Hot Oil Campaign

Hot Oil Campaign

Scope and Overview

The hot oil (HO) system is a closed-circuit circulation system designed to provide heat for various units within the CRISP project, including DAU SU (DAU Oil-in), PFBS, DHU 1 & 2, CCFU, and CCFU SS (through South Battery Limit). The system operates with a furnace outlet temperature of $740^{\circ}F$. It marked the first hydrocarbon introduction at the site and was the initial process system to start up in CRISP.

The hot oil system startup triggers the hot oil furnace startup and dry out, which, in turn, triggers the Flare SU/light up. The main equipment includes:

• Expansion drum & circulating pump

• Furnace heater

• Reclaimer

• Fill pump, makeup tank & pump, and filtration system

Startup Procedure

Specific subsystems need to be turned over (TO), followed by cold commissioning activities like GALT (Gasket Air Leak Test), $O_2$ freeing, and service tests (ST) according to different phases in the HO SU campaign. Pre-required subsystems are needed for each phase. ANRO (Abnormal and Emergency Response) scenarios and emergency response drills and training were conducted.

To address delays in the TO of the two main subsystems—HO treatment and distribution—the team divided the work according to the SU phase. Some subsystem boundaries were shifted to meet minimum kit considerations for each phase. This approach was also used for punch closure.

Initially, three subsystems are required to start up the hot oil unit: tank fill, hot oil treatment, HO distribution, and instrument air for operating all instrument valves and controls. Oxygen in the makeup tanks was displaced through the tank's atmospheric vent.

During operation, heated hot oil at $740^{\circ}F$ is supplied to high-temperature users like CCFU and DHU before cascading to lower-temperature users like DAU and PFBS. Distillation is performed in the reclaimer to prevent degradation of the hot oil.

In the reclaimer, oil is supplied using a makeup pump and circulated by a reclaimer pump along with overhead and bottom pumps with a re-boiler & condenser which is feed back to the expansion drum.

Cold Commissioning and Filtration

To circulate the HO throughout the site, cold commissioning steps such as GALT, $O<em>2$ freeing, service tests, blower MRT (Motor Running Test), and logic checks are necessary. Given the distribution size, the lines were divided into seven groups—Black, Brown, Blue, Dark Blue, Light Blue, Light Green, and Yellow—for GALT and $O</em>2$ freeing, which were executed successfully. For GALT, each circuit was tested individually, whereas for $O<em>2$ freeing, once one circuit was completed, the adjacent circuit was opened and $O</em>2$ freed.

To remove dirt and mill scales from the pipe (despite being clean built), an external filtration skid was proposed. Since no prefabricated filtration skid was available for the required temperature and flow, EM (Engineering & Maintenance) hired Wood to engineer and fabricate it. The skid was stick-built at the site by EM Metals. Hydrotests and welding inspections were completed at the fabrication shop before transferring to the site.

One challenging subsystem was hot oil tracing tapped from the hot oil distribution line using SS tubing to supply heat for the DAU process piping. Numerous locations had mismatched fittings, damaged and bent tubing, and no redundancy for the hot oil safety-critical tracer as per the specifications. GALT is ongoing for these tubings, and leak rectification is in progress. Cold flushing these lines with HO will occur once cold commissioning is complete.

Workflow

Hot oil from the truck is filled into the makeup tank using a tank fill pump. The makeup pump then transfers the stored hot oil from the makeup tank to the hot oil expansion drum. From there, the oil is distributed to users all over the site using a hot oil circulation pump through the hot oil furnace (F-20801) to heat it up to $740^{\circ}F$.

CRISP and Campaign Stages

The Hot oil SU campaign is divided into four phases:

1. Tank Fill: System fill and inventorization.

2. Cold Circulation: Cold Flush & Filtration, cleanliness hold points.

3. Furnace light-up & refractory dry-out.

4. Hot commissioning & Main circulation pump MRT.

Tank Fill Phase

For tank filling, the process SS needed are HO Treatment (the tank belongs to this SS) and HO Distribution (P-20806 belongs to this SS). HO Cold Drain and all DAU drains are blinded. Instrument Air, a utility SS, is used by pneumatic-activated instruments like control valves, on-off valves, and dampers. All SIS (Safety Instrumented System) and DCS (Distributed Control System) alarms were tested.

