Embed Size (px)
Citation preview
ATTACHMENT No. D.1
Operational Information Requirements
Contents Attachment D.1.1 Overall Plot Plan; Plot Plan Equipment List Attachment D.1.2 Simplified Process Flow Diagram of Terminal
Operations Attachment D.1.3 Process Control – General Attachment D.1.4 Process Unit Operations Attachment D.1.5 Utilities Attachment D.1.6 Safety Systems
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
ATTACHMENT No. D.1.1
Overall Plot Plan, Plot Plan Equipment List
Attachment D.1.1 Overall Plot Plan (Drg No IPPCL-008)
Plot Plan Equipment List (Drg No IPPCL-009)
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
ATTACHMENT No. D.1.2
Simplified Process Flow Diagram of Terminal Operations
Attachment D.1.2 Simplified Process Flow Diagram of Terminal
Operations (Drg. No. IPPCL-002)
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
ATTACHMENT No. D.1.3
Process Control General
Attachment D.1.3 Process Control General
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
D.1.3 Process Control - General The Terminal facilities are designed to operate over a range of flow and pressures determined by the production profiles and gas reservoir characteristics. Conditioned or “Sales” gas is exported directly into the Bord Gáis transmission network at a defined pressure. The delivery rate of gas, fiscally measured, from the Terminal will be controlled according to daily nominations from the customer(s). The whole Corrib Field Development (onshore and offshore) will be controlled from the onshore Terminal control room. A Control System will control the onshore facilities and an Electro-Hydraulic system will control the offshore facilities. Based upon a manning philosophy that is sufficient for safe operation, the Terminal control room will provide all the necessary information to safely control the offshore facility, gas and liquid processing at the onshore terminal and gas export to the national grid. The control system will provide for the continuous processing and production requirements of the facility on a 24 hour, 365 day per year basis. The control system will allow the control room operators to view all the necessary process variables and make appropriate adjustments as required. In the event of process upsets, operator initiated or fully automatic predetermined logic sequences will bring the Terminal to a safe state, ranging from unit shutdowns to total plant shutdown. Programmable Logical Controllers (PLC) / Remote Terminal Units (RTU) for the control system field interface hardware will be mounted in the local equipment room (LER 1), located in the field adjacent to the process area to minimise buildings and field cabling. The Corrib Field offshore (sub-sea) facilities will be controlled and monitored via an electro-hydraulic remote control system. Electrical power, control and data signals, along with hydraulic control and methanol and corrosion inhibitor will be carried in an underwater umbilical cable buried in the seabed.
The overall availability of the control system will be commensurate with continuous operation and will provide facilities for on-line maintenance without loss of control or display features. To this effect the system will have inherent module and component redundancy with diagnostic features that will allow rapid and detailed fault recognition to module level. Safety systems will be provided which are intentionally separate from the control system in terms of separate field instrumentation and separate system electronics. The systems provided will recognise predicted hazards and have pre-configured logic sequences that will bring the Corrib facility to a safe state regardless of operator action . Additionally, operator initiated shutdowns shall be provided to initiate the predetermined shutdown logic sequences should an impending hazard be recognised by the operator. The Emergency Shutdown (ESD) system at the Terminal will ensure the safe isolation and shutdown of equipment under fault or fire conditions and will provide a basis for the safe and efficient shutdown of process operations and the isolation of flammable / toxic materials within the facilities. Emergency shutdown (ESD) and isolation will be initiated by fire and/or gas detection or by process deviations.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
ATTACHMENT No. D.1.4
Process Unit Operations
Attachment D.1.4 Process Unit Operations D.1.4.1 Inlet and Reception Facilities
PFD 1
D.1.4.2 Gas Conditioning PFD 2; Dwg No. IPPCL-010
D.1.4.3 Gas Compression and Export
PFD 3
D.1.4.4 Condensate Recovery and Stabilisation PFD 4
D.1.4.5 Methanol Recovery, Regeneration and Chemical Injection
PFD 5
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
D.1.4 Process Unit Operations This section includes process descriptions and simplified process flow diagrams (PFDs) for the main process unit operations at the Terminal. For ease of reference, in the process descriptions, the main equipment is numbered in accordance with the Overall Plot Plan included as Attachment D.1. 1.
D.1.4.1 Inlet and Reception Facilities Purpose A simplified Process Flow Diagram (PFD 1) of the process is attached. The purpose of the Inlet and Reception Facilities is to receive the gas from the offshore Corrib Gas Field and remove the entrained water and liquid hydrocarbons. The fluids from the Corrib Gas Field that are received at the Terminal will be mainly gas, but some liquid will also be present. Gas (and production fluids) will arrive at the Terminal, generally as a very fine mist, but the liquids will not arrive at the Terminal in a uniform manner. The liquids in the pipeline will tend to run back along the pipe particularly at times of low gas flow and will collect at low-points, or dips, in the pipeline. As liquid builds up at these low points, it will be picked up by the fast-flowing gas and will arrive in varying quantities, or ‘slugs’. The liquids consist primarily of:
Water phase: • Water: Water of Condensation (present as a vapour within the gas reservoir rocks
in the offshore Field and condenses out from the gas as it’s temperature and pressure fall) and Formation Water (present in the liquid form in the aquifer within the gas reservoir rock which, if it is produced, it is only expected later in the field life)
• Methanol (injected from the Terminal to prevent freezing and hydrate formation in the subsea equipment and pipeline).
• Corrosion inhibitor (chemical injected into the subsea system to prevent corrosion).
Liquid Hydrocarbon phase: • Condensate (liquid hydrocarbons that condense from the gas as its temperature
and pressure is lowered to meet sales gas specification)
Process Description If required, build-up of liquids in the pipeline are cleared by running a sphere (known as a pig) through the line. A Pig Receiver (D-1001) receives pigs launched off-shore.
Operating temperatures and pressures at the Terminal are indicated on IPPCL010 in the attachment.
The pipeline fluids enter the Slugcatcher (D-1002) where the liquid phases (aqueous and hydrocarbon) are removed. The Slugcatcher is a finger type design, made up of 8 x 24 inch (diameter) fingers of 92m length each. Primary separation is achieved by
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
slowing the velocity sufficiently to allow liquids to drop out of the gas phase. The hydrocarbon and aqueous phases are removed under level control to the condensate recovery and methanol regeneration systems respectively. Gas exits the Slugcatcher and, in normal operation, bypasses the Inlet Heater (E-1002). The Inlet Heater is only used during plant start-up to avoid the occurrence of excessively low temperatures downstream of the inlet pressure control valve. The Inlet Heater is a shell and tube exchanger, using the heating medium (Triethylene Glycol (TEG)/water), to raise the gas temperature to 12°C. The gas is then passed under pressure control to the Inlet Separator (D-1003). The slug catcher has been designed to allow processing of slugs to a volume of up to 200 m3/hr. There are two types of slugging potentially relevant to the Corrib field export pipeline and Terminal design:
1) Terrain slugging – where liquid tends to collect in the low points of the pipeline until it is forced forward by the pressure of the gas behind it.
