Category Archives: Chemistry

What to do with Carbon Dioxide

In my 17 December 2016 post, “Climate Change and Nuclear Power,” there is a chart that shows the results of a comparative life cycle greenhouse gas (GHG) analysis for 10 electric power-generating technologies. In that chart, it is clear how carbon dioxide capture and storage technologies can greatly reduce the GHG emissions from gas and coal generators.

An overview of carbon dioxide capture and storage technology is presented in a December 2010 briefing paper issued by the London Imperial College. This paper includes the following process flow diagram showing the capture of CO2 from major sources, use or storage of CO2 underground, and use of CO2 as a feedstock in other industrial processes. Click on the graphic to enlarge.

Carbon capture and storage process

You can download the London Imperial College briefing paper at the following link:

https://www.imperial.ac.uk/media/imperial-college/grantham-institute/public/publications/briefing-papers/Carbon-dioxide-storage—-Grantham-BP-4.pdf

Here is a brief look at selected technologies being developed for underground storage (sequestration) and industrial utilization of CO2.

Store in basalt formations by making carbonate rock

Iceland generates about 85% of its electric power from renewable resources, primarily hydro and geothermal. Nonetheless, Reykjavik Energy initiated a project called CarbFix at their 303 MWe Hellisheidi geothermal power plant to control its rather modest CO2 emissions along with hydrogen sulfide and other gases found in geothermal steam.

Hellisheidi geothermal power plantHellisheidi geothermal power plant. Source: Power Technology

The process system collects the CO2 and other gases, dissolves the gas in large volumes of water, and injects the water into porous, basaltic rock 400 – 800 meters (1,312 – 2,624 feet) below the surface. In the deep rock strata, the CO2 undergoes chemical reactions with the naturally occurring calcium, magnesium and iron in the basalt, permanently immobilizing the CO2 as environmentally benign carbonates. There typically are large quantities of calcium, magnesium and iron in basalt, giving a basalt formation a large CO2 storage capacity.

The surprising aspect of this process is that the injected CO2 was turned into hard rock very rapidly. Researchers found that in two years, more that 95% of the CO2 injected into the basaltic formation had been turned into carbonate.

For more information, see the 9 June 2016 Washington Post article by Chris Mooney, “This Iceland plant just turned carbon dioxide into solid rock — and they did it super fast,” at the following link:

https://www.washingtonpost.com/news/energy-environment/wp/2016/06/09/scientists-in-iceland-have-a-solution-to-our-carbon-dioxide-problem-turn-it-into-stone/?utm_term=.886f1ca92c56

The author notes,

“The researchers are enthusiastic about their possible solution, although they caution that they are still in the process of scaling up to be able to handle anything approaching the enormous amounts of carbon dioxide that are being emitted around the globe — and that transporting carbon dioxide to locations featuring basalt, and injecting it in large volumes along with even bigger amounts of water, would be a complex affair.”

Basalt formations are common worldwide, making up about 10% of continental rock and most of the ocean floor. Iceland is about 90% basalt.

Detailed results of this Reykjavik Energy project are reported in a May 2016 paper by J.M. Matter, M. Stute, et al., Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions,” which is available on the Research Gate website at the following link:

https://www.researchgate.net/publication/303450549_Rapid_carbon_mineralization_for_permanent_disposal_of_anthropogenic_carbon_dioxide_emissions

Similar findings were made in a separate pilot project in the U.S. conducted by Pacific Northwest National Laboratory and the Big Sky Carbon Sequestration Partnership. In this project, 1,000 tons of pressurized liquid CO2 were injected into a basalt formation in eastern Washington state in 2013. Samples taken two years later confirmed that the CO2 had been converted to carbonate minerals.

