Understanding the Methane Impact

Natural gas is a clean, reliable and low GHG emitting fuel. Nonetheless, growing public attention to methane has focused attention on the fugitive emissions from natural gas systems. While its high hydrogen content contributes to low CO2 and air pollutant emissions, the resulting light weight of gaseous methane (CH4) can cause it to more easily leak from operating components.   Modern best operating practices can minimize methane venting blowdowns at compressor stations and during construction of high pressure pipelines.

The Canadian Energy Partnership for Environmental Innovation (CEPEI) has for many years led the Canadian Gas Association’s efforts to understand and measure natural gas pipeline systems’ emissions profile. The group’s first major research in the early 1990’s involved the quantification of fugitive methane emission rates and preventative solutions which, by 2000 had become a valuable gas industry-led research and outreach program. This research provides CGA’s transmission and distribution companies’ with a comprehensive, timely, science-based annual inventory of their emissions profiles and rigorous measurements of a wide range of air pollution statistics they are required to report for provincial and national reporting requirements.

CEPEI-led studies, that include facility-level field testing across Canada, have shown that the fugitive methane losses at a site can be reduced by 90 per cent by focussing on just two or three major components through a program of regular basic maintenance. CEPEI research has contributed to the development of several leak detection methods, from simple soap bubble testing to modern hi-flow sampling and optical laser remote sensing, resulting in major reductions in system methane losses. CEPEI research also shows that a number of other important benefits, beyond the emissions reductions, were also realized when action to cut emissions levels was undertaken including:

  • an increased awareness of health and safety best practices;
  • increased economic savings from fuel savings;
  • a better understanding of system operations and efficiency (a good training tool); and
  • minimizing non-methane volatile organic emissions for some applications.

Pipeline Sector GHG Emissions Profile (2000 vs 2013)

As a result of CEPEI’s research and collaboration, the Canadian natural gas pipeline industry has benefitted from dozens of very cost-effective solutions to reduce methane fugitive and venting losses. CEPEI research shows that these emissions have decreased by at least 50 per cent over the past decade, driven in part by new techniques and technologies that are of significant benefit. These include the use of gas transfer compressors and new hot-tap welding procedures during construction, improved valve and low-bleed pneumatic systems, accelerated replacement of older distribution system piping, and installation of dry gas seals on centrifugal compressors.

Pipeline safety - gas warning pole.

Pipeline safety – gas warning pole.

Successful innovation and understanding can generate improvements beyond the distribution system. Continued research efforts will help push these improvement into the upstream natural gas production sectors as well. As upstream methane losses decrease, the full fuel cycle emissions profile of natural gas will also decline. Moreover, as natural gas is increasingly partnered with conservation initiatives and with other renewable fuels, it will continue to bring more of the benefits of affordable reliable, clean, and safe natural gas energy solutions to more and more consumers and regions.

Manfred Klein is an energy consultant, recently retired after 33 years at the National Energy Board, Environment Canada, and the National Research Council. With an Engineering degree from Carleton University, he has been involved in federal policies and training with the natural gas industry on environmental issues, industrial gas turbine and pipeline technologies, and cogeneration systems.