There are several dire takeaways from the United Nations Intergovernmental Panel on Climate Change (IPCC)’s latest report on climate change. One that stands out in particular is the projected future carbon dioxide (CO2) emissions: “Projected cumulative future CO2 emissions over the lifetime of existing fossil fuel infrastructure without additional abatement exceed the total cumulative net CO2 emissions in pathways that limit warming to 1.5°C (>50%) with no or limited overshoot.”
In other words, existing technologies that can reduce carbon emissions, and all greenhouse gas (GHG) emissions, from existing fossil fuel infrastructure post-haste need to be operationalised. One area of focus has been in shifting fossil fuel consumption to natural gas. Natural gas, while still a fossil fuel, offers a significantly more environmentally-sustainable energy source than oil or coal. The US, in particular, has come to rely on natural gas more than any other country in the world. According to the US Department of Energy, natural gas generates nearly 40% of the electricity consumed in the US. Natural gas is critical to the reliability of the US’ integrated energy grid today, and, truth be told, is likely to continue to play a significant role in the future.
Reducing emissions in the midstream sector
While opportunities exist to reduce emissions throughout the natural gas supply chain, one interesting area to focus on is the midstream sector. While the midstream contributes an overall low percentage of emissions in the natural gas supply chain, it has important implications for transitioning to cleaner energy, both today and in the future. Focusing on the midstream - i.e. the transport of energy from producers to downstream users — presents the opportunity to future-proof any emissions gains because it is unlikely the US will fully overhaul its vast energy infrastructure anytime soon. Existing midstream infrastructure is likely to play a role even while transitioning to new energy sources. A secure, reliable, and efficient midstream sector will be key to enabling the clean energy transition.
For midstream operators, there are immediate opportunities to reduce emissions - among them, shifting to renewable energy consumption, modernizing infrastructure, and preventing worst-case scenarios.
“Cleaning up” combustion
One area where midstream operators can make meaningful impact on reducing emissions in the short-midterm is by “cleaning up” combustion, for example by converting compressors to electric. In fact, Energy Transfer, a midstream provider that in 2018 contributed to the highest midstream emissions of the top 10 US midstream operators according to a University of Amherst Political Economy Research Institute index, won the Environmental Excellence Award from the GPA Midstream Association in 2021 for their ‘Dual Drive’ natural gas compression system. The company estimates that their system reduced CO2 emissions by more than 630 000 t in 2020.
Leveraging existing technology
Another area where midstream operators can reduce emissions is by leveraging existing technology that is already on the market to shift electricity consumption to renewable electricity. For example, Sapphire’s FreeSpin® In-line Turboexpander (FIT) technology converts energy wasted in pressure reduction processes in natural gas pipelines into clean electric power. This same technology is as applicable today as it will be in a future where the same infrastructure can be utilized to move alternative fuels (e.g. hydrogen) or renewable fossil fuels. Each FreeSpin system generates up to 2.6 HWh/y of clean electricity, offsetting 2000 t CO2-e. With 300 000 natural gas pressure let down stations globally, this turboexpander, which has a low total cost of ownership, has the potential to offset 600 million t of CO2-e immediately.
Reducing methane emissions
According to the International Energy Agency (IEA), reducing methane emissions from oil and gas operations is one of the most cost-effective ways to fight climate change. In fact, one of the worst climate disasters in 2022 occurred from a single methane leak from a natural gas well in Pennsylvania that negated the positive emissions impact of half the electric vehicles sold in the US in 2022. Policymakers are already on top of this specific problem, thanks in part to a decades-long push from the Environmental Defense Fund (EDF) to research and document the scale and impact of methane emissions. A specific methane fee is included in the Inflation Reduction Act, signed into law in August 2022. Technology already exists to prevent and mitigate the damage of methane emissions across sectors. A 2021 EDF report stated that by pursuing all currently available methane emission mitigation measures “could slow the global-mean rate of near-term decadal warming by around 30%” and “avoid one-quarter of a degree centigrade of additional global-mean warming by mid-century.”
Conclusion
There are myriad technologies that exist today to help reduce emissions in midstream natural gas, an important sector that plays a critical role in both the current and future energy systems. The goal is not to enumerate all of the technologies on the market or to support one over another, but to suggest that more must be done to operationalise all existing technologies while continuing to invest in research and development to explore new ones. Transitioning to clean energy is a monumental task, and it must be acknowledged that fossil fuel companies have their hands full in planning a path toward a cleaner future that does not completely disrupt life and industry as it is known today. Cleantech solution providers must play their part as subject matter experts and educate fossil fuel energy providers on not only the short-term benefits of our technologies, but also how these technologies will play a role in the long-term evolution of energy supply chains.
