Cracking Down on Methane Emissions

Posted on December 13th, 2021
Posted in Uncategorized   

Photo  Credit: NASA/JPL-Caltech.

Methane has been in the spotlight of the Climate Change discussion as of late. More than 100 countries pledged, including the U.S., to reduce methane emissions by 30% from 2020 to 2030. In addition, the EPA has proposed changes to emission regulations forNew Source Performance Standards (NSPS). These pledges and proposed changes particularly affect Oil and Gas, as the largest source of industrial methane emissions.

Taking a step back, why are methane emissions important? There are four major categories of greenhouse gases (GHG): carbon dioxide, methane, nitrous oxide, and fluorinated gases. Carbon dioxide is by far in a way the most commonly emitted molecule, however, each gas has its own global warming potential (GWP) and its own atmospheric half-life. For methane, the GWP is 25X more than carbon dioxide over a 100-year period. Methane being a valuable product (primary component in natural gas) coupled with the fact that there are cost effective ways of reducing methane emissions (combustion), it’s a logical target for regulation.

The EPA proposed change covers 40 CFR Part 60 Subpart OOOOa (existing), Subpart OOOOb (new), Subpart OOOOc (new). The OOOOa (Quad Oa) proposed rule aims to revert the methane standards to the original 2016 regulation. Quad Ob and Quad Oc are integrally related with Quad Ob imposing standards and Quad Oc providing emission guidelines intended to advise State level authority so that decisions can be made adhering to emission reduction standards. These new rules will impact new, modified, and/or reconstructed sources. In the following breakdown, we’ll focus on surface facility related items around zero-emitting pneumatic controllers, pneumatic pumps, and strengthened requirements for storage tanks. However, operators should be aware that these regulations also extend to fugitive emissions, well unloading, completions, associated gas, equipment leaks, and compression.

  • Zero-emitting pneumatic controllers – The proposed rule adds intermittent vent controllers as an affected facility and states continuous bleed and intermittent vent must be zero-emitting for methane and VOCs. Currently, zero bleed controllers are only required at natural gas processing plants. Elsewhere the bleed rate is limited to 6 scfh.
  • Pneumatic pumps – The proposed rule adds natural gas driven piston pumps and natural gas driven pneumatic pumps at transmission and storage facilities to the affected facilities. Currently only natural gas driven pneumatic pumps at well sites require 95% control of emissions.
  • Storage Tanks – The proposed rule would change how the affected facility threshold is determined with 6 tpy being calculated based on the aggregate potential to emit for the entire tank battery as opposed to a single storage vessel.

At Halker, we can help aid in compliance to these regulations or other ESG initiatives through: a) evaluation of alternatives to pneumatic controllers or pumps, b) working with flare vendors to ensure destruction efficiency of flare systems are adequate, c) supporting selection of thief hatches, PSVs, or other potential fugitive emission sources, and d) through adequate design we can reduce the probability of major release events by performing safety reviews, process hazard analysis, and pre-start up safety reviews. Outside of regulatory compliance, striving towards maximizing methane capture promotes public relations and can affect the bottom line through increased sales volume.