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Sun powered carbon capture

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As the world struggles to implement technologies and find the political will to reduce carbon emissions, there are also ongoing efforts to find ways to capture carbon from emitting sources and from the atmosphere itself.  After capturing carbon dioxide, there is then the need to safely store it or make use of it.

Current methods for capturing and then releasing carbon dioxide are expensive and energy intensive.  In fact, some methods even require the use of fossil fuels.  Recently, researchers at Cornell University have developed a method for capturing carbon dioxide that is powered by sunlight.

The Cornell method mimics the mechanisms that plants use to store carbon which involves using sunlight to make a reactive enol molecule that grabs carbon dioxide.  

Existing chemical-based carbon capture techniques make use of amines, which are organic ammonia-derived compounds that react selectively with carbon dioxide.  But amines are not stable in the presence of oxygen and don’t last, which necessitates the energy-intensive production of more and more amines.

The Cornell method uses the same method that the plant enzyme RuBisCo uses in photosynthesis.  It is based on an inexpensive sorbent material that is capable of a high rate of carbon capture.

The researchers tested the system using flue samples from Cornell’s Combined Heat and Power Building, an on-campus power plant that burns natural gas.  The system was successful in isolating carbon dioxide.

Ultimately, they would like to stage the reaction on what looks like a solar panel, but one that would capture carbon instead of generating electricity.

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In a first, system uses sunlight to power carbon capture

Photo, posted August 8, 2015, courtesy of Holly Victoria Norval via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Investing in carbon capture

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The interests of billionaires seldom seem to coincide with our own.  In fact, they often seem to be quite the opposite.  But there are a number of billionaires who are trying to help the world combat climate change.  Yes, they want to make money doing it, but doing it is nevertheless in everyone’s interest.

A group headed by Bill Gates that included some of the wealthiest people from around the world met last summer in London to evaluate companies working to mitigate the effects of climate change.  These included companies developing carbon dioxide removal technologies.  Stripping carbon dioxide out of the atmosphere is an obvious way to deal with the fact that we continue to dump too much of it into the atmosphere –   obvious, but extremely difficult to do at any scale that makes a difference.

Companies working on carbon capture have raised more than $5 billion since 2018.  There are hundreds of companies working on it and investors include billionaires, venture capitalists, private equity firms, and major corporations.  Companies like Microsoft, Google, and United Airlines have committed billions of dollars to purchase removal credits:  payments to companies for removing carbon dioxide.

There are only a few dozen carbon removal facilities operational today and together they only capture a tiny fraction of the carbon dioxide humans release into the atmosphere.  The hope is that such facilities will scale up in size and number so that they will make a real dent in the problem.  But it will take many years at best, and the planet doesn’t have that much time.  To make a difference, carbon emissions must be reduced as quickly as possible.

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The New Climate Gold Rush: Scrubbing Carbon From the Sky

Photo, posted April 19, 2020, courtesy of Greg Rubenstein via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Capturing hot carbon dioxide

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Decarbonizing industries like steel and cement is a difficult challenge.  Both involve emitting large amounts of carbon dioxide both from burning fossil fuels and from intrinsic chemical reactions taking place.  A potential solution is to capture the carbon dioxide emissions and either use them or store them away.  But this sort of carbon capture is not easy and can be quite expensive.

The most common method for capturing carbon dioxide emissions from industrial plants uses chemicals called liquid amines which absorb the gas.  But the chemical reaction by which this occurs only works well at temperatures between 100 and 140 degrees Fahrenheit.  Cement manufacturing and steelmaking plants produce exhaust that exceeds 400 degrees and other industrial processes produce exhaust as hot as 930 degrees.

Costly infrastructure is necessary to cool down these exhaust streams so that amine-based carbon capture technology can work. 

Chemists at the University of California, Berkeley, have developed a porous material – a type of metal-organic framework – that can act like a sponge to capture CO2 at temperatures close to those of many industrial exhaust streams.  The molecular metal hydride structures have demonstrated rapid, reversible, high-capacity capture of carbon dioxide that can be accomplished at high temperatures.

Removing carbon dioxide from industrial and power plant emissions is a key strategy for reducing greenhouse gases that are warming the Earth and altering the global climate.  The captured CO2 can be used to produce value-added chemicals or can be stored underground or chemically-reacted into stable substances.