2) Ramp up slugging – accumulation of liquid pockets in a pipeline at transient operating conditions (start up, ramp up, pigging)
Following extensive study work, it has been concluded that the only type of slug expected at the Bellanaboy Bridge Gas Terminal are ramp-up slugs. When a slug arrives in the slug catcher, if the overall high liquid level (HLL) is reached then a HHL level alarm will be activated in the Control Room, the level controller will open the aqueous flow control valve and route all flow to the Raw Methanol storage tanks (T-4001 A/B/C) until interface levels in the slug catcher are restored to normal. In the event that the liquid level rises to the pre-determined High-High liquid level, the inlet valve to the slugcatcher closes to prevent any liquid carryover into the gas system. Figure D.1.4.1(i) shows the main components of a slug catcher typical of the design that will be constructed for the Bellanaboy Bridge Gas Terminal.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
Figure D.1.4.1(i) - Bellanaboy Bridge Gas Terminal Slug Catcher Schematic The Inlet Separator (D-1003) The Inlet Separator (D-1003) provides secondary separation of the gas from any carryover condensate and water. The aqueous phase is discharged under level control to the Methanol Flash Drum (D-4001) with the condensate layer being level controlled into the MP Flash Drum (D-3001). The separator contains a demister at the gas outlet nozzle to ensure that the liquid carry-over in the gas stream exiting the separator is minimised. The gas then flows to gas conditioning.
Process Control Gas flowrate and pressure through the slugcatcher and up to the pressure control valve (PCV) are primarily controlled via chokes located at the well head which are operated from the terminal control room.
Pressure in the onshore pipeline is limited by the the Landfall Valve Installation (LVI) at Glengad The LVI consists of two hydraulically opened, fail closed 16” Landfall Pressure Limitation Valves (LPLVs) in series in the bypass of a normally closed 20”
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
Landfall Mainline Isolation Valve (LMIV), with three independent pressure transmitters continuously monitoring the pipeline pressure.
Environmental Emissions
Air Main: There are no main emissions to air from Inlet and Reception Facilities. Minor: Maintenance activities may require depressurisation of some facilities
using the Maintenance Flare resulting in minor emissions. Potential: There may be some fugitive hydrocarbon emissions during normal
operation. Emergency situations may require depressurisation to the HP and LP Flares.
Water This process system is fully contained with no direct liquid releases to the environment. Aqueous methanol streams removed from the gas stream (including Produced Water) are routed to the Methanol Recovery System and, after distillation, in the Produced Water Treatment System. Operational and maintenance drainage from the Process areas is collected via a dedicated closed drain collection network and routed to the Closed Drains Drum (D-8201) for either off-site disposal or recovery to process (Refer to Section F.1.2 of the IPPC Application Form for a description of the Produced Water Treatment system and the Closed Drains system).
Waste There is no waste generated from this operation other than from normal maintenance activities.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
PRODUCTION FLUIDS FROM CORRIB FIELD
SlugcatcherD-1002
Inlet HeaterE-1002
Inlet Pressure Control Valve
Inlet SeparatorD-1003
Pig ReceiverD-1001
METHANOL RECOVERY (PFD 5)
Aqueous
Hydrocarbon CONDENSATE STABILISATION (PFD 4)
Feed
ReturnHEATING MEDIUM (PFD 7)
NORMALLY BY-PASS
Hydrocarbon
Aqueous
GAS CONDITIONING
(PFD 2)
PFD 1 - Gas Reception and Primary Separation
METHANOL RECOVERY (PFD 5)
CONDENSATE STABILISATION (PFD 4)
Notes1. Inlet Heater is used on start-up only
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
D.1.4.2 Gas Conditioning
Purpose The Corrib gas can be considered a lean dry natural gas (predominantly methane) and therefore the conditioning required to meet the gas export specification is very simple. The purpose of the gas conditioning is to remove any trace mercury (if present) and the sales gas specification. A Simplified Gas Process Schematic showing pressures and temperatures is presented in Drawing IPPCL-010.
Process Description Gas from the Inlet Separator passes to the Feed Gas Mercury Removal Bed (N-1001). The mercury removal absorbent bed contains a mixture of copper, zinc and aluminium sulphides/oxides. Mercury is removed from the gas stream by a process of oxidation as it comes into contact with the absorbent bed. The treated gas stream (<10ng/Nm3 mercury) then flows to the Gas/Gas Exchanger (shell and tube unit) (E-2004), where it cross-exchanges with the chilled gas from the Cold Separator (D-2010) which cools the treated gas stream. The planned cold separator (D-2007) will now not be used and has been isolated. A new cold separator has been added since the original application. The new cold separator (D-2010) has been added to ensure that the Terminal can cater for the design throughput of natural gas. There are no additional emissions arising from the inclusion of this new cold separator. The additional separator was subject of a planning amendment application (PA007). The Gas/Gas Exchanger may be bypassed in early years of operation, when the chilling effect of this heat exchanger is not required to augment the subsequent cooling in ensuring the gas specification is met.
The gas is then expanded in a controlled manner through a valve called a Joule-Thompson (J-T) valve (duty/standby) to give the desired dew point, which is indicative of the required gas quality. Aqueous and hydrocarbon liquids are condensed thus conditioning / drying of the gas occurs.
The two-phase fluid then passes directly into the Cold Separator (D-2010), where the liquids are separated. The aqueous phase is retained and discharged under level control to the methanol recovery system. Condensate is transferred under level control to the condensate stabilisation system. Conditioned gas then flows, via the Gas/Gas Exchanger, to the Gas Compression and Export process operation.
A simplified Process Flow Diagram (PFD 2) of the gas conditioning process is attached.
Process Control Gas pressure and temperature are controlled via the Terminal control systems in the Control Room. The gas is temperature controlled to a set-point to meet the gas
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
quality specification. The pressure controller is reset by a temperature controller, which acts to maintain a controlled gas temperature downstream of the J-T valve to achieve a constant gas quality and allow steady operation of downstream compressors. The efficacy of the mercury removal bed is confirmed by manual sampling of the gas on a regular basis.
Environmental Emissions
There are no changes to environmental emission. Information is repeated from 2004 application. Air Main: There are no main emissions to air Minor: There are normally no minor emissions to air. Maintenance activities
may require depressurisation of the plant using the Maintenance Flare (used on a limited infrequent basis).
Potential: There may be some fugitive hydrocarbon emissions during normal operation. Emergency situations may require depressurisation to the HP and LP Flares.
