A new way to harness wasted methane

A new way to harness wasted methane
MIT chemistry professor Yogesh Surendranath and three colleagues have found a way to use electricity, which could potentially come from renewable sources, to convert methane into derivatives of methanol. The researchers developed a low-temperature electrochemical process that would continuously replenish a catalyst material that can rapidly carry out the conversion. Credit: Massachusetts Institute of Technology

Methane gas, a vast natural resource, is often disposed of through burning, but new research by scientists at MIT could make it easier to capture this gas for use as fuel or a chemical feedstock.

Many oil wells burn off —the largest component of natural gas—in a called flaring, which currently wastes 150 billion cubic meters of the gas each year and generates a staggering 400 million tons of carbon dioxide, making this process a significant contributor to global warming. Letting the gas escape unburned would lead to even greater environmental harm, however, because methane is an even more than carbon dioxide is.

Why is all this methane being wasted, when at the same time natural gas is touted as an important "bridge" fuel as the world steers away from fossil fuels, and is the centerpiece of the so-called shale-gas revolution? The answer, as the saying goes in the real estate business, is simple: location, location, location.

The wells where methane is flared away are primarily being exploited for their petroleum; the methane is simply a byproduct. In places where it is convenient to do so, methane is captured and used to generate electrical power or produce chemicals. However, special equipment is needed to cool and pressurize , and special pressurized containers or pipelines are needed to transport it. In many places, such as offshore oil platforms or remote oil fields far from the needed infrastructure, that's just not economically viable.

But now, MIT chemistry professor Yogesh Surendranath and three colleagues have found a way to use electricity, which could potentially come from renewable sources, to convert methane into derivatives of methanol, a liquid that can be made into automotive fuel or used as a precursor to a variety of chemical products. This new method may allow for lower-cost methane conversion at remote sites. The findings, described in the journal ACS Central Science, could pave the way to making use of a significant methane supply that is otherwise totally wasted.

"This finding opens the doors for a new paradigm of methane conversion chemistry," says Jillian Dempsey, an assistant professor of chemistry at the University of North Carolina, who was not involved in this work.

Existing industrial processes for converting methane to liquid intermediate chemical forms requires very high operating temperatures and large, capital-intensive equipment. Instead, the researchers have developed a low-temperature electrochemical process that would continuously replenish a catalyst material that can rapidly carry out the conversion. This technology could potentially lead to "a relatively low-cost, on-site addition to existing wellhead operations," says Surendranath, who is the Paul M. Cook Career Development Assistant Professor in MIT's Department of Chemistry.

The electricity to power such systems could come from wind turbines or solar panels close to the site, he says. This electrochemical process, he says, could provide a way to do the methane conversion—a process also known as functionalizing—"remotely, where a lot of the 'stranded' methane reserves are."

Already, he says, "methane is playing a key role as a transition fuel." But the amount of this valuable fuel that is now just flared away, he says, "is pretty staggering." That vast amount of wasted natural gas can even be seen in satellite images of the Earth at night, in areas such as the Bakken oil fields in North Dakota that light up as brightly as big metropolitan areas due to flaring. Based on World Bank estimates, global flaring of methane wastes an amount equivalent to approximately one-fifth of U.S. consumption.

When that gas gets flared off rather than directly released, Surendranath says, "you're reducing the environmental harm, but you're also wasting the energy." Finding a way to do methane conversion at sufficiently low cost to make it practical for remote sites "has been a grand challenge in chemistry for decades," he says. What makes methane conversion so tough is that the carbon-hydrogen bonds in the methane molecule resist being broken, and at the same time there's a risk of overdoing the reaction and ending up with a runaway process that destroys the desired end-product.

Catalysts that could do the job have been studied for many years, but they typically require harsh chemical agents that limit the speed of the reaction, he says. The key new advance was adding an electrical driving force that could be tuned precisely to generate more potent catalysts with very high reaction rates. "Since we're using electricity to drive the process, this opens up new opportunities for making the process more rapid, selective, and portable than existing methods," Surendranath says. And in addition, "we can access catalysts that no one has observed before, because we're generating them in a new way."

