
Even quantum physics obeys the law of entropy
https://www.eurekalert.org/news-releases/1072034
INTRO: It is one of the most important laws of nature that we know: The famous second law of thermodynamics says that the world gets more and more disordered, when random chance is at play. Or, to put it more precisely: That entropy must increase in every closed system. Ordered structures lose their order, regular ice crystals turn into water, porcelain vases are broken up into shards. At first glance, however, quantum physics does not really seem to adhere to this rule: Mathematically speaking, entropy in quantum systems always remains the same.
A research team at TU Wien has now taken a closer look at this apparent contradiction and has been able to show: It depends on what kind of entropy you look at. If you define the concept of entropy in a way that it compatible with the basic ideas of quantum physics, then there is no longer any contradiction between quantum physics and thermodynamics. Entropy also increases in initially ordered quantum systems until it reaches a final state of disorder... (MORE - details, no ads)
Chemical looping turns environmental waste into fuel
https://www.eurekalert.org/news-releases/1072066
INTRO: Turning environmental waste into useful chemical resources could solve many of the inevitable challenges of our growing amounts of discarded plastics, paper and food waste, according to new research.
In a significant breakthrough, researchers from The Ohio State University have developed a technology to transform materials like plastics and agricultural waste into syngas, a substance most often used to create chemicals and fuels like formaldehyde and methanol.
Using simulations to test how well the system could break down waste, scientists found that their approach, called chemical looping, could produce high-quality syngas in a more efficient manner than other similar chemical techniques. Altogether, this refined process saves energy and is safer for the environment, said Ishani Karki Kudva, lead author of the study and a doctoral student in chemical and biomolecular engineering at Ohio State.
“We use syngas for important chemicals that are required in our day-to-day life,” said Kudva. “So improving its purity means that we can utilize it in a variety of new ways.”
Today, most commercial processes create syngas that is about 80 to 85% pure, but Kudva’s team achieved a purity of around 90% in a process that takes only a few minutes.
This study builds on decades of previous research at Ohio State, led by Liang-Shih Fan, a distinguished university professor in chemical and biomolecular engineering who advised the study. This previous research used chemical looping technology to turn fossil fuels, sewer gas and coal into hydrogen, syngas and other useful products.
In the new study, the system consists of two reactors: a moving bed reducer where waste is broken down using oxygen provided by metal oxide material, and a fluidized bed combustor that replenishes the lost oxygen so that the material can be regenerated. The study showed that with this waste-to-fuel system, the reactors could run up to 45% more efficiently and still produce about 10% cleaner syngas than other methods.
The study was recently published in the journal Energy and Fuels... (MORE - details, no ads)
https://www.eurekalert.org/news-releases/1072034
INTRO: It is one of the most important laws of nature that we know: The famous second law of thermodynamics says that the world gets more and more disordered, when random chance is at play. Or, to put it more precisely: That entropy must increase in every closed system. Ordered structures lose their order, regular ice crystals turn into water, porcelain vases are broken up into shards. At first glance, however, quantum physics does not really seem to adhere to this rule: Mathematically speaking, entropy in quantum systems always remains the same.
A research team at TU Wien has now taken a closer look at this apparent contradiction and has been able to show: It depends on what kind of entropy you look at. If you define the concept of entropy in a way that it compatible with the basic ideas of quantum physics, then there is no longer any contradiction between quantum physics and thermodynamics. Entropy also increases in initially ordered quantum systems until it reaches a final state of disorder... (MORE - details, no ads)
Chemical looping turns environmental waste into fuel
https://www.eurekalert.org/news-releases/1072066
INTRO: Turning environmental waste into useful chemical resources could solve many of the inevitable challenges of our growing amounts of discarded plastics, paper and food waste, according to new research.
In a significant breakthrough, researchers from The Ohio State University have developed a technology to transform materials like plastics and agricultural waste into syngas, a substance most often used to create chemicals and fuels like formaldehyde and methanol.
Using simulations to test how well the system could break down waste, scientists found that their approach, called chemical looping, could produce high-quality syngas in a more efficient manner than other similar chemical techniques. Altogether, this refined process saves energy and is safer for the environment, said Ishani Karki Kudva, lead author of the study and a doctoral student in chemical and biomolecular engineering at Ohio State.
“We use syngas for important chemicals that are required in our day-to-day life,” said Kudva. “So improving its purity means that we can utilize it in a variety of new ways.”
Today, most commercial processes create syngas that is about 80 to 85% pure, but Kudva’s team achieved a purity of around 90% in a process that takes only a few minutes.
This study builds on decades of previous research at Ohio State, led by Liang-Shih Fan, a distinguished university professor in chemical and biomolecular engineering who advised the study. This previous research used chemical looping technology to turn fossil fuels, sewer gas and coal into hydrogen, syngas and other useful products.
In the new study, the system consists of two reactors: a moving bed reducer where waste is broken down using oxygen provided by metal oxide material, and a fluidized bed combustor that replenishes the lost oxygen so that the material can be regenerated. The study showed that with this waste-to-fuel system, the reactors could run up to 45% more efficiently and still produce about 10% cleaner syngas than other methods.
The study was recently published in the journal Energy and Fuels... (MORE - details, no ads)