July 01, 2018

Fugitive Methane and Fracking - Unintended Consequences

The Basics of World Natural Gas

Natural gas (“gas”) is generally naturally extracted as a variable mixture of methane and other light hydrocarbons, CO2 and other contaminants. It is also produced as “associated” crude petroleum.  It has a history as a commercial fuel starting about 500 BC in China, where gas seeping from the ground was captured and used as fuel to heat salt concentrators. The world’s first true industrial use of natural gas was in the United States, in Fredonia, N.Y., in 1825, according to local archives. Most natural gas is produced today in North America, the Persian Gulf, Russia, China, Norway, and a number of other countries and regions to a lesser extent.   Gas is distributed by pipeline around the continents where it is produced, but with the growth of LNG as an option, is now also traded among continents by ship. Nexant licenses and maintains a World Gas Model that helps developers and other stakeholders to better understand the global scene.

The Fraught History of Methane Fuel and Emissions

The subject “unintended consequences” are some of the upshots of the triumph of methane in the world economy. This was a long time coming, and its advent is fraught with reversals and enigmas. In the geopolitically unstable period in late 1973, with Arab-Israeli-Western Allies conflicts, the crude oil price went from $3/barrel to $12/barrel, causing a panic at fuel pumps in the United States and allied countries. This led to the creation of the US Department of Energy in 1977, during the Carter Administration.  In early 1977, my friend and former colleague, Dr. Christian Knudsen, was working at Energy Research and Development Administration (ERDA), the immediate precursor of US Department of Energy (US DOE). Chris testified before Congress, based on a study he was doing, that plenty of natural gas could be available at lower prices than were then prevalent, if the gas industry were deregulated and thereby incentivized to do more exploration and development. A furor within and between Congress and DOE followed this testimony, not the least because DOE had been busy for a decade trying to convert coal to synthetic natural gas, so this testimony was off-message.   Dr. Knudsen was subsequently redeployed to other assignments.

In 2004, Nexant groups in Washington and White Plains, sponsored by the US Agency for International Development (USAID) and others, collaborated on a broad-based study of mitigating or capturing fugitive methane nicknamed “M2M” for methane to market.   Study of the Market Potential for Recovered Methane in Developing Countries, which could serve as a leverage point and/or template for further work, considers anthropogenic sources such as landfill gas (LFG), coal mines and coal beds, upstream and downstream oil and gas emissions, and biological systems – sewage, crops and other vegetation, and livestock.  Of course there are other important sources that are less anthropogenic, or only indirectly man-made, such as permafrost melting, and vegetation decay in natural swamps.

The 2004 report focuses on a limited list of developing countries only – Brazil, Colombia, India, Indonesia, Kazakhstan, Mexico, Pakistan, Peru, Russia, South Africa, and Ukraine -- which seems now to have been determined by US geopolitical priorities at the time rather than any other economic or scientific criteria.  It estimates methane’s market potential in residential, commercial, institutional, transportation, agricultural, and industrial feedstock and energy end uses.  It considers potential carbon trading, opportunities and barriers, and implementation strategies for each country – covering policies and histories of mitigation initiatives.   This is an information-rich study could be leveraged to address these issues fourteen years later by expanding and updating its geographic, demographic, policy, and technological scope.

Fracking – Who saw the coming?

The phenomenal growth of gas and oil fracking in the United States and to a lesser extent elsewhere has accelerated the replacement of coal-fueled thermal generators, and even nuclear generation capacity, with large gas-fired gas turbine combined cycle generators. These latter have been easier to permit, faster to build, and more reliable to operate than legacy and revamped existing coal and nuclear stations, which utility companies have largely been eager to shut down.  At the same time, solar PV and wind renewable generation systems have expanded beyond anyone’s earlier hopes and both have plummeted in cost to grid average levels or lower.  Replacing nuclear with gas generation does not reduce GHG emissions but replacing coal does significantly, and of course wind and solar have little or no GHG emissions.  

For the many New York and New Jersey citizens who have for years campaigned to shut down the Indian Point nuclear plant 30 miles north of New York City on the banks of the Hudson River, the dirty little secret is that it was not necessarily their efforts, but more likely economics that will make this happen in 2020.  The operator, Entergy, is apparently delighted to be free of this financial and public relations albatross. Ironically, the Trump DOE is proposing to subsidize failing coal and nuclear plants in the name of “grid resilience”, but many studies show that the grid is adequately resilient without these generators.

