improving hf alkylation operational safety...
TRANSCRIPT
Ian Willetts, Schneider Electric
Cristina Martinez, PDVSA
Improving HF Alkylation Operational Safety Through the Use of Operator Training Simulators
Agenda
� Introduction
� What is Multi-Purpose Dynamic Simulation
� Driving Safe Operation in HF Alkylation Units
� Unique Challenges in developing OTS for HF Alkylation
� PDVSA Puerto La Cruz Experience
Alkylation
●Alkylation is the process of synthesizing isooctane (alkylate) through the reaction of iso-butane with C3 and C4 olefins using either sulfuric or hydrofluoric acid
●Both H2SO4 and HF Acids are extremely hazardous chemicals and require careful management to ensure safety
●Alkylation has grown in importance driven by the growth of FCCs and Coker Units which produce olefins or alkenes from the heavier crude components
●Europe and North America produces approximately one million barrels per day of alkylate in 75% of the world’s HF Alky Units
●SimSci has dedicated solutions to help refiners operate their alkylation units safely and profitably including Operator Training Simulators and the Acid Catalyst Analyzer
What is Multi-Purpose Dynamic Simulation?
Multi-Purpose Dynamic Simulation One Simulator for the Life of the Project
Equipment Design
CheckoutControls
Train Personnel
ImprovePerformance
design testing
• Test control system modifications
• APC Pre-tuning
• Alarm Management
• Control and process design testing
Procedures
• User interface familiarization
• Startup training
• Emergency response training
• I&C diagnostic training
• Validation of operating Procedures
Test instrument ranges
• Control logic and graphic design verification and correction
• Graphic display improvement
• Pre-tune control loops
• Test instrument rangesanalysis
• Process equipment design
• Relief system design
• Control strategy validation
• Process operability analysis
PROCESS
ENGINEERING
CONTROLS
CONFIGURATION
INITIAL
START
PLANT
OPERATION
Driving Safe Operation in HF Alkylation Units
Safety Competency Pyramid
●New operators can learn to start up, shut down and operate the plant in a completely safe environment, on the simulator, before they are entrusted with the real plant
●Can be used to help operating companies with:
˃ Understanding process fundamentals
˃ Preventing accidents
˃ Teaching best practices
˃ Adoption of rules and procedures
˃ Analyzing impact of operations on plant safety
˃ Critical situation preparedness
˃ Routine re-training
˃ Lessons learned analysis
API Recommended Practice 751
●The American Petroleum Institute Recommended Practice Number 751 (Third Edition June 2007) specifically discusses the safe operation of HF Alkylation Units
●Two key requirements of API Recommended Practice 751 are:
1. Maintaining a process hazards management plan involving a process hazards analysis. The RP states that the hazards analysis should consider routine operations; start-up; shutdown; upset and failure conditions and emergencies..
2. Training - Training is required to ensure the persons assigned to the facility possess the required knowledge and skills to carry out their duties, including start-up, shutdown, and emergency procedures
●An Operator Training Simulator can add great value to a company’s hazard management plan and a company’s training program helping to drive the highest level of safety
October 07, 2015 Presented by Cristina Martinez
Improving HF Alkylation Operational Safety
through the use of Operator Training Simulators
CONTENT
Unique Challenges of developing an OTS for HF
Alkylation
PDVSA Puerto la Cruz Experience
OTS SCOPE
DA-2
DA-3
FCC
051-052
ALK
NHT REF
HDT
G91
G95
JET A-1
DSL HDT
RESIDUE
DSL MARINO
PARAFFIN
GLP
MESA 30°
MEREY
16°
AW/SB 40°
PARAFINOSO
Crude Oils PRODUCTS
DA-4
DA-1
DSL
OTS Phase II
Unique Challenges of developing an OTS for HF Alkylation
CONVERSION UNITS
FCCU ALKYLATION
80% AGO
20% AR
DRY GAS
F. iC4
LCO HCO DO
REFORMATE
G95
FUEL
GASAMINE
NAPHTHA
C3C4
ALKYLATE
DOMESTIC
GAS
C4
C3
Unique Challenges of developing an OTS for HF Alkylation
Amine/Caustic
Treatment
Olefin
From FCCTo Gas System
Fresh IC4
Water
Dryers
T-1
Fresh Acid
IC4 Recycle
ASO/CBM
IC4 from Depropanizer
Acid Rerun Tower T-6
Acid to Reactor
Depropanizer
HF to Acid Recontactor
Accumulator
IC4 Recycle
Isostripper
Propane
Defluorinator Propane
KOH Treater
Alkylate
Alkylate
Product
Butane
Defluorinator
Butane
Debutanizer
HF Stripper
Acid from Recontactor
Acid
Recontactor
DR
-2
D-6
E-41
T-21
T-2
T-22
T-3
D-8E-11
E-42
Acid Settler
Reactor D-4
T-6
T-1
4
T-9
T-1
3
T-7
T-8
T-4
E-15
E-20
Deethanizer
PROCESS DESCRIPTION
Unique Challenges of developing an OTS for HF Alkylation
AccumulatorD-7
KOH Treater
KOH Treater
Solubility of propane into HF
Fractionation
Feed Conditioning Reaction and
Regeneration
Product Treatment
L-L separation of propane and HF Temp profile and HF-propane separationTemperature decreaseHF content
Schneider-Electric has addressed these challenges by
developing a special thermo calculation set HEXAMER
specifically for this type of process and this is delivered with
the DYNSIM product. The complete solution provides a
perfect environment for executing training exercises
repetitively in a safe environment ensuring effective learning.
