Pre-fire plan and emergency response for Diesel Hydrotreater Unit (DHDT) in oil refinery
Pre-fire plan and emergency response for Diesel Hydrotreater Unit (DHDT) in oil refinery
The pre-fire plan and emergency response
strategy are crucial at oil refineries to mitigate any gas leak, fire and
explosion emergency through a proactive approach. The pre-fire plan helps
emergency responders to manage any emergency efficiently by identifying the
proactive mitigation action line for each credible identified emergency
scenario and thus helps to minimize the losses.
The Diesel Hydrotreater Unit (DHDT) is very prone to major accidents,
including fires, toxic releases and explosions due to extreme process
conditions (high pressure and temperature) and handling highly flammable gas
hydrogen. This article provides information on the best mitigation techniques
for effective emergency response by preparing a pre-fire plan and
the best firefighting strategies for Diesel Hydrotreater Unit emergencies,
including fires, explosions and the release of toxic gases.
In this article, we will discuss the different emergencies,
credible scenarios in the Diesel Hydrotreater Unit and action
plan to mitigate these emergencies by improving the implementation and practice
of the pre-fire plan (PFP) or the pre-incident plan (PIP). We
start with the general operational process of the Diesel Hydrotreater
Unit, what are the products of DHDT, the Hazards of DHDT, the required
fire protection system, emergency response planning and firefighting
strategies.
Diesel Hydrotreater Unit (DHDT) process in refinery
The prime objective of Diesel hydrotreater unit (DHDT) is
to maximize the diesel production by improving the quality of diesel ie. to
produce high grade diesel as per present market requirement.
In DHDT unit, feed (viz LGO, HGO, Vacuum diesel, LKO, HKO,
heavy naphtha from CVU/VDU, Coker naphtha, LCGO from DCU, LCO from FCCU and
steam from LPG treatment unit ) from different units and storage is mixed with
recycle hydrogen in present of catalyst in the reactor at temperature about 300-400°C
and high pressure of about 35- 125 kg/cm2.
The chemical reactions viz hydrodesulphurization, hydro-de-nitrification
and saturation of aromatic and olefin are the main reactions happening in
Diesel hydrotreater unit. There is separator column where reactor effluent is
separated into gas and liquid. Light Gas and hydrogen sulfide is removed by amine wash and gas is recycled
to reactor along with makeup hydrogen.
The hydrotreatment processes differ depending on the raw
materials and the catalysts. Hydrodesulfurization removes sulfur from kerosene,
reduces aromatic and gum-forming characteristics and saturates any olefin.
Hydroforming is a dehydrogenation process used to recover excess hydrogen and
produce gasoline with a high octane number. Hydrotreated products are mixed or
used as a raw material for catalytic reform.
Hazards of Diesel Hydrotreater Unit (DHDT)
Below
are the major hazards of Diesel Hydrotreater Unit (DHDT)
·
Fire Hazard- Jet
Fire/Pool Fire/Flash Fire
·
Toxic Release like H2S
·
Explosion –UVCE/VCE
·
Hydrocarbon Leak &
Spill
·
Hazardous Chemical Leak
·
Electrical Fire
·
High pressure and high
temperature
Safety consideration in DHDT unit
Inspection
and testing of safety relief devices is important due to the high pressures in
this process. Adequate process control is necessary to protect against clogging
of the reactor beds. Due to operating temperatures and the presence of
hydrogen, the hydrogen sulfide content of the raw material should be kept
strictly to a minimum to reduce the risk of severe corrosion.
Wet
corrosion of carbon dioxide in areas of condensation should also be considered
as while processing feed with a high nitrogen content, ammonia, and hydrogen
sulfide form ammonium hydrosulfide, which causes severe corrosion at
temperatures below the dew point of water.
Since
the Diesel hydrotreater unit (DHDT) operates at very high pressures and
temperatures, it is important to control oil leaks and hydrogen releases to
avoid fires.
As this
is a closed process, exposures are minimal under normal operating conditions.