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Breakthrough in capturing ‘hot’ CO2 from industrial exhaust

Photo, posted March 3, 2010, courtesy of Eli Duke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Better wood for storing carbon

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Scientists have discovered a new type of wood that is highly efficient at storing carbon.  A comprehensive survey of the microscopic structure of the wood from many species of trees revealed that there is a type of wood that is neither softwood, such as pine and conifers, or hardwood, such as oak, ash, and birch.

The scientists from Cambridge University and Jagiellonian University in Poland analyzed some of the world’s most iconic trees using electron microscopy to survey their microscopic structure.

They found that tulip trees, which are related to magnolias and can grow over 100 feet tall, have a unique type of wood.  The trees, which diverged from magnolias far back to a time when atmospheric CO2 concentrations were low, grow very tall and very quickly.  These features were an adaptation to those conditions and result in the ability to store larger concentrations of carbon to compensate based on their microstructure.  The elementary units of wood are known as macrofibrils, and tulip trees have much larger macrofibrils than hardwoods but smaller than those of softwoods.  This unusual intermediate structure makes the trees highly effective at carbon storage.

Based on the research, it may be the case that tulip trees will end up being useful for carbon capture plantations – tree plantings specifically for the purpose of mitigating the effects of climate change.  Some east Asian countries are already using various tulip tree species in plantations for locking in carbon.  This was based on their large size and rapid growth, but it turns out that their novel wood structure may be the most compelling reason to use them.

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Scientists discover entirely new wood type that could be highly efficient at carbon storage

Photo, posted March 3, 2021, courtesy of Thomas Quine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wind farms and sea farms

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There has been increasing use of agriculture coexisting with solar farms.  This dual use of land is a win-win situation.  Recently, Danish researchers have been investigating the potential for farming marine products at offshore wind farms.

Scandinavia’s largest wind farm, Kriegers Flak, is the site of a four-year-old project in which long lines are stretched between the wind farm’s pylons and are used to grow mussels and seaweed.  With the first harvest that has taken place after 18 months, it is showing signs of early success.

Seaweed and mussels are low trophic aquaculture crops.  That means that that they don’t need to be fed or fertilized.  They take up nutrients from the sea and produce healthy foods.

The 328-foot lines spread between the turbines can be used to grow substantial quantities of the underwater seafood.  According to modeling by Aarhus University – the institution conducting the study – using just a tenth of Denmark’s wind park area could produce tons of seafood annually while using only the naturally-available resources.  This form of aquaculture captures emissions instead of producing them.

Researchers say that it is time to develop guidelines to encourage companies to plan for multiple uses of the ocean because countries are ramping up production of clean energy from offshore wind farms.  Denmark was the first country in the world to install a commercial offshore wind park in 1991.  Over 30 years later, nearly half of the country’s electricity comes from wind turbines.

The benefits of such sea farms combined with offshore wind farms go beyond food production and clean energy production.  They also help improve water quality and capture carbon.  It is another win-win situation.

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Beneath offshore wind turbines, researchers grow seafood and seaweed

Photo, posted August 5, 2007, courtesy of Andreas Klinke Johannsen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Marine carbon dioxide removal

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About 30% of the carbon dioxide emitted by human activity is absorbed by the oceans.  As a result, they are getting warmer and more acidic, and the currents that help shape global weather are shifting.  To try to reduce global warming, people want to be able to store even more carbon dioxide in the oceans without the negative effects of doing so.

There are multiple efforts across the globe to achieve effective marine carbon dioxide removal.  Some are based on sinking carbon-rich materials to the bottom of the sea.  This is the marine equivalent of capturing CO2 from the air and storing it underground.  Other efforts involve increasing the alkalinity of the ocean, which increases its ability to chemically react with carbon dioxide as well as lowers its acidity, which is desirable in many ways.

Running Tide, a U.S.-based company, has been dumping thousands of tons of wood-industry waste 190 miles off the coast of Iceland.  The company has also been experimenting with dumping algae and kelp and sinking it deep below the ocean.  Such materials on land either get burned or decay, in both cases releasing CO2 into the atmosphere.  On the deep-sea bottom, the carbon is trapped.

Other efforts involve pumping seawater through electrodialysis filter systems to remove excess acidity or adding alkaline rocks to increase water alkalinity.

