Catalyst turns carbon dioxide into gasoline

by Andrew Myers, Stanford University

PART-1: WHAT THE ARTICLE SAYS

Engineers working to reverse the proliferation of greenhouse gases know that in addition to reducing carbon dioxide emissions we will also need to remove carbon dioxide from the skies. But, what do we do with all that captured carbon? Matteo Cargnello, a chemical engineer at Stanford University, is working to turn it into other useful chemicals, such as propane, butane or other hydrocarbon fuels that are made up of long chains of carbon and hydrogen. We can create gasoline, basically,” said Cargnello, who is an assistant professor of chemical engineering. “To capture as much carbon as possible, you want the longest chain hydrocarbons. Chains with eight to 12 carbon atoms would be the ideal.”A new catalyst, invented by Cargnello and colleagues, moves toward this goal by increasing the production of long-chain hydrocarbons in chemical reactions. It produced 1,000 times more butane—the longest hydrocarbon it could produce under its maximum pressure—than the standard catalyst given the same amounts of carbon dioxide, hydrogen, catalyst, pressure, heat and time. The new catalyst is composed of the element ruthenium—a rare transition metal belonging to the platinum group—coated in a thin layer of plastic. Like any catalyst, this invention speeds up chemical reactions without getting used up in the process. Ruthenium also has the advantage of being less expensive than other high-quality catalysts, like palladium and platinum. Cargnello and his team describe the catalyst and the results of their experiments in their latest paper, published this week in the journal Proceedings of the National Academy of Sciences. Cargnello and his team took seven years to discover and perfect the new catalyst. The hitch: The longer the hydrocarbon chain is, the more difficult it is to produce. The bonding of carbon to carbon requires heat and great pressure, making the process expensive and energy intensive. In this regard, the ability of the new catalyst to produce gasoline from the reaction is a breakthrough, said Cargnello. The reactor in his lab would need only greater pressure to produce all the long-chain hydrocarbons for gasoline, and they are in the process of building a higher pressure reactor. Gasoline is liquid at room temperature and, therefore, much easier to handle than its gaseous short-chain siblings—methane, ethane and propane—which are difficult to store and prone to leaking back into the skies. Cargnello and other researchers working to make liquid fuels from captured carbon imagine a carbon-neutral cycle in which carbon dioxide is collected, turned into fuel, burned again and the resulting carbon dioxide begins the cycle anew. The key to the remarkable increase in reactivity is that layer of porous plastic on the ruthenium, explained lead student author Chengshuang Zhou, a doctoral candidate in Cargnello’s lab, who conducted the search and experimentation needed to refine the new coating. An uncoated catalyst works just fine, he said, but only produces methane, the shortest chain hydrocarbon, which has just a single atom of carbon bonded to four hydrogens. It’s not really a chain at all. “An uncoated catalyst gets covered in too much hydrogen on its surface, limiting the ability of carbon to find other carbons to bond with,” Zhou said. “The porous polymer controls the carbon-to-hydrogen ratio and allows us to create longer carbon chains from the same reactions. This particular, crucial interaction was demonstrated using synchrotron techniques at SLAC National Laboratory in collaboration with the team of Dr. Simon Bare, who leads Co-Access there.” While long-chain hydrocarbons are an innovative use of captured carbon, they are not perfect, Cargnello acknowledges. He is also working on other catalysts and similar processes that turn carbon dioxide into valuable industrial chemicals, like olefins used to make plastics, methanol and the holy grail, ethanol, all of which can sequester carbon without returning carbon dioxide to the skies. “If we can make olefins from CO₂ to make plastics,” Cargnello noted, “we have sequestered it into a long-term storable solid. That would be a big deal.” CO2 and hydrogen molecules react with the help of a ruthenium-based catalyst. On the right, the uncoated catalyst produces the simplest hydrocarbon, methane. On the left, the coated catalyst produces longer chain hydrocarbons, like butane, propane and ethane. Credit: Chih-Jung Chen. Engineers working to reverse the proliferation of greenhouse gases know that in addition to reducing carbon dioxide emissions we will also need to remove carbon dioxide from power plant fumes or from the skies. But, what do we do with all that captured carbon? Matteo Cargnello, a chemical engineer at Stanford University, is working to turn it into other useful chemicals, such as propane, butane or other hydrocarbon fuels that are made up of long chains of carbon and hydrogen. “We can create gasoline, basically,” said Cargnello, who is an assistant professor of chemical engineering. “To capture as much carbon as possible, you want the longest chain hydrocarbons. Chains with eight to 12 carbon atoms would be the ideal.” A new catalyst, invented by Cargnello and colleagues, moves toward this goal by increasing the production of long-chain hydrocarbons in chemical reactions. It produced 1,000 times more butane—the longest hydrocarbon it could produce under its maximum pressure—than the standard catalyst given the same amounts of carbon dioxide, hydrogen, catalyst, pressure, heat and time. The new catalyst is composed of the element ruthenium—a rare transition metal belonging to the platinum group—coated in a thin layer of plastic. Like any catalyst, this invention speeds up chemical reactions without getting used up in the process. Ruthenium also has the advantage of being less expensive than other high-quality catalysts, like palladium and platinum. Cargnello and his team describe the catalyst and the results of their experiments in their latest paper, published this week in the journal Proceedings of the National Academy of Sciences. Cargnello and his team took seven years to discover and perfect the new catalyst. The hitch: The longer the hydrocarbon chain is, the more difficult it is to produce. The bonding of carbon to carbon requires heat and great pressure, making the process expensive and energy intensive. In this regard, the ability of the new catalyst to produce gasoline from the reaction is a breakthrough, said Cargnello. The reactor in his lab would need only greater pressure to produce all the long-chain hydrocarbons for gasoline, and they are in the process of building a higher pressure reactor. Gasoline is liquid at room temperature and, therefore, much easier to handle than its gaseous short-chain siblings—methane, ethane and propane—which are difficult to store and prone to leaking back into the skies. Cargnello and other researchers working to make liquid fuels from captured carbon imagine a carbon-neutral cycle in which carbon dioxide is collected, turned into fuel, burned again and the resulting carbon dioxide begins the cycle anew. Perfecting the polymer: The key to the remarkable increase in reactivity is that layer of porous plastic on the ruthenium, explained lead student author Chengshuang Zhou, a doctoral candidate in Cargnello’s lab, who conducted the search and experimentation needed to refine the new coating. An uncoated catalyst works just fine, he said, but only produces methane, the shortest chain hydrocarbon, which has just a single atom of carbon bonded to four hydrogens. It’s not really a chain at all. An uncoated catalyst gets covered in too much hydrogen on its surface, limiting the ability of carbon to find other carbons to bond with. The porous polymer controls the carbon-to-hydrogen ratio and allows us to create longer carbon chains from the same reactions. This particular, crucial interaction was demonstrated using synchrotron techniques at SLAC National Laboratory in collaboration with the team of Dr. Simon Bare, who leads Co-Access there.”While long-chain hydrocarbons are an innovative use of captured carbon, they are not perfect, Cargnello acknowledges. He is also working on other catalysts and similar processes that turn carbon dioxide into valuable industrial chemicals, like olefins used to make plastics, methanol and the holy grail, ethanol, all of which can sequester carbon without returning carbon dioxide to the skies. If we can make olefins from CO2 to make plastics, we have sequestered it into a long-term storable solid. That would be a big deal.

