Tag Archives: climate change

Turning CO2 back into fuel

Typically, when you burn a hydrocarbon fuel, you get waste products like CO2, a serious greenhouse gas. But what if we could turn CO2 back into fuel? A research team at Oak Ridge National Laboratory in Tennessee has made a breakthrough: they found a simple method to do just that. By embedding copper into nanospikes, they were able to make a powerful electrocatalyst that works something like many tiny lightning rods, which concentrate an electric field. This is able to turn CO2 into ethanol.

The reaction starts by reducing CO2 to carbon monoxide, CO. Then two CO molecules connect to form a dimer with the two carbon atoms bonded to each other. Finally, this dimer is reduced, removing an oxygen atom and gains hydrogen atoms. Although they initially believed this process would produce methanol, the final product is actually ethanol.

The structure of ethanol.

The structure of ethanol. This public domain image is from https://commons.wikimedia.org/wiki/File:Ethanol-2D-flat.png.

The process is fairly efficient, but not efficient enough to use on an industrial scale yet. The electrons have a yield of 63 percent, meaning only 27 percent of electrons will be “lost” during the reaction, mostly being taken up by hydrogen. The CO2 has a yield of 84 percent. The energy efficiency is not as good, only around 20 percent. On the positive side, the process only needs common materials, such as carbon, nitrogen, copper, and CO2.

It is hoped that this process will someday help reduce CO2 added to the atmosphere. Since it uses CO2 as a reagent, it would only add about as much to the atmosphere as it removes. The reaction could even work as efficient, clean energy storage – excess energy from renewable sources could be used to convert CO2 into ethanol, storing it as chemical energy for later use. However, it is still in development and has a long ways to go before it’s ready for large-scale use.

~ Nat Shipp

 

Sources:

Popular Mechanics – Meet the scientists turning CO2 into ethanol

Discover – Nanospikes Convert Carbon Dioxide Back Into Ethanol

Oak Ridge National Laboratory – Nano-spike catalysts convert carbon dioxide directly into ethanol

SciShow – Using Devil’s Milk to kill superbugs

 

Montreal Protocol amendment limits hydrofluorocarbon manufacture

In 1987, after the hole in the ozone layer was discovered over Antarctica, an international treaty called the Montreal Protocol was agreed to. This treaty basically ended chlorofluorocarbon (CFC) manufacture all over the globe. CFCs were widely-used refrigerants used in refrigerators and air conditioning. CFCs were replaced by hydrofluorocarbons (HFCs). This treaty was a success – a couple of years ago, the ozone layer was clearly showing signs of recovering. However, since 1987 it has been found that while it varies from chemical to chemical, HFCs as a whole tend to be just as bad as CFCs. This is why, a few days ago in Rwanda, delegates from the 197 countries involved in the treaty agreed to an amendment that aims to cut down on HFC production.

An example of a CFC an an HFC.

An example of a CFC an an HFC. HFCs contain hydrogen instead of chlorine. Both are gases used as refrigerants, and are greenhouse gases and harmful to the ozone layer.
This public domain image is courtesy of Wikimedia and the original can be found at https://commons.wikimedia.org/wiki/File:CFC-12_HFC-134a(catal%C3%A0).svg

According to this new agreement, the richest countries such as the US, Canada, and the EU countries are required to begin cutting down by 2019, developing countries such as China and Latin American countries begin in 2024, and some of the poorest countries such as Pakistan and Iran do not need to begin until 2028. However, China and India already say they will actually begin phasing out HFCs later than they agreed to in the treaty. India doesn’t have widespread use of air conditioning or refrigeration, but China produces the most HFCs in the world.

Experts estimated that this treaty will lessen atmospheric CO2 by 70 billion tons by 2050 – this may not be enough to reduce global warming by 0.5 degrees as hoped, but it is no small feat. It must have been hard for 197 nations to come to an agreement, although I’m a little disappointed it took them seven years of negotiation to do it. Overall, though, I think this is pretty exciting.

~ Nat Shipp

 

Sources:

BBC – “Climate Change: ‘Monumental’ deal to cut HFCs, fastest growing greenhouse gases”

Euronews – “‘Historic’ climate change deal reached in Rwanda”

Business Standard – “Global deal on climate-changing refrigeration gases sealed in Rwanda”

Bits of Science – “Transition from CFCs to HFCs under Montreal Protocol hurts climate – adjustment required”

BBC – “Ozone layer showing ‘signs of recovery,’ UN says”

 

A Solution for Climate Change?

CO2 concentrations over the last 400,000 years

A graph showing the rise and fall of CO2 concentration in the atmosphere, recorded over thousands of years. The magnified area indicates the dramatic increase of CO2 concentration during the Industrial Revolution. (c) Robert A. Rohde, used under Creative Commons Attribution-Share Alike 3.0 Unported

There is no doubt that climate change is real, dangerous, and occurring at an alarming rate that is unprecedented in the past 1,300 years. A major of the cause of this change is due to carbon dioxide gas, the product of burning fossil fuels for energy to run our cars, factories, for the production of electricity, and more. Carbon dioxide, one of many greenhouse gas, naturally acts as sort of a “blanket”, absorbing and emitting infrared radiation from the earth, causing the atmosphere to warm up, which known as the greenhouse effect.

A diagram illustrating the greenhouse effect.

A diagram illustrating the greenhouse effect. (c) US EPA used under public domain

Initiatives to reduce carbon dioxide emissions have already been implemented in our everyday lives, for example a simple thing like biking or taking public transit can reduce the amount of carbon dioxide emitted by automobiles. However, new carbon dioxide emissions data shows that our  efforts are not paying off. Every year, it is estimated that 38 billion tons of unnecessary carbon dioxide is released into the atmosphere. Even as you read this article 2.4 million pounds of this greenhouse gas is released into the atmosphere per second!

It seems that our efforts to reduce carbon dioxide emissions have failed and each year we can see a steady increase in emissions. Our economic and societal infrastructure has made us incredibly dependent on burni

Simple illustration of the conversion of CO2 into CO using silicon. (c) Chenxi Qian, used under Creative Commons Attribution 4.0 International License.

ng fossil fuels for energy. Perhaps the real solution lies in taking the excess carbon dioxide gas and converting it back into usable energy.

Recently, scientists from the University of Toronto believe to have discovered a method of converting carbon dioxide gas into energy-rich fuel. Professor Geoffrey Ozin and his team have developed a method using silicon, naturally found in sand, to efficiently and selectively convert gaseous carbon dioxide to carbon monoxide without any harmful emissions. Carbon monoxide can then be converted into hydrocarbon fuels such as petrol through a series of chemical reactions known as the Fischer-Tropsch process.

“A chemistry solution to climate change requires a material that is a highly active and selective catalyst to enable the conversion of CO₂ to fuel. It also needs to be made of elements that are low cost, non-toxic and readily available,” said Dr. Ozin.

Right now they are working on ways to increase the activity, enhance the scale, and boost the rate of production. Hopefully in the near future, there will be even more research dedicated to converting other greenhouse gases, not just carbon dioxide, into reusable energy, and then maybe we will be able to resolve the issues that have been caused by the detrimental amounts of greenhouse gases in our atmosphere.

– Charlie Wei