Water This process system is fully contained with no direct liquid releases to the environment. Aqueous methanol streams removed from the gas stream (including Produced Water) are routed to the Methanol Recovery System and ultimately treated in the Produced Water Treatment System. Drainage from the Process areas is collected via a dedicated closed drain collection network and routed to the Closed Drains Drum (D-8201) for either off-site disposal or recovery to process (Refer to Sections E.2 and F.1.2 of the IPPC Application Form for further information on the Produced Water Treatment system and the Closed Drains system). Waste Absorbent from the mercury removal bed will be periodically replaced and transported off-site for treatment/disposal. Refer to Tables H.1(i) and H.1(ii) of the IPPC Application Form for details on the waste quantities generated.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
FROM INLET SEPARATOR (PFD 1)
Mercury Removal Bed
N-1001
Gas/Gas Exchanger
E-2004
J-T Expansion Valve (x2)
PFD 2 - Gas Conditioning
SALES GAS COMPRESSOR (PFD 3)
Cold SeparatorD-2007/D-2010 METHANOL RECOVERY
(PFD 5)
CONDENSATE STABILISATION (PFD 4)
Condensate
Aqueous
Spent Absorbent
WASTE
Note 1
Note 2 FUEL GAS SYSTEM (PFD 6)
Notes
1. Bypass for temperature control in tandem with J-T valve
2. During plant start-up only gas may be taken from this point to supply the fuel gas system
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
D.1.4.3 Gas Compression and Export
Purpose Gas is compressed to the required export pressure, fiscally metered, and then odorised for leak detection purposes, prior to export to the Bord Gais distribution network.
Process Description Prior to the Sales Gas Compressors the gas stream passes through a Suction Knockout (KO) Drum (D2009 A/B). The KO drum prevents any residual liquid in the gas stream from entering the compressors. The conditioned gas is compressed to export pressure by the Sales Gas Compressors (K-2002 A/B). Two compression trains (compressors), operating on a duty/standby basis are provided with each compressor rated for 100% flow of 350 MMSCFD of natural gas. Each compressor is powered by a gas turbine fuelled from the High Pressure (HP) fuel gas supply. The gas turbines will operate in simple cycle and have Waste Heat Recovery Units (E-5002 A/B) installed. The Waste Heat Recovery Units will use surplus heat from exhaust gases from the gas turbines to provide heat for the Terminal. The exhaust gases from the gas turbines are represented by A2-1 and A2-2. The turbines will incorporate low NOx burners. Each turbine has a maximum rating / compressor duty of 7.7 MW and a corresponding maximum net rated thermal input of 25.7 MW. Each gas turbine consists of three basic sections: an air compressor section in which air is compressed in a compressor, the combustor section in which fuel (gas) is mixed with the compressed air and burned, and the turbine section where mechanical energy is extracted from the hot gases. The expansion of the gases against the blades of the turbine provide power to drive the directly coupled inlet air compressor and sales gas compressor.
After compression the gas stream is cooled to 35 °C in the Sales Gas Compressor Aftercoolers (E-2005A/B). Gas for the fuel gas system will be taken downstream of the Aftercoolers.
Sales Gas flow and quality will then measured in the Sales Gas Metering Package (N-2001), which consists of 2 x 100% metering runs. Gas quality is measured by on-line gas chromatographs and the data reported to the control system.
Odourant is then added to the sales gas by the Odourisation Package (N-2002). This consists of an odourant storage tank and dosing pumps. The odourant is a mixture of Tertiary Butyl Mercaptan (80%) and Di-Methyl Sulphide (20%). The package is specified as ‘zero discharge’ during operation and loading and includes activated carbon (anthracite) filters on both the instrument cabinet and storage tank. Any fugitive emissions of odourant generated during tank filling or maintenance will neutralised by a hand held spray deodorizer used by the maintenance contractor. Therefore there should not be any malodorous fugitive emissions generated.
A simplified Process Flow Diagram (PFD 3) of the process is attached.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
Process Control Pressure relief is provided for each compression train routed to the HP Flare header. Emergency blowdown of each train (to HP Flare) is by operator initiation. Each compressor is protected by an anti-surge recycle valve, which ensures a minimum flow through the machine to avoid surge. The required gas export rate is set in the control system and the compressor speed is controlled to achieve this. Environmental Emissions
Air Emissions Main: Combustion byproducts (NOx, CO, unburnt hydrocarbon and water
vapour) from the gas turbines are discharged via Emission Points A2-1 and A2-2.
Minor: Maintenance activities may require depressurisation of the plant using the Maintenance Flare (used on a limited infrequent basis). Additionally a small amount (ca. 9 kg/hr) of seal gas (80% nitrogen, 20% natural gas) from one of the sales gas compressors (duty/standby) will be vented on a continuous basis to the LP flare. There will also be limited turbine fuel gas purging on start-up/shutdown typically once every 3 months.
Potential: There may be some fugitive hydrocarbon emissions during normal operation. Emergency situations may require depressurisation to the HP and LP Flares.
Water Emissions This process system is fully contained with no direct liquid releases to the environment. Drainage from the Process areas is collected via a dedicated closed drain collection network and routed to the Closed Drains Drum (D-8201) for either off-site disposal or recovery to process (Refer to Section E.2 of the IPPC Application Form for further information on the Closed Drains system).
Waste Activated Carbon (anthracite) on the odourisation package will be periodically replaced and transported off-site for treatment/disposal. Refer to Tables H.1(i) and H.1(ii) of the IPPC Application Form for details on the waste quantities generated.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
FROM GAS CONDITIONING
(PFD 2)
Suction KO Drums D-2009 A/B
Sales Gas Compressor (powered by Gas Turbine)
K-2002 A/B
Compressor After CoolersE-2005 A/B
Metering PackageN-2001
PFD 3 - Gas Compression & Export
Odourisation PackageN-2002
BORD GAIS (BG) DISTRIBUTION SYSTEM
Combustion By-Products
ATMOSPHERE EMISSION POINTS
A2-1, A2-2
Fuel Gas
Air
SpentAnthracite Filters
WASTE
FUEL GAS SYSTEM (PFD 6)
Waste Heat Recovery Units
E-5002 A/B
HEATING MEDIUM FROM PROCESS
HEATING MEDIUM TO PROCESS
Seal gas
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
D.1.4.4 Condensate Recovery & Stabilisation
Purpose Hydrocarbon condensate recovered from the Corrib Field natural gas is stabilised and stored for off-site export via tankers. Gas flashed from the process is used as LP fuel gas.
Process Description Condensate from the slugcatcher is fed under flow control through the HP Condensate Filter (F-1002A/B) which removes any residual solids from the condensate stream, then mixed with condensate from the Inlet Filter Separator (D-1003), Cold Separators (D-2010) and Knock-Out drums (D-2009A/B), before passing to the MP Flash Drum (D-3001). In the MP flash drum, light hydrocarbons are flashed from the condensate stream and routed to the LP fuel gas system. The aqueous phase is separated in a water boot or sump and returned, under level control, to the Methanol Flash Drum (D-4001). A new Cold Separator D-2010 has been added and replaces the use of D-2007 to provide improved capability of meeting the gas sales specification at a wider range of process conditions.
