP blowing Task - Overview • Air Blowing • Drying • Rupture Blowing • Steam Blowing • Water Flushing • Cycling • Pickling • Chemical Cleaning • Function Test • Test Run • Leak Test
Precommissioning • General Points • Project specific definition of milestones • Change of work tasks from construction to operation • Change in construction philosophy (i.e. construction area -> HOS) • HSE to be involved (new or different work tasks for this site) • Clear responsibilities and working with HOS to be established • Connections to up- and downstream plants to be established • Lock Out/Tag Out-System to be established • Operation to be involved in the permit system
Content • Definition of tasks and terms • Precommissioning • Commissioning • Start-Up - Concepts - Special Equipments • Operation • Summary
Commissioning • General Points - Task Overview • Inertizing of plant • Introduction of hydrocarbons • Intended operation of systems • Operation of Cracked Gas Compressor for dryout • Operation of utilities as Steam-, Fuel Gas- and Cooling Water System • Start-up of Flare System • etc.
Commissioning • General Points - Aspects • Hand Over from construction to operation • Inertizing of plant • HSE alert • Drastic change of working conditions • Confined space entire, etc. • Concepts for initial start up • Filling of hydrocarbons • Liquid or gaseous • Availability and amounts • Alternatives (Ethane for Ethylene, Propane for Propylene, Naphtha for Pyro. Oil ) • Impurities (Sulfur, H2S, CO, CO2, Arsenic) • Composition (unsaturated hydrocarbons, catalyst requirements, pour point)
(C) (C) (C) 5 3 PC Turbine CW Supply CW Return M M M 1 Condenser 6 4 Flare 2 M TC TC TC 5 Propane or Propylene Suction Drum Suction Drum Suction Drum 7 LI Collecting Drum 7 7 LC LC LI 2 Tail Gas Consumer Consumer Consumer Subcooler Tail Gas 5 Propane or Propylene Commissioning • Introduction of Hydrocarbons - example filling of C3 Refrigerant Cycle
Commissioning • Introduction of Hydrocarbons - example filling of C3 Refrigerant Cycle • Condensers are filled with cooling water (CW) and in service. • Cycle is lined up (consumer inlets are closed, outlets are open, motor operated valves in suction and kickback lines are open). • Turbine/Compressor is prepared according to vendor instructions (Seal Gas System, Lube Oil System, etc.). Be aware that rotor may rotate during filling. • Nitrogen gets released to flare (PSV bypasses, inert vents). • Route liquid Propane or Propylene into the collecting drum. If line is available, route additional liquid to the 2nd stage suction drum. The liquid will vaporize and pressurize the system (<5 barg). Avoid to build up liquid in any drum. • Pressurize and depressurize (PDP) the cycle 3 times to flare and take a sample (<1%vol N2). • Fill liquid into the collecting, suction drums (exclusive 1st stage) and liquid lines. • Important: For a detailed description refer to the related operating manual and the operating manual of the turbine/compressor vendor. The vendor documentation is authoritative.
Commissioning • Introduction of Hydrocarbons - example filling Ethan Evaporator Gaseous Ethane 21 bar 60 °C Ethane Evaporator Start-Up Evaporator Start-Up Line 25 bar 0 °C Liquid Ethane
Content • Definition of tasks and terms • Precommissioning • Commissioning • Start-Up - Concepts - Special Equipments • Operation • Summary
Start-Up – Concepts • Concepts - General • Project specific and individual concept for each olefin plant • Influenced from • Feedstock • Process design • Client philosophy • Environmental laws/local laws • Project (revamp or new plant) • Special equipments • Requirements • Safe • Quick • Low effort • Use of available sources (i.e. Ethane instead of Ethylene for filling) • Low emissions
Start-Up - Concepts • Linde Concept - General The Linde start-up concept aims for minimizing the flaring activitiesin the start-up process. It considers: • Minimization of cracking furnaces with hydrocarbon load • Provision of recycle lines • Application of nitrogen cool-down • Reprocessing / intermediate storage • Training for operator personnel for special start-up operation conditions • Interconnection of different plants (if possible)
Feed Preheating/-treatment Process Steam Wash Water C3/C4 Sep. CGC Furnaces Boiler and Steam System C3 Refrigerant Precooling Utilities (i.e. BFW, Instr. Air) C2H4/C2H6 Separation C2/C3 Sep. C2H4/C2H6 Separation C2 Hydrog. C2 Refrigerant C1/C2 Sep. Cold Train Start-Up - Concepts • Start-Up Sequence • Example Ethan Cracker C3+ 3 C2H4 1 Time FEED IN 2 Machine Sequence X