There is a possibility of exposure to aliphatic naphtha containing benzene,
carcinogenic, emissions of hydrocarbon gases and vapors, hydrogen-rich
gases and hydrogen sulfide gases as a result of high-pressure leaks . Large
amounts of carbon monoxide can be released during change of catalyst. The
removal of catalyst vapor creates waste streams containing acidic water and
ammonia.
Safe
work practices and appropriate personal protective equipment are required when
handling the spent catalyst. In some processes, care must be taken that
explosive concentrations of catalytic dust do not form during recharging. The
discharge of the catalyst requires special precautions to avoid fires caused by
iron sulfide. The coked catalyst should be cooled to below 49 ° C before
pouring, or it should be placed in containers with nitrogen until it cools.
Credible
Emergency Scenarios in Diesel Hydrotreater Unit
The major fire incident
can take place in the process equipment involving the following scenarios.
·
Jet Fire / Flash fire in hydrocarbon
·
Pool fire in flammable liquid
·
Toxic
release (H2S)
·
Spillage of Hydrocarbon (No fire)
·
Hydrogen fire and explosion
·
Fire in heater (Furnace)
·
Explosion in heat exchanger
·
Fire in Electrical equipment
Refinery emergency response plan for DHDT
Planning for emergency preparedness and
response at a refinery is an important document developed with
reference to the quantitative risk assessment (QRA), including modelling of gas
dispersion.
Here in this article we discuss the emergency response
plan for the Diesel Hydrotreater Unit only.
We have
already identified the credible scenarios for Diesel Hydrotreater Unit reference to QRA,
then need to examine the availability of firefighting facilities and the
manpower required to manage the major risks in the DHDT.
The emergency response and the action plan must
include the mitigation measures by the operations team, the maintenance team,
the site incident controller, the security team, the firefighting crew and
medical team applicable to all credible scenarios. Now we discuss here the
course of action for all types of emergencies by each key member applicable to
the Diesel Hydrotreater
Unit.
Emergency response plan - Action by the operational team:
In the event of an emergency, by any person, activate the
manual call point (MCP) nearby and simultaneously transmit the message to the
operator of the control panel and operational Shift In charge of Diesel Hydrotreater Unit plant
via Walkie Talkie.
The control room panel officer must inform the respective plant
manager, the chief operating officer and the manager of the refinery shift.
The DHDT panel officer must inform the panels officer of
neighbouring units. Then, he must make an announcement via the public address
system to stop all work and evacuate the area immediately.
The operating team, including the field officer and the site
manager, initiates mitigation measures based on the fire / toxic release / oil
leak scenario.
Simultaneously, the operations team must initiate isolation of
the equipment / pipeline / section of the locally affected unit / plant DHDT
panel in accordance with the requirement to control the situation.
The operation team should assist the firefighting team and the
medical team by directing them to the emergency scene. They must inform the
scenario, the product involved with the operating parameters. The initial
firefighting or any other mitigation measure must be initiated by the operating
team, viz. operation of fire extinguishers, water spray system for cooling
equipment and structures, operation of fire monitors and fire hydrant, etc.
The operating team must monitor the LEL / toxic concentration
during the emergency and after completion.
DHDT incharge must maintain constant communication with the
site incident controller on the measures taken and must work under the
direction of the site incident controller.
Emergency
action by Site Incident Controller
Upon receipt of the emergency call, the site incident
controller must reach the incident site and assume overall command in
accordance with the refinery's emergency response and disaster
management plan.
Assess the situation, establish the command post in a safe
place and obtain all the information on the measures taken by the area manager
/ shift manager, the fire commander, the security officer and the maintenance in-charge.
Depending on the situation, site incident controller will
guide the operating team to initiate the necessary isolation or the emergency shutdown
of plant, if necessary. site incident controller must ensure that all of the
above emergency actions have been taken by the operations team.
The site incident controller will take all relevant
information from the fire commander and decide on the strategy to follow in
consultation with Fire chief for additional resources, calling for mutual aid
and adopting alternative methods to mitigate the emergency.
