According to the IPCC definition, fugitive emissions are those that are “not intentionally generated by a stack or vent” and generally “include leaks from industrial facilities and pipelines.”
Different industries define fugitive emissions in different manners; for instance, according to the fossil fuel industry, they are generally conceptualized as any emissions that are independent of the fuel’s final usage; in the context of air pollution, a fugitive emission is described as “the discharge of pollutants into the open atmosphere after they have managed to evade with a hood, seal, or any other mechanism for assuring the capture and retention of these pollutants.”
As a result, no consistent and uniform definition of fugitive emissions exists. In reality, they typically involve unintended yet non-productive emissions, leaks, and diffuse escapes.
According to statistical data, fugitive emissions account for around 5% of the world’s total greenhouse emissions. However, in the industries where they are commonly discharged, fugitives can account for more than half of a facility’s scope 1 and scope 2 GHG emissions.
Because of the difficulties in measuring or quantifying emissions, fugitive emissions are sometimes disregarded when establishing a GHG inventory, yet, they should be a significant factor when creating a GHG inventory.
Fugitive emissions are recognized as their own class of Scope 1 emissions in a GHG inventory. According to the EPA, Scope 1 emissions are “direct GHG emissions from sources managed or owned by an entity.”
Major Sources Of Fugitive Emissions
Three main activities contribute to fugitive emissions:
1. Refrigerant Usage
In accordance with the Kyoto Protocol, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF6) are all greenhouse gases that are released when the refrigerant is used in portable or stationary equipment such as HVAC systems. These greenhouse gas emissions might come from refrigerant discharge at the end of the equipment’s lifespan, leaks during equipment operation, or production.
2. Oil & Gas Activities
The hydrocarbon industry significantly contributes to fugitive methane emissions at all phases of its activities. During excavation, manufacturing, shipping, refining, and distribution processes, methane (CH4) may be produced. Methane emissions may be accidental or deliberate; spontaneous emissions are brought on by equipment leaks, faulty seals, or joints during the storage and transportation of fossil fuels. When natural gas cannot be used or retrieved economically, it may be purposefully expelled rather than sold or burnt. Planned releases frequently occur owing to safety concerns regarding plant design.
Source: Methane leakage rates from the natural gas system
3. The Coal Sector
A significant source of fugitive emissions after the petroleum sector is the coal industry; like oil reserves, coal seams frequently contain methane that may be released into the atmosphere during resource extraction.
Fugitive emissions from coal mostly take place when:
3.1. Coal Mining
Over millions of years, the heating and compression of biogenic materials result in the formation of coal. CO2 and methane are entrapped in the coal deposits during this geological process. Seam gas, the term for trapped gas, often contains 95–97% pure methane. Following ore mining and extraction, seam gas is emitted.
The gas spreads in the passageways when the mining is underground before being expelled by the air vents. Methane levels in the vented air outside mines are typically a few tenths of one percent, but the chance of an explosion increases as methane levels rise.
3.2. Storage & Transportation
The ore’s remaining gas is expelled into the atmosphere during handling and transportation.
Gaps and wells made throughout the operation may allow methane to continue escaping. For instance, there are thousands of old mines in the US, 400 of which have been linked to considerable methane emissions.
3.4. Flaring of Natural Gas
Flaring of gas is the practice of burning gas without utilizing the heat generated. Carbon dioxide is released, yet this process simplifies eliminating flammable fumes after oil extraction or processing. Conventionally, emissions from flaring are referred to as fugitive emissions. Last year, gas flared 140.57 billion cubic meters, or 3% of the natural gas produced globally. For the first time since 2010, this practice declined in 2017. Despite a 0.5% rise in global oil output, the volume of gas flared was reduced by almost 5%. However, flaring continues to cause 300 million tonnes of CO2 emissions annually.
Source: Annual Volume of the Gas Flared in the world
Although fugitive emissions are frequently forgotten to include in a GHG inventory, they should be taken into grave account because they have more potential to cause global warming than CO2.
Let us examine some of the efforts to control fugitive emissions.
Solutions and Initiatives
Regardless of the source, there are ways to lower these fugitive emissions. Apart from significant leakage and those that endanger employees, reducing fugitive emissions is not financially feasible.
1. Coal-related gas can be retrieved and utilized as natural gas for power production, vehicle fuel, or petrochemical operations. It may also be used in mining, for example, to heat tunnels and dry off minerals. Therefore, reducing fugitive emissions in the coal industry may be a financially successful endeavor. In Europe, coal degassing would result in €1.8 to €2.2 per tonne of averted CO2 equivalent.
In order to minimize methane emissions, the Global Methane Initiative, a public-private collaboration established in 2004, identified approximately 200 projects in the coal industry in 2016.
2. Corporations can be encouraged to respond to low-volume breaches through local regulation, community activism, and NGO-led initiatives.
To promote voluntary action among oil tankers, the Climate and Clean Air Coalition have established the Oil and Gas Methane Partnership to achieve this target globally. Its foundational pillars for decreasing methane emissions in the gas business have been endorsed by ten of the biggest oil corporations in the world, including Royal Dutch Shell, Total, and BP, as well as Mexico’s PEMEX and Thailand’s PPT.
3. There are numerous ways to prevent fugitive emissions from flaring, even when the gas cannot be transferred at all or at a reasonable cost. Re-injecting gas into wells is one method that can boost tank pressure, making it simpler to recover oil while preserving gas so that it can be retrieved later, should that be necessary. An alternative approach is to use a turbine to burn the gas in place of a flare to produce power.
With the help of governments and oil tankers, the World Bank has created the “Zero routine flaring” program, which aims to end routine facility flaring by 2030.
The Bottom Line
Despite having a substantial impact on greenhouse gas emissions, fugitive emissions are one of the most neglected aspects of climate change prevention. To properly evaluate and reduce fugitive emissions, considerable work must be done. According to the currently available data, the most significant cause of fugitive emissions is the mining of fossil fuels, followed by their processing and transportation to a minor degree. Consequently, the oil, gas, and coal industries have the ultimate responsibility for their minimization, with assistance from other stakeholders such as researchers, local governments, local communities, and NGOs.