All of these efforts are a form of geoengineering, and like proposed ideas to cool the atmosphere, pose potential risks.  There is no silver bullet to solve the climate crisis.  It will take a combination of many solutions to address the issue of excess carbon dioxide in the atmosphere.  Marine carbon dioxide removal is one of the solutions that may play a role.

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Scientists Are Trying to Coax the Ocean to Absorb More CO2

Photo, posted February 22, 2018, courtesy of Bobbie Halchishak/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Iceland power

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Iceland burns very little fossil fuel to power its economy and heat its homes.  About 85% of its energy comes from geothermal power and hydropower.  Its unique geology provides it with the highest percentage of renewable energy in the world.  The fossil fuel that Iceland does burn is primarily used to power cars and trucks as well as boats in its fishing fleet.  And Iceland is rapidly embracing the use of electric vehicles.

Iceland can make far more electricity than its 373,000 people can use.  The majority of its electricity is essentially exported as bars of aluminum.  Iceland is one of the world’s largest refiners of aluminum.  The aluminum ore comes from other countries but gets shipped to Iceland where electricity is cheap.  Refining aluminum is so energy-intensive that some say that aluminum is basically just pure electricity in solid metal form.

Electricity-rich Iceland is finding other ways to make use of its resources.  There is a proposed project called Icelink, which is an electricity interconnector between Iceland and Great Britain.  The high-voltage direct current link would run between 620 and 750 miles and would be the longest sub-sea power interconnector in the world.  It is controversial in Iceland and it may or may not happen.

Another technology that is establishing an early foothold in Iceland is carbon capture.  An Icelandic company called Carbix is doing leading work on taking captured carbon dioxide and sequestering it underground.  Capturing and storing carbon dioxide is energy-intensive and the promise of cheap, clean geothermal power makes Iceland an attractive place to do it.

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Iceland Is Living in our Future

Photo, posted July 2, 2012, courtesy of  Emily Qualey / PopTech via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Moisture swing carbon capture

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As the world grapples with limiting the amount of carbon dioxide in the atmosphere, there is a growing need to capture the carbon dioxide that is emitted as well as preventing it from being emitted in the first place.  Carbon capture can be accomplished at the source of emissions (such as power plants) or it can be done by taking it out of the atmosphere.  The latter is called “direct air capture”.

It is not at all clear whether direct air capture can be accomplished on a scale that would really make a difference and at an acceptable cost either in dollars or energy expended.  But if it can be done that way, it would be a major tool in combatting climate change.

Direct air capture technology generally makes use of sorbent materials whose capacity to capture carbon dioxide and later release it is a function of temperature.  The process requires significant amounts of energy to release the carbon dioxide that has been captured. 

New research from Northwestern University makes use of the “moisture-swing” technique which uses materials whose ability to capture and release carbon dioxide depends on humidity rather than temperature.  While it takes some amount of energy to humidify the volume of air containing the sorbent material, it is very small compared to temperature-driven systems. 

There are many groups working with moisture-swing technology, but the Northwestern Group has identified a number of new sorbent materials with superior properties.

The fundamental questions of scalability and cost remain, but moisture-swing is a promising approach to direct air capture.  If carbon dioxide can be pulled out of the atmosphere in large volumes, it can be concentrated and stored or converted into useful products.

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Pulling carbon dioxide right out of the air

Photo, posted May 15, 2020, courtesy of James Watt via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cheaper Carbon Capture | Earth Wise

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As the years roll by without sufficient progress in reducing carbon dioxide emissions, the need for technologies that can capture CO2 from its sources or remove it from the air becomes stronger and stronger.  People have developed various ways to capture carbon dioxide, but to date, they generally suffer from some combination of being too costly or not being able to scale up to the necessary magnitude.

Scientists at the Pacific Northwest National Laboratory in Richland, Washington recently announced the creation of a new system that they claim is the least costly to date that captures carbon dioxide and turns it into a widely-used chemical: methanol.

Technologies that simply capture carbon dioxide that then needs to be stored in some secure location are difficult to implement from a cost perspective.  The PNNL researchers believe that turning CO2 into methanol can provide the financial incentive for widespread implementation.   Methanol can be used as a fuel, a solvent, or an important ingredient in plastics, paint, construction materials, and car parts.