The site incident controller must ensure that the area is
barricaded, that the movement of vehicles is restricted, that evacuation and
enumeration at the assembly point are done by security team.
The site incident controller must request the maintenance team
to perform a maintenance activity to stop the leak in accordance with their
standard operating procedures.
He must ensure that the injured person has been transferred to
the health center and also ensure the availability of first aiders and
auxiliary firefighters.
The site incident controller must initiate an adequate level
of emergency siren after discussion with the chief incident controller (Refinery
Head).
He is responsible for declaring "All Clear" after
ensuring the safe mitigation of the emergency. Before declaring “All Clear”, he
must assess the situation for damage and the environmental / toxic level.
Emergency
mitigation action by Maintenance Team
The maintenance lead must ensure that the maintenance team
immediately reaches the incident site with the necessary non-sparking tools and
resources in accordance with their standard operating procedures and initiates
the action line in accordance with safe maintenance practices.
Maintenance in charge must report to the site incident
controller and issue directives for the continuation of the maintenance
activities to be carried out.
Emergency
action by Security Team:
The security officer must report to the incident site immediately
after receiving an emergency call and report to the site incident controller.
They must delimit the area and restrict the movement of
non-essential people. They must regulate traffic and authorize only emergency
vehicles on the emergency site.
Ensure an orderly evacuation to the assembly point. A security
officer counts the workforce and rebroadcasts it to the site incident
controller.
All emergency team leaders must ensure the safety of their
team members and mandatory PPE is used.
So far, we have discussed the general course of action of all
key personnel to mitigate any type of emergency in the DHDT unit.
Let's start specific emergency mitigation measures for specific types of
emergencies, as noted above.
Pre-fire plan
The pre-fire plan or pre-incident plan
is prepared to effectively mitigate any emergency to minimize the losses.
Generally, the pre-fire plan is developed by emergency responders
such as fire and rescue services. NFPA 1620 provides detailed guidelines for
developing pre-fire plans to assist emergency responders in
effectively mitigating emergencies. When developing the pre-fire plan,
it is necessary to ensure the protection of plant peoples, emergency response
personnel, property and the environment.
Pre-fire plan for DHDT in oil refinery |
The pre-fire plan must be prepared for a
specific machine / equipment / sphere/ vessel or structure in a specific installation
in refinery or oil terminal with reference to the QRA. It must be documented
and guarantee its accessibility to all emergency responders. It can be
communicated at the facility level for better understanding and to reduce the
response time of emergency responders.
Below important points must be considered in the pre fire plan document.
Data collection: QRA report and list of
credible scenarios for specific equipment.
Scope: When preparing the pre-fire
plan, the physical site condition must be taken into account.
Procedure and Templates: The
procedure for developing a pre-fire plan with a standard template
must be finalized for standardization.
Human occupation: When preparing the pre-fire
plan, the density and type of occupation and the level of exposure to a
particular equipment / area must be taken into account.
Fire protection system: During
the preparation of the pre-fire plan, collect all data to know
the availability of existing water supply and fire protection systems
Hazard Consideration: List all
possible hazards and communicate to the responders and mitigation team,
including special hazards.
Emergency management action plan and strategy:
finalize emergency operations, fire-fighting tactics, dilution and dispersion
tactics of toxic gases / flammable gases.
Resources requirement:
Estimated resources including manpower, firefighting equipment, firefighting media, etc
Welfare and medical facility:
Estimated welfare facility must be considered while preparing pre-fire plan for
major emergencies. It must also include ambulance and other emergency
transportation facility and first Aid.
Fire drill / Mock drill: Pre-incident
plan must be practiced by conducting regular fire drills/ mock drill. It should
be dynamic document and should be reviewed and revised with changes in
technology and for new hazard identification.
Pre-fire plan for Diesel hydrotreater Unit (DHDT)
Ref. Quantitative Risk Assessment (QRA) of
the Diesel hydrotreater Unit, the risk
level should be considered while preparing the pre-fire plan and
developing an emergency response plan.