The result of the reaction is a pair of liquid chemicals, methyl bisulfate and methanesulfonic acid, which can be further processed to make liquid methanol, a valuable chemical intermediate to fuels, plastics, and pharmaceuticals. The additional processing steps needed to make methanol remain very challenging and must be perfected before this technology can be implemented on an industrial scale. The researchers are actively refining their method to tackle these technological hurdles.

"This work really stands out because it not only reports a new system for selective catalytic functionalization of methane to methanol precursors, but it includes detailed insight into how the system is able to carry out this selective chemistry. The mechanistic information will be instrumental in translating this exciting discovery into an industrial technology," Dempsey says.


Explore further

A new way to directly convert methane to methanol using gold-palladium nanoparticles

More information: Matthew E. O'Reilly et al. Catalytic Methane Monofunctionalization by an Electrogenerated High-Valent Pd Intermediate, ACS Central Science (2017). DOI: 10.1021/acscentsci.7b00342
Journal information: ACS Central Science

This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.

Citation: A new way to harness wasted methane (2017, October 17) retrieved 24 April 2019 from https://phys.org/news/2017-10-harness-methane.html
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Oct 17, 2017
The electricity to power such systems could come from wind turbines or solar panels close to the site


Or, from methane, as it is already present and essentially free and always available.

Though in any case, the original logistics problem remains: the site is too far away from consumers and building a separate pipeline to pump the methanol out isn't cost-effective.

Oct 17, 2017
Though in any case, the original logistics problem remains: the site is too far away from consumers and building a separate pipeline to pump the methanol out isn't cost-effective.


Methanol can be stored in tanks and trucked out when it's more convenient. No pipeline needed.

Oct 17, 2017
"Or, from methane, as it is already present and essentially free and always available."

How true!

But yet they chose to tout renewables as a source of electricity as if the process could not stand on it's own merits using methane only. They are diluting the value of their own process and do not even realize it.

Oct 17, 2017
Methanol can be stored in tanks and trucked out when it's more convenient. No pipeline needed.


If it's so little that it can be simply trucked out every now and then, it's not really worth the trouble driving all the distance to places where there's often no proper road infrastructure for trucks in the first place. Methanol wholesale prices round to about $1.20 a gallon, and a truck carries about 11,000 gallons, so each truckload is only worth about $10-15k on the market.

What's the cost of the conversion plant? Millions? Times how many wellheads? It's going to need to do better than that to pay back.

Oct 17, 2017
@Eikka.

Mate, you were doing so well in the other discussions after I pointed out how your pessimism/biases are making you impotent/blind to the solutions possible (sometimes right under your nose even! Like in this instance:
What's the cost of the conversion plant? Millions? Times how many wellheads? It's going to need to do better than that to pay back.
CONSIDER the options which your pessimism/bias has blinded you to:

Each well-head can pipeline via a cheap small-diameter pipeline to a CENTRAL location where a SOKAR/WIND energy plant can process the total methane 'waste stream' from ALL the well-heads at once. Hence the economies of scale of ONE plant and ONE methanol 'product shipping/trucking point' therefrom. See your problem now, mate? Please CHEER UP and LOOK before making pessimistic/unheeding noises like that, hey? :)

PS: BTW, what energy/fuel sources currently used by drill-rigs/well-head machinery/processing etc? Do they make use of some of the methane?

Oct 17, 2017
@Reality - your post gave me a chuckle thank you. I hate to be the first one to point out the rather obvious fact that your pumps and pipes from each wellhead scales by the number of wellheads. Exactly you are not changing the scaling realities using your solution at all. And it seems like a installation/maintenance cost nightmare. Pipes are cheap, but they are also inherently leaky over long periods of time.

Oct 18, 2017
Each well-head can pipeline via a cheap small-diameter pipeline to a CENTRAL location


If it was economical to pipe the methane to a central location for processing and transport, it would have been done already - conversion or not. The problem is exactly that you have small amounts of methane coming from numerous wellheads that are scattered over a thousand of miles of desert, and the value of each isn't enough to cover the system cost.

You're simply trying to force the solution because you want to contradict me - you're playing an ego game - not because you want to evaluate whether it would actually work.