The condensate stream is also passed through a level control valve which reduces the pressure. It is then heated in Condensate Heaters (E-3001/E-3005) and flows to the LP Flash Drum (D-3002) where this condensate is further stabilised. The condensate Heater E-3005 is an additional electric heater added since the original IPPC application. The new condensate heater has been added to give improved operability at low condensate flowrates. The existing planned heater is sized for 578kw and is retained, the new additional heater is 20kw and will mean more consistent production of on-spec condensate particularly during turn down and low flow situations. The introduction of the new heater represents an improvement in overall plant energy efficiency. There are no direct emissions from the condensate heater and a slight reduction in overall plant emissions may be expected due to the decrease in energy demand with its use. Low pressure flash gas produced is fed, via the LP flash drum (D-3002) to the suction of the LP Gas Compressors (K-3001A/B) which compress the gas for use in the LP fuel gas system.
The condensate is then pumped under level control to the Condensate Cooler (E-3002), which is a fin/fan air cooler. The temperature control acts to adjust the fan pitch or louvre position to vary the cooling achieved. The condensate then passes through a Mercury Removal Bed (N-3001) to reduce the mercury content (if present) of the condensate to < 0.5ppm wt before flowing to the Condensate Storage Tanks. The mercury removal absorbent bed contains a mixture of copper, zinc and aluminium sulphides/oxides. Mercury is removed from the condensate by a process of oxidation as it comes into contact with the absorbent bed. There are two Condensate Storage Tanks (T-3001 A/B). One will be an on-line tank and is used to collect stabilised condensate whilst the second, or the off-line tank, is used to store stabilised condensate for export. The storage tanks are used alternatively for collection from process and supply to road tanker. The storage tanks have fixed roofs with internal floating covers and are nitrogen blanketed.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
All condensate will be exported offsite as a by-product by a licensed contractor. The Off-spec condensate tank (T-3002) will not be used as a storage tank and will only be used as a buffer vessel during upset conditions for immediate rerouting of off spec condensate back through the condensate stabilisation process. The off-spec condensate tank is a closed vent fixed roof nitrogen blanketed tank.
A simplified Process Flow Diagram (PFD 4) of the process is attached.
Process Control Condensate is reduced in pressure across flow and level control valves before passing to the MP Flash Drum (D-3001). The MP flash drum is pressure controlled to approximately 6 barg, thus flashing the light hydrocarbons, and the separated aqueous phase is level controlled to the Methanol Flash Drum (D-4001). The resulting condensate stream is level controlled through to the Condensate Heaters E-3001/E3005 where it is heated to approximately 120°C. The flow of heating medium is controlled to satisfy the required condensate exit temperature.
The heated condensate flows to the LP Flash Drum (D-3002), which operates at approximately 1.5 barg, resulting in gas/liquid separation, stabilising the liquid condensate to a Reid Vapour Pressure (RVP) of 12 psia. The low pressure flash gas produced is fed to the suction of the LP Gas Compressors (K-3001A/B) which compress the gas to 5 barg for use in the LP fuel gas system.
The efficacy of the mercury removal beds is confirmed by manual sampling on a regular basis.
Environmental Emissions Air
Main: There are no main emissions to air Minor: The process is normally operated with no minor emissions.
Maintenance activities may require depressurisation of the plant using the Maintenance Flare (used on a limited infrequent basis).
Potential: There may be some fugitive hydrocarbon emissions from the condensate storage tanks during normal operation. Emergency situations may require depressurisation of the plant using the HP and LP Flares.
Water This process system is fully contained with no direct liquid releases to the environment. Aqueous methanol streams removed from the gas stream (including Produced Water) are routed to the Methanol Recovery System and ultimately treated in the Produced Water Treated System. Operational and maintenance drainage from the Process areas is collected via a dedicated closed drain collection network and routed to the Closed Drains Drum (D-8201) for either off-site disposal or recovery to
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
process (Refer to Sections E.2 and F.1.2 of the IPPC Application Form for further information on the Produced Water Treatment system and the Closed Drains system).
Waste All surplus condensate will be exported off–site as a by-product from the process. Filter cartridges from the condensate filter (F-1002A/B) will be periodically replaced and transported off-site as hazardous waste for treatment/disposal. Spent absorbent from the mercury removal bed will be periodically replaced and transported off-site for treatment/disposal. Refer to Tables H.1(i) and H.1(ii) of the IPPC Application Form for details on the waste quantities generated.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:14
MP Flash DrumD-3001
Condensate Heaters E-3001/E-3005
LP Flash DrumD-3002
PFD 4 - Condensate Recovery & Stabilisation
Condensate Coolers E-3002
HP Condensate FilterF-1002 A/B
FROM SLUGCATCHER D-1002
INLET SEPARATOR D-1003
COLD SEPARATOR D-2007 / D-2010
METHANOL FLASH DRUM D4001
Flash Gas
Aqueous
LP FUEL GAS SYSTEM (PFD 6)
METHANOL RECOVERY (PFD 5)
Flash Gas
Mercury Removal Bed
N-3001
Condensate Storage Tanks
T-3001 A/B
Off-Spec Condensate
Storage Tank T-3002
EXPORT BY TANKER
ATMOSPHERE
Spent Absorbent
Off-Spec Condensate Recycle
ATMOSPHERE
WASTE
Spent Cartridge WASTE
LP FUEL GAS SYSTEM (PFD 6)
COMPRESSOR SUCTION K.O. DRUM D-2009 A/B
N2 to tank
N2 to tank
CONDENSATE FROM METHANOL FLASH DRUM AND METHANOL COALESCER
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.4.5 Methanol Recovery, Regeneration and Chemical Injection Purpose Methanol essentially acts as an antifreeze agent and is used to prevent freezing (and hydrate formation) within the off-shore and on-shore facilities. Methanol that is injected to the offshore facilities (via the umbilical cable) is recovered from the production fluids entering the Terminal, and regenerated for re-use. Methanol used in the on-shore facilities (primarily at start-up) is similarly recovered as an aqueous liquid, and regenerated for re-use (product methanol). Corrosion inhibitor is injected into the methanol that is pumped offshore. The corrosion inhibitor prevents corrosion of the offshore facilities. Process Description The aqueous layer that is separated from hydrocarbons in the slugcatcher is fed under level control through the Aqueous Filter (F-1001) which removes any residual solids and then mixed with the aqueous streams from the inlet filter separator (D-1003) and cold separator (D-2010) from there to the Methanol Flash Drum (D-4001). In the flash drum light hydrocarbons are flashed from the methanol streams for use in the LP fuel gas system. The hydrocarbon phase is separated and transferred, under level control, to the MP Flash Drum (D-3001). The methanol stream then flows to the Raw Methanol Storage Tanks (T-4001 A/B/C) for additional settling and separation of entrained hydrocarbons. The three tanks are operated in fill, settle and draw mode. The three tanks have fixed roofs and internal floating covers equipped with nitrogen blanketing. Methanol solution is then pumped to the Methanol Still (C-4001) via the Still Feed/Bottoms Heat Exchanger (E-4001) which heats the raw methanol stream with the water effluent from the still. A Methanol Coalescer (D-4003) is provided downstream of the exchanger to remove any final trace hydrocarbons. Separation of the methanol and water solution takes place in the Still (column), generating two streams; product (98% methanol) and produced water (with 50 ppmwt methanol).