PART-2: CRITICAL COMMENTARY

THE PRESENCE OF CARBON DIOXIDE IN THE ATMOSPHERE DOES NOT CAUSE WARMING. THE GLOBAL WARMING ISSUE OF OUR TIME IS NOT THAT THERE IS TOO MUCH CARBON DIOXIDE IN THE ATMOSPHERE. IT IS THAT ATMOSPHERIC CO2 CONCENTRATION IS RISING BECAUSE OF FOSSIL FUEL EMISSIONS AND THAT RISING ATMOSPHERIC CO2 CONCENTRATION CAUSES WARMING.

CURRENTLY, FOSSIL FUEL EMISSIONS ARE ESTIMATED AT 36 GIGATONNES PER YEAR CORRESPONDING TO ABOUT 98.6 MILLION TONNES PER DAY THAT IS CAUSING ATMOSPHERIC CO2 TO RISE. WHAT CLIMATE SCIENCE WANTS IS THAT WE HUMANS MUST STOP BURNING FOSSIL FUELS AND STOP THIS RISING TREND IN ATMOSPHERIC CO2. THIS IS THE ISSUE IN CLIMATE SCIENCE AND IT HAS NOT BEEN ADDRESSED IN THE CARBON CAPTURE PROPOSAL.

TO PROPOSE THAT REMOVAL OF ATMOSPHERIC CO2 AND ITS USE IN THE SYNTHESIS OF FOSSIL FUELS IS SOME KIND OF CLIMATE ACTION IT MUST BE SHOWN THAT THE PROCEDURE WILL SLOW AND EVENTUALLY ELIMINATE THE OBSERVED RISE IN ATMOSPHERIC CO2 CONCENTRATION. CURRENTLY, FOSSIL FUEL EMISSIONS ARE 36 GIGATONNES PER YEAR AND CLIMATE SCIENCE SAYS THAT THIS RATE OF FOSSIL FUEL EMISSIONS IS CAUSING ATMOSHERIC CO2 TO RISE AND CAUSE GLOBAL WARMING. THE CLIMATE ACTION PROPOSITION PRESENTED IN THE SOURCE ARTICLE IS IRRELEVANT IN THIS CONTEXT.

FOR IT TO BE RELEVANT, IT MUST BE SHOWN THAT THE PROPOSED REMOVAL OF ATMOSPHERIC CO2 WILL STOP THE RISE IN ATMOSPHERIC CO2 AND THE RATE OF GLOBAL WARMING. WITHOUT THAT CONNECTION, THE PROPOSED CO2 REMOVAL PLAN IS IRRELEVANT IN THE CLIMATE ACTION CONTEXT.

WHAT IS GOING ON IN STANFORD? WE SHOULD TAKE NOTE HERE THAT FAMOUS STANFORD SCIENTIST PAUL EHRLICH THE POPULATION BOMB GOOFBALL WHO HAS APPARENTLY GIVEN UP ON THE POPULATION BOMB AND TURNED INTO SOME KIND OF GLOBAL WARMING CATASTROPHE FORECASTER. HE IS NOW WARNING US ABOUT A GLOBAL WARMING ANTHROPOCENE AND A HUMAN CAUSED MASS EXTINCTION EVENT. THIS KIND OF ALARMIST MADNESS AND A BIZARRE CLIMATE ACTION PLAN THAT DOES NOT ADDRESS THE GLOBAL WARMING ISSUE AS STATED BY CLIMATE SCIENCE DO NOT SERVE AS POSITIVE FACTORS IN HOW PEOPLE WILL JUDGE THIS ONCE PRESTIGIOUS UNIVERSITY.