The CW (Cooling Water) system was ready and turned over for use before the HO campaign started.

Tank filling and cold circulation/filtration do not require a Temporary Fire Permit, TOP (Temporary Occupancy Permit)/Mitigation, or NEA (National Environment Agency) clearance. Although NEA clearance is not required at this stage, containment for leaks must be available. Any leak during tank fill will be contained in the dike, which has 100% tank capacity, with an option to divert the drain to PCSWS (Process Contaminated Sewer Water System). Standby vacuum trucks were available in case of loss of containment.

For leak mitigation:

• Booms were launched in place with one more on standby at the site.

• Spill kits with absorbent pads, chemical gloves, and trash bags were placed near the HEX (Heat Exchanger) to be used when needed.

• A temporary safety shower was placed near P-20806.

Before tank fill, a PSSR (Pre-Startup Safety Review) walkdown was conducted, and punch lists were raised and closed by TR (Technical Review) & TT (Turnover Team).

During this phase, 43 BLCs (Bulk Liquid Containers) were ordered, with 4-5 BLCs kept on standby per day. A total of 50 BLCs were filled within 15 days without safety issues or spillage. All personnel were trained in safety measures for leakage or safety issues.

Initially, 4 BLCs were loaded during the day shift, which was improved to 8 trucks per day with morning and night shifts. Therminol VP1 (hot oil) from the truck is filled into the Makeup Tank TK-20801 using P-20806, during which the pump MRT is performed. Pumps were vented before starting the MRT.

The Hot Oil Makeup Tank (TK-20801) is used to dose makeup to the hot oil circuit and as a shutdown holding tank for the thermal fluid. The emergency quick-release BLC valve functionality was also tested as part of the pump MRT. During normal operation, each truck unloading time is approximately 50 minutes. The discharge flow pressure was monitored continuously.

If the needle fluctuates for approximately 45 minutes, the pump is stopped. The tank has a blanketing injection system with Nitrogen, which was not available during the tank fill but was later implemented. The missing gauging hatch was removed from HC8 tank and installed in TK-20801 (MOC 2300895) to enable tank gauging level calibration during SU of the new HO unit and sampling.

Minimizing Hot Oil Wastage

To minimize hot oil wastage during tank fill, the hot oil BLCs (total: 50) were totally depleted using the tank fill pump (P20806, centrifugal type) by pumping it dry. This repeated activity may cause damage due to cavitation. As mitigation, a temporary pump (diaphragm type, plant air-driven) was installed (MOC 2303320) to do the top-up after P20806 pump MRT was completed. This required two tie-in modifications, which will be made permanent for future use.

Cold Circulation Phase

The SS needed for cold circulation of Hot oil in the highway and to HEX are HO Hot Drain, all HO system in DAU, PFBS, CCFU, CCFU SS, DHU 1 & 2. $N<em>2$ pumper truck was used for blanketing the D20801. GALT & $O</em>2$ freeing were performed. A new SS was created by splitting 20200-P-0703 into 2, HO to HN HC8 20200-P-0704 for enabling the Cold circulation through the HEX E-20245 since we faced challenge on TO the full 2020-P-0703 SS.

Alarms and instrumentation checks, including a temperature alarm for PDV% to trigger filter cleaning, were also tested. As mentioned earlier, the hot oil tracing system was supposed to be cold circulated in this phase. Cold circulation will be done once the system is ready after all punch clearing and cold commissioning activities are done. As of now, the HO system is in hot standby, but once the HO tracing system is ready for cold circulation, the HO temperature will be brought back to ambient, and cold circulation will be done to remove debris. Once acceptance criteria are achieved, the system will be heated to operating temperature.

Before starting cold circulation, a rule was implemented: no open flame within 7 meters of TK-20801.

To mitigate the potential overpressure scenario of a blocked outlet due to filter pluggage or inadvertent valve closure, a soft clamp at a minimum of 18% open (equivalent to 12% of maximum flow, $5079326 lb/hr$ or $261.5 m^3/h$ using a cold HO density of $66 lb/ft^3$) for PDV-0049 was used to mitigate this overpressure scenario. PDV-0049 provides an alternative relief path.

The HAZOP/Safety Review was facilitated by PSE (Process Safety Engineering), with additional mitigations in place. A detailed SIMOPs plan was developed between TR, EM, and Sinopec. EMTEC PSE reviewed the updated PED domain (blast study).

