NEW CRUDE HEATER FOR

BETTER EFFICIENCY,

RELIABILITY & ENVIRONMENTAL

PERFORMANCERAJ GHETIA

TECHNICAL SERVICES DEPARTMENT

THANGARAJ RAJU

PLANT ENGINEERING DEPARTMENT

BAPCO, BAHRAIN

NEW CRUDE HEATER FOR BETTER

EFFICIENCY, RELIABILITY & ENVIRONMENTAL PERFORMANCE

24 October 2018

RAJ GHETIA

TECHNICAL SERVICES DEPT.

THANGARAJ RAJU

PLANT ENGINEERING DEPT.

Agenda

• Introduction

• Present Situation

• Proposal

• Project Objectives

• Economic Justification

• Challenges

• Project aspects - Overview

• Project Execution Plan

• Project work and challenges

• Concluding Remarks

2

Introduction

• Refinery started in 1936 at 22 MBPD, in operation for more than 80 years

• Current crude processing capacity is 267 MBPD

• 5 Crude Units & 5 Vacuum Units

• Conversion units: HVGO hydrocracker, FCCU, Lube Base Oil, Visbreaker and Platformer

• Fired heaters - largest consumers of energy, similar to other refineries

• Efficiency and performance improvements can deliver substantial energy savings and improve profitability

3

Background4

• Bapco refinery has 45 fired heaters ages between 5 and 82 years.

• Extensive operating experience with fired heaters and their optimisation and troubleshooting

• Post Bapco Modernisation Program (BMP) - many old and inefficient process units will be decommissioned

• No. 5 Crude Unit (5CDU) will remain

• Three parallel fired heaters - built in 1943 (75 years old)

• Initiative launched in 2015 to replace these 3 heaters

Present Situation - Existing 5CDU Heaters

• Heater type - natural draft, cabin type with two radiant cells and a common overhead convection section.

• Low efficiency - 60%, flue gas >1000°F & Excess O2 - 6.5%

• High coking rate →intermediate shutdowns to decoke tubes

• Low operating flexibility - turndown 85%

• Poor control of draft and excess O2

• High maintenance cost

• Poor operability - tube configuration

• NOx emissions sometimes exceed limit

• Burners cannot fire low heating value gas

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Present Situation (cont’d)

Why do we have these issues?• Insufficient tube heat transfer area & no finned tubes in convection section

✓ Very high average radiant heat flux - 18,000 vs 12,000 Btu/hr-ft2 (Best Practice)

• Tube pass configuration - cannot measure flow split between the passes

• Insufficient instrumentation to monitor, control, optimize performance

✓ No online excess oxygen/combustibles measurement

✓ No automatic damper control mechanism

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Present Situation (cont’d)

• Burner type – dual head premix Ramshorn

✓ High number - 60 total

✓ Not designed to fire low heating value gas

✓ Alignment concern

✓ Fouling issues

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Ramshorn Burner

Present Situation (cont’d)

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Refractory fall-out

Deposits/scale

from burner

pipe

Inside the air-fuel mixer

Proposal

• Build a single heater to replace the existing 3 heaters

✓ Vertical cylindrical natural draft - minimise cost & space requirement

✓ Design radiant heat flux - 12,000 Btu/hr-ft2

✓ Efficiency - 90%

✓ Low NOx burners - 12 in total

✓ Improved turndown - 50%

✓ Instrumentation - O2 & combustibles analysers, draft , TI’s

✓ Remote damper control

✓ Burner flexibility to fire gases, individually or in combination, of varying heating values (700 to 1750 Btu/Scf)

✓ Access doors to allow cleaning of convection section tubes

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Project Objectives

• Significantly increase efficiency and thus, profitability

✓ Energy saving - 60 MMBtu/hr

• Increase operational availability

✓ 6 year continuous run

• Reduce maintenance

✓ No tube replacement and much lower burner count

• Improve environmental performance (reduce CO2 & NOx)

✓ CO2 reduction 45 tons/day

✓ NOx – guaranteed <100 mg/Nm3 : predicted < 60mg/Nm3

• Enhance operability and control

✓ State-of-the-art instrumentation

✓ Improved safety with SIL rated ESD system

• Meet latest standards and industry best practices

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Economic Justification11

• Pre-BMP:

✓ Fuel gas saving due to heater efficiency improvement

▪ Heater fires FCCU/Visbreaker off-gases

✓ Heater runs for a full 6 year T&I cycle

▪ Saves one decoke shutdown cost & loss of crude throughput

• Post-BMP:

✓ Heater fires 100% low LHV Khuff gas (FCCU/Visbreaker decommissioned)

✓ Higher benefit after BMP due to recovery of C3, C4 & Naphtha which had to be burned in the old heaters to maintain minimum LHV

✓ Heater runs for a full 6 year T&I cycle

▪ Saves two decoke shutdown cost & loss of crude throughput

✓ IIR - 15% with simple payback of 6 years

Challenges

• Selection of location for new heater

✓ Brown field project

✓ Compliance with Bapco safety standard

• Requirement to replace existing crude booster pump

• Providing bypass around Crude/Atmospheric Resid exchanger

• Execution constraints

✓ Many lines - rerouted to create space for new pipelines and supports

✓ 2800 people working simultaneously in congested plant area

✓ Hot tapping 8”x 8” planned for 550# superheated steam line

✓ Demolition of existing 3 heaters (with unit in operation)

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Empowering Progress

Engineering and execution

13

Thangaraj Raju

Plant Engineering Department

Project Aspect - Overview

• 5CDU Heaters replacement project followed Chevron Project Development Evaluation Process (CPDEP)

• Scope of project includes:

✓ Vertical cylindrical heater 32 ft diameter, 213 ft height, with 12 burners

✓ CFD Analysis to ensure acceptable firing pattern

✓ Fuel gas knockout drum followed by coalescer & pilot gas knockout drum

✓ Two crude booster pumps

✓ Demolition of existing 3 heaters (with unit onstream)

• Features:

✓ Modular construction of radiant, convection & stack assemblies

✓ Ex-situ refractory dryout

• Front End Engineering Design(FEED) - Engineers India Ltd (EIL)

• Engineering, Procurement & Construction (EPC) - JGC Gulf International Ltd

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Project Execution Plan

• Project schedule - 20 months

• 4 Phases of execution :

✓ Before 5CDU T&I (unit onstream) - 5%

✓ During 5CDU T&I (Nov 2017) - 30%

✓ After 5CDU T&I (unit onstream) - 60%

✓ Short shutdown for commissioning - 5%

• Challenging job due to brownfield project in congested area

• Jobs provisionally planned before unit T&I could not be done due to safety

concerns

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Project Work - During T&I

• Jobs carried out during 22 days of T&I :

✓ Civil foundation supports for pipe rack & pipe supports (100 nos)

✓ Installation of pipe rack 50 metres and its pipe supports

✓ Piping tie-ins >100 nos

✓ Installation of pipelines ~1000 metres on new pipe rack/supports

✓ Hydrotesting, painting & insulation

✓ Welding of reinforcements for fireproofing for pipe rack & pipe supports

✓ Demolition of work station

✓ Re-location of guy wires on existing heater stack

✓ Replacement of UPS

✓ Modification of 2.3KV switch-gear for power supply to new booster pump motor

✓ Underground survey and trial pit for booster pump foundations

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Project Work - During T&I (cont’d) 17

Work In Progress - During 5CDU T&I18

Challenges faced during T&I

• Integration of project schedule with shutdown maintenance T&I schedule

• Difficulty in welding new and old alloy steel pipelines due to magnetization

• Sharing of work space, resources and cranes with Maintenance Department

• Plan integration

• Alternative technique of Phased Array Ultrasonic Testing (PAUT) in place of radiography

• Additional stress relieving machines to cater for 200 alloy steel & NACE weld joints

• Some H2S emission and continuous release of oily water during excavation for foundation of pipe supports

• All the T&I related work for new heater were done with zero incidents

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EPC Work after T&I

• 30%, 60% & 90% 3D Model review

• HAZOP & SIL study

• Heater vendor package finalized and fabrication is in progress

20

• Crude booster pump design review due to NPSH issues and relocation of pumps

• Coalescer design modified for maintenance work

Concluding Remarks

• Engineering and T&I activities done safely and successfully without incidents

• Now we need to safely install and commission the new heater on-schedule to meet the key objectives of improving Efficiency, Reliability & Environmental performance

❑ Key Success Factors

✓ Technically strong, experienced, aligned and motivated in-house multidisciplinary team

✓ Concept developed in-house

✓ Vital to involve the right people in the evaluation and decision-making process

✓ Close working relationship with the contractors and vendors

✓ Alignment of Bapco - Project / Maintenance teams and EPC/sub-contractor teams in completing jobs within stipulated time

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THANK YOU