The pre-fire plan can be
prepared by the fire department in consultation with the operations team.
For preparing pre-fire plan,
always ref refinery QRA study and select credible emergency scenarios. Let’s
consider that in company QRA, the risk identified as “Jet Fire in hydrocarbon mixed with hydrogen”. Jet fire / flash fire
can occur in process equipment (viz. Reactor, columns, vessels, heater charge
pumps, feed pumps and other pumps and heat exchangers, etc) with
heat radiation ranging from 1 KW/m2 to 37 KW/m2 as per QRA report. Here we must list out numbers of flash fire /
jet fire scenarios as per QRA study.
Pre-fire plan should be
prepared for all credible scenarios. Here for understanding, we are considering
below major scenarios having maximum impacts.
So, let’s start the
preparation of pre-fire plan with an example-1.
PRE-FIRE PLAN
TITLE
Pre-fire plan for jet fire due to leakage of saturated
hydrocarbon with hydrogen gas from 16’’ pipeline connecting Separator (No-xvz)
to Flash drum (No-abc) through 26mm bore /crack at Diesel hydrotreater Unit
(DHDT)
EMERGENCY
SCENARIO DESCRIPTION
Fire due to leakage of hydrocarbon
mixed with H2S and dissolved hydrogen through 26 mm hole/puncture from 16’’ pipeline
connecting Separator (No-xvz) to
Flash drum (No-abc).
Process stream is
mainly containing hydrocarbon (Naphtha and diesel), dissolved hydrogen, H2S and
trace of sour water. In case of leakage, immediately fire will take place due
to presence of hydrogen and lighter hydrocarbon
(naphtha) at auto ignition temperature. Quantity of release of material from
leak point will be higher due to high system operating pressure. Release of H2S
will create toxic and hazardous environment.
CONSEQUENCE
ANALYSIS
For Jet fire scenario, affected range would be 29 meter for 37.5 kw/m2 radiation and 72 meters for 4 KW/m2.
For pool fire scenario,
affected range would be 83 meter for max 4 KW/m2. This scenario would result
into jet fire, 3D fire with pool of burning liquid at the base and has the probability
of BLEVE in Separator or Flash Drum.
If we consider the worst
case scenario, jet fire impinging the Separator or Flash drum as it increases
the chances of BLEVE and rupture of vessel or the pipeline is quite expected.
Very careful strategy to be adopted without time wastage to avoid escalation of
emergency.
DETAIL
OF INCIDENT SITE and PROCESS INVOLVED
Incident
Location:
Oil
leakage at about 6 meters height in Diesel hydrotreater unit (DHDT) near
reactor column. Location of incident is north east corner of reactor heater.
There are two approach to incident side from north east and north west.
Equipment
Description:
Separator
(No-xvz) to Flash drum (No-abc) are provided to disengage and individually
remove hydrocarbon vapors, liquid and water. Separator splits the Recycle gas
stream from both the Hydrocarbon liquid & sour water, which contains
Ammonia & Hydrogen Sulphide. Water from Separator is diverted to flash drum
water section which is finally routed to SWS unit, Hydrocarbon liquid from Separator is sent to Flash drum under level control
& Recycle gas is sent to Recycle Gas Scrubber via Recycle gas cooler to
remove H2S. Separator pressure is controlled by PIC. Separator is operated at a temp of 57°c and pressure of 85.02 kg/cm2g.
Liquid
from flash drum feeds to Stripper under level control through fractionator bottom-Flash drum liquid exchanger, Effluent-Flash drum liquid cold
exchanger and Effluent-Flash drum liquid hot exchanger.
Flash drum pressure is controlled by purging lighters to VGO Union fining unit through. Sour water from Flash drum is diverted to SWS unit. Flash drum operated at a temp of 59°C and pressure of 36 kg/cm2g.
Flash drum pressure is controlled by purging lighters to VGO Union fining unit through. Sour water from Flash drum is diverted to SWS unit. Flash drum operated at a temp of 59°C and pressure of 36 kg/cm2g.
