Presentation of

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Presentation of Gas Recovery Systems A/S at TSA
CONFERENCE 2002
Presented by Capt. Bård Norberg
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GRSs position in Transportation and storage
logistics
The I.M. Skaugen group is engaged in the marine
transportation of petrochemical gases, LPG and
organic chemicals, as well as ship to ship
transfer of crude oil.
I.M. Skaugen ASA, Oslo
Parent Company
Kosmos AS
PetroTrans Holdings Ltd.
Norwegian Gas Carriers Ltd.
Holding Company
Lightering /
LPG Petrochemical gas
ship-to-ship transfer of crude oil
transportation - World Wide
Princess Carriers
Skaugen PetroTrans Inc.
Norwegian Gas Carriers AS
Chemical Carriers in Asia
TNGC -Hubei Tian En Petroleum
SPT Marine Services Inc.
Gas Recovery Systems AS
Gas Transportation Co. Ltd.
Gas vessel purgings
Recovery of cargo heel
and fender rentals
when gasfreeing of tanks
LPG transportation China
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The gas business
However
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Consequences of current practice

• The loss of valuable product is
• The environmental effect contributes to the
• Green house theory
• Toxic compounds in atmosphere
• Carbon residues in atmosphere
• Human exposure during gas freeing operations

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The current operation causes

• Loss of a considerable amount of valuable product
• Emission to atmosphere of VOC s
• Emission to atmosphere of TOXIC gases
• Emission of exhaust gases
• Annual emission from world gas tanker fleet only
  above 275.000 MT(Figures published by SIGTTO)
• Time consuming operation and extra port calls
  for gas tankers

LPG 220.000 C2H4 11.000 C3H6 10.000 C4H6
4.000 VCM 3.000 NH3 is excludedfrom
statistics
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Physical Properties Common Commercial Gases
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The GRS principle
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GRS Technology
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GRS Technical Description

• Recovery of cargo vapours during gas freeing,
  inerting or simply during discharging of tanks by
  the use of liquid nitrogen is developed and
  patented by Gas Recovery Systems AS.
• Nitrogen vapours, originated by vaporising Liquid
  Nitrogen in the GRS are used for gas freeing and
  inerting of cargo tanks having previously
  contained a liquefied gas or a condensable vapour
  atmosphere.
• The heat of vaporizing liquid Nitrogen in the
  recovery unit is used to condensate the cargo
  vapour atmosphere from the tanks and seperates
  them from incondensable compounds.
• The recovery unit acts as a nitrogen vaporizer,
  supplying gaseous Nitrogen to the cargo tank of
  which cargo vapours are to be re liquified. The
  vapour atmosphere in the cargo tank is displaced
  by the Nitrogen vapours. This should preferably
  be done with a minimum of turbulense. The
  overpressure of the cargo tank is led to the
  vapour recovery unit.
• The heat necessary for vaporizing Liquid Nitrogen
  is extracted from the cargo vapours with a result
  of condensation the organic compounds.
• The vaporization temperature of liquid nitrogen
  is -196 C at atmospheric pressure. This
  temperature is lower than the freezing point of
  most products to be recovered in this unit.The
  problem of solidifying of hydrocarbons is avoided
  by the use of an intermediate heat exchange fluid
  (Propane) with low freezing point.

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GRS The Process

• The cargo vapours are fed into the GRS unit
  precooled and partially condensed in the heat
  exchangers marked 1 and 2 by counter current heat
  exchange with cold nitrogen stream from the heat
  exchangers marked 4 and 5.
• From heat exchangers 1 and 2 the precooled and
  partly condensed product stream is led through
  the cargo condenser marked 7 where the product is
  liquefied in a counter current heat .exchange
  with the Propane heat transfer fluid.This
  Propane fluid is sufficiently cooled by
  vaporizing Liquid Nitrogen in the heat exchangers
  marked 4 and 5.
• The recovered liquid product is led to the
  Nitrogen separator tank marked 6 prior being
  pumped out of the gas recovery unit.
• Liquid nitrogen is fed to the GRS unit. The
  Nitrogen is vaporised in counter current heat
  exchange by the Propane heat transfer fluid in
  the heat exchangers marked 4 and 5. The heat
  transfer fluid is continuously circulated by a
  pump. Nitrogen vaporization, Nitrogen
  temperature, and the Propane heat transfer fluid
  temperature are continuously controlled to avoid
  freezing of hydrocarbons in the heat exchangers
  marked 1, 2 and 3.
• The vaporised Nitrogen for purging purposes may
  be warmed up to 80 C by an electrical heater.
  Excess of Nitrogen is released to the atmosphere
  or to reception facilities.

