1400 - isimite - dynamic simulation of texas city refinery explosion for safety studies
TRANSCRIPT
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
1/17
Dynamic simulation of Texas City
Refinery explosion for safety studies
Joseph Isimite
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
2/17
Outline
Introduction & background
Previous studies
Simulation approach
Simulation results
Quantitative HAZOP
Conclusion
Questions
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
3/17
Plant background
30 miles South East of
Houston, TX
Rated capacity of
460,000 bpd of
gasoline
29 oil refining
units and 4
chemical units
covering 1200
acre siteEmploys approx. 1800
employees, plus contractors
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
4/17
Incident Introduction
Catastrophic failure of
isomerisation units raffinatesplitter
Explosion occurred at 1:20pm on23 March 2005, with subsequentfires
15 deaths, many injuries
financial losses exceeded
US$1.5b
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
5/17
Previous studies
Woodward & Moosemiller (2005): Baker Risk Report,evaluation of possible event scenarios
Palacin-Linan (2005): PSE, gPROMS model
Manca & Brambilla (2012): Aspen HYSYS simulation
Khan and Amyotte (2007): consequence modelling
Kalantarnia et al. (2010): predictive consequence model
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
6/17
ISOM Unit Description
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
7/17
Raffinate unit Process Flow Diagram
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
8/17
Why another Texas City simulation?
Its not new
However, increased legislative oversight, ageing assets,shortage of skilled personnel and prospecting and
production activities in increasingly dangerous terrainrequire fresh thinking in the way dynamic simulators areemployed in oil and gas operations.
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
9/17
Process simulation
Suitability of Aspen Hysys
Replicate column filling dynamics
2-phase flow of sub-cooled liquid in the blowdown pipe
Dynamic HAZOP
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
10/17
Process Flowsheet
total liquid volume: 583 m3
35 light HCs lumped into 4 categories: C5-C8
Water and Nitrogen
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
11/17
Simulation approach
Initial conditions
Transient process variables evolution from 0200am 0120pm
Isothermal temperature regime before 1000am
Model validation with published accident data
Results showColumn filling dynamicsFeed vapourisation dynamicsFeed temperature profile
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
12/17
Simulation results
Dynamic simulation of Texas City Refinery explosion for safety studies
0
10
20
30
40
50
60
10 10.5 11 11.5 12 12.5 13 13.5 14 14.5
LiquidLevel
[m]
Time [Hrs]
Column liquid filling dynamics
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
13/17Dynamic simulation of Texas City Refinery explosion for safety studies
0
0.2
0.4
0.6
0.8
1
1.2
10 11 12 13 14
Feedvapourfraction
Time [Hrs]
Feed vapour fraction [1000hrs to 1320hrs]
0
20
40
60
80
100
120
140
10 10.5 11 11.5 12 12.5 13 13.5
Feed
tempe
rature[C]
Time [Hrs]
Feed temperature
Feed vapourisationdynamics
Feed temperaturedynamics
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
14/17
Dynamic HAZOP
Extrapolation of model for use in dynamic HAZOP studies
Provide a visual representation of quantified level of risks
All four burners lit instead of two
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
15/17
Dynamic HAZOP feed vapourisation dynamics
Dynamic simulation of Texas City Refinery explosion for safety studies
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
10 10.5 11 11.5 12 12.5 13 13.5 14
Feedvapourfraction
Time [Hrs]
Actual incident
DynHAZOP
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
16/17
Conclusions
Additional temperature increase of 43% occurred, leading toa mixed phase feed flow with a vapour fraction of 0.4
Complete vaporisation of the feed takes place at 1230pm
Help secure management buy-in by demonstrating the likelyconsequences
Effective close-out of HAZOP actions
Further investigations of coupled process hazard analysestools
Dynamic simulation of Texas City Refinery explosion for safety studies
-
8/10/2019 1400 - Isimite - Dynamic Simulation of Texas City Refinery Explosion for Safety Studies
17/17
We do it safely, or not at all.