A new environmentally friendly technology created by scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory may revolutionize the production of the world's most commonly produced organic compound, ethylene.
An Argonne research team led by senior ceramist Balu Balachandran devised a high-temperature membrane that can produce ethylene from an ethane stream by removing pure hydrogen. “This is a clean, energy-efficient way of producing a chemical that before required methods that were expensive and wasteful and also emitted a great deal of pollution,” Balachandran said.
Ethylene has a vast number of uses in all aspects of industry. Farmers and horticulturalists use it as a plant hormone to promote flowering and ripening, especially in bananas. Doctors and surgeons have also long used ethylene as an anesthetic, while ethylene-based polymers can be found in everything from freezer bags to fiberglass.
Because the new membrane lets only hydrogen pass through it, the ethane stream does not come into contact with atmospheric oxygen and nitrogen, preventing the creation of a miasma of greenhouse gases – nitrogen oxide, carbon dioxide and carbon monoxide – associated with the traditional production of ethylene by pyrolysis, in which ethane is exposed to jets of hot steam. The world’s ethylene producers manufacture more than 75 million metric tons of ethylene per year, causing millions of metric tons’ worth of greenhouse gas emissions.
Unlike pyrolysis, which requires the constant input of heat, the hydrogen transport membrane (HTM) produces the fuel needed in order to drive the reaction. By using air on one side of the membrane, the already-transported hydrogen can react with oxygen to provide energy. “By using this membrane, we essentially enable the reaction to feed itself,” Balachandran said. “The heat is produced where it is needed.”
The new membrane reactor also performs an additional chemical trick: by constantly removing hydrogen from the stream, the membrane alters the ratio of reactants to products, enabling the reaction to make more ethylene that it theoretically could have before reaching equilibrium. “We are essentially confusing or cheating the thermodynamic limit,” Balachandran said. “The membrane reactor thinks: ‘hey, I haven’t reached equilibrium yet, let me take this reaction forward.’”
While Balachandran’s team, which included chemists Stephen Dorris, Tae Lee, Chris Marshall and Charles Scouton, designed this experiment merely to prove the membrane’s capability to produce ethylene, he hopes to extend the project by pairing with an industrial partner who would produce the membranes commercially. Since the membrane reduces the number of steps required to produce ethylene, the technology could enable the chemical to be produced more cheaply, he said.
The results of the research are expected to be presented at the 2008 Clean Technology conference in Boston in June. The work was funded by the Department of Energy's Industrial Technology Program, which resides within its Office of Energy Efficiency & Renewable Energy.
Steve McGregor | EurekAlert!
New manufacturing process for SiC power devices opens market to more competition
14.09.2017 | North Carolina State University
Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
25.09.2017 | Power and Electrical Engineering
25.09.2017 | Health and Medicine
25.09.2017 | Physics and Astronomy