Oct 18, 2017
Mate, you were doing so well in the other discussions after I pointed out how your pessimism/biases are making you impotent/blind to the solutions possible


I can't even remember any of that - and impotent to what? I'm not the one building chemical processing plants in the desert - I neither could nor would.

If something works, it works despite the naysayers and negative opinions. If it doesn't work, it won't work no matter how much hype and positive thinking. Blame doesn't hurt it, and praise doesn't help it; the whole question of negative/positive thinking is a distraction by those who wish to make some technical matter or problem more than it actually is, for political or personal ends like pundits and hucksters.

All ideas need holes poked in them, every insult and injury thrown at them to see if it holds. Otherwise you end up fooling yourself.

For someone called RealityCheck, you seem to forget that quite often.

Oct 18, 2017
All in all, flaring wastes about 3.5% of the output of wellheads, so it isn't actually that big of a deal. Even at the Bakken oil fields, it's hovering around 10% of the gas produced, but it may peak up to 35%

That is the other part of the problem, the varying output, because the oil extraction rates follow market demands, while the gas output is fixed to the oil production, so when oil is in more demand the gas is flared because it cannot be sold at any reasonable price even if it were piped out. Supply has to meet demand.

A chemical processing plant to turn the gas into more valuable chemicals would then have to be oversized in capacity to deal with the peak extraction rates, and thus more expensive on the end product, or undersized for the issue and unable to solve the need to flare.

Of course, if you only had a pipeline with gas bells for storing the excess methane for later use...

Oct 18, 2017

If it was economical to pipe the methane to a central location for processing and transport, it would have been done already - conversion or not. The problem is exactly that you have small amounts of methane coming from numerous wellheads that are scattered over a thousand of miles of desert, and the value of each isn't enough to cover the system cost.


The article said they were looking at ways to integrate the converter into the wellhead itself. You wouldn't need to pipe methane, you'd have methanol. Liquids are easier and cheaper to send by pipe (lower pressure, etc.), or to keep in tanks (no pressurization needed).

Oct 18, 2017
It seems that the world's transportation system may be moving to hydrogen powered vehicles. Why can't this wasted methane be used to produce hydrogen instead of using natural gas to produce it?

Oct 18, 2017
Ok. Sounds all good and sweet until you actually have to deal with methanol. Methanol is soluble in water, and very toxic to all life. It's not a good fuel for an advanced civilization.

Oct 19, 2017
The article said they were looking at ways to integrate the converter into the wellhead itself.


Which goes back to the point of, how much methanol do you get for what investment in the coverter?

Mind you, the problem is still that you get varying amounts of excess methane at different times, so the utilization of the converter will be low.

It seems that the world's transportation system may be moving to hydrogen powered vehicles. Why can't this wasted methane be used to produce hydrogen instead of using natural gas to produce it?


Because the methane is easier and safer to handle than hydrogen.

And it -is- natural gas.

Oct 19, 2017
@Eikka.

Not at all, mate; you and I are agreed on the critiquing thing....but I do so constructively and optimistically while you seem to be doing it for the obverse. That's how it comes across, mate. As to the specifics in this instance, I was addressing the suggestion/problem that each well-head needed to be provided with converter plant/system of its own. I pointed out that ONE centrally located plant would have economy of scale advantages and waste gas piped via cheap and easily laid narrow-diameter piping system between many well-heads and a centralized converter plant/shipping point for 'conversion product' therefrom. In the case where, as you point out, there may be many well-heads spread across thousands of square miles, then they would be 'sectioned off' in the optimal numbers to be serviced by a plant dedicated to each SECTION of many well-heads. It's a matter of scaling/sectioning accordingly to give the same many-to-centralized economy of scale setups. Cheers. :)

Oct 19, 2017
@Parsec.
@Reality - your post gave me a chuckle thank you. I hate to be the first one to point out the rather obvious fact that your pumps and pipes from each wellhead scales by the number of wellheads. Exactly you are not changing the scaling realities using your solution at all. And it seems like a installation/maintenance cost nightmare. Pipes are cheap, but they are also inherently leaky over long periods of time.
The suggested smaller pumps/pipes are cheaper and more convenient/timely than a complete conversion plant for each well-head (Eikka originally observed that point re cost of plant for each well-head). For further info, please also read my preceding post to Eikka just above. Thanks. :)

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