Product
Data:
(Note:
only relevant product data must be captured in pre-fire plan which would
help to emergency responders .i.e. fire fighters)
Name
and composition of hazardous material :
HC, H2S, Hydrogen
Important
process parameters (operating pressure) :
85 kg/cm2
Important
process parameters (operating temperature): 57 Deg. C.
Flammability
range of most flammable material involved: 4 – 74% (H2)
TLV for
toxic gas :
10 ppm (H2S)
Flash
point :
>32 deg C.
Autoignition
temperature :
256 Deg C.
Vapour
density :
3 to 5 gm/cc
Water
solubility :
Insoluble
DETAIL
OF FIRE PROTECTION SYSTEM
(Note: When preparing the pre-fire plan, the total
number of fire protection systems must be taken into account with their
identification / tagging.)
- Fire Hydrants = ___Nos and location
- HVLRM (2000 GPM) = ___Nos and location
- Water cum foam monitors = ___Nos and location
- Water spray systems (DV) = ___Nos and location
- Water spray systems (manual MVWS) = ___Nos and location
- Manual Call points = ___Nos and location
- Fire & Gas detectors= ____Nos and location and
location
- Fire Extinguishers = ___Nos and location
- Foam Trolley = ___Nos and location
- Hose Box = ___Nos and location
- Booster Pumps for tower monitors: ___ Main pumps
& ___ Jockey Pumps.
- Clean gas system for satellite buildings and
control room ___Nos
Fire hydrants, fire water monitors, & MVWS
system are
connected with main fire water header having header pressure of 10 kg/cm2, all pumps are in auto mode and pressure shall be maintained by sequential auto mechanism.
connected with main fire water header having header pressure of 10 kg/cm2, all pumps are in auto mode and pressure shall be maintained by sequential auto mechanism.
BASIC
OPERATIONAL CONTROLS AND SAFE AREA FOR FIRST RESPONDERS
Fuel supply reduction method
Basic operational control system helps to shut down of DHDT unit and will be taken by emergency depressurization to reduce
system pressure. Isolation of separator and flash drum by closing the isolation
valves and other feed.
Safe working area for firefighting
Leakage & fire from the said pipeline will contain mainly HC, Hydrogen
& H2S. Gases of combustion would include mainly Oxides of Sulphur - SO2, CO
etc apart from high radiation heat. These vapours are hazardous to health.
Possibilities of burns due to high radiation cannot be ruled out. Splashing /
3D rain fire possible. Approach fire from safe distance. All responders to wear
three-layer proximity suits along with face shield and SCBA is must. Approach
from upwind direction and maintain safe distance. Danger area is considered as
29 meters radius from point source of leakage and fire.
PRIORITIZING
THE PROTECTIVE MEASURES
Stop all work and immediate evacuation of all the
personnel in downwind or cross wind direction. Isolate the affected equipment
immediately and start depressurization.
Immediately start the water spray deluge system
by operation peoples to and operate the fire water monitor in spray mode. Water
monitor jet-cum-spray application should be angled in such a manner to cut the
path of Jet flame if it is impinging on other vessel.
Start the water spray cooling system Deluge
valves to protect nearby vessels and Fin fan cooler.
Use available portable firefighting foam trolley to apply foam for fighting ground pool fire.
Water stream from fire hydrants should be used for cooling the structures and pipelines. Continuous Foam supply shall be ensured by connecting the foam fire engine with Foam Nurser.
In case of suspected BLEVE, entire area should be evacuated including firefighters and other emergency responders. Nearby facility to keep vigilant watch.
Use available portable firefighting foam trolley to apply foam for fighting ground pool fire.
Water stream from fire hydrants should be used for cooling the structures and pipelines. Continuous Foam supply shall be ensured by connecting the foam fire engine with Foam Nurser.
In case of suspected BLEVE, entire area should be evacuated including firefighters and other emergency responders. Nearby facility to keep vigilant watch.