Start-Up - Concepts • Low Load • Trend to increased plant capacities • Less flexible • Upstream plants to produce more (utilities , feed) • Downstream plants to consume more • Special measures to be foreseen • Design of equipments to be considered (e.g. min. load of trays) • New, additional or higher minimum flows (piping, control valves etc.) • Process Design/Functionality • Operation to be stabilized, process conditions may change • Partly new set points for controllers required (tuning parameters, auto function, cascade control) • Mainly cold section including CGC (Steam System) is influenced • Hot section/furnaces can handle bigger variations
Start-Up - Concepts • Reduced Flaring • Environmental aspects, like CO2 and emission reduction • Commercial aspects, like loss of product and feedstock • Operation aspects, like increase of flexibility and plant safety • Reputation aspects
Ethane Recycle Feed Ethylene Min. Flow Tail Gas Min. Flow Tail Gas Min. Flow C2- Fraction Furnaces Oil and Water Quench Cracked Gas Compression Precooling Drying C2/C3 Separation C2 Hydrogenation Cold Train Demethanizer C2H4/C2H6Separation C2- Process C2H4/C2H6Separation Steam C2- Fraction C2- Fraction H2 Tail Gas Pyrolysis C4 Fraction Start-up Oil C3+ C3/C4 Separation C4/C5 Separation Pyrolysis C3 Fraction Start-up Ethylene Gasoline C4 Fraction C5 Fraction C3H6/C3H8 Separation Propane Recycle C3H6 Start-Up - Concepts • Low Load / Reduced Flaring
Start-Up - Concepts • Low Load / Reduced Flaring - Principle • Allowing to perform the plant and the dedicated process units on minimum load, by using recycle and start-up lines • Key points • Cracked gas composition stable and within design range (only tail gas or C3 recycling is not helpful) • Mass balance needs to be considered • Start-up lines to produce “on-spec” streams by reduced flaring (i.e. C2- fraction for start-up of C2 hydrogenation) • Utilities consumptions to be considered, i.e. • Less furnaces producing less steam -> increased boiler load or import
Start-Up - Concepts • Nitrogen Cool Down • Cold Section is cool down by using N2 • Advantages • Reducing of flaring time during Start-Up • Reducing time from feed-in to onspec production • Leak Test under process conditions (low temperature, high pressure) • Operation team gets familiar with the plant • Needs to be consider in the design for equipment, i.e. • Cracked Gas Compressor (CGC), Dryers, Plate Fin Heat Exchangers • Additional cooling down and supply lines required to allow cycling of N2 • Critical steps, like starting CGC (steam and N2 consumption) and replacement of N2, to be planed and considered properly by operation team
Expander-Booster I Expander-Booster II Cold Train 1.-3. Stage CGC 4.-5. Stage CGC C2 Refr. Ethane Recycle Demethanizer Flare Drier Flare CW Quench Tower C2 C3 Refrigerant Furnaces (HSSB) C2+ Guard Drier N2 Make-Up Flare Reg.-Gas C3 Adsorber Hydrogenation Fuel gas/Flare Start-Up - Concepts • N2 Cool Down C3 Refr.
Start-Up - Concepts • Comparison • Liquid Cracker • Hot Section • Cold Section • Warm Section • Utilities (individual for each plant) • Gas Cracker
Start-Up - Concepts • Liquid / Gas • Hot section of liquid cracker is more complex • Commissioning activities, like filling and warming up, for oil fractionation unit including cracked gas line • Interconnection of quench oil cycles via heat exchangers for good energy efficiency, i.e. process steam generation partly with Quench Oil • Cold section of liquid cracker has to handle higher amount of tail gas • Different setup of Cold Train, C2 Absorber and Demethaniser (no expander-booster required to generate chilling duty) • Warm section of liquid cracker has to handle higher amounts of C3+ • As higher amounts of gasoline is available, the product range is extended • Commissioning activities, like filling, for hydrogenations • Licensor packages, like Butadiene and Benzene Extraction, can be included • The start-up concept for a liquid cracker has to consider an extended process and more interconnections between the plant sections
Start-Up - Concepts • Liquid Cracker – Quench Oil
Content • Definition of tasks and terms • Precommissioning • Commissioning • Start-Up - Concepts - Special Equipments • Operation • Summary
Start-Up – Special Equipment • Plate-Fin Heat Exchangers • Hazard Analysis (HAZAN) • Investigation of operating scenarios • Influences to control and operating procedures • Cooling down/warming up rate to be considered (i.e. 6K/min or 60K/h) • Maximum allowable differential temperature to be considered, i.e.
