Research gives clues to CO2 trapping underground

CO2 is an environmentally important gas that plays a crucial role in climate change.

It is a compound that is also present in the depth of the Earth but very little information about it is available. What happens to CO2 in the Earth’s mantle? Could it be eventually hosted underground? A new publication in Nature Communications unveils some key findings.

Carbon dioxide is a widespread simple molecule in the Universe. In spite of its simplicity, it has a very complex phase diagram, forming both amorphous and crystalline phases above the pressure of 40 GPa. In the depths of the Earth, CO2 does not appear as we know it in everyday life. Instead of being a gas consisting of molecules, it has a polymeric solid form that structurally resembles quartz (a main mineral of sand) due to the pressure it sustains, which is a million times bigger than that at the surface of the Earth.

Researchers have been long studying what happens to carbonates at high temperature and high pressure, the same conditions as deep inside the Earth. Until now, the majority of experiments had shown that CO2 decomposes, with the formation of diamond and oxygen. These studies were all focused on CO2 at the upper mantle, with a 70 GPa of pressure and 1800-2800 Kelvin of temperature.

>Read more on the European Synchrotron (ESRF) website

Picture: Mohamed Mezouar, scientist in charge of ID27, on the beamline.
Credit: S. Candé. 

ALBA opens a liquid helium recovery plant

This installation allows recycling 80% of the liquid helium consumed in ALBA for operating the superconducting magnets and for experiments at ultra-low temperatures.

Despite being the second most abundant element in the universe, helium is very scarce on Earth and it is expected to be completely exhausted in a few decades. This inert gas, which is generated by fusing hydrogen atoms, is hidden in the subsoil of some natural gas reserves and its extraction is expensive and difficult to obtain. This is why different systems are being explored to recover helium and thus facilitate its application in the wide range of equipment in which it is used (beyond the popular balloons).

Liquid helium is basic for the operation of medical equipment such as magnetoencephalography (MEG) to cool down the superconducting magnets they contain to almost 270 ºC. It is also necessary for carrying out different scientific experiments; at the ALBA Synchrotron there are currently two superconducting magnets: one for producing synchrotron light in one of the beamlines and the other one for the sample area of another beamline, needing both a considerable amount of helium. Besides, four of the eight beamlines use it to keep cold the samples that must be analysed when they are irradiated with synchrotron light.

In order to guarantee the availability of this limited substance (it is foreseen that its cost will double in the near future), ALBA has built a plant to liquefy the helium gas and reuse it again once liquefied.

“With the new plant we can recycle 80% of the helium that we consume in our experiments and save more than € 10 per litre nowadays”, says Joan Casas, Head of the Engineering division of the ALBA Synchrotron.

>Read more on the ALBA website


Structure and Catalytic Activity of Copper Nanoparticles

Research investigates the addition of ceria on the activity of catalysts for the water-gas shift reaction

Catalysts are substances that promote and accelerate chemical reactions without being consumed during the process and are widely used in industrial processes to produce various chemicals.

Catalysts based on copper nanoparticles dispersed in an oxide support benefit various reactions, such as the synthesis of methanol, the alcohol dehydrogenation, or the water gas shift (WGS) reaction which is one of the main processes for hydrogen production on an industrial scale. In this reaction, carbon monoxide reacts with water to produce carbon dioxide CO2 and hydrogen gas H2.

>Read more on the LNLS website

Figure 1: Correlation between the bond length of CuO and the catalyst turnover frequency (TOF) for the catalysts analyzed under WGS conditions with different proportions of copper and ceria.