Before cold circulation, a PSSR walkdown was conducted, and punch lists were raised and urgent items were closed by TR & TT, except for P&ID updates.

During this phase, HO is circulated using the HO circulation pump P-20801A/B/C to the main highway first and then to each HEX, initially at 15 KBD, followed by 300 KBD (20 KBD/hr). The HEX was divided into 8 groups & 2 TIERs:

• TIER 1: CCFU & DHU

• TIER 2: DAU & PFBS.

A temporary filtration skid was designed (MOC 2283638) & fabricated by WOOD and installed at the site by EM Metals to capture all debris during Cold & Hot Circulation. Spare filters were purchased and kept on standby for both the HO circulation pump and this temporary filtration skid. The circulating hot oil is stored in a large vertical expansion drum (D-20801) sized to hold the volumetric expansion of the oil heated from ambient temperature to its service temperature. This tank is filled by Hot Oil Makeup Pump P-20802; during filling, the pumps MRT is performed and found satisfactory.

Next, the P20804 Lo system was started. A MOC Temporary filter designed by Woods is installed for Cold & Hot Circulation purpose. The intent of this filtration is to remove construction debris, pipe mill scale, and other solids from the piping circuit such that the hot oil is clear of particulates (up to $100\text{um}$). Two trains of 3 parallel T-strainers (8”) with a mesh size of $100\text{um}$ were installed, with only one train running at a time and the other on standby for changeover during maintenance. Cold circulation started with $400\text{um}$ filters to remove larger debris first before lowering to $100\text{um}$ size filters at an operating pressure of 212-263 psig. The maximum delta P across each filter circuit was approximately 50 psi.

The main HTF (Heat Transfer Fluid) pump was also protected with 20 mesh (840um) strainers as recommended by the machinery engineer.

After hot circulation, the filtration skid was isolated and blinded at the first root valve. The main skid was removed. The original spools will only be re-installed during the next shutdown window (e.g., in 2029TA). The engineering took 2 months, fabrication 1.5 months, installation at site 18-20 days, and demobilization 4-5 days.

All hydro tests for the filtration skid were done at the workshop, and GALT for the tie-in was performed at the site. The filter skid was purged with $N_2$ and cold hot oil prior to filter changeout.

To achieve design momentum/flow rate in every line (CFR=1) through the $100\text{um}$ filter, the system volume needed to be turned over 4 times. The target duration was based on the velocity of the flush (a function of flow rate and pipe size) and the total length of the circuit. The target duration:

• $300\text{kbd} = 2000 m^3/h$

• System volume ~ $900 m^3$

• Duration for 4x system volume = $\frac{900 \times 4}{2000} = 1.8 \text{hrs}$

Cold circulation was done in 3 phases:

• 2A – Cold Circulation of the highway,

• 2B – Cold Circulation through CCFU & DHU HEX,

• 2C - Cold Circulation through DAU & PFBS.

As the HO lateral covers the whole of CRISP, hourly checks for leaks and abnormalities were conducted during the start of circulation and temperature ramping.

Flushing the Main Highway

Main HO Circulation through the highway was split into different phases. During the filling operation, P-20802 was used to fill the expansion drum D-20801 until the Normal Liquid Level (NLL) was reached. Once NLL is reached, only one pump P-20801A, B, or C is used to fill the system. One Pump P-20801A, B, or C is at 50% of the capacity.

Due to CCFU not being started, D-20801 vented to the relief header of DAU using the bypass of HO-PR-0002, and the T-20801 vented to the relief header of DAU using the bypass of HO-PR-0003.

The makeup flow rate will be limited up to the pump maximum (192,200 lb/h). The system (excluding the users) is filled with a flow rate of 192,200 lb/h, and the rest is recirculating to the expansion drum.

• Phase 1:

  • Bypass furnace out PR-0004

  • D-20801 = 20%

• Phase 2:

  • Bypass furnace out PR-0004.

  • OPEN PDV-0046 A/B Furnace inlet

  • D-20801 = 40%

• Phase 3:

  • Bypass furnace out PR-0004 CLOSE.

  • OPEN PDV-0046 A/B.

  • OPEN PDV-0049, PDV-1203.