The system is designed to be installed in fossil fuel-fired power plants as well as cement and steel plants.  Using a capture solvent developed by PNNL, the system grabs carbon dioxide molecules before they are emitted and converts them into methanol. Creating methanol from CO2 is nothing new, but capturing the carbon dioxide and converting into methanol in one continuously flowing system is new.

More work is needed to optimize and scale the process and it may be several years before it is ready for commercial deployment.

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Scientists Unveil Least Costly Carbon Capture System to Date

Photo, posted November 25, 2022, courtesy of Massachusetts Department of Environmental Conservation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon Capture In Wyoming | Earth Wise

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Wyoming produces about 40% of our country’s coal and many towns in the state were built because of and make their living from it.  With coal’s plummeting share in the nation’s electricity, there is a great deal of anxiety among residents of those towns.

As carbon dioxide levels in the atmosphere continue to climb, there is a growing sense that cutting emissions will not happen quickly enough and it will be necessary to pull the greenhouse gas out of the atmosphere.  The current long-term government climate strategy assumes that carbon removal will account for 6 to 8 percent of the nation’s greenhouse gas reductions by 2050.

The Inflation Reduction Act passed in August provides $3.5 billion to help build “direct air capture hubs” around the country, with an emphasis on fossil fuel-dependent communities such as many in Wyoming. 

The town of Rock Springs, Wyoming is home to the Jim Bridger Coal Plant. A company called CarbonCapture, Inc., is launching Project Bison, which will build a direct air capture facility outside of town that is set to begin operations next year.  It will initially capture 10,000 metric tons of CO2 per year but plans to expand that to 5 million tons a year by 2030. 

That would be far more than any current carbon capture plant can do. The largest plant in the world, located in Iceland, pulls in only about 4,000 metric tons a year.

There are many problems associated with carbon capture.  It uses up very large amounts of energy, possibly presents environmental problems, and is very expensive.  In short, the technology has a long way to go before becoming viable.  However, this may ultimately be another example where necessity is the mother of invention.

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Carbon Removal Is Coming to Fossil Fuel Country. Can It Bring Jobs and Climate Action?

Photo, posted July 22, 2012, courtesy of Max Phillips via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon Capture Booming | Earth Wise

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For the world to reach a state of net-zero emissions, it is going to require more than the ongoing transition to renewable energy sources.  There will also need to be efforts to capture the emissions from sources that can’t easily eliminate their pollution.  These include steel mills, cement plants, and other industrial sites.  At least for the foreseeable future,  a number of essential industries have no other viable path to deep decarbonization, and carbon capture and storage projects are the only promising strategy on hand.

Companies use CCS to filter emissions from fossil fuel power plants and industrial facilities and then bury the captured carbon underground, often in deep caverns.

Over the past 12 months, the pipeline for carbon capture and storage projects has grown by 44%.  This year, firms have announced 61 new CCS projects, bringing the total number of commercial projects in the global pipeline to 196, which includes about 30 that are already in operation.  Another 11 are under construction, and 153 are in development.

When all of these projects are completed, they will have the capacity to capture a total of about 270 million tons of carbon dioxide per year.  Estimates are that there need to be 1,400 million tons locked away each year to reach zero-emissions.  So, the existing project pipeline constitutes about 20% of what is ultimately needed.

The recently passed Inflation Reduction Act boosts tax incentives for carbon capture.  Analysts believe this could multiply U.S. deployment of the technology more than 10-fold.  Globally, it is expected that CCS will continue its rapid growth as countries ramp up investments in the technology.

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Carbon Capture Projects See Meteoric Growth in 2022

Photo, posted August 22, 2022, courtesy of Nenad Stojkovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

California Climate Legislation | Earth Wise

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At the end of its summer session, California’s state legislature passed five climate-related bills including ones that it had been unable to pass in previous sessions.  Taking all of these actions puts California in the position of blazing a trail for the country and the rest of world in taking aggressive action on climate issues.

One bill confirmed California’s goal of reaching net-zero emissions by 2045.  Another bill added interim-term targets to go along with the state’s goal of 100% renewable electricity by 2045.  It sets a target of 90% by 2030 and 95% by 2040.  That bill mandates that California state agencies use 100% clean energy by 2035, which is a decade earlier than the previous requirement.