The column is heated via a Kettle Reboiler (B-4001) operating at 113oC. Vapour product from the column is condensed in a forced draught Air Cooler (the Condenser) and flows to the Methanol Reflux Drum. Methanol from the Reflux Drum is pumped back to the column under flow control as reflux and to product storage in tanks (T-4002 A/B) under level control. The two tanks are fixed roof with internal floating covers equipped with nitrogen blanketing. Product methanol from the storage tanks is pressurised by centrifugal booster pumps, passes through the Export Filters (F4002A/B) (to remove any residual solids) and is then pumped to either the Terminal or the offshore system. Under normal operation the overhead stream (methanol) from the Still is totally condensed and there is no venting of gas to the LP flare system. Under upset conditions, such as the ingress of non-condensables into the column, the reflux drum will be vented to the LP flare header. Corrosion inhibitor is injected into the methanol stream downstream of the Export Filters by methanol injection pumps. The Corrosion Inhibitor Package (N-9001)
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
stores and injects inhibitor into the methanol system for transfer to the offshore facilities. A simplified Process Flow Diagram (PFD 5) of the process is attached.
Process Control The methanol still consists of 35 valved trays and a bottom tray as feed to the reboiler (heating element). The feed-stream enters at the 18th tray from the top of the column. Heat input to the column is achieved via the kettle reboiler utilising the heating medium.
Methanol from the Reflux Drum is pumped as a reflux back to the column under flow control to control overhead temperature, and to product storage under level control. The two product methanol tanks (T-4002 A/B) are operated on alternate fill and empty mode. All control points are set and trended in the Terminal control system.
Methanol Distillation Column Design Capacity The methanol distillation column is designed to process approx 13 m3/h of aqueous material comprising approx 18-35% methanol in water. The distillation column is designed to turndown to less than 50% of maximum throughput. The column is designed to provide constant methanol quality over the range of operating flowrates.
Acid Wash A methanol still acid wash system is provided in case there is need to periodically de-scale the system using 5% hydrochloric acid solution dosed with corrosion inhibitor. Spent acid will be removed by road tanker and disposed of in the correct manner by a licensed waste contractor.
Environmental Emissions Air Main: There are no main emissions to air Minor: The process is normally operated with no minor emissions. Although
not intended during normal operation, if required overhead pressure control on the Methanol Reflux drum will be provided by cold venting to the LP flare stack.
Potential: The storage tanks are nitrogen blanketed with relief vent to atmosphere. There may be some fugitive hydrocarbon emissions during normal operation. Emergency situations may require depressurisation of the plant using the HP and LP Flares.
Water This process system is fully contained with no direct liquid releases to the environment. Still bottoms (ie. Produced Water) is treated in the Produced Water Treatment System. Operational and maintenance drainage from process areas is collected via a dedicated closed drain collection network and routed to the Closed
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
Drains Drum (D-8201) for either off-site disposal or recovery to process (Refer to Sections E.2 and F.1.2 of the IPPC Application Form for further information on the Produced Water Treatment system and the Closed Drains system).
Waste The Aqueous Filter (F-1001A/B) and Export Filter (F-4002A/B) cartridges will be periodically replaced and transported off-site for treatment/disposal. Acid washing of the reboiler will remove scale, which will be transported off-site for treatment/disposal. The valves, trays of the methanol still and reboiler tubes may require intermittent replacement and will be treated/disposed off-site. Refer to Tables H.1(i) and H.1(ii) of the IPPC Application Form for details on the waste quantities generated.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
Methanol Flash Drum D-4001
Raw Methanol Storage TanksT-4001 A/B/C
PFD 5 - Methanol Recovery, Regeneration & Chemical Injection
Still Feed/Bottoms
Exchanger E-4001
FilterF-1001
FROM SLUGCATCHER D-1002
INLET SEPARATOR D-1003
COLD SEPARATORSD-2007/D-2010
MP FLASHDRUM D-3001
Flash Gas
Hydrocarbon CONDENSATE STABILISATION(PFD 4)
PRODUCED WATERTREATMENT
Still Bottoms/ Produced Water
Coalescer D-4003Still C-4001
Reboiler B-4001
Product Methanol
Storage Tanks T-4002 A/B
ATMOSPHERE
N2 TO TANK
Condenser Reflux Drum
LP FLARE
TERMINALFACILTIES
HEATING MEDIUM
Produced Water
Spent Filter Cartridge
Spent Filter Cartridges
CorrosionInhibitor
LP FUEL GAS SYSTEM (PFD 6)
Export FiltersF4002A/B
WASTE
WASTE
ATMOSPHERE
OFF-SHORE FACILTIES
CLOSED DRAINS DRUM D-8201
WASTE Reboiler Acid Wash
Oxygen Scavenger
N2 TO TANK
MAKE-UP METHANOL FROM TANKER
SCALE INHIBITOR
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
ATTACHMENT No. D.1.5
Utilities
Attachment D.1.5 Utilities D.1.5.1 Fuel Gas System
PFD 6
D.1.5.2 Heating Medium System and Waste Heat Recovery PFD 7
D.1.5.3 Utility Gases D.1.5.4 Potable and Service Water Systems
PFD 8
D.1.5.5 Power Generation
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.5 Utilities
This section includes process descriptions and simplified process flow diagrams (PFDs) (where appropriate) for the main utilities at the Terminal. For ease of reference, in the process descriptions, the main equipment is numbered in accordance with the Overall Plot Plan included as Attachment D.1.1.
D.1.5.1 Fuel Gas System
Purpose Natural gas that is used as a fuel in the Terminal is referred to as fuel gas. High Pressure (HP) fuel gas is used as a fuel in the sales gas compressor turbine drivers. Low Pressure (LP) fuel gas is used as a fuel in the gas engines used as power generators, and also provides back-up for the nitrogen purge to the LP and HP flare headers.
Process Description HP fuel gas is sourced from the sales gas supply. A secondary supply is available from the Inlet Gas (after mercury removal), during plant start-up, although this is unlikely to be used now given the availability of backfeed gas from the BGE network. The gas is pre-heated in the electric Fuel Gas Pre-Heater (E-8403 A/B) and pressure is then let-down to the HP system operating pressure (25-35 barg) as it enters the HP Fuel Gas Knockout (KO) Drum (D-8402) which removes any residual liquids from the gas stream. The gas stream then passes through the electric HP Fuel Gas Heater (E-8402) which provides 20oC superheat before passing to the sales gas compressor turbines.
LP Fuel Gas is primarily sourced (approx. 90%) from sales quality gas. The balance (approx 10%) is from the MP Flash Drum. The amount of mercury in the LP fuel gas stream would be in the region of less than 0.01μg/m3.
Flash gas from the condensate recovery system is compressed in the LP Gas Compressor (K-3001A/B) before passing through the LP Gas Compressor KO Drum (D-3003 A/B) which removes any residual liquids from the gas stream. This gas stream is combined with HP fuel gas that has been let-down to the operating pressure of the LP fuel gas system. The stream then enters the LP Fuel Gas KO Drum (D-8401), which removes any residual liquids. The LP Fuel Gas Heater (E-8401) then provides 20oC superheat to the LP fuel gas for supply to the gas engines.