These results were published in a November 2016 paper by B. P McGrail, et al., “Field Validation of Supercritical CO2 Reactivity with Basalts.” The abstract and the paper are available at the following link:

http://pubs.acs.org/doi/pdf/10.1021/acs.estlett.6b00387

Store in fractures in deep crystalline rock

Lawrence Berkeley National Laboratory has established an initiative dubbed SubTER (Subsurface Technology and Engineering Research, Development and Demonstration Crosscut) to study how rocks fracture and to develop a predictive understanding of fracture control. A key facility is an observatory set up 1,478 meters (4,850 feet) below the surface in the former Homestake mine near Lead, South Dakota (note: Berkeley shares this mine with the neutrino and dark matter detectors of the Sanford Underground Research Facility). The results of the Berkeley effort are expected to be applicable both to energy production and waste storage strategies, including carbon capture and sequestration.

You can read more about this Berkeley project in the article, “Underground Science: Berkeley Lab Digs Deep For Clean Energy Solutions,” on the Global Energy World website at the following link:

http://www.newswise.com/articles/view/663141/?sc=rssn&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+NewswiseScinews+%28Newswise%3A+SciNews%29

Make ethanol

Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have defined an efficient electrochemical process for converting CO2 into ethanol. While direct electrochemical conversion of CO2 to useful products has been studied for several decades, the yields of most reactions have been very low (single-digit percentages) and some required expensive catalysts.

Key points about the new process developed by ORNL are:

  • The electro-reduction process occurs in CO2 saturated water at ambient temperature and pressure with modest electrical requirements
  • The nanotechnology catalyst is made from inexpensive materials: carbon nanospike (CNS) electrode with electro-nucleated copper nanoparticles (Cu/CNS). The Cu/CNS catalyst is unusual because it primarily produces ethanol.
  • Process yield (conversion efficiency from CO2 to ethanol) is high: about 63%
  • The process can be scaled up.
  • A process like this could be used in an energy storage / conversion system that consumes extra electricity when it’s available and produces / stores ethanol for later use.

You can read more on this process in the 19 October 2016 article, “Scientists just accidentally discovered a process that turns CO2 directly into ethanol,” on the Science Alert website at the following link

http://www.sciencealert.com/scientists-just-accidentally-discovered-a-process-that-turns-co2-directly-into-ethanol

The full paper is available on the Chemistry Select website at the following link:

http://onlinelibrary.wiley.com/doi/10.1002/slct.201601169/full

 

 

 

 

Where in the Periodic Table Will We Put Element 119?

The first periodic table of elements

In 1869, Russian chemist Dimitri Mendeleev proposed the first periodic table of elements, in which he arranged the 60 known elements in order of their increasing atomic masses (average mass, considering relative abundance of isotopes in naturally-occurring elements), with elements organized into groups based their similar properties. Mendeleev observed that certain properties recur at regular intervals in the periodic table, thereby defining the groupings of elements.

Mendeleev stamp Source: http://we-are-star-stuff.tumblr.com

This first version of the periodic table is compared to the modern periodic table in the following diagram prepared by SIPSAWIYA.COM. Mendeleev’s periodic table consisted of Groups I to VIII in the modern periodic table.

Mendeleev_sipsawiyagif

The gaps represent undiscovered elements predicted by Mendeleev’s periodic table, for example, Gallium (atomic mass 69.7) and Germanium (atomic mass 72.6) . You can read more about Mendeleev’s periodic table at the following link:

http://www.sipsawiya.com/2015/07/history-of-periodic-table.html

German chemist Lothar Meyer was competing with Mendeleev to publish the first periodic table. The general consensus is that Mendeleev, not Meyer, was the true inventor of the periodic table because of the accuracy and detail of Mendeleev’s work.

Element mendelevium (101) was named in honor of Dimitri Mendeleev.

Evolution of the Modern Periodic Table of Elements

The modern periodic table organizes elements according to their atomic numbers (number of protons in the nucleus) into 7 periods (vertical) and 18 groups (horizontal). The version shown below, in the International Union of Pure and Applied Chemistry (IUPAC) format, accounts for elements up to atomic number 118 and color-codes 10 different chemical series.