A third bill requires the California Air Resources Board to determine steps and regulations for carbon-capture and storage projects at pollution hotspots like oil refineries.

A fourth bill requires the state to set goals for removing carbon dioxide from the atmosphere through natural means such as tree planting.

The California state budget includes a record-breaking $54 billion to be spent on climate programs over the next five years, including $6.1 billion toward electric vehicles, $14.8 billion towards public transit projects, more than $8 billion for electric grid stabilization, $2.7 billion towards preventing wildfires, and $2.8 billion towards managing drought.

California has been dealing with ongoing drought and numerous wildfires and is highly motivated to take decisive action in dealing with the climate crisis.  California’s environmental initiatives often result in comparable actions taken by other states.

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California Passes Massive Climate Legislation Package

Photo, posted March 16, 2019, courtesy of Raymond Shobe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Cheap Material For Carbon Capture | Earth Wise

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The recently passed Inflation Reduction Act includes significant support for carbon capture technologies. Eliminating fossil fuel burning is essential for halting climate change, but in the interim, methods for capturing emissions of carbon dioxide and either storing it or turning it into usable products are increasingly necessary.

There are a variety of techniques being developed for carbon capture but at this point, none of them are commercially viable.  The best technique in use today involves piping flue gases through chemicals called liquid amines, which bind CO2.  The process requires large amounts of energy to release the bound carbon dioxide so it can be concentrated and stored.  As a result, it is complicated and expensive.

Researchers at UC Berkeley, Stanford, and Texas A&M University have developed a carbon capture method using melamine, which is an inexpensive polymer used to make Formica, as well as low-cost dinnerware, industrial coatings, and other plastics.  Porous melamine itself adsorbs CO2 to a limited extent.  But the researchers discovered that adsorption could be much improved by adding the chemical DETA (diethylenetriamine) to bind the CO2.  In addition, adding cyanuric acid increased the melamine pore size and radically improved CO2 capture efficiency even more.

The result is a material that is more efficient even than exotic carbon capture materials like metalorganic frameworks and is much cheaper and easier to make. The researchers aim to design equipment that can used in industrial facilities, attached to buildings and other structures, or even to the tailpipes of gas-powered vehicles.

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A simple, cheap material for carbon capture, perhaps from tailpipes

Photo, posted June 10, 2006, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon Capture: Solution Or Band-Aid? | Earth Wise

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The idea of capturing the CO2 emissions from industry and locking them up is nothing new.  It’s been going on for decades in some places.  Norway’s state-owned oil company Equinor has been holing away a million tons of CO2 a year for a long time.  But overall, CCS – carbon capture and storage – has had very limited use.  As of last year, there were only about 30 large-scale projects in operation around the world, capturing only 0.1% of global emissions.

There is now growing interest in CCS and many new projects are underway.  A combination of rising carbon prices in Europe, tax breaks for CCS in the US, national net-zero targets, and the increasing need to ramp down global emissions are all driving rising CCS activities. 

While recent reports from the Intergovernmental Panel on Climate change still claim that it is possible to remain below 2 degrees Celsius of warming without using carbon capture, there is growing belief that it may be necessary given the present pace of the transition away from fossil fuels.

Two industries that together produce about 14% of global CO2 emissions are cement and steel.  These are both industries for which it is difficult to eliminate emissions regardless of the energy sources used. CCS may be the best approach to reducing their emissions.

But there is considerable pushback against CCS.  The concern is that CCS is primarily a way to delay decarbonization.  It encourages various industries to continue to use fossil fuels instead of shifting away from them.  Nonetheless, CCS no doubt has its place as part of the solution to climate change.

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Solution or Band-Aid? Carbon Capture Projects Are Moving Ahead

Photo, posted June 5, 2022, courtesy of Mark Dixon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Primary Ways To Mitigate Climate Change | Earth Wise

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The most recent report issued by the Intergovernmental Panel on Climate Change states that the world must halt the increase in greenhouse gases within three years, reduce emissions by 43% in the next seven years, and eliminate them entirely by 2050.  Otherwise, there will likely be catastrophic and irreversible impacts on the climate.

With respect to achieving these reductions, the report emphasizes decarbonizing the energy sector through electrification by replacing fossil fuels anywhere and everywhere possible.  Where that isn’t yet practical – such as in shipping and aviation – the use of biofuels and hydrogen can provide a stopgap until battery technology becomes a viable alternative.