A simplified Process Flow Diagram (PFD 6) of the process is attached.
Process Control Both the LP and HP systems are controlled by fuel gas demand. Sales gas is electrically pre-heated to approximately 50°C by the electric Fuel Gas Pre-Heater and then let-down to a pressure of 20 to 24 barg, prior to feeding the HP and LP fuel gas systems. The HP Fuel Gas Heater heats the gas stream to 38oC (normal) prior to use in the sales gas compressor turbines.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
Gas sourced for the LP System is let-down to the LP fuel gas system operating pressure of 5 barg as it enters the LP Fuel Gas KO Drum. The LP Fuel Gas Heater provides 20oC superheat to the gas before distribution.
Environmental Emissions
Air Main: There are no main emissions to air
Minor: The process is normally operated with no minor emissions. Maintenance activities may require depressurisation of the plant using the Maintenance Flare (used on a limited infrequent basis).
Potential: There may be some fugitive hydrocarbon emissions during normal operation. Emergency situations may require depressurisation of the plant using the HP and LP Flares.
Water This process system is fully contained with no direct liquid releases to the environment. Operational and maintenance drainage from process areas is collected via a dedicated closed drain collection network and routed to the Closed Drains Drum (D-8201) for either off-site disposal or recovery to process (Refer to Section E.2 of the IPPC Application Form for further information on the Closed Drains system).
Waste There is no waste generated from this system other than from normal maintenance activities.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
LP Fuel Gas KO Drum D-8401
PFD 6 - Fuel Gas System
LP Gas CompressorKO Drum
D-3003 A/B
Condensate
CONDENSATE STABILISATION (PFD 4)
LP Fuel Gas HeaterE-8401
POWER GENERATORS
HP Fuel Gas KO Drum D-8402
HP Fuel Gas HeaterE-8402
GAS TURBINES
Fuel Gas Pre-HeaterE-8403 A/B
FROM INLET GAS
FROM SALES GAS
CONDENSATE RECOVERY & STABILISATION (PFD 4)
Flash Gas
LP Gas Compressor K-3001 A/B
FLARE PURGE (BACK-UP)
Flash Gas
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.5.2 Heating Medium System and Waste Heat Recovery
Purpose A 40 %wt Tri-Ethylene-Glycol (TEG)/Water mixture is used as a heating medium to provide heating to various terminal process operations. The use of 40 %wt TEG elevates the boiling point of the mixture to safe operating levels and avoids use of a steam system for heat distribution on site.
Process Description The Heating Medium System uses a 40 %wt Tri-Ethylene-Glycol (TEG)/Water mixture with make-up, storage and dedicated drainage facilities provided for system maintenance. The Heating Medium Storage Tank (T-5001) provides first fill of the system, supplies intermittent make-up to the surge drum, and provides storage of the total inventory of the circuit during shutdown. The Heating Medium Transfer Pump (P-5001) is used to transfer the make-up fluid to the surge drum. The users and header pipework all drain to the Heating Medium Closed Drains Drum (D-8202). The fluid in the heating medium closed drain drum is pumped to the storage tank using the Heating Medium Drains Pump (P-8202); the pump will only operate if the fluid temperature is below 70ºC to ensure only stable product is transferred to the heating medium storage tank. A minimum flow path via the dump cooler is provided for low flow requirements.
The heating medium is circulated from the surge drum through the Waste Heat Recovery Units (E-5002A/B). These units heat the heating medium fluid. The waste heat recovery units will increase the overall energy efficiency of the terminal. They will be attached to the gas turbine exhausts to recover heat energy that would be otherwise lost. This recovered heat is then utilised for other terminal applications. The heated heating medium fluid is then distributed to the process users (Inlet Heater, Cold Condensate Heater, Methanol Reboiler and Condensate Heater). The heating medium fluid then returns to the surge drum completing the closed circuit.
A simplified Process Flow Diagram (PFD 7) of the process is attached.
Process Control TEG make-up concentration, in the storage tanks, is controlled by dilution of tankered TEG with service water. The heating medium supply temperature to the users is controlled by modulation of the dampers on the WHRU. Each of the heating medium end users has local temperature and flow control to deliver the necessary duty.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
All control points are set and trended in the Terminal control system.
Environmental Emissions
Air
Main: There are no direct emissions for the heating medium system. Main air emissions are associated with the Sales Gas Compressors (A2-1 and A2-2) which supply heat to the heating medium system via the Waste Heat Recovery Units.
Minor: The process is normally operated with no minor emissions. Potential: The heating medium storage tanks is fixed roof with vent to
atmosphere.
Water This process system is fully contained with no direct liquid releases to the environment. Operational and maintenance drainage from the heating medium system is collected via a dedicated closed drain collection network and routed to the Heating Medium Closed Drains Drum (D-8202) for recovery to the storage tank (Refer to Section E.2 of the IPPC Application Form for further information on the Closed Drains system).
Waste The tri-ethylene glycol inventory will require replacement periodically due to the slow degradation of TEG itself and will be transported off-site for treatment/disposal. Refer to Tables H.1(i) and H.1(ii) of the IPPC Application Form for details on the waste quantities generated.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
PFD 7 - Heating Medium System & Waste Heat Recovery
TURBINE EXHAUST GAS
Heating Medium Storage Tank
T-5001
PROCESS USERS• Inlet Heater• Methanol Reboiler• Condensate Heater• Dump Cooler
Surge DrumD-5001
N2
HEATING MEDIUM CLOSED DRAINS DRUM
D-8202
TEG MAKE-UP
MAKE-UP WATER
Waste Heat Recovery Units E-5002A/B
ATMOSPHERE EMISSION POINTS
A2-1, A2-2
Heating Medium Closed Drains Drum
D-8202
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.5.3 Utility Gases Purpose Utility gases (instrument air, plant air, nitrogen) are generated on site for utility supply and use as a blanketing gas (nitrogen). Nitrogen is used in the blanketing / purging of tanks, process vessels and pipework for safety purposes and it reduces fugitive hydrocarbon emissions. The use of nitrogen ensures an inert atmosphere (absence of oxygen) and prevents the occurrence of potentially flammable / explosive atmospheres. It also limits oxygen ingress which could lead to corrosion of some equipment.
Instrument Air The Instrument Air Package (N-8501) supplies clean, dry, compressed air at 10 barg to the Instrument Air Receiver (D-8501). The package comprises 3 x 50% capacity compressors, a wet air receiver and air drier/filter, and provides 1050 Nm3/hr of air. The instrument air leaves the instrument air receiver through instrument air filters for distribution to users via a dedicated header.
Plant Air The plant air is supplied from the instrument air system. The plant air is pressure controlled to 6.5 barg, prior to distribution to users, such as portable air tools. Normally there are no plant air users. In the event that the plant air consumption draws down the instrument air pressure to 8 barg, the third compressor starts. If the pressure falls below 6 barg, the plant air system isolation valves are closed to avoid further depletion of the instrument air system pressure.
