Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plastics, fuels and chemical feedstocks from CO2? They're working on it

10.09.2019

SUNCAT researchers discover a way to improve a key step in these conversions, and explore what it would take to turn the climate-changing gas into valuable products on an industrial scale.

One way to reduce the level of carbon dioxide in the atmosphere, which is now at its highest point in 800,000 years, would be to capture the potent greenhouse gas from the smokestacks of factories and power plants and use renewable energy to turn it into things we need, says Thomas Jaramillo.


Researchers at Stanford and SLAC are working on ways to convert waste carbon dioxide (CO2) into chemical feedstocks and fuels, turning a potent greenhouse gas into valuable products. The process is called electrochemical conversion. When powered by renewable energy sources, it could reduce levels of carbon dioxide in the air and store energy from these intermittent sources in a form that can be used any time.

Credit: Greg Stewart/SLAC National Accelerator Laboratory

As director of SUNCAT Center for Interface Science and Catalysis, a joint institute of Stanford University and the Department of Energy's SLAC National Accelerator Laboratory, he's in a position to help make that happen.

A major focus of SUNCAT research is finding ways to transform CO2 into chemicals, fuels, and other products, from methanol to plastics, detergents and synthetic natural gas. The production of these chemicals and materials from fossil fuel ingredients now accounts for 10% of global carbon emissions; the production of gasoline, diesel, and jet fuel accounts for much, much more.

"We have already emitted too much CO2, and we're on track to continue emitting it for years, since 80% of the energy consumed worldwide today comes from fossil fuels," says Stephanie Nitopi, whose SUNCAT research is the basis of her newly acquired Stanford PhD.

"You could capture CO2 from smokestacks and store it underground," she says. "That's one technology currently in play. An alternative is to use it as a feedstock to make fuels, plastics, and specialty chemicals, which shifts the financial paradigm. Waste CO2 emissions now become something you can recycle into valuable products, providing a new incentive to reduce the amount of CO2 released into the atmosphere. That's a win-win."

We asked Nitopi, Jaramillo, SUNCAT staff scientist Christopher Hahn and postdoctoral researcher Lei Wang to tell us what they're working on and why it matters.

First the basics: How do you convert CO2 into these other products?

Tom: It's essentially a form of artificial photosynthesis, which is why DOE's Joint Center for Artificial Photosynthesis funds our work. Plants use solar energy to convert CO2 from the air into carbon in their tissues. Similarly, we want to develop technologies that use renewable energy, like solar or wind, to convert CO2 from industrial emissions into carbon-based products.

Chris: One way to do this is called electrochemical CO2 reduction, where you bubble CO2 gas up through water and it reacts with the water on the surface of a copper-based electrode. The copper acts as a catalyst, bringing the chemical ingredients together in a way that encourages them to react. Put very simply, the initial reaction strips an oxygen atom from CO2 to form carbon monoxide, or CO, which is an important industrial chemical in its own right. Then other electrochemical reactions turn CO into important molecules such as alcohols, fuels and other things.

Today this process requires a copper-based catalyst. It's the only one known to do the job. But these reactions can produce numerous products, and separating out the one you want is costly, so we need to identify new catalysts that are able to guide the reaction toward making only the desired product.

How so?

Lei: When it comes to improving a catalyst's performance, one of the key things we look at is how to make them more selective, so they generate just one product and nothing else. About 90 percent of fuel and chemical manufacturing depends on catalysts, and getting rid of unwanted byproducts is a big part of the cost.

We also look at how to make catalysts more efficient by increasing their surface area, so there are a lot more places in a given volume of material where reactions can occur simultaneously. This increases the production rate.

Recently we discovered something surprising: When we increased the surface area of a copper-based catalyst by forming it into a flaky "nanoflower" shape, it made the reaction both more efficient and more selective. In fact, it produced virtually no byproduct hydrogen gas that we could measure. So this could offer a way to tune reactions to make them more selective and cost-competitive.

Stephanie: This was so surprising that we decided to revisit all the research we could find on catalyzing electrochemical CO2 conversion with copper, and the many ways people have tried to understand and fine-tune the process, using both theory and experiments, going back four decades. There's been an explosion of research on this - about 60 papers had been published as of 2006, versus more than 430 out there today - and analyzing all the studies with our collaborators at the Technical University of Denmark took two years.

We were trying to figure out what makes copper special, why it's the only catalyst that can make some of these interesting products, and how we can make it even more efficient and selective - what techniques have actually pushed the needle forward? We also offered our perspectives on promising research directions.

One of our conclusions confirms the results of the earlier study: The copper catalyst's surface area can be used to improve both the selectivity and overall efficiency of reactions. So this is well worth considering as a chemical production strategy.

Does this approach have other benefits?

Tom: Absolutely. If we use clean, renewable energy, like wind or solar, to power the controlled conversion of waste CO2 to a wide range of other products, this could actually draw down levels of CO2 in the atmosphere, which we will need to do to stave off the worst effects of global climate change.

Chris: And when we use renewable energy to convert CO2 to fuels, we're storing the variable energy from those renewables in a form that can be used any time. In addition, with the right catalyst, these reactions could take place at close to room temperature, instead of the high temperatures and pressures often needed today, making them much more energy efficient.

How close are we to making it happen?