The economics of this approach continue to improve.  Since 2010, the cost of wind, solar, and batteries has declined by as much as 85%.  In many cases, costs have fallen below those of fossil fuels.  Nonetheless, the report stresses that continuing to provide national, state, and local incentives for using renewable energy is a key factor in achieving the necessary reductions.

However, reducing emissions will no longer be enough.  This is the first major IPCC report that states that man-made carbon dioxide removal strategies will be necessary to meet the goals of the Paris Climate Agreement.  So-called natural carbon storage options, like planting trees and using farming methods that sequester carbon in soil, are also important parts of the strategy.

It is up to governments, policymakers, and investors to implement the necessary changes to mitigate climate change.  There is lots of talk about it, but it will take concerted action to avoid increasingly dire consequences.

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Report highlights affordable, available ways to mitigate climate change now

Photo, posted September 8, 2007, courtesy of Kevin Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Better Way To Capture Carbon | Earth Wise

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The goal of carbon capture and storage technology is to remove carbon dioxide from the atmosphere and safely store it for the indefinite future.  There are existing industrial facilities that capture carbon dioxide from concentrated sources – like the emissions from power plants.  The technology currently captures and stores only about a tenth of a percent of global carbon emissions.

Most existing CCS technologies use chemical binders to trap carbon dioxide quickly and efficiently, but they are extraordinarily energy intensive as well as expensive.

Researchers at the University of Colorado Boulder have developed a new tool that could lead to more efficient and cheaper ways to capture carbon dioxide directly out of the air.  The tool predicts how strong the bond will be between carbon dioxide and a candidate molecule for trapping it – that is, a binder.  This new electrochemical diagnostic tool can be used to identify suitable molecular candidates for capturing carbon dioxide from everyday air.

Current carbon capture technologies are very expensive at the scale required to be able to turn the captured CO2 into useful substances, such as carbonates – which are an ingredient in cement – or formaldehyde or methanol, which can be used as fuels.  Making useful materials out of the captured CO2 is an important way to offset the cost of capturing it that merely storing it away does not permit.

The new electrochemical analytical tool developed by the Colorado researchers offers the potential for identifying binders that will be more efficient and less expensive, thereby making direct air carbon capture a realistic part of the efforts to address climate change.

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New method could lead to cheaper, more efficient ways to capture carbon

Photo, posted October 25, 2015, courtesy of Frans Berkelaar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Safely Storing Carbon | Earth Wise

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As carbon dioxide levels continue to increase in the atmosphere and emissions reductions aren’t happening as fast as needed, there is growing interest in carbon capture and storage technologies.

The idea is to capture the CO2 emitted from industrial processes or from the burning of fossil fuels in power generation, and then permanently store it out of harm’s way.  There are several different types of sites where the CO2 might be stored.  Deep saline aquifers are particularly desirable for the purpose, but depleted hydrocarbon reservoirs are commonplace and relatively simple to use.  These are oil and gas wells that have been drained of their resources.

In many cases, CO2 has already been injected into these depleted wells as a means of enhanced oil recovery.  Therefore, such wells provide a unique opportunity to study what happens to carbon dioxide when it’s stored in these places.

Researchers from Oxford University recently published a paper in the journal Nature that compared the state of depleted wells with injected carbon dioxide to that of wells without the injected gas.  They found that nearly 3/4 of the CO2 was dissolved in the groundwater.  Unexpectedly, they also found that 13-19% of the carbon dioxide was converted into methane by methanogenic bacteria.  Methane is less soluble, less compressible, and less reactive than carbon dioxide.

Producing methane in these wells is therefore undesirable.  Deeper sites that have temperatures too high for the bacteria to thrive are much more suitable.  This research is important for identifying future carbon capture and storage sites and for designing long-term monitoring programs that are essential for low-risk, long-term carbon storage.

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Safer carbon capture and storage

Photo, posted November 6, 2015, courtesy of CL Baker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon Capture In Denmark | Earth Wise

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Denmark has pledged to reduce greenhouse gas emissions 70% by 2030 compared with 1990 levels. The country has also banned oil exploration in Danish waters and plans to phase out offshore drilling in the North Sea by 2050.

