An unsaturated vapour may be defined as not being in contact with its liquid phase. Which of the given options is the main source of unsaturated vapour in a cargo tank of a crude oil tanker?
Your answer is correct:
Air and Inert Gas.
2
As a crude oil tanker cargo tank fills with liquid cargo what will occur in the ullage space of the cargo tank:
Your answer is correct:
Saturated and unsaturated vapour mix together and become the Total Vapour Pressure.
3
As part of the VOC control measures certain operational records must be maintained. Select, from the given options, all of those that should be recorded when any VOC is released from a crude oil tanker:
Your answer is correct:
Target operating pressure for the voyage.; Time and pressure within the system before releasing the VOC.; Time and pressure within the system after the releasing the VOC.; Person in charge of the VOC release.; Location of vessel at the time of release.
4
As a part of recommended VOC emission control measures, which of the given options is the condition when COW operations are allowed to be carried out at sea?
Your answer is correct:
Between multiple discharge ports.
5
Best practice for VOC control, as detailed in this module, recommends that the ship should define a cargo tank target operating pressure which should be as high as safety possible. What should the target pressure be relative to the P/V valve setting pressure?
Your answer is correct:
About 70 % of P/V valve setting pressure of 1 400 mmWG.
6
Controlling emissions of volatile organic compound (VOC) from ships is expected to have a significant beneficial impact. Which of the given options is expected to be the most beneficial result of these control measures?
Your answer is correct:
Reduced atmospheric pollution and reduced human health risk.
7
During loading of a crude oil cargo, the vapour displaced by the cargo is released to the atmosphere via the mast riser. Which of the given options best describes the most likely composition of the released vapour?
Your answer is correct:
All compounds in VOC including inert gas.
8
During the loaded voyage, the temperature of the gases or vapours in the ullage space of the cargo tanks and the liquid cargo varies. Which of the given options is the main reason that the liquid phase temperature varies less than the gas or vapour phase temperature?
Your answer is correct:
Hull design and sea water temperature.
9
In a CVA type adsorption process used for VOC emission control the crude oil vapours are filtered through active carbon beds. What means is normally used to lower the pressure in the carbon bed for the purpose of desorbing the gases?
Your answer is correct:
A vacuum pump.
10
In a condensation type VOC control system, the vapours are liquefied and drained to the NMVOC storage tank. Which of the given options is the maximum pressure in the tank at ambient temperature, as stated in this module?
Your answer is correct:
14 bar.
11
In an Absorption System being used for VOC emission control the NMVOCs are absorbed into the oil. Which gases are normally routed to the riser?
Your answer is correct:
Methane, ethane and inert gas.
12
In which IMO regulations are the detailed requirements regarding VOC Management Plans to be found?
Your answer is correct:
In MARPOL Annex VI.
13
In which publication would you find the safety device requirements for the vapour control system on tankers?
Your answer is correct:
In SOLAS.
14
One of the VOC emission control systems found on board crude oil tankers is known as the KVOC system. What is the significant feature of a KVOC type emission control system?
Your answer is correct:
It uses a large diameter drom column.
15
One of the requirements within a VOC Management Plan is that an estimate of the quantity of VOC released during a voyage is recorded. How can this requirement be met?
Your answer is correct:
By recording the pressure at the start and end of release and the length of time of the release.
16
Record keeping is necessary in order to document compliance with the requirements of VOC emission control. Is this statement True or False?
Your answer is correct:
True.
17
Select from the given options all of those, that are considered to be “best practices” to be adopted to reduce VOC emissions during a loaded voyage on a crude oil tanker?
Your answer is correct:
Set the target operating pressure for the cargo tanks as high as safety possible.
18
Select from the given options all of those that are considered to be “best practices” to be adopted to reduce VOC emissions during cargo loading on a crude oil tanker:
Your answer is correct:
Reduce the loading rate.; Plan the loading procedure to reduce cargo agitation in the oil tanks.; Keep the cargo tank pressure as high as safely possible.; Use the vapour returns lines when shore facilities are available.; Communicate with the terminal before loading starts.
19
Select, from the given options, all of those that are considered to be “best practices to be adopted to reduce VOC emission during cargo discharge and COW operations on a crude oil tanker”:
Your answer is correct:
Continuously monitor the pressure of the cargo tanks during discharge to avoid excessive supply of inert gas.; As far as possible a closed cycle method should be used for COW operations.; Use a defined volume of crude oil for the COW from a specified cargo tank instead of fresh crude oil.; All COW operations should comply with the requirements and procedures set out in the class approved COW manual.; Excessively gassy cargoes should not be used for crude oil washing.
20
Select, from the given options, the one which most accurately completes the following statement: “The temperature of the gas phase in a crude oil cargo tank will change more rapidly…”
Your answer is correct:
During day and night cycle.
21
Select from the options given all of those, which are criteria that influence the VOC release from the cargo of a crude oil tanker:
Your answer is correct:
The volatility or vapour pressure of the crude oil.; The temperature of the liquid and gas phases of the crude oil tank.; The pressure setting or control of the vapour phase within the cargo tank.; The size or volume of the vapour phase within the cargo tank.
22
The Gothenburg Protocol has set emission limits for which of the pollutants?
Your answer is correct:
Sulphur, NOx, VOCs and ammonia.
23
The temperature of the liquid phase in a crude oil cargo tank does not vary much, except:
Your answer is correct:
When heating or cooling of the cargo is being carried out.
24
There are various methods used to control VOC emissions from crude oil tankers including cargo tank pressure variations. Will increasing the pressure in the cargo tanks by adding inert gas prevent VOC release?
Your answer is correct:
No.