Start-Up – Special Equipment 7 4 • Fixed Tube Heat Exchangers • Hazard Analysis (HAZAN) • Investigation of operating scenarios • Influences to control and operating procedures • Warm Up, risk to bulge tubes • Mandatory to warm up shell side first • Open the upper vent valve on the shell side exchanger. • Open the key locked valve in the vapour line between the reboiler and the column and lock it open. • With the free key from the valve in the vapour line between the reboiler and the column, unlock the steam inlet block valve and open it. The condensate outlet block valve of the reboiler remains closed. Slightly open the bypass around the steam inlet control valve. • Fill-up the shell side of the reboiler with condensate until condensate flows out of the vent valve to atmosphere. • Close the vent valve on the reboiler’s steam side. • Open slowly the block valve in the liquid line between column and reboiler and fill the reboiler up with liquid from the bottom of the column. • Take normal steam supply control into operation. • Slowly lower the steam condensate level in the reboiler by opening the condensate outlet valve. 3 2 1,4,5 8 6
Start-Up – Special Equipment • Turbine/Compressor • Steam System to be prepared for big consumer (coordination with utility section/plant) • Vendor instructions to be followed, i.e. • Lube Oil, Seal Gas, Sealing Steam • Warm up of turbine, turning gear • Cold start/warm start curves • Machine monitoring system
Start-Up – Special Equipment • CGC (Cracked Gas Compressor) • Air Run during precommissioning • BFW-/Wash-Oil-Injection for fouling migration, corrosion protection and temperature adjustment • Condensation System
Content • Definition of tasks and terms • Precommissioning • Commissioning • Start-Up - Concepts - Special Equipments • Operation • Summary
Operation • Organization Plant Manager Fire Station Technology Department Projects Revamps Turn-arounds Maintenance Engineer Process Engineer Process Engineer Maintenance Engineer Process Engineer Process Engineer Maintenance Maintenance Engineer Maintenance Engineer Maintenance Engineer Senior Shift Supervisor Shift Supervisor Shift Supervisor Senior Shift Supervisor Shift Supervisor Shift Supervisor Workshop Storage Laboratory Shift I, II, III and IV Shift I, II, III and IV Cold Section Warm Section Mechanic Instrument- ation Hot Section Utility Section Electric DCSOperators Field Operators DCSOperators Field Operators DCSOperators Field Operators DCSOperators Field Operators Substation Field Supervisor Mechanics DCS Field
Operation • HSE (Health, Safety, Environmental) • Work permit system • Lock out/tag out system • Fire/Gas alarm management • Work safety, i.e. • Standard procedures for handover to maintenance or routine activities • PPE (personal protective equipment) • Hazardous materials, i.e. • Filling of chemicals • Leakages during start-up • Planning of complex activities, like plant turnarounds • Please refer also to the presentation “HSE in Operating Plant”
Operation • Field Operation • Line up of systems, i.e. • Block valve operation, first slow, then fast • Sequences, key interlocks • Line up/change over of equipments, i.e. • Pumps (sealing system, liquid gas, cool down, min. flow) • Special equipments (fixed tube/plate fin excha., turbine driven pumps or compressors) • Dosing of chemicals, i.e. • Refilling/unloading of chemicals • Calibration pot for displacer pumps • Routine rounds and cross check of instruments with DCS, i.e. • TMT (Tube Metal Temp.) on coils and laval nozzle pressure furnace end of run • abnormal sound or smell (leaks, vibrations, hammering)
Operation • Field Operation • Passing valves, i.e. • Icing flare lines in cold section • High or uncommon level in warm blow down drum or slop drums • Hand Over to maintenance, i.e. • Steaming out (C4+, Polymers/Fouling Products), flushing (Caustic) • Lock out-tag out/permit system to be followed • Routine sampling and special samples • Icing, Methanol Injection • Find water source (dryer break through, guard dryer) • Avoid contamination of product (only up to -96°C) • Draining to flare to avoid CO production in furnaces and disturbance in hydrogenation
Operation • DCS (Distributed Control System) • Manual/Auto/Cascade Mode • Trends long/short term • Instrumentation plausibility check • Coordination and guiding of field activities • DCS Operation • Alarm management • Event Lists • Troubleshooting/What to do when… • Coordination of sections, i.e. • Load changes • Presulfiding/CO content/ Hydrogenation • Recycles (Ethane Feed)
Operation - DCS • Example C2/C3 Separation • Front-End-Deethanizer for Gas Cracker
Operation - DCS • Example C2/C3 Separation
Content • Definition of tasks and terms • Precommissioning • Commissioning • Start-Up - Concepts - Special Equipments • Operation • Summary
Summary • Plant Operation • Detailed knowledge about equipments and an overall understanding about the interactions of the process sections of a plant is required for a sound plant operation • Operating experience ensures stable and reliable plant production • Concepts for safe, environmental friendly and fast pre-commissioning, commissioning and start-up are available • Client specific operation philosophy is taken into consideration • Safe and stable operation with high productivity to be achieved