Instead of pumping oil from the North Sea, Denmark plans to capture CO2 and store it there.  To meet its climate goals, Denmark is investing $2.4 billion in a plan to capture carbon dioxide from its energy and industrial sectors and inject it into the seabed in geological formations that previously held oil and gas deposits.

The first North Sea carbon capture and storage facilities will be put into service in 2025 and will remove nearly half a million tons of emissions from the atmosphere each year.  The carbon dioxide will be captured from energy and industrial sectors such as waste incineration and cement production.

There are multiple carbon capture projects underway around the world.  Many are directed at so-called direct air capture, which is taking carbon dioxide out of the air once it is already there.  In Iceland, a project named “Orca” is extracting CO2 from the air and piping into a processing facility where it is mixed with water and diverted into a deep underground well.  Other large direct air capture plants are being built in the U.S. Southwest and in Scotland.

Whether capturing carbon from industrial operations or directly from the air ultimately makes environmental and economic sense remains to be seen.  What is driving the development of these technologies is the troubling math that reducing emissions is not happening fast enough to stave off the destructive effects of climate change that will result from global temperatures rising too much.

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Denmark bets on North Sea carbon capture to hit climate goals

Photo, posted July 2, 2018, courtesy of Ansgar Koreng via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Reducing Emissions From Cement Manufacturing | Earth Wise

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Cement is the basic ingredient of concrete, which is the most widely used construction material in the world.  About 8% of global carbon dioxide emissions are associated with cement production.

More than half of these emissions come from making clinker, which is a major component of cement produced by heating ground limestone and clay to a temperature of over 2500 degrees Fahrenheit.  Some of the emissions come from burning fossil fuels to heat the materials, but much of them come from the chemical reaction that creates the clinker.

The Portland Cement Association, which represents 92% of US cement manufacturing capacity, has recently released its “Roadmap to Carbon Neutrality”, which lays out a plan to reach carbon net zero across the cement and concrete value chain by 2050.

The plan includes the greater use of alternative fuels to reduce emissions from energy use.  It also involves the adoption of newer versions of cement such as Portland limestone cement, which reduces CO2 levels.  The industry has already reduced emissions by some shifting to Portland limestone cement, but it still only represents a small fraction of cement production.

The most significant strategy would be the adoption of carbon capture, utilization, and storage (or CCUS) technologies.  The idea is to capture the CO2 generated in the production of clinker and inject it into the fresh concrete.  It would actually be permanently sequestered in the concrete and would not be released even if a structure is demolished in the future.

It will take a combination of technologies and initiatives for the cement industry to reduce its emissions.  Fortunately, the industry appears to be committed to that goal.

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US cement manufacturers release their road map to carbon neutrality by 2050

Photo, posted March 26, 2014, courtesy of Michael Coghlan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Direct Air Capture | Earth Wise

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There is a lot of interest in carbon capture and sequestration (or CCS) in the context of trapping the carbon dioxide emissions from power plants and industrial facilities.  The fossil fuel industry is especially enthusiastic about the potential for continuing to burn fuels without harming the environment.  Apart from the technical challenges, there is the looming problem of CCS adding significant costs to power generation that is already losing the economic battle to renewable sources.

Direct air capture is a different matter.   This is the idea of actively taking CO2 out of the atmosphere.  This already happens by natural means such as sequestering it in soil or forests.  But there is considerable work going on aimed at developing technology to capture atmospheric carbon dioxide in massive quantities.

This September marks the opening of a new project called “Orca” in Iceland, which will, for the time being, be the largest direct air capture system in the world.  Once it is running around the clock, Orca will remove up to 4,000 metric tons of CO2 from the atmosphere each year.

Even larger DAC plants – one in the southwestern U.S and another in Scotland – are planned to come online in the next few years.

Ultimately, the question is whether direct air capture is feasible at large enough scale and affordable cost.  The numbers are daunting.  Society releases over 30 billion metric tons of carbon dioxide into the atmosphere each year.  Removing significant amounts of that with DAC technology is an enormous challenge.  Eliminating emissions remains the most practical way to mitigate the effects of climate change.

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The Dream of Carbon Air Capture Edges Toward Reality

Photo, posted November 10, 2017, courtesy of Governor Jay and First Lady Trudi Inslee via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)