Putting pressure on fugitive emissions

Heavy industry has a long-standing fugitive emissions problem. It is unintentionally releasing volatile organic compounds (VOCs) into the atmosphere through the widespread leakage of gases and vapours, as well as flaring at oil and gas refineries.

Climate impacts

This is a significant problem; the unintentional release of VOCs from pressurised equipment accounts for around 5% of global greenhouse gas emissions, but likely more because of conservative estimates made during product design and monitoring. Fugitive emissions are thought to account for 20% of global methane emissions from the petrochemicals sector, among the most potent contributors to the greenhouse effect.¹

Fugitive emissions are a significant environmental problem, but they are also a long-standing issue that has been overlooked, having been largely untracked since the 1950s. Yet this situation is beginning to change. COP26’s Global Methane Pledge is now dominant in industry thinking, aiming to reduce global methane emissions by at least 30% from 2020 levels by 2030. It is hoped this could curb 0.2°C of global warming by 2050.

Health impacts

The impact of fugitive emissions, however, is not limited to climate change. They are also a significant cause of air pollution, causing ground-level ozone when NOx and VOCs react with each other in sunlight and hot temperatures. This increases health risks to the surrounding environment. Hundreds of thousands of deaths annually are driven caused by smog accelerated by ozone – a key factor in the establishment of testing standards.² As well as the long-term issues associated with the leakage of VOCs, there is the more immediate hazard of fire and explosion, with many VOCs being highly flammable. Beyond this, hydrogen sulphide can be deadly if it leaks in significant quantities.

While identification and measurement are important first steps in tackling the problem of fugitive emissions, they do not deal with the issue of the sub-standard maintenance of valve packing that is the root cause of most leaks. Control valves drive around 60% of a plant’s emissions, a figure which rises to 70% in refineries. This is despite only representing around 1% of a facility’s total installed assets.³ Control valves generally, and rising stem control valves in particular, are especially susceptible to leakage due to constant modulation. In contrast, standard on/off valves generally suffer fewer leaks because they are not used all the time.

Tightening standards

Various standards have been introduced because of increased awareness of the dangers of fugitive emissions in industrial applications. Recent years have seen the industry begin to align towards recognising ISO 15848-1 as the leading guideline to…

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