EMERGENCY
RESPONSE AND FIREFIGHTING STRATEGY FOR FIREFIGHTERS
After receiving an emergency call, the fire team must present
themselves urgently with all appropriate firefighting equipment, personal
protective equipment and report to the emergency site.
While taking emergency turnout from the fire station, make
sure of the wind direction, be in constant contact with the fire control room.
After reaching the emergency site, the fire tender / fire engines should only
be parked in the upwind / crosswind direction. The fire tender must be parked
in a safe place and directed towards the exit.
Evaluate the scenario, get all the information about the emergency
site from the plant shift in-charge or site incident controller and a brief
final mitigation action to all firefighters.
firefighting strategy for DHDT in oil refinery |
All members of the fire crew must wear self-contained
breathing apparatus (SCBA). Two firefighters must ensure the connection of the
hydrant to the Fire tender for make-up water and be ready for firefighting.
The rescue operation must be launched at the initial level by
two firefighters and the other firefighters must be ready for the dispersion of
gas and firefighting.
Since most of the equipment in the Diesel hydrotreater Unit are
at a high temperature and pressure, the fire commander should contact the site
incident controller to take decision on application of water / foam to the
affected processing equipment to avoid thermal stress on process equipment /
piping. If necessary, apply foam as well as DCP.
If necessary, call in for additional fire assistance and
resources. If possible, cool nearby equipment using the deluge water spray (DV)
system.
The fire commander should assess the situation and ask the
firefighting team to use a fire suit / heat resistant suit / other specialized
equipment.
Operate the groundwater monitor / tower monitor and HVLRM (high-volume long-range monitor)
for water / foam application depending on the situation.
Help the operations and maintenance team to mitigate the
incident. If there is a demand to close the process isolation valve which is engulf
in fire, the responder must wear a fire entry suit with a water spray back-up
line. These water spray must continue to provide a cooling effect to the
personnel involved in closing the isolation valve.
The fire commander must ensure the continuous application of
extinguishing means to control, contain and extinguish the fire. Water curtain
must be provided to isolate the radiant heat, if possible. Intensive cooling of
the surrounding installations must be ensured to prevent the spread of fire.
The fire chief must ensure the required fire water header pressure
of the fire water system in coordination with the operator of the fire water
pump house. If situation demand, the fire chief may consult the site incident
controller for any further assistance from mutual aid members, the auxiliary
team, etc.
All actions to mitigate the incident must be carried out under
the instructions of the fire chief. Check the LEL / toxic gas level with the
operating team in consultation with the site incident controller.
Ensure adequate drainage of spills and take the necessary
measures to eliminate any contaminated surface.
After ALL CLEAR, stop the operation of fire protection system
and communicate the fire water pump house about no further demand. Ensure the
restoration of all emergency fire equipment / appliances.
