Wednesday, October 19, 2016

US Team Make Breakthrough in Ethanol Production from Waste Carbon Dioxide

Generation of Possible Future Fuel from Atmosphere Degenerative Gas
Shipping News Feature
US – The US Government's Department of Energy’s Oak Ridge National Laboratory has made an unexpected breakthrough in converting the greenhouse gas Carbon Dioxide (CO2) into ethanol, a substance that is undergoing multiple reviews and testing as a potential supplement to, or even replacement for, fossil fuels. Conducting an experiment in converting waste emission into fuel, the scientists at Oak Ridge found that making the conversion is much easier and cheaper than they had originally believed possible.

“We discovered somewhat by accident that this material worked,” said ORNL’s Adam Rondinone, lead author of the team’s study published in ChemistrySelect. “We were trying to study the first step of a proposed reaction when we realized that the catalyst was doing the entire reaction on its own.”

“We’re taking carbon dioxide, a waste product of combustion, and we’re pushing that combustion reaction backwards with very high selectivity to a useful fuel. Ethanol was a surprise, it’s extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst.”

A video of the work at Oak Ridge is viewable here and makes interesting watching with a detailed explanation of the nano technology involved in the process. The use of ethanol as a fuel is long established, with Brazil long regulating that vehicles in the country must run on an ethanol-petroleum mixed fuel, and a number of studies being undertaken to examine the use of ethanol as a fuel for freight transportation. A 1996 study found that though trucks converted to run on E95 fuel (95% ethanol, 5% petrol) ran with an 8% degradation in fuel economy they emitted much reduced Nitrogen Oxide and particulate matter pollution, the elements that contribute primarily to pollution related disease and deaths in major cities. The key issue identified at that time was the relative cost of ethanol versus petroleum products.

Additionally, the use of biofuels has caused some other concerns in its production methods. To now the main production method has been to grow certain crops (sugar cane and corn are current favourites) and then ferment them to produce ethanol. This has led to concerns that widespread use of ethanol as fuel could lead to starvation in the developing world as valuable farm lands are used to grow ethanol crops for the developed worlds fuel need at the expense of people living in these regions.

The Oak Ridge team's finding is of particular interest as they propose that their method can produce ethanol from atmospheric carbon dioxide (a primary cause of global warming) and renewable energy sources. One of the issues with renewable energy sources such as solar and wind generation is the 'feast-or-famine' nature of its power generation. Rondinone envisages that: “A process like this would allow you to consume extra electricity when it’s available to make and store as ethanol. This could help to balance a grid supplied by intermittent renewable sources.”

The revolutionary discovery may even boost other technologies still evolving. In June Nissan announced it was developing an e-Bio-Fuel-Cell, a solid oxide fuel cell (SOFC), something normally associated with hydrogen power and the billions of dollars of infrastructure required to promulgate hydrogen powered vehicles. Using CO2 generated ethanol, by a strange twist mixing this with water it may just be possible to feed the liquid into the vehicle mounted converter which divides it into pure hydrogen and ironically back to carbon dioxide. The hydrogen is fed into the solid-oxide fuel cell, which generates electricity to power the electric vehicle, which is also equipped with a battery and the ability to store regenerated energy.

Nissan is currently focusing on that Brazilian market as the country already relies so heavily on ethanol powered vehicles and the fuel is freely available at sites right across the country. The Japanese manufacturer expects to have a commercial product by 2020 and the news that the controversial use of organic matter to produce the fuel may be a thing of the past will doubtless mean a boost for the project and associated technology.