L06 - SOx Flashcards
What is Sulphur Oxide?
- It is normally SO2 and sometime SO3.
SO2:
- Properties:
Sulfur dioxide is a colorless gas with a sharp, pungent odor. It is highly soluble in water, forming sulfurous acid (H₂SO₃). - Sources:
Major sources of sulfur dioxide include the burning of fossil fuels (coal, oil, and natural gas) that contain sulfur compounds, industrial processes such as the production of cement, steel, and paper, and natural sources like volcanic eruptions.
SO3:
1. Properties:
Sulfur trioxide is a colorless to white crystalline solid or a liquid that fumes in air. It is highly reactive and readily dissolves in water to form sulfuric acid (H₂SO₄).
- Sources:
Sulfur trioxide is mainly produced industrially, particularly during the production of sulfuric acid via the contact process. It can also form in the atmosphere as a secondary pollutant from the oxidation of sulfur dioxide.
What does SOx cause?
Acid rain
Sea and soil acidification.
Human health issue
- contributes to smog formation
What is Particulate Matter?
Particulate matter (PM) refers to a mixture of tiny solid particles and liquid droplets suspended in the air. These particles vary in size, composition, and origin, and they are classified based on their diameter into two main categories:
- PM10 (Coarse Particles)
- PM2.5 (Fine Particles)
How is SOx and Particulate Matter connected?
PM is produced due to non-complete combustion of fuel.
- Level of PM is dependent on fuel sulphur level.
- Reduction of fuel sulphur will reduce SOx but also PM.
Are SOx levels directly related to type of fuel and fuel sulphur level?
- Various fuels have different sulphur levels.
- SOx is produced from oxidation of fuel sulphur.
- S+O2 -> SO2 +1/2O2 -> SO3
- All the fuel sulphur converts to SOx as a result of combustion.
What is the impact of SOx?
- Human respiratory system – Lung irritation
- Acid rain: Leads to acid rain via combining with water vapour.
– SO2 + H2O H2SO3
– SO3 + H2O H2SO4 - Human mortalities in areas associated with high SOx emissions.
- Contributes to smog formation.
what is smog?
Smog is a type of air pollution characterized by a mixture of smoke and fog, which reduces visibility and can have significant health and environmental impacts. There are two main types of smog: classical smog (or London smog) and photochemical smog (or Los Angeles smog). Each type has different causes and characteristics.
Classical Smog (London Smog)
- Composition: Mainly a combination of smoke, sulfur dioxide (SO₂), and particulate matter.
- Formation: Occurs when smoke and sulfur dioxide from burning coal and other fossil fuels combine with fog or mist in the air.
- Conditions: Typically forms under cool, damp conditions and is more common in winter.
- Historical Example: The Great Smog of London in 1952, which caused severe health problems and fatalities.
Photochemical Smog (Los Angeles Smog)
- Composition: A mixture of ground-level ozone (O₃), nitrogen oxides (NOx), volatile organic compounds (VOCs), and other pollutants.
- Formation: Occurs when sunlight reacts with nitrogen oxides and volatile organic compounds in the atmosphere.
- Conditions: More common in urban areas with high traffic and industrial activities, especially during sunny and warm weather.
- Components:
- Ozone (O₃): A major component of photochemical smog, formed by the reaction of sunlight with pollutants like NOx and VOCs.
- NOx and VOCs: Emitted from vehicle exhaust, industrial processes, and other sources.
- Characteristics: Typically manifests as a brownish haze, particularly prevalent in cities like Los Angeles.
What are the options to reduce SOx?
- LNG
- Low Sulphur fuel (marine gas oil)
- Electrification
LNG is generally the best option for reducing SOx emissions due to its negligible sulfur content and additional environmental benefits, such as reduced NOx and particulate matter emissions. However, the choice between LNG, SOx scrubbers, and low sulfur fuels depends on several factors:
- Best for Comprehensive Emission Reduction: LNG
Ideal for new builds or major retrofits where long-term environmental benefits and compliance with future regulations are prioritized.
- Best for Existing Vessels: SOx Scrubbers
Suitable for ships that continue to use high-sulfur fuels while meeting SOx emission limits, balancing long-term cost and compliance.
- Best for Immediate Implementation:
Low Sulfur Fuels
Effective for vessels that need a quick, straightforward solution to comply with current sulfur regulations without significant retrofitting.
Explain how SOx is formed? In your view SOx is produced more by
heavy fuels or light fuels and why?
What are the main impacts of SOx emissions? Name 3 of them
What is acid rain? Explain the likely impacts of acid rain.
Specify 3 methods for SOx reduction in shipping.
In your view, as far as SOx is concerned, shipping emissions is most dangerous in which areas?