  • Back to exp drum D20801 = 70%

The whole HO highway is filled using HO circulation, starting from 70% of D-20801 until 20% of D-20801 is reached, which signifies the entire highway is packed with HO. The drum vents any light cracking products to supply reliable NPSH to the circulation pumps (P-20801 A/B/C). In normal operation, two pumps were run with one on standby. N2 pumper truck was used (since NG was not available) for pressuring up and maintaining pressure for D20801 at 50 psig for providing NPSH for the HO circulation pump. The $N_2$ pumper truck was connected using a hose connection at SP-010 through PV-0005A and passed through PV-0005B to D-20149 DAU Relief and vented to the atmosphere through PRV007 (MOC 2299363).

As the CCFU circuit was not live yet during the HO circulation stage, the PCV outlet was routed to DAU relief (to flare) via the PR-0002 bypass line.

The hot oil expansion drum also acted as a disengaging drum to remove light cracked products formed by thermal degradation of circulating hot oil. The level in the drum is controlled by LT-0004 to cater to hot oil losses and guarantee the required volume of hot oil is stable to assure thermal balance in the closed circuit.

MRT Results of HO Circulation Pump and Reclaimer Commissioning

T-20801 was lined up using P-20805 (bottom pump), where the MRT was also performed and found satisfactory. To facilitate the MRT for P-20803, P-20804 & P-20805 without heat input/degradation product in the reclaimer, a temporary jumpover line from P20805 suction to P20803/4 suction was used for pump MRT.

P20801 A/B/C pump discharge min flow line cavitrol valves (FV-0001/2/3) were temporarily replaced with globe valves since the $~3 \text{mm}$ trim Cavitrol valves are prone to pluggage during SU due to construction debris. These were replaced with temporary valves during SU (MOC 2294465). All MRTs were proven satisfactory, and T-20801 was put on standby with only bottom circulation using the P-20805 CV valve replaced with a globe valve. Flex hoses were used in P-20803, P-20804, and P-20805.

Acceptance Criteria

A visual check on particles was found to be OK. There was no pluggage for 24 hours after continuous flushing. The maximum particle count is more of a long-term degradation/HEX fouling concern, not a criterion for start-up. This will be removed gradually by the permanent 10um filter after start-up. Moisture content tests (KF method) will be done for reference but are not a passing criterion, as moisture will be removed once the system is heated up.

Flushing of HEX

Flushing of HEX was done in 2 tiers. Tier 1 consisted of all HEX from CCFU & DHU, and Tier 2 consisted of all HEX from DAU & PFBS. These tiers were divided into 8 groups, with approximately 1~2 of flushing in each HEX. All the Tier 1 (CCFU/DHU) heat exchangers were isolated before starting the flushing of Tier 2 (DAU/PFBS) exchangers to avoid flushing back debris to Tier 1 exchangers.

During Cold circulation, the D20801 HO expansion drum outlet EBV and P20801A/B/C pump suction block valves were passing and required D20801 to be emptied for OPE (Operations, Process, and Engineering) for repair/cleaning. A temporary jumpover (SS hoses) from the P20801A drain line to the P20806 pump suction was connected (MOC 2305662) to facilitate draining from D20801 back to TK20801.

There is a permanent line up from P20801 discharge to E20801 to tank, but it may result in P20801 cavitation if that section were pumped dry; hence, this temporary drain line was preferred.

HEX Isolation

HO Distribution supplies HO to 30 exchanges across the site, from DAU to CCFU SS, to remove construction debris, pipe mill scale, and other solids from the piping circuit such that the hot oil is clear of particulates (up to $100\text{um}$) during cold circulation. To avoid pinhole leaks passing to the process side of the pipe, all process inlets and outlets are isolated either by DBB (Double Block and Bleed) or by blinds or air gaps. EV (Energy Verification) points are provided to check for pinhole leaks in process lines.

Deviations

Two OIM 6.2 deviations were approved:

• Deviation 1: Energy Isolation

  • All forms of energy in the system shall be isolated before opening process equipment.

  • To deviate from isolating the Process side of Hot Oil exchangers (under TR custody) for blinding / de-blinding work:

    • During Blinding, the hot oil side will be empty, and the process side will be with the construction team.

    • During De-blinding, the hot oil side was isolated, drained, and purged after cold circulation. Hot circulation happened only through the Hot oil header and not through the exchangers. The process side was with construction or TO to Commissioning team.