Nitrogen System Nitrogen is generated by the Nitrogen Generation Package (N8601A/B) which consist of 2 x 100% membrane air separation units, and the generated nitrogen is stored in the Nitrogen Receiver (D-8601) at 6-8 barg, prior to distribution to users via a dedicated header. The package is capable of providing 250 Nm³/hr nitrogen to the downstream Nitrogen Receiver, and is fed with compressed air from the instrument air system. A bottled back-up, consisting of two Nitrogen Bottle Racks (N-8602A/B) and a manifold (N-8603) is provided in case of loss of the nitrogen generation.
Process Control All utility gas package systems are locally controlled with feedback and monitoring via the Terminal control system. Environmental Emissions
Air
Main: The process is normally operated with no emissions to air. Minor: There are normally no minor emissions to air except for the
venting of air from drier packages. Potential: There are no potential emissions
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
Water There are no direct emissions to surface waters / ground waters from these packages. Small quantities of water may be discharged from the air dryer package and is directed to the oily water treatment system via the open drains sump.
Waste Silica gel in the air drier and the membranes from the Nitrogen generation units will be periodically replaced and transported off-site for treatment/disposal. Refer to Tables H.1(i) and H.1(ii) of the IPPC Application Form for details on the waste quantities generated.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.5.4 Potable and Service Water Systems Purpose
The local authority water supply will be used for firewater makeup and will undergo treatment at the Terminal prior to use as a supply of potable and service water.
Process Description It is estimated that the Terminal will require ca. 18 m3/day of water from the local authority supply during operation. The local authority supply originates from the potable water treatment facilities at Carrowmore Lake (Barnatra). Make-up water for the Firewater Pond (T-8701) is taken from the incoming local authority water supply prior to the initial Water Filters (F-8901 A/B). The incoming water supply is pumped, on level control, through the Water Filters (F-8901 A/B) for particulate removal. Water is disinfected with a Chlorination Package (N-8902) to prevent algae growth in the holding tank and then passes to the Potable Water Tank (T-8901), which is sized for 7 days storage.
The potable water pumps (P-8901 A/B) transfer water from the Potable Water Tank to the UV Sterilisation Package (N-8901), where the water is irradiated with ultra-violet light. This sterilises the water to ensure that it is suitable for personnel consumption and safety showers.
Service water is taken off after the incoming local authority water is filtered at the Water Filters. The filtered water is transferred to the Service Water Break Tank (T-8902) through a float valve to maintain the level. The service water is used for make-up to the heating medium and chemical systems (e.g. regenerants in water treatment). All water for hosing is taken from the firewater system. The use of the break tank avoids the possibility of back-contamination of the potable water supply. The Service Water Distribution Pumps (P-8902 A/B) supply up to 7.9 m³/hr for distribution to users.
A simplified Process Flow Diagram (PFD 8) of the process is attached.
Process Control The potable water tank provides 7 days storage to satisfy the domestic and potable water demand. Chlorination is controlled by continually measuring chlorine residual. The UV lamp intensity is continuously monitored and feedback triggers cleaning and replacement. All potable water systems are locally controlled with feedback and monitoring via the Terminal control system.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
Environmental Emissions
Air Main: There are no main emissions to air
Minor: There are no minor emissions to air Potential: There are no potential emissions to air
Water There are no direct emissions to surface waters / ground waters from this system.
Waste The inlet filters will generate waste for disposal. The potable water tanks will be cleaned as required and some sludge material may be generated for disposal. Waste streams will be transported off-site for treatment/disposal. Refer to Tables H.1(i) and H.1(ii) of the IPPC Application Form for details on the waste quantities generated.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
PFD 8 - Potable & Service Water System
Water Filters F-8901 A/B
LOCAL AUTHORITY WATER SUPPLY
Particulates
ChlorinationPackageN-8902
Potable Water Tank T-8901
Potable Water Pumps
P-8901 A/B
UV SterilisationPackage N-8901
Service Water Break Tank
T-8902
Distribution Pumps
P-8902 A/B
FIREWATER POND T-8701
DOMESTIC USE AND SAFETY SHOWERS
HEATING MEDIUM AND CHEMICAL
SYSTEMS
WASTE
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.5.5 Power Generation Purpose The power requirements of the Terminal are provided by on-site generator sets driven by natural gas fuelled spark ignition (SI) engines. Process Description The plant will be self-sufficient in power generation, with 3 x 50% Power Generators (G-8801 A/B/C) each with a rating / duty of 1.32 MW (maximum net rated thermal input of 3.22 MW). The Power Generators will be LP fuel gas fired SI engines incorporating and Selective Catalytic Reduction (SCR) units on their exhausts. Each generator set will be capable of supplying half the maximum power demand of the Terminal. During normal operating conditions the power requirement of the Terminal will be supplied by two of the generators running at equal load, with the third unit on standby. Depending on Operational and Commercial requirements, a small percentage of overall load will be taken from the grid supply. The primary use of the grid supply is to provide a backup power supply to the firewater transfer sumps. The configuration of the electrical switchgear allows the grid to partially replace power from the gas engine generators. The objective of installing the SCR units (G-8801A/B/C) is to reduce the emissions of the exhaust gas from the main electrical power generator engines and thus ensure that emission levels are within the emission limit values set down in current IPPC license. The SCR process equipment is located in a new building, which is an annex building to the main generation building. The SCR process is a catalytic process based on the selective reduction of nitrogen oxides with ammonia or urea in the presence of a catalyst. The process chosen by SEPIL will use urea as the reducing agent, and will have a dedicated catalyst system for each gas engine. An Emergency Generator (G-8802), with a rating / duty of 0.65 MW (maximum net rated thermal input of 1.9 MW) will provide emergency power to critical users on loss of the normal power supply, or to meet black-start demands. The Emergency Generator will be a diesel fired compression ignition engine. Diesel is stored in a main Diesel Storage Tank (T-8803), and is pumped to the local day tanks for each user through a distribution header by the Diesel Distribution Pump (P-8801). The emergency generator will be provided with its own diesel storage day tank to ensure security of supply. In the event that the emergency generator were also to fail, then a battery back-up system, known as the uninterruptable power supply (UPS), will take over to allow safe shutdown of all plant systems and to provide minimum power for essential control functions.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
Process Control The power generation package control systems include automatic and manual start mode, load sharing and load management. Each unit will include automatic control of output voltage control and frequency. Signal interfaces are provided to the Terminal control system allowing all status and operating data to be displayed in the control room. Environmental Emissions Air Main: Combustion by-products from the three Power
Generators are discharged via Emission Points A2-4, A2-5 and A2-6.
Minor: Combustion by-products from the emergency power generator are discharged via Emission Point A3-2. Minor emission of ammonia will occur from operation of the SCR units.
Potential: There are minor potential emissions.
