Technological Breakthrough In Fight To Cut Greenhouse GasesScienceDaily (Apr. 27, 2008) — Scientists at Newcastle University have pioneered breakthrough technology in the fight to cut greenhouse gases. The Newcastle University team, led by Michael North, Professor of Organic Chemistry, has developed a highly energy-efficient method of converting waste carbon dioxide (CO2) into chemical compounds known as cyclic carbonates.See also:Matter & Energy * Organic Chemistry * Chemistry * PetroleumEarth & Climate * Global Warming * Environmental Science * Energy and the EnvironmentReference * Automobile emissions control * Catalysis * Carbon cycle * HydrocarbonThe team estimates that the technology has the potential to use up to 48 million tonnes of waste CO2 per year, reducing the UK's emissions by about four per cent.Cyclic carbonates are widely used in the manufacture of products including solvents, paint-strippers, biodegradable packaging, as well as having applications in the chemical industry. Cyclic carbonates also have potential for use in the manufacture of a new class of efficient anti-knocking agents in petrol. Anti-knocking agents make petrol burn better, increasing fuel efficiency and reducing CO2 emissions.The conversion technique relies upon the use of a catalyst to force a chemical reaction between CO2 and an epoxide, converting waste CO2 into this cyclic carbonate, a chemical for which there is significant commercial demand.The reaction between CO2 and epoxides is well known, but one which, until now, required a lot of energy, needing high temperatures and high pressures to work successfully. The current process also requires the use of ultra-pure CO2 , which is costly to produce.The Newcastle team has succeeded in developing an exceptionally active catalyst, derived from aluminium, which can drive the reaction necessary to turn waste carbon dioxide into cyclic carbonates at room temperature and atmospheric pressure, vastly reducing the energy input required.Professor North said: 'One of the main scientific challenges facing the human race in the 21st century is controlling global warming that results from increasing levels of carbon dioxide in the atmosphere.'One solution to this problem, currently being given serious consideration, is carbon capture and storage, which involves concentrating and compressing CO2 and then storing it,' he said. 'However, long-term storage remains to be demonstrated'.To date, alternative solutions for converting CO2 emissions into a useful product has required a process so energy intensive that they generate more CO2 than they consume.Professor North compares the process developed by his team to that of a catalytic converter fitted to a car. 'If our catalyst could be employed at the source of high-concentration CO2 production, for example in the exhaust stream of a fossil-fuel power station, we could take out the carbon dioxide, turn it into a commercially-valuable product and at the same time eliminate the need to store waste CO2', he said.Professor North believes that, once it is fully developed, the technology has the potential to utilise a significant amount of the UK's CO2 emissions every year.'To satisfy the current market for cyclic carbonates, we estimate that our technology could use up to 18 million tonnes of waste CO2 per year, and a further 30 million tonnes if it is used as an anti-knocking agent.'Using 48 million tonnes of waste CO2 would account for about four per cent* of the UK's CO2 emissions, which is a pretty good contribution from one technology,' commented Professor North. The technique has been proven to work successfully in the lab. Professor North and his team are currently carrying out further lab-based work to optimise the efficiency of the technology, following which they plan to scale-up to a pilot plant.* Based on 2004 figures from the UN.The paper 'Synthesis of cyclic carbonates from atmospheric pressure carbon dioxide using exceptionally active aluminium(salen) complexes as catalysts' s been published in the European Journal of Inorganic Chemistry.The project was funded by the Engineering and Physical Sciences Research Council.Technological Breakthrough In Fight To Cut Greenhouse Gases
ScienceDaily (Apr. 24, 2008) — Last year alone global levels of atmospheric carbon dioxide, the primary driver of global climate change, increased by 0.6 percent, or 19 billion tons. Additionally methane rose by 27 million tons after nearly a decade with little or no increase. NOAA scientists released these and other preliminary findings today as part of an annual update to the agency’s greenhouse gas index, which tracks data from 60 sites around the world.
The burning of coal, oil, and gas, known as fossil fuels, is the primary source of increasing carbon dioxide emissions. Earth's oceans, vegetation, and soils soak up half of these emissions. The rest stays in the air for centuries or longer. Twenty percent of the 2007 fossil fuel emissions of carbon dioxide are expected to remain in the atmosphere for thousands of years, according to the latest scientific assessment by the International Panel on Climate Change.Viewed another way, last year’s carbon dioxide increase means 2.4 molecules of the gas were added to every million molecules of air, boosting the global concentration to nearly 385 parts per million (ppm). Pre-industrial carbon dioxide levels hovered around 280 ppm until 1850. Human activities pushed those levels up to 380 ppm by early 2006.
The rate of increase in carbon dioxide concentrations accelerated over recent decades along with fossil fuel emissions. Since 2000, annual increases of two ppm or more have been common, compared with 1.5 ppm per year in the 1980s and less than one ppm per year during the 1960s.
Methane levels rose last year for the first time since 1998. Methane is 25 times more potent as a greenhouse gas than carbon dioxide, but there’s far less of it in the atmosphere—about 1,800 parts per billion. When related climate affects are taken into account, methane’s overall climate impact is nearly half that of carbon dioxide.
Rapidly growing industrialization in Asia and rising wetland emissions in the Arctic and tropics are the most likely causes of the recent methane increase, said scientist Ed Dlugokencky from NOAA’s Earth System Research Laboratory.
”We’re on the lookout for the first sign of a methane release from thawing Arctic permafrost,” said Dlugokencky. “It’s too soon to tell whether last year’s spike in emissions includes the start of such a trend.”
Permafrost, or permanently frozen ground, contains vast stores of carbon. Scientists are concerned that as the Arctic continues to warm and permafrost thaws, carbon could seep into the atmosphere in the form of methane, possibly fueling a cycle of carbon release and temperature rise.