Tom: Chris and I explored this question in a recent Perspective article in Science, written with researchers from the University of Toronto and TOTAL American Services, which is an oil and gas exploration and production services firm.

We concluded that renewable energy prices would have to fall below 4 cents per kilowatt hour, and systems would need to convert incoming electricity to chemical products with at least 60% efficiency, to make the approach economically competitive with today's methods.

Chris: This switch couldn't happen all at once; the chemical industry is too big and complex for that. So one approach would be to start with making high-value, high-volume products like ethylene, which is used to make alcohols, polyester, antifreeze, plastics and synthetic rubber. It's a $230 billion global market today. Switching from fossil fuels to CO2 as a starting ingredient for ethylene in a process powered by renewables could potentially save the equivalent of about 860 million metric tons of CO2 emissions per year.

The same step-by-step approach applies to sources of CO2. Industry could initially use relatively pure CO2 emissions from cement plants, breweries or distilleries, for instance, and this would have the side benefit of decentralizing manufacturing. Every country could provide for itself, develop the technology it needs, and give its people a better quality of life.

Tom: Once you enter certain markets and start scaling up the technology, you can attack other products that are tougher to make competitively today. What this paper concludes is that these new processes have a chance to change the world.

###

Citations:

L. Wang et al., Nature Catalysis, 17 June 2019 (10.1038/s41929-019-0301-z)

S. Nitopi et al., Chemical Reviews, 22 May 2019 (10.1021/acs.chemrev.8b00705)

P. De Luna et al., Science, 26 April 2019 (10.1126/science.aav3506)

Glennda Chui | EurekAlert!
Further information:
https://www6.slac.stanford.edu/news/2019-09-09-plastics-fuels-and-chemical-feedstocks-co2-theyre-working-it.aspx
http://dx.doi.org/10.1038/s41929-019-0301-z

Further reports about: Accelerator CO2 CO2 emissions EMISSIONS Plastics SLAC catalyst renewable energy surface area

More articles from Ecology, The Environment and Conservation:

nachricht Corals take control of nitrogen recycling
04.09.2019 | King Abdullah University of Science & Technology (KAUST)

nachricht Making More Plastics Recyclable
02.09.2019 | Julius-Maximilians-Universität Würzburg

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicists from Stuttgart prove the existence of a supersolid state of matte

A supersolid is a state of matter that can be described in simplified terms as being solid and liquid at the same time. In recent years, extensive efforts have been devoted to the detection of this exotic quantum matter. A research team led by Tilman Pfau and Tim Langen at the 5th Institute of Physics of the University of Stuttgart has succeeded in proving experimentally that the long-sought supersolid state of matter exists. The researchers report their results in Nature magazine.

In our everyday lives, we are familiar with matter existing in three different states: solid, liquid, or gas. However, if matter is cooled down to extremely...

Im Focus: World record for tandem perovskite-CIGS solar cell

A team headed by Prof. Steve Albrecht from the HZB will present a new world-record tandem solar cell at EU PVSEC, the world's largest international photovoltaic and solar energy conference and exhibition, in Marseille, France on September 11, 2019. This tandem solar cell combines the semiconducting materials perovskite and CIGS and achieves a certified efficiency of 23.26 per cent. One reason for this success lies in the cell’s intermediate layer of organic molecules: they self-organise to cover even rough semiconductor surfaces. Two patents have been filed for these layers.

Perovskite-based solar cells have experienced an incredibly rapid increase in efficiency over the last ten years. The combination of perovskites with classical...

Im Focus: A molecular 'atlas' of animal development

Researchers from the University of Pennsylvania provide a molecular map of every cell in a developing animal embryo

In a paper in Science this week, Penn researchers report the first detailed molecular characterization of how every cell changes during animal embryonic...

Im Focus: Next generation video: WDR and Fraunhofer HHI present significantly improved video quality at IFA 2019

The demand for even higher resolution videos will continue to increase in the coming years. For this reason, the German public service broadcaster WDR and the Fraunhofer Heinrich Hertz Institute HHI will collaborate in the coming months to test the Video Coding possibilities offered by the next international standard VVC/H.266.

VVC/H.266 is the successor standard to HEVC/H.265. The latter is currently the most modern and efficient standard for Video Coding and is used, for example, in...

Im Focus: Nanodiamonds in the brain

The recording of images of the human brain and its therapy in neurodegenerative diseases is still a major challenge in current medical research. The so-called blood-brain barrier, a kind of filter system of the body between the blood system and the central nervous system, constrains the supply of drugs or contrast media that would allow therapy and image acquisition. Scientists at the Max Planck Institute for Polymer Research (MPI-P) have now produced tiny diamonds, so-called "nanodiamonds", which could serve as a platform for both the therapy and diagnosis of brain diseases.

The blood-brain barrier is a physiological boundary layer that works highly selectively and thus protects the brain: On the one hand, pathogens or toxins are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

AI for Laser Technology Conference: optimizing the use of lasers with artificial intelligence

29.08.2019 | Event News

 
Latest News

Plastics, fuels and chemical feedstocks from CO2? They're working on it

10.09.2019 | Ecology, The Environment and Conservation

Fermilab achieves world-record field strength for accelerator magnet

10.09.2019 | Physics and Astronomy

Using existing cellular networks for drones

10.09.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>