  • Reason: It was assessed as not possible to isolate the process side of Hot Oil exchangers due to:

    • A large part of the isolation circuit of the process side of the exchanger being under construction.

    • Isolation locations being inaccessible, with parts of the piping not installed.

• Deviation 2: Potential hazards and mitigations were addressed with SIMOPs and permit endorsements.

As part of HEX isolation:

• 30 RS were removed, and bleeder blinds were installed for energy verification.

• 16 spacers were removed, and bleeder blinds were installed for energy verification.

• 10 spectacle blinds were removed, and bleeder blinds were installed for energy verification.

• 20 plus tracings were removed and reinstated once cold circulation was done.

• Mobile cranes were used to remove & re-instate 44 RS. During the removal and re-instating the removable spools from the HEX, two flange faces were damaged on E-20123 and E-20151. The damage to E-20123 was away from the gasket area and was accepted. The damage to E-20151 was assessed as per ASME PCC-1 table D-3-1M and accepted after machining inspection.

During blinding, flange face damage was discovered with scratches across the gasket seating surface and through the serrations. This was rejected as per ASME PCC-1 table D-3-1M.

Filter Strainer Pluggage

Remarks

Photographs were collected for strainer, temporary filter, and sample.

Furnace SU & Refractory Dry Out

Pre-requisites

Subsystems (SS) needed for Furnace SU, Refractory dry out, and Hot Circulation include:

• HO Hot drain

• NG and its distribution line from ES

• FG and its distribution line from ES

• Part of the FG compressor SS (split for bringing in gas for furnace light up)

• Flare main header

• Close drain header for the FG drum

• F&G system for HO

• FW

• HO Steam tracing

GALT & $O_2$ freeing and ST were completed before introducing gases.

Safety, Environment, and Regulatory Requirements

• Hot circulation & Furnace light up requires temporary fire permit, BCA TOP, and NEA clearance.

• GHG emissions reporting to NEA – GHG Monitoring Plan developed and MEI work process setup.

• For Hot Circulation: PCSWS/FFB/TPI was ready and leveraged for managing leaks/spills, and PAC/Sembcorp was ready to receive our waste.

PSSR walkdown was conducted before Furnace SU/dry out with punch lists raised and critical items closed by TR & TT except for P&ID updates.

Work Scope

The furnace is the main source of heat, heating the HO to $740^{\circ}F$, which is then distributed across the site. Natural Gas, Fuel gas & Off gas are used for burning the furnace. The pilot is supplied with NG, and FG is the main gas source. Once all process systems are ready, Off Gas will be produced and used as the burning medium. All FG & Off Gas systems are steam-traced.

The furnace was lit as per the procedure, and COT (Coil Outlet Temperature) was increased to $350^{\circ}F$ by $50^{\circ}F/HR$, followed by refractory dry out. Once $500^{\circ}F$ was reached, the HO system was stabilized for DAU SU, and P-20801 ABC pump hot alignment was done and found satisfactory. Later, the circulation rate increased to 350-400 KBD at 20 KBD/hr. Also, F-20801 COT was increased to $500^{\circ}F$ by $25^{\circ}F/Hr$. After this, the HO system was declared ready and put on standby, maintaining a constant temperature of around $160^{\circ}F$ until HO tracing was ready. After the tracing system is ready, the temperature would be reduced to ambient, and cold flushing would be done before hot flushing.

Cold Start-up

To light up F-20801 burners during a cold startup (defined as a start-up after extended downtime where the fired heater bridge wall temperature has cooled to ambient conditions), burner cleaning was done as per the SU procedure & process planning sheet. All Pilot gas line, ignitor line, and FG line were blinded as per the standard EIC procedure.

Instrumentation

A valve stroke test was performed and successful before furnace light up.

Instrumentation checks performed include:

• Cause & Effect Safety Instrumented Function Test

• HO Furnace Function Test with XV trip valves & dampers actuation

• Forced Draft Fan (FDF) function test

• Heater Purging Sequence test

• Induced Draft Fan (IDF) function test

• Pilot Gas Startup

• Fuel Gas Startup

• Off Gas Startup

• Partial Shutdown - Pilot Gas Restart

• Total Shutdown - Fuel Gas & Off Gas Restart

• Firebox High-Pressure Cutout & Trip

• HO Furnace ESD

Discoveries from HO Furnace Function Checks

Pending items have been communicated to TR for resolution:

• Lost IA to all valves and dampers (temporary to permanent air conversion). Resolved.

