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PAUL GUNTER
HEAD OF RDI & QUALITY
Quadrise Fuels International plc

Should an MSAR® spill occur in the ocean, the fuel self-disperses readily in the body of water.

ENVIRONMENTAL QUALITIES

Macro Environmental Topics & MSAR®

 

Emissions from Oil Refining

Petroleum refineries are complex systems of multiple linked operations that convert the refinery crude and other intake into useful products. A refinery uses large quantities of energy to heat process streams, promote chemical reactions, and provide steam and generate power. This is usually accomplished by the combustion of fuels in boilers, furnaces, heaters, gas turbines, and generators that result in emissions. Production of MSAR® within a refinery does not result in any change to these emissions, unless consumed internally to benefit NOx and particulates.

Refinery residual fuels have higher levels of sulphur and impurities than distillate fuels, such as gas oil or diesel. Therefore, where environmental legislation dictates, either emissions scrubbing equipment is required or a switch to distillate (or other low sulphur) fuel is needed for compliance purposes.

This is especially relevant in the marine fuels sector, where MARPOL fuel sulphur limits reduced to 3.5% in 2012, with a further reduction to 0.5% proposed for 2020-2025. Furthermore, Emission Control Areas (ECA’s) are becoming prevalent, with marine fuel sulphur limits reduced to 0.1% in 2015 in sensitive regions such as the North Sea, Baltics and certain USA coastal regions.

There is a global debate currently as to whether there will be sufficient distillate fuels available to meet this potential future demand. Furthermore, refinery owners are questioning whether to invest in the necessary upgrading equipment, especially as the financial returns for these billion dollar investments are uncertain and the overall environmental impact (including much increased CO2 emissions) may be worse from cradle to grave when compared with the status quo of fuel oil plus scrubbing on the vessel.

At a macro level, any refinery converting to MSAR® technology increases the output of distillate hydrocarbons and reduces the amount of hydrocarbons in the conventional fuel oil “pool”. The investment for MSAR® is several orders of magnitude less than the conventional upgrading alternative and the environmental impact for the refiner is significantly lower.

If some of the refinery cost savings for MSAR® versus fuel oil production are passed to the consumer, the capital cost of upgrading existing assets (including scrubbing equipment) can be subsidised. This concept of “affordable compliance” guides Quadrise in commercialising MSAR®.

Emissions from Combustion

Globally, legislation is increasingly more stringent to reduce the emissions from fossil fuels to limit the environmental impact and risks to human health from:

  • Nitrogen Oxides (NOx) – a significant pollutant of the lower atmosphere that contributes to smog formation can react to form nitric acid vapour and related particles. Inhalation of these particles can cause respiratory disease or lung damage, causing premature death in extreme cases.
  • Particulate Matter (PM) – found in the atmosphere can be from natural or man-made sources, those from the latter currently account for about 10% of the total amount of aerosols. Increased levels of PM in the air are linked to health hazards such as heart disease, altered lung function and lung cancer.
  • Black Carbon (or Soot) – are impure carbon particles resulting from the incomplete combustion of hydrocarbons which associates with PM. These include residual pyrolysed fuel particles, some of which are classified as human carcinogens. Black Carbon has the ability to warm the earth by absorbing heat in the atmosphere and reducing the ability, on deposition, for snow and ice to reflect sunlight and has been classified as the second largest contributor to global warming other than carbon dioxide and methane.
  • Sulphur Oxides (SOx) – reacts with other substances in the atmosphere to form harmful compounds, such as sulphuric acid, sulphurous acid and sulphate particles.  Short-term exposures can harm the human respiratory system and make breathing difficult, particularly for children, the elderly, and those who suffer from asthma.  SOx can also react with other compounds in the atmosphere to form small particles that can penetrate the lungs and cause additional health problems. At high concentrations, gaseous SOx can harm trees and plants by damaging foliage and decreasing growth and can contribute to acid rain that harms sensitive ecosystems.  Emissions of SOx do however contribute to reducing the impact of global warming.
  • Greenhouse Gases (Predominantly Carbon Dioxide and Methane) – over the past several decades, rising concentrations of greenhouse gases have been detected in the Earth's atmosphere. Although there is not universal agreement within the scientific community on the impacts of increasing concentrations of greenhouse gases, it has been theorised that they may lead to an increase in the average temperature of the Earth's surface.

Modern combustion and emissions abatement technologies are today increasingly installed in industrial facilities to reduce the impact of emissions to the environment and human health. MSAR® fuel is fully compliant with such technologies and has favourable features that reduce some of the environmental impacts from combustion including NOx, PM/Soot.

Thumbnail
PAUL GUNTER
HEAD OF RDI & QUALITY
Quadrise Fuels International plc

Should an MSAR® spill occur in the ocean, the fuel self-disperses readily in the body of water.

ENVIRONMENTAL QUALITIES

Environmental Benefits of MSAR®

 

Manufacture & Transportation

MSAR® fuel can be stored and transported at ambient temperatures of 20-30°C, compared with fuel oil that requires heating to in excess of 50°C. As a result, the energy requirements for handling and transporting MSAR® are lower than fuel oil.

The toxicity of MSAR® is largely a function of the refinery residue or heavy crude oil feedstock, which is generally lower than fuel oils that contain lighter toxic hydrocarbons.

Water for the emulsification process can be derived from a number of sources including standard utility water, desalinated water, oil-contaminated waste water or sour water stripping streams that are conventionally sent to water treatment, or disposal.

Operations procedures and contingency plans developed for fuel oil are generally suitable, and where necessary adapted, for MSAR® purposes. In terms of accidental spillages MSAR®, poses similar or fewer environmental risks to those of fuel oil, of which some 450 million tonnes is handled annually, and precautions against spillage are similar.

Crude and fuel oil spills at sea tend to float to the water surface to form suffocating oil slicks, after which chemicals are typically applied retrospectively to disperse the slick. Should an MSAR® spill occur in the ocean, the fuel self-disperses readily in the body of water, due to the presence of surfactants and micron-sized hydrocarbon droplets.

Combustion

The emulsification of hydrocarbons is especially beneficial when burning heavier asphaltenic residual fuels with more challenging combustion characteristics.

The MSAR® process results in a 'pre-atomised' fuel, the micron particle size of which (at 5-10µm) is much smaller than possible through conventional oil or water-in-oil emulsion systems.  MSAR® fuel droplets have orders of magnitude higher surface area available for rapid and complete combustion. MSAR® fuel can as a result be combusted at lower pre-heat temperatures (~60°C) when compared with fuel oil combustion (typically 120-160°C), reducing energy consumption.

Quadrise MSAR® flame diagram

As MSAR® fuel is extremely stable, it can be distributed optimally in the combustion zone. Water in the fuel immediately evaporates, causing secondary atomisation and distribution. This water also reduces combustion temperatures, typically reducing emissions of nitrogen oxides (NOx) by over 20% and in some cases up to 50%.

MSAR® will burn down to the fuel ash, with virtually no black soot remaining. This makes the production of particulate matter insensitive to combustion air levels, thereby offering the opportunity to reduce excess air and further enhance efficiency. The inorganic nature of any residual ash enhances its suitability for recovery of valuable metal constituents.

Emissions of carbon dioxide and sulphur oxides are largely a function of the hydrocarbon used to manufacture MSAR® and generally comparable with conventional fuel oil.