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GRS applications for recovery of

• Ethylene
• Ethane
• Propylene
• Propane
• Butadiene
• Butane
• VCM
• NH3
• Halons
• Chlorofluorcarbons
• Isoprenmonimer
• Various chemical gases

• The system can be used for VOC recovery at
• Oil and gas terminals
• Gas carriers and gas shipping industry
• Petrochemical industry
• Offshore installations
• Rail and road transport

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GRS for purging Shoretanks
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GRS as reliquefaction unit
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GRS for purging Railcars
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GRS and Gassing-up / Cooling-down
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GRS Benefits

• Economics
• High capacity
• Vapour recovered on spec.
• Recovery and Purging simultaneously
• Low capital cost
• Low operational cost
• Low maintenance cost
• Commercial
• Increases terminal versatility
• Transportable for spot operation
• Serves as an emergency reliquifaction unit

• Operational
• Safe to operate
• Easy to operate
• Easy to maintain
• Easy to move for spot operations
• Easily adjusts to concentration and flow
• Environmental
• Emissions reduced to a minimum
• No secondary pollution
• Eliminates human exposure to VOC and toxic gases

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GRS ready for shipment
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GRS in operation
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The GRS unit

• Capacity
• 3700 kg VCM vapour/hour
• or 2000 kg Ethylene vapour/hr
• in a purging process.
• Operation
• Fully automatic mode
• Unit size
• Built into a 10 foot std. Container frame

• Low energy consumption
• About 5 kW. for the process
• About 60 kW for the nitrogen heater
• Weight
• About 5000 kg
• The unit is transportable for spot operation

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The Vopak operation, 6650 CBM VCM Sphere
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GRS and the VOPAK Sphere condition

• Volume 6647 CBM
• Storage of VCM
• Storage of VCM under ambient condition
• VCM atmosphere remaining 47945 Kg
• VCM pressure 2,6 bar absolutt.
• Sphere is free of liquid
• Un-pumpable VCM liquid in lines abt 13 MT

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GRS decontamination task

• Recover from the sphere all remaining VCM to a
  level of less than 100 ppm of VCM in N2
  atmosphere - equal to abt 1,5kg
• Drain and recover all VCM liquid and VCM
  atmosphere from the piping system
• All recovered product to be pumped into
  roadtankers and transported to Hydro Polymers
• Project time 6 days

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GRS decontamination process phases

• Phase 0 Pre- draining of lines
• Phase 1 Reduction of tank pressure
• Phase 2 Stratification in tank
• Phase 3 Gas-freeing of tank
• Phase 4 Pressure reduction of Sphere
• Phase 5 Draining and gas-freeing of lines
• Phase 6 Draining and gas-freeing of GRS

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GRS VOPAK decontamination result

• Phase 0 From lines 13020 kg 8,5 hrs
• Phase 1 Pr. reduct. 20350 kg 13,2 hrs
• Phase 2 Stratifcat. 23700 kg 14,1 hrs
• Phase 3 Gas-free 4700 kg 48,0 hrs
• Phase 4 From lines 4900 kg 8,0 hrs
• Accumulated GRS 66670 kg 91,8 hrs
• Total weighbridge fig. 66580 kg

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GRS VOPAK result - Emission

• Phase 0 emission 0 gram
• Phase 1 emission 0 gram
• Phase 2 emission 75 grams aprox
• Phase 3 emission 1000 grams aprox
• Phase 4 Emission 500 grams aprox
• Left in Sphere 2150 grams
• Total emission 3725 grams

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GRS VOPAK consumption

• The entire recovery process consumed 92.760 kg of
• Liquid Nitrogen
• VCM recovered was 66.600 kg of VCM
• Liquid nitrogen cost is about 70 / MT
• VCM price is about 450 / MT

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GRS installation at VOPAK October 2001
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GRS installation at VOPAK October 2001
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LIN delivery at VOPAK october 2001
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GRS gas-chromatograph
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GRS trailer with control panel
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GRS Economical benefits for Terminals

• Total recovery of cargo vapours when gas freeing
• Complete discharge of cargo overpressure
• Eliminate flare system
• Fast reliquefaction facility
• High chilling capacity

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GRS Benefits Advantages

• Complete in specification recovery of cargo
  vapours
• Minimisation of emission of VOC s and /or
  poisonous vapours
• Compact and transportable unit
• No solidification of recovered product as Propane
  is used as intermediate coolant
• Easy to adjust on flow and concentration
  fluctuations
• No need for using IG generator on gas carriers
• General cooling / reliquefaction unit
• Low capital investment
• Low annual operating cost
• Low energy consumption
• No secondary pollution

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Gas Recovery Systems A/S
Many thanks to the TSA Conference 2002, Visitors
and Listeners
Gas Recovery Systems A/S P.O.Box 23 Skøyen N-0212
Oslo Norway e.mail bard.norberg_at_ngc.no phn 47
23120380