HEXAMER
Unique Challenges of developing an OTS for HF Alkylation
THERMODYNAMIC MODEL CHALLENGE
SCOPE DEFINITION
•Review of P&IDS
•Functional Specification Document
TECHNICAL INFORMATION
• Heat and Mass Balance
• Equipment data sheets
• Controls and Alarms
MODEL DEVELOPMENT
PREFAT TEST
SAT TEST FAT TEST
MODEL FIXES
Definition of timelines,
participation of each department
FINAL MODEL DELIVERY
Unique Challenges of developing an OTS for HF Alkylation
OTS SOLUTION
OTS SOLUTION
Graphical interface
for operator similar to DCS
Graphical interface
For engineer or instructor
Unique Challenges of developing an OTS for HF Alkylation
PDVSA Puerto la Cruz Experience
OTSworkers to
operate more
efficiently
CLEAR
UNDERSTANDING
OF PROCESS
DISTURBANCES
highly corrosive acid, lethal if inhaled by humans
MINIMUN
HUMAN
ERROR
OTS
HUMAN
RELIBIALITY
SAFETY
� Phillips Licensor (Now UOP)
HF Catalyst
� Design Capacity: 4500 BPD
� Since 1962 (2271 BPD)
Revamp in 1991 (4500 BPD)
� DCS is ABB MOD300
PLC Refinery HFAU
PDVSA Puerto la Cruz Experience
The operator training was done in
traditional fashion, where
theoretical classes and seminars
were delivered by experienced
senior personnel from PDVSA.
Formal program to train the
operators and new engineers on
the HF Alkylation unit by using the
OTS system
PDVSA Puerto la Cruz Experience
�Personnel is going through different operational scenarios as
in real life but in a safe environment
�Process Engineers make evaluations and continuously update
the operational procedures
�Operators are reproducing process trips or malfunctions to
find causes and implement corrective actions and minimize
future occurrences
PDVSA Puerto la Cruz Experience
is always aware of the danger of catastrophic failure if
the plant is operated with an inadequate I/O ratio
it is possible to show the operator how this operational upset
can occur and what actions he has to perform to successfully
recover the plant from that situation. All these actions have to
be taken repeatedly until the operators feel comfortable of how
to operate the unit
PDVSA Puerto la Cruz Experience
� REACTION TEMPERATURE
� I/O RATIO
� ACID PURITY
� ACID CONSUMPTION
�ACID/HC RATIO
� ALKYLATE OCTANE
KEY OPERATION PARAMETERS
Malfunctions, Scenarios and challenges addressed with the OTS system
PDVSA Puerto la Cruz Experience
INSTRUCTOR VARIABLES @DYNSIM
� Acid loss in the Rerun Tower
�Optimal point of control for the rerun column reduce lose acid
through the bottom, minimize the acid consumption and promote
the reactions efficiency
�Depropanizer overhead pressure is difficult to build up during plant
startup
�The OTS system helps operators to find the optimal way to control
that section during the startup of the plant
�Corrosion problems on the treatment section due to high
n-butane/fluoride rate
�PDVSA is planning to use the simulator for testing of a new way of
operating the debutanizer, to get more volume of n-butane to avoid
corrosion caused by the low velocity trough the heat exchanger
Malfunctions, Scenarios and challenges addressed with the OTS system
PDVSA Puerto la Cruz Experience
Looking to the future
� Refreshing and strengthen knowledge of the experienced staff
at the Alkylation unit
� Test new operational procedures
� Implementation of new control philosophies
� Optimize the operation
� Implement best practices in the refinery operation
PDVSA Puerto la Cruz Experience
Our main project. The target
is to build new process units
to cover the demand of
products (gasoline, jet, diesel)
increasing capacity of the
actual conversion units in
order to meet international
market regulations
DEVELOPMENT OF NEW TECHNOLOGIES
UNDER INTERNATIONAL STANDARDSAPI
ASTM
ASME
Looking to the future
PDVSA Puerto la Cruz Experience
There are numerous ways to provide training to operators and a
holistic training approach will encompass classroom training,
training on the job and various other means. However, state-of-
the-art training with a clear focus on enhancing plant safety
through an operator-centric approach should include an operator
training simulators as a key element.
This argument is supported by the PDVSA Puerto La Cruz Refinery
where the Operator Training Simulator is strongly driving
increased safety at the plant. An Operator Training Simulator is a
critical tool that can be used to provide training well beyond the
control room. Today’s commercial simulation software is now
ready for prime time when it comes to driving improved safety on
HF Alkylation Units.
Conclusion