ESTIMATED
RESOURCES FOR MITIGATING THE EMERGENCY
Fire water Requirement
Equipment/ system
|
Area to be protected
|
Application rate (lpm)
|
Duration
(Minutes)
|
Water Required
(KL)
|
Hand line
|
Firemen shielding
|
925
|
60
|
55.5
|
Portable monitor –
2Nos
|
Creating water
curtain
|
4000
|
60
|
240
|
Fixed monitor -01
|
Vessel/Pipes
|
2555
|
60
|
153
|
Fixed monitor -02
|
Vessel/Pipes
|
2555
|
60
|
153.3
|
Fixed monitor -03
|
Vessel/Pipes
|
2555
|
60
|
153.3
|
DV
|
Finfan, column and
vessels
|
16730
|
60
|
1004
|
Fire engine
|
Firefighting stripper
and drum
|
4000
|
60
|
240
|
Firefighting
foam concentrate requirement
Equipment/ system
|
Area to be protected
|
Application rate (lpm)
|
Duration
(Minutes)
|
Foam Required (Ltr)
|
Monitor – 4 Nos
|
Spill on floor
|
306
|
60
|
18360
|
Fire engine monitor
|
Spill on floor
|
135
|
60
|
8100
|
Handline foam branch
– FB-10
|
Left over pockets
|
450
|
30
|
405
|
Firefighting
equipment and appliances requirement
Resources
|
Requirement
|
Unit of measurement
|
Available (Yes/No)
|
Firefighting suit
|
08
|
Nos
|
Yes
|
SCBA
|
15
|
Nos
|
Yes
|
Portable gas meter
|
2
|
Nos
|
Yes
|
Foam Engine
|
2
|
Nos
|
Yes
|
Foam nurser
|
2
|
Nos
|
Yes
|
3% foam concentrate
|
26.5
KL
|
KL
|
Yes
|
Fire water
|
857
KL
|
KL
|
Yes
|
DCP
|
500
kg
|
Kg
|
Yes
|
Foam branch FB 10x
|
2
|
Nos
|
Yes
|
Fire nozzles
|
2
|
Nos
|
Yes
|
Portable ground
monitors
|
2
|
Nos
|
Yes
|
Delivery hoses (15 m
length)
|
38
|
Nos
|
Yes
|
Dividing breaching
|
4
|
Nos
|
Yes
|
Portable foam trolley
|
4
|
Nos
|
Yes
|
Spare SCBA cylinders
|
40
|
Nos
|
Yes
|
Manpower
requirement
Fire
fighters : 14 Nos
Fire engine
drivers: 4 Nos
Fire
officers: 02 Nos
Fire
chief: 1 No
Auxiliary
fire squad members: 12 Nos
First
Aiders: 3 Nos
Addition
manpower and reliving manpower: 20 % of total first responders.
FIRE
WATER DRAINAGE AND SALVAGE
Ensure
proper draining and flushing of used high quantity water, firefighting foam and
spilled oil in WWTP system. Fire standby duty must be continue still plant
normalization and maintenance operation.
Total
fire water usages is estimated approximately is 3900 KL whereas fire fighting
foam concentrate is 27 kl
WELFARE
REQUIREMENT FOR EMERGENCY HANDLING TEAM
As the
expected duration for mitigation of this emergency is 1 hour, welfare
arrangement is required for supporting the emergency handling team. Sufficient
drinking water, dehydration material and relaxing facility with manpower
replacement facility and transportation need to be ensured.
Ambulance
with first Aiders and doctor at Occupation Health center must be ensured till
completion of emergency.
EMERGENCY CONTACT & COMMUNICATION SYSTEM
Emergency No of fire control room: XXXXXXXX
DHDT panel contact No: XXXXXXXX
******* End******
Above
is the one example of pre-fire plan for diesel
hydrotreater unit (DHDT) for one emergency scenario. Similarly, pre-fire
plan must be prepared separately for each credible scenario with ref to QRA
study.
Pre-fire
plan template
Here is
the standard template for the pre-fire plan developed according
to our experience. This template can be revised depending on the site condition.
Standard NFPA 1620, latest edition 2020 can be referenced for a pre-incident
template, but it is mainly applicable for building and may not be
suitable for a refinery.
Click
here to download
Standard template for Pre-fire plan for oil Refinery
credible scenarios
Conclusion
The Diesel Hydrotreater Unit (DHDT )is
extremely prone to major accidents, including fires, toxic releases and
explosions due to its severe process conditions. Preparation of Pre fire
plan or Pre incident plan for specific equipment in
specific operational area is the key for effective mitigation of any
emergencies. Quantitative Risk assessment must be referred while preparing the pre
fire plan. Effective emergency response can be assured by
regular practicing i.e. conducting fire drill based on pre-fire plan. Practical
firefighting strategies must be included in pre fire plan for all
emergencies, including fires, explosions and the release of toxic
gases. Important topics such as diesel hydrotreater unit (DHDT) process
description, list of hazards substances with their properties, list of
available fire protection system, layout, approach rout marking on layout, line
of action and firefighting strategies, etc must be the part of pre-fire
plan.
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