Capturing VOCs Emissions – and Methane

Mark Green
Posted September 24, 2019

A key factor in EPA’s recent decision not to directly regulate methane is the simple fact that existing regulation of emissions of volatile organic compounds (VOCs) associated with natural gas and oil production also reduces methane as a co-benefit.

It might surprise some, but on this point current EPA officials are aligned with their agency predecessors under President Obama.

As discussed here, EPA’s recently proposed New Source Performance Standards (NSPS) modifications – to reduce duplication with state programs and clarify regulatory compliance for industry – not only make sense, they could further lower methane and other emissions and protect the environment.

Still, the decision was met with claims EPA was retreating from environmental protections. However, improving regulation and fostering greater clarity for working to comply with regulation is smart and promotes desired outcomes.

The technologies and procedures industry use to capture VOCs also capture methane. Again, this was recognized by the Obama EPA earlier this decade when it published the final rule on NSPS and national emission standards for hazardous air pollutants (HAP) in in the Federal Register in August 2012. From Page 49496:

The final oil and natural gas sector NSPS and NESHAP amendments are expected to result in significant reductions in existing emissions and prevent new emissions from expansions of this industry. These emissions include HAP, VOC (a precursor to both PM2.5 and ozone formation) and methane (a GHG and a precursor to global ozone formation).

Similarly, from Page 49534:

The final Oil and Natural Gas NSPS and NESHAP amendments are expected to result in significant reductions in existing emissions and prevent new emissions from expansions of the industry. These final rules combined are anticipated to reduce 12,000 tons of HAP, 190,000 tons of VOC (a precursor to both PM (2.5 microns and less) (PM2.5) and ozone formation) and 1.0 million tons of methane (a GHG and a precursor to global ozone formation).

And from Page 49535:

This rulemaking requires emission control technologies and regulatory alternatives that will significantly decrease HAP and VOC emissions from the oil and natural gas sector in the United States. As a co-benefit, the emission control measures the industry will use to reduce HAP and VOC emissions will also decrease methane emissions. … The EPA recognizes that the methane reductions from this rule will provide for significant economic climate benefits to society …

Again, while some keep pressing for separate methane regulation, those emissions are being reduced as a co-benefit of existing VOCs regulation, negating the need for another layer of government regulation. This question obviously was contemplated by the Obama EPA nine years ago. EPA officials then made clear that the new NSPS regulation targeting emissions of VOCs also would capture methane emissions.

More fact: Industry is successfully capturing more and more methane from production. While natural gas production grew more than 50% from 1990-2017, methane emissions dropped 14%:

While this doesn’t fit the “rollback” narrative, remember as well that a recent National Oceanic and Atmospheric Administration study found that there has been “major overestimation” of industry’s methane emissions in the past. In major shale plays we’ve seen significant decreases in methane emissions relative to production – nearly 40% in the Permian, for example.

At the same time, surging domestic natural gas production is helping on another greenhouse gas front. Increased use of natural gas is the main reason U.S. energy-related carbon dioxide emissions have decreased to their lowest levels in a generation.