PeriodicTableMeltingPoint

Source: http://sciencenotes.org/printable-periodic-table/

Hundreds of versions of the periodic table of elements have existed since Mendeleev’s first version. You can view a great many of these at The Internet Database of Periodic Tables curated by Dr. Mark R. Leach and presented at the following link:

http://www.meta-synthesis.com/webbook/35_pt/pt_database.php?Button=All

Glenn T. Seaborg (1912 – 1999) is well known for his role in defining the structure of the modern periodic table. His key contributions to periodic table structure include:

  • In 1944, Seaborg formulated the ‘actinide concept’ of heavy element electron structure, which predicted that the actinides, including the first 11 transuranium elements, would form a transition series analogous to the rare earth series of lanthanide elements. The actinide concept showed how the transuranium elements fit into the periodic table.
  • Between 1944 and 1958, Seaborg identified eight transuranium elements: americium (95), curium (96), berkelium (97), californium (98), einsteinium (99), fermium (100), mendelevium (101), and nobelium (102).

Element seaborgium (106) was named in honor of Glenn T. Seaborg.  Check out details Glenn T. Seaborg’s work on transuranium elements at the following link:

http://www.osti.gov/accomplishments/seaborg.html

Four newly-discovered and verified elements

On 30 December 2015, IUPAC announced the verification of the discoveries of the following four new elements: 113, 115, 117 and 118.

  • Credit for the discovery of element 113 was given to a team of scientists from the Riken institute in Japan. This will be the first element to be named in Asia.
  • Credit for discovery of elements 115, 117 and 118 was given to a Russian-American team of scientists at the Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory in California.

These four elements complete the 7th period of the periodic table of elements. The current table is now full.

You can read the IUPAC announcement at the following link:

http://www.iupac.org/news/news-detail/article/discovery-and-assignment-of-elements-with-atomic-numbers-113-115-117-and-118.html

Dealing with super-heavy elements beyond element 118

The number of physically possible elements is unknown.

In 1969, Glenn T. Seaborg proposed the following extended periodic table to account for undiscovered elements from atomic number 110 to 173, including the  “super-actinide” series of elements (atomic numbers 121 to 155).

Glenn Seaborg 1969 extended periodic table copy R1Source: W. Nebergal, et al., General Chemistry, 4th ed., pp 668 – 670, D.C. heath Co, Massachusetts, 1972

In 2010, Finnish chemist Pekka Pyykkö at the University of Helsinki proposed an extended periodic table with 54 predicted elements. The extension, shown below, is based on a computational model that predicts the order in which the electron orbital shells will fill up, and, therefore, the periodic table positions of elements up to atomic number 172. Pekka Pyykkö says that the value of the work is in showing, “how the rules of quantum mechanics and relativity function in determining chemical properties.”

Pyyko 2010 periodic tableSource: Royal Society of Chemistry

You can read more on Pekka Pyykkö’s extended periodic table at the following link:

http://www.rsc.org/Publishing/ChemScience/Volume/2010/11/Extended_elements.asp

You can read more general information on the extended periodic table on Wikipedia at the following link:

https://en.wikipedia.org/wiki/Extended_periodic_table

So where will we place element 119 in the periodic table of elements?

Based on both the Seaborg and Pyykkö extended periodic tables described above, element 119 will be the start of period 8 and it will be an alkali metal. Element 120 will be an alkaline earth. With element 121, we’ll enter the new chemical series of the “super-actinides”.

These are exciting times for scientists attempting to discover new super-heavy elements.

Where does neutronium fit in the periodic table?

Neutronium is a name coined in 1926 by scientist Andreas von Antropoff for a proposed “element of atomic number zero” (i.e., because it has no protons) that he placed at the head of the periodic table. In modern usage, the extremely dense core of a neutron star is referred to as “degenerate neutronium”.

Neutronium also finds many hypothetical applications in modern science fiction. For example, in the 1967 Star Trek episode, The Doomsday Machine, neutronium formed the hull of a giant, autonomous “planet killer”, and was portrayed as being invulnerable to all manner of scans and weapons. Since free neutrons at standard temperature and pressure undergo β decay with a half-life of 10 minutes, 11 seconds, a very small quantity of neutronium could be quite hazardous to your health.