the control of volatile organic compounds emissions from crude oil tankers the vocon project
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INTERTANKO International Association of Independent Tanker Owners Safe Transport, Cleaner Seas, Free Competition. The Control of Volatile Organic Compounds Emissions from Crude Oil Tankers The VOCON Project. The VOCON Project The Objectives. - PowerPoint PPT PresentationTRANSCRIPT
INTERTANKOINTERTANKOInternational Association of Independent Tanker OwnersInternational Association of Independent Tanker Owners
Safe Transport, Cleaner Seas, Free CompetitionSafe Transport, Cleaner Seas, Free Competition
The Control of Volatile Organic Compounds
Emissions from Crude Oil Tankers
The VOCON Project
The VOCON Project
The Objectives• Using the data already available from the
CRUCOGSA project, compare and contrast the Vapour Pressure developed from cargoes at differing loaded conditions.
• Monitor the pressure drops during vapour releases in order to develop methods to limit VOC emissions.
• Monitor the concentration of VOC displaced during defined stages of loading.
The VOCON Project
The Scope of Data Collection• Cargo quantification at load and discharge
ports• Cargo Temperatures daily during voyage• Environmental Data every four hours
during voyage• VOC pressure release data for each vapour
release• VOC concentration during loading
The VOCON Project Cargo Operations creating VOC
Emissions • During Transportation
• Vapour Releases due to Volatility and Cargo temperature
• Inert Gas Pressure Variations• Loading - displacement of VOC from:
• Previous Cargo• Incoming Cargo
The VOCON Project The Reason for VOC Emissions
• EQUILIBRIUM of PRESSURE– Equilibrium between the Cargo Vapour
Pressure and the Maximum Operating Pressure of the Hull Construction (P/V Valve)
– IF Cargo Vapour Pressure Greater then Release follows until EQUILIBRIUM is achieved.
VOCON ProjectIs this the Source of the Problem?
– NO!
The VOCON Project Measures for VOC Emission
Reduction• Better Stabilisation (Reduction of Vapour
Pressure) of Cargo for shipment
• Operational Measures for VOC Emission control
• Technical and Design Solutions for VOC Emission Control and Recovery
The VOCON Project Crude Oil StabilisationRVP of Differing Crude Oil types
0
2
4
6
8
10
12
Ano
a
Ara
b Li
ght
Bac
h H
o
Bin
tulu
Nea
t
Bre
nt B
lend
Dai
Hun
g
Dra
ugen
Es S
ider
Foro
ozan
Irani
an H
eavy
Ker
apu
Lava
n
Low
er Z
akum
May
a
Miri
Nan
hai
Odu
du
Ose
berg
Qat
ar L
and
Rab
i
Soyo
Trol
l
Crude Oil
Pres
sure
psi
a
RVP Minimum
With a Reid Vapour Pressure
(RVP) above 6 psia some degree of vapour release seems most likely
to occur
The VOCON Project
Operational Measures (1)• The Problem
– A P/V valve will be opened at a defined pressure but at what pressure should it be closed? If the closing pressure can be determined then unnecessary VOC release can be avoided.
• The Physics of Gas and Vapours– If the Saturated Vapour Pressure for the
prevailing cargo temperature is known then the valve should be closed at this Pressure.
The VOCON Project Operational Measures (2)
Voyage 141
0
200
400
600
800
1000
1200
1400
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23Voyage Days
Pres
sure
mm
WG
83
84
85
86
87
88
89
90
91
92
93
94
Tem
pera
ture
deg
F
The VOCON Project Operational Measures (3)
Pressure Release Report
Vessel Code: VOC2294Voyage No: 141Voyage Start: June 18, 2001 Commenced Loading at ForcadosVoyage End: July 11, 2001 Moored at LOOP
All releases are from forward mast riserTime
Start End Mins Start End20-Jun-01 Release 06:06 06:40 36 1200 30020-Jun-01 Release 10:28 10:54 26 1219 25420-Jun-01 Release 17:36 18:06 30 1219 25421-Jun-01 Release 09:48 10:24 36 1168 10222-Jun-01 Release 13:37 13:52 15 1245 12725-Jun-01 Release 10:23 10:42 19 991 25427-Jun-01 Release 10:21 10:42 21 1016 25428-Jun-01 Release 16:48 17:06 18 1220 40630-Jun-01 Release 14:26 14:38 12 1245 25402-Jul-01 Release 13:26 13:38 12 1245 25404-Jul-01 Release 13:53 14:13 20 1295 25406-Jul-01 Release 15:55 16:12 17 1245 20308-Jul-01 Release 14:08 14:27 19 1245 25610-Jul-01 Release 14:53 15:08 15 1270 279
Time Inert Gas Press(mmWG)Date Operation
Total release time for voyage
Total volume (gas) released
4hrs 56 mins
233906 m3
The VOCON Project An Operational Solution (1)
October 9th releaseArab Light crude Oil
0100200300400500600700800900
1000
0 5 10 15 20 25 30 35 40 45Time (minutes)
pres
sure
mm
WG
Is there a need to release below the
True Vapour Pressure of the
Cargo at its prevailing liquid
temperature?
P/V Valve Release
The VOCON Project
An Operational Solution (2)Oseberg Gas release
0
200
400
600
800
1000
1200
1400
0 5 10 15 20Time - mins
Pres
sure
mm
WG
The True Vapour
Pressure is recognised when the pressure decline
becomes linear
Mast Riser Releases
The VOCON ProjectAn Operational Solution (3)
• The VOCON Valve• Controlled closing
pressure by hydraulics from cargo control room
• Now used also for VOC control during loadings
The VOCON Project An Operational Solution (4)
Simply operated
equipment that can measure
prevailing TVP per ASTM
Test Method
Cost Approx:
Euro 16,500
The VOCON ProjectLoading Emissions (1)
Appendix 2
Total Vapour Pressure Isotherms at different Vapour to Liquid ratios
3
5
7
9
11
13
15
17
19
21
0 0.1 0.2 0.3 0.4 0.5
Vapor to Liquid Ratio
Pres
sure
(psi
a)
Champion
Forcados
Palanca
Brent
Maya
Oseberg
Oman
Iranian Light
Arabian Super Light
Arabian Light
The VOCON ProjectLoading Emissions (2)
VOC (%) During Loading of Bonny Light and Brass River Crude Oils
0%
10%
20%
30%
40%
50%
60%
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% Fill of Cargo Tanks
% H
ydro
carb
on V
apou
r
Unsaturated Vapour
Conditions
Increased Vapour
concentrations creating
increased Pressure
Diffusion of Vapour from First Crude Oil
whilst awaiting commencement of Second Crude Oil
The VOCON Project Loading Emissions (3)
Loading Arab Light C.O.
0
10
20
30
40
50
60
70
0% 20% 40% 60% 80% 100%%Fill
% V
OC
l
Vapor VOC (%)
Loading VOC Emissions
• Two differing Philosophies developed:– Re-capture after VOC evolves– Prevent VOC evolving
• Re-capture System – Absorption or compress gases for deck storage and discharge.
• Prevent VOC evolving – KVOC System
VOC being ControlledProactively by Industry
Thank you for your Attention
Questions?