• IDF IGV PV-0505 air leak to valve and could not open beyond 5%. Connection retightened. Resolved/Tested.

• Pilot Gas valve XV-0106 open limit intermittent status. Faulty limit switch replaced. Resolved/Tested.

• P1 alarm “HOESD0002 G1 F20801 BURNERS <8 PILOT OFF” activates on a single loss of pilot. The alarm description was changed to “HOESD0002 G1 F20801 PILOT LIT COMMON ALARM”. An IGQ was submitted to update SHE VDU P1 alarm description.

• XV Trip Valves have a 10-second timer, which is insufficient. The timer was changed to 60 seconds (IGQ submitted for HO (F-20801) and DHU furnaces (F-20201 & F-20251)). Resolved/Tested.

• Pilot and Main Fuel Gas pressure must reach above the low-pressure setpoint within 30 seconds, which is insufficient. The timer was changed to 60 seconds (IGQ submitted for HO and DHU furnaces). Resolved/Tested.

• LCP HMI First Out alarms continuously display after a trip but do not normalize until blowers are running and a reset is engaged. An IGQ was submitted for logic update. Resolved/Tested.

• Air Preheater bypass valve XV-0505:

  • Initially understood to be always opened (de-energized) unless running IDF. Existing logic is okay for XV to closed (energized) prior to FDF running. Resolved.

  • Open/Close limit switch status intermittent. TR adjusted the air regulator. Resolved/Tested.

• PV-0017 Stack Damper:

  • When commanded 0% closed, field position is at ~17\text{%} open. Pending.

  • The LCP local/remote switch position does not match DCS status. Applications corrected the status indication. Resolved/Tested

MOC 2298756 HO:FG Relief Path During Furnace Light Up

NG was lined up to the HO furnace via:

• North interface ->< 60\text{#} FG drum D20273 ->< 30\text{#} FG drum D20803

To protect against potential overpressure from $270\text{psi}$ NG, it was proposed to CSO (1) D20273 overhead outlet valve and (2) PCV055 bypass valve to take credit of D20803 PSV0107 to provide relief.

Operating Strategy and Safety Considerations

D20273 will be operating at ~$40\text{psi}$ (controlled by PCV0050). PSV0107 provides sufficient relief capacity for the fail-open scenario of PCV0050. The potential overpressure scenario ($270\text{psi}$, protected by upstream PSV0007A/B) is within 1.5x of the D20273 hydrotest pressure ($204.5\text{psi}$). Therefore, credit can be taken for CSO valves.

Furnace Failure Scenarios and Mitigation

Discussions on furnace failure scenarios, mitigation, and responsible parties were crucial for successful furnace startup.

Key Mitigation Actions During Furnace Startup by Phase

Operational Protocol for Startup and Maintenance

• Prior to start-up, F-20801 PG electric igniters were tested before introducing gases, and refractory dry-out will be performed.

• F-20801 pilots were lit up as per the usual furnace startup procedure, and the furnace was heated to $250^{\circ}F$ at a rate of $50^{\circ}F/HR$, held for 13 hours (1 ½ hour per inch of refractory thickness).

• The Main burner was started, temperature increased to a minimum of $400^{\circ}F$ at $100^{\circ}F/hour$, and was holded for 13 hours.

• Finally, the temperature increased to $950^{\circ}F$ and holded for 13 hours to complete the dry-out successfully at the designated parameters, and then gradually reduced to around $600^{\circ}F$.

Key Activities:

• NG introduction to FG system, HO furnace pilots were successfully ignited, followed by 1 burner (250F BWT).

• Fired up more burners, total to 3 (400F BWT).

• Ramped to a total of 9 burners (950F BWT).

• Strainer Cleaning & Furnace Restarted after Pump Strainer Plug.

• Third hold for the refractory dry out (950F BWT), and heated for operationg COT (12 burners).

• Furnace Trip with HO Flow (LL), the root cause was at higher COT of $700^{\circ}F$.

• Cycle the hot circulation and completed.

Hot Circulation

The Main objective of Hot Oil (HO) hot circulation is to:

• Heat every heat exchanger in the whole plant.

• Hot oil is heated to a temperature of around $$750^{\circ