As an unintended consequence, gas and oil fracking have added greatly to the potential for methane leaks all along the supply chain, but most drastically upstream because of the widely distributed and, in some cases, haphazard nature of the fracked gas sources.  Findings of the M2M study and of other analyses by Environmental Defense Fund, US DOE, US EPA, energy companies, and other stakeholders are loaded with disagreement and controversy over the scale of the leakage from the United States infrastructure alone. 

Bottom Line – Gas is better than Coal

This diversity of data and views needs to be analyzed and reconciled as much as possible. But, regardless of the results of any such reconciliation efforts, it seems clear that even in the worst case, no argument could be made economically or environmentally for retreating from replacing coal fueled power generation with gas-fired systems.  

A comprehensive analysis in the International Energy Agency (IEA) World Energy Outlook 2017 supports this view.  According to the most credible global inventories, we are well within the “gas is better than coal” range. But the comparison is not straightforward, depending on what timeframe is considered. A ton of methane is equivalent to between 84 and 87 tons of CO2 over a 20-year timeframe (GWP20) and between 28 and 36 tons over a 100-year timeframe (GWP100). Also, generating electricity from gas tends to have a higher efficiency than coal, so emissions are lower for natural gas in terms of electricity produced instead of heat.

But, as the IEA observes, even if natural gas is better than coal, this comparison sets the bar too low. We need to ensure that its emission intensity is as low as practicable. In many cases, economic as well as environmental considerations will prevail if there is a readily available path to market for the captured methane to be sold (back to the future with the Nexant M2M report). If methane’s value is greater than the cost to capture it, avoiding the emissions of a potent greenhouse gas will simultaneously generate a profit.  All good, but ultimately, these are all stop-gap measures.  To more aggressively address greenhouse gas emissions responsible for climate change, economically viable lower-carbon, carbon-neutral, and even carbon-negative solutions are needed, with or without carbon taxes or carbon trading.  The lowest-hanging fruit is to mitigate or avoid energy demand through energy conservation measures, which generally yield payback in the very short term, and are as simple as changing incandescent lighting for LEDs and building insulation. Nexant’s Energy Efficiency Delivery group works to design and implement energy conservation and demand programs focused on energy customers.   

Biorenewable Methane to the Rescue

Nexant’s Energy & Chemical Advisory has expertise in low-carbon solutions from bio-based methane sources.  These do not all relieve the methane leakage GHG problem, but would assure that the CO2 entering the atmosphere (either immediately, or eventually by oxidation of bio-methane) will not add to net atmospheric CO2.  Such solutions include:

Producing biogas (a roughly equal mixture of methane and CO2) by anaerobic digestion of food and other organic wastes found in garbage (municipal solid waste or MSW), manure or other agricultural waste, food processing, and sewage, and combusting it for renewable power and heat production (called Waste-to-Energy or WTE).  Or, biogas can be added to pipeline gas supplies or used as natural gas vehicle fuel after removing CO2 and other contaminants.  These strategies are highly commercialized in Europe and in other places, and in the United States also for garbage truck CNG/LNG fuel
Collecting landfill gas (LFG), or coal bed or mine mouth methane, which are about the same as biogas, and using them in the same ways

These two solutions are discussed and assessed in Nexant’s report, Biorenewable Insights:  Biogas and LFG. 

Gasifying biomass to produce bio-syngas (mixtures of H2, CO, and CO2) to catalytically produce SNG (Synthetic Natural Gas).  Relevant technologies are discussed and assessed in  Biorenewable Insights:  Biomass Gasification
So-called “activation of CO2” in reverse catalytic reforming, using hydrogen made by water electrolysis with renewable electricity to make renewable methane. There are fairly conventional routes for this using only mineral catalysts, and also routes that enhance biological methane production from CO2 by applying renewable electricity directly to the process.  Such routes are discussed and assessed in Nexant’s recent report, Biorenewable Insights:  Electrochemicals and Electrofuels

Anything but immediate and direct use of biogas in WTE would risk fugitive methane along the supply chain to market, just as with fossil natural gas.   Other options for keeping bio-methane local include using it as a fermentation feedstock for making a number of highly desirable products including biopolymers that biodegrade in soil and in the oceans, and single cell proteins as alternative feed for aquaculture, to help us avoid emptying the oceans of small fish to feed big fish and other seafood we like better.   These technologies are covered in Biorenewable Insights: Polyhydroxyalkanoates (PHAs) and Biorenewable Insights:  Methanotrophs and Syngas Fermentation. 


Ron Cascone, Principle