Water: There are no direct emissions to surface waters / ground waters from this system. Waste: There is no waste generated from this system other than from normal maintenance activities.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
ATTACHMENT No. D.1.6
Safety Systems
Attachment D.1.6 Safety Systems D.1.6.1 Flaring D.1.6.2 Firewater D.1.6.3 Nitrogen Blanketing D.1.6.4 Emergency Shutdown and Depressurisation (ESD) system
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.6 Safety Systems This section includes descriptions of the safety systems at the Terminal. For ease of reference, the main equipment is numbered in accordance with the Overall Plot Plan included as Attachment D.1.1.
D.1.6.1 Flaring Purpose
Flare systems will be provided at the Terminal for depressurisation of the plant for maintenance purposes (Maintenance Flare) during upset conditions and emergency situations (HP and LP Flare). Process Description Maintenance Flare System The maintenance flare will be used only to depressurise equipment during planned and unplanned maintenance. Unplanned events such as failure of a compression train would require the use of the maintenance flare. When the terminal is shutdown for planned annual maintenance there will be no emissions from other sources, except the emergency generator. After the initial depressurisation of a system to the maintenance flare, the system will remain lined up to the maintenance flare to act as a safe ventilation route for the duration of the maintenance activity. The Maintenance Flare is a ground flare sized for 10 MMSCFD (million standard cubic feet per day) of gas. Ignition of the flare is by a pilot which burns fuel gas, with propane from cylinders being available as back up. The pilot is only ignited during flare use. The flare header is normally purged by nitrogen to ensure that a flammable atmosphere never occurs in the header system. HP and LP Flare System The plant has two discrete flare systems from High Pressure (HP) and Low Pressure (LP) sources. The emergency flare systems have separate collection headers, knock-out drums, stacks and flare tips, but the stacks utilise a common structure. The HP flare system is sized for a flow of 350 MMSCFD providing full flow relief of the gas export system. The flare header collects all HP relief lines and blowdown lines from the process and passes them to the HP Flare KO Drum (D-8101) for liquids removal. The LP flare system is sized for a flow of approximately of 23.6 MMSCFD. The flare header collects all LP sources from the process and passes them to the LP Flare KO Drum (D-8102) for liquids removal. During normal operation, when there is no demand for flaring, the pilots are not ignited. However, when a significant flow of gas is detected to either the HP or LP Flare stacks, pilots on both stacks are automatically ignited by the common Ignition Control System. Propane stored in cylinders is provided as back-up to fuel gas ignition. The flare
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
header is normally purged by nitrogen to ensure that a flammable atmosphere never occurs in the header system. Process Control The flare system collects all flows from relief valves and routes them directly to the appropriate flaring system. All flares have automatic ignition systems. Flare system status is displayed and trended on the Terminal control system.
Environmental Emissions (Refer to section E for emissions associated with flaring)
Air Main: There are no main emissions associated with flaring.
Minor: Combustion by-products from the maintenance flare are discharged via Emission Point A3-1.
Potential: Combustion by-products from the HP and LP flares are discharged via Emissions Points A4-1 and A4-2 respectively.
Water This process system is fully contained with no direct liquid releases to the environment. Operational and maintenance drainage from the Process areas housing process equipment is collected via a dedicated closed drain collection network and routed to the Closed Drains Drum (D-8201) for either off-site disposal or recovery to process (Refer to Section E.2 of the IPPC Application Form for further information on the Closed Drains system).
Waste There is no waste generated from this system other than from normal maintenance activities.
For in
spec
tion p
urpo
ses o
nly.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.6.2 Firewater Purpose The firewater system provides water for fire-fighting purposes and delivers water to hydrants, monitors, automatic deluge systems, foam systems and hose reels at the Terminal. Process Description Water for fire-fighting purposes (i.e. firewater) will be stored in the Firewater Pond (T-8701). The design capacity (peak demand) of the firewater system is 1200 m3/hr which is based on the worst case fire scenario of a condensate tank fire with simultaneous deluge of the affected tank and adjacent tanks, the latter requirement to prevent escalation. The firewater supply will be provided by 4 No. 50% Firewater pumps (P-8701A/B/C/D) fired on diesel. Two electrically driven Jockey Pumps (P-8702A/B) are provided sized at 5% of fire pump capacity and sufficient for one hydrant. Due to the remote location of the terminal from the nearest emergency services, a total of 6 hours storage (7200 m3) of firewater will be provided in the Firewater Pond. Make-up water to the pond will be provided by local freshwater supplies. The fire mains (ringmain) is a 16 inch (diameter) grid system designed to provide a minimum discharge pressure of 7.0 barg at the furthest monitor or hydrant. The fire main system provides water for the deluge and foam generating systems. The ringmain contains sectionalising valves capable of isolating various sections of the fire main for maintenance purposes.
Hydrants provide a source of firewater for the fire hose, portable monitors, mobile foam units, mobile foam trailers and fire fighting vehicles. Water monitors provide a source of firewater for extinguishing and cooling vulnerable parts of equipment, storage tanks and structure throughout the terminal. Fixed firewater deluge systems are provided for the protection of hydrocarbon tanks, pumps, compressors, vessels and tanker loading areas. All fixed roof tanks, containing condensate or methanol, have fixed foam chambers designed to pour foam solution onto the liquid surface. Process Control A fire detection system will initiate alarms in the control room from where the firewater system will be initiated. The fire-main contains sectionalising valves capable of isolating various sections of the fire-main for maintenance purposes. Each deluge system is capable of local manual operation at the skid and remote operation from the control room.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
Environmental Emissions Air: Main: There are no main emissions from the firewater system.
Minor: Combustion by-products from the firewater pump engines are discharged via Emission Points A3-3, A3-4, A3-5 and A3-6.
Potential: There are no potential emissions from the firewater system. Water:
Used or contaminated firewater is collected in the Open Drains System and routed to the Used Firewater Pond (T-8306) prior to appropriate treatment / disposal. Refer to Section J of the IPPC Application Form for further information.
Waste There is no waste generated from this system other than from normal maintenance activities.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
D.1.6.3 Nitrogen Blanketing
Purpose Nitrogen will be used for blanketing / purging of process vessels and pipework. The use of nitrogen ensures an inert atmosphere (absence of oxygen) and prevents the occurrence of potentially flammable / explosive atmospheres. Nitrogen will be provided to tanks, flare headers and also for compressor gas seals. Refer to Section D.1.5.3 on Utility Gases for further information on nitrogen generation and use at the Terminal.
D.1.6.4 Emergency Shutdown and Depressurisation (ESD) system
The facilities will be provided with an ESD to ensure the safe isolation and shutdown of equipment under fault or fire conditions. The emergency shutdowns will operate at four levels: Confirmed fire or gas from the F&G system will result in a Terminal shutdown which will close all the terminal isolation valves and automatically blow down the relevant parts of the plant.
For
insp
ectio
n pur
pose
s only
.
Conse
nt of
copy
right
owne
r req
uired
for a
ny ot
her u
se.
EPA Export 26-07-2013:18:40:15