25
There are various methods used to control VOC emissions from crude oil tankers including the so called Venturi system. Which of the given options may be considered as the main feature of the Venturi system?
Your answer is correct:
The VOC is re-absorbed back into the cargo.
26
Under new IMO requirements all crude oil tankers must carry a VOC Management Plan on board. Which authoritative body is required to approve the VOC Management Plan?
Your answer is correct:
The Administration.
27
VOC emissions will occur during COW operations on board crude oil tankers. Which of the given options is used to reduce VOC emission when COW operations are carried out during a laden voyage?
Correct answer:
Reduce the duration of the closed cycle washing program.
Your Answer:
Reduce the pressure on the COW machines.
28
VOCs are classed as organic chemicals. What is the definition of the term organic chemicals as used in this module?
Your answer is correct:
Organic chemicals are substances that contain of hydrocarbons.
29
Vapours that are released directly into the air during cargo operations on board crude oil tankers are considered hazardous. Which of the given options is the most likely to be adversely affected by the release of these vapours?
Your answer is correct:
Human health and the atmosphere.; Marine environment.; Coastal Plants and land animals.
30
What is the definition of true vapour pressure (TVP)?
Your answer is correct:
The true vapour pressure (TVP) is the combined result of the saturated and unsaturated vapour pressures present in a defined closed system.
31
What is the main benefit of using closed cycle crude oil washing (COW) on board crude oil tankers?
Your answer is correct:
VOC emissions are reduced as only a defined amount of crude oil is used.
32
What is the main purpose of P/V breaker fitted to the cargo system of a crude oil tanker?
Your answer is correct:
It provides secondary protection to the tank structure from over and under pressure.
33
What is the main purpose of P/V valve fitted to a cargo tank of a crude oil tanker?
Your answer is correct:
It provides primary protection to the tank structure from over pressure.
34
What is the main purpose of the VOC management plan?
Your answer is correct:
To ensure that the operation of a tanker, to which regulation 15.6 of the revised Annex VI applies, prevents or minimizes VOC emission to the extent possible.
35
What is the main purpose of the vapour emission control pipe line fitted on board a crude oil tanker?
Your answer is correct:
Direct the vapours from the cargo tanks to the shore system.; Direct the cargo vapours from cargo tank to the engine room.; Direct the cargo vapours from cargo tank to vapour absorption system.
36
What is the major source of volatile organic compound from ships?
Your answer is correct:
The majority of VOC comes from cargo tanks of oil tankers.
37
What is the procedure for the maintenance of the P/V valves fitted to the cargo system of crude oil tankers?
Your answer is correct:
The maintenance should be carried out in accordance with the directions in the vessel’s planned maintenance system and the maker’s manual.
38
What is the purpose of VOC emission control from ships?
Your answer is correct:
To prevent or minimize the release of VOC as much as possible during loading, discharging and transit.
39
What is the purpose of the vapour recovery systems installed on-board crude oil tankers?
Your answer is correct:
To control the VOC emissions to the atmosphere, when the plant is in operation.
40
What is the requirement, if any, with regard to the experience of the person intended to act as a designated person in relation to VOC control?
Your answer is correct:
They should have at least one-year experience on crude oil tankers where their duties included all cargo handling operations relevant to VOC management and COW operations.
41
What target pressure, according to this training module, should be maintained in the ullage spaces of tanks during loading to minimise VOC release to the atmosphere?
Your answer is correct:
As high as safely possible, at about 70 % of the pressure release setting on the P/V valves.
42
What was the main goal of the Kyoto Protocol?
Your answer is correct:
To lower overall emissions from six greenhouse gases – carbon dioxide, methane, nitrous oxide, sulphur hexafluoride, HFCs and PFCs.
43
What will be the probable result when VOCs react chemically with NOx in the atmosphere in the presence of sun-light?
Your answer is correct:
Ozone and smog will be produced.
44
When considering crude oil tanker operations what is meant by the term volatile organic compounds?
Your answer is correct:
They are organic chemicals that easily vaporize at normal conditions and enter in to the atmosphere.
45
Which of the factors given in the options will determine whether a crude oil is suitable for use in COW operations?
Your answer is correct:
How potentially gassy the crude is.
46
Which of the given options best describes the main factors that will influence the effect on health of human of exposure to VOC emissions on board a crude oil tanker?
Your answer is correct:
The concentration of the VOCs and the level and length of time of exposure.
47
Which of the given options is a common, alternative name for methane?
Your answer is correct:
Natural gas.
48
Which of the given options is considered as the main cause of the evolution of NMVOC in the cargo pipeline system during loading?
Your answer is correct:
Pressure drops in the loading pipeline (drop lines).
49
Which of the given options is generally regarded as the primary safety mechanism for the protection of cargo tanks from over or under pressure?
Your answer is correct:
The P/V valve.
50
Which of the given options is generally taken as the maximum design pressure of a cargo tank of a crude oil tanker?
Your answer is correct:
At least 2 500 mmWG.
51
Which of the given options is one of the preferred requirements described in this module for the person appointed as the VOC designated person on board a crude oil tanker?
Your answer is correct:
They should have at least one year’s experience on crude oil tankers.
52
Which types of ship are required to carry and follow an approved VOC management plan on board?
Your answer is correct:
Every oil tanker carrying crude oil regardless of whether existing or new.
53
Why are the emission control requirements for crude oil tankers limited to non-methane volatile organic compounds, NMVOCs, and do not include methane?
Your answer is correct:
As it is not deemed cost-efficient to recover methane.
54
Why is methane treated differently from other VOC’s?
Your answer is correct:
Because methane boils at -162 °C and its emissions are deemed to be too costly to control.
55
With regard to VOC emissions, what effect, if any, will increasing the cargo tank pressure have during cargo loading operations?