When you drink alcohol, enzymes in your liver break it down into a series of byproducts, including carbon dioxide. A group of scientists in Austria are trying to run the process in reverse, using the same sort of enzymes to convert CO2 to alcohol and other products that can be used as fuel or as raw materials for the biochemical industry.
The ever-useful buckminsterfullerene, or buckyball, has a new potential application: carbon capture. Researchers at Rice University in Texas used buckyballs (carbon-60 molecules, technically) as a “cross-linker” with polyethyleneimine (PEI), and produced a compound that binds carbon dioxide very well, avoids binding methane, and can be used at lower temperatures than other materials.
“We had two goals,” said Andrew R. Barron, of Rice, senior author of the paper describing the advance, in a press release. “One was to make the compound 100 percent selective between carbon dioxide and methane at any pressure and temperature. The other was to reduce the high temperature needed by other amine solutions to get the carbon dioxide back out again. We've been successful on both counts.”
The researchers published their findings in Nature’s Scientific Reports. They discovered that the PEI-C60 compound bound about one-fifth of its weight in carbon dioxide, and essentially zero methane—a big deal for carbon capture materials. The buckyballs are hydrophobic, and push the hydrophilic amines of the PEI to the outer surface of the compound; carbon dioxide floats past, and binds to exposed nitrogen atoms.
The PEI-C60 captured carbon better than materials known as metal organic frameworks (MOFs), which are nanoporous materials considered among the most promising for trapping CO2. The idea of using buckyballs was a natural progression for Barron’s lab; in previous work, the team found that single sheets of graphene did well at absorbing carbon dioxide. Multiwalled carbon nanotubes did better, and nanotubes with thinner single walls did even better still. The spherical buckyball takes the level of curvature to its extreme, which Barron said clearly plays a role in how well the molecules bind.
Another advantage comes up when the CO2 needs to let go of its new home—the final step on its road to toward the “sequestration” part of CCS. Other materials require temperatures to reach 120 and 130 degrees Celsius for the “amine scrubbing process” where the carbon dioxide is released. PEI-C60, meanwhile, has a lower “temperature of regeneration,” below 90 degrees Celsius.
The downside? Cost. “Compared to the cost of current amine used, C60 is pricy,” says Barron. “But the energy costs would be lower because you’d need less to remove the carbon dioxide.”
Progress toward deployment of a practical CCS regime remains slow, so any advances are obviously welcome. One of the first utility-scale CCS plants did recently openin Canada—a billion-dollar add-on to a half-century old coal plant. But without some major advances, or political shifts involving huge infusions of cash to the idea, projects like that are going to remain exceptions rather than the rule.
Bangalore-based IBM Research India has a bright idea for keeping discarded lithium laptop batteries out of landfills: repurposing their cells as energy supplies for the powerless. The idea, presented at this weekend's fifth annual Symposium on Computing for Development (DEV 2014) in San Jose, has passed a small proof-of-principle test run with Bangalore's working poor.
Making ceramic fuel cells with a 3-D printer would be a quick and easy way to manufacture the devices and could lead to new fuel cell designs that do a better job of converting a gas into electricity, according to researchers at Northwestern University.
Blu-ray had the misfortune to arrive at the very end of the era of optical storage media. Blu-ray discs are (were) certainly better than DVDs, but it was an incremental improvement at best, as they didn’t offer the same kind of revolution that the DVD offered over VHS. And with the cloud and high speed Internet becoming the standards for media storage and distribution, the future for the Blu-ray disc is a bleak one, full of shiny plastic shards in recycling bins.
In an intriguing footnote to their historic climate deal this month, Chinese President Xi Jinping and U.S. President Barack Obama called for demonstration of a hitherto obscure tweak to carbon capture and storage (CCS) technology that could simultaneously increase its carbon storage capacity and reduce its thirst for water. Such an upgrade to CCS holds obvious attraction for China, which is the world's top carbon polluter and also faces severe water deficits, especially in the coal-rich north and west.
As the Union of Concerned Scientists puts it in its The Equation blog, “Cracking this nut … could be a huge issue for China.”
Obama and Xi's deal pledges joint funding for a project that would inject about 1 million tons per year of captured carbon dioxide deep underground and, in the process, produce approximately 1.4 million cubic meters of water annually. One potential target is is GreenGen, an advanced coal-fired generating plant in Tianjin that was explicitly designed as a CCS test bed.
Such ‘enhanced water recovery’ can be understood as an extension of the CCS-based enhanced oil recovery that is financing installation of carbon capture equipment at several North American coal-fired power plants. These include the upgraded coal generator in Estevan, Saskatchewan, that recently became the first coal plant to capture its CO2. Canadian utility SaskPower sells 1 million tons (1 megaton) of compressed CO2 to an aging oilfield nearby where it is pumped down into the oil-bearing formation to accelerate the upward flow of petroleum.
If enhancing oil production is a revenue option for CCS, producing water with CCS is primarily about easing the storage of captured CO2 in deep saline aquifers. Geologists see carbonating saline aquifers as the most likely storage target for CCS if it becomes a universal aspect of fossil fuel power generation. Bringing up briny water in the process is not as lucrative as oil production, but offers some potentially significant benefits, starting with decreasing the pressure of the aquifer.
High pressures could fracture overlying rock layers and release injected CO2—a threat highlighted by unforeseen surface deformation detected five years ago atop a CO2 injection site in Algeria. None of the 3.85 megatons of CO2 stored in the 2-kilometer-deep reservoir escaped, but operators prematurely terminated CO2 injection, and anxiety over leakage risks paralyzed Germany’s leading CCS project. In May, the lead company on the German project, European power giant Vattenfall, terminated its CCS research and development activities.
The displaced water, meanwhile, can be put to good use—assuming it can be desalinated. One needs look no further than the coal-fired power plants that release most of China's CO2. Those plants use lots of water for cooling, and adding carbon capture is likely to make them consume even more.
In July, at one of the bilateral meetings that laid the groundwork for this month's presidential deal, the U.S. and China's joint Clean Energy Research Consortium commissioned a feasibility study for enhanced water recovery near the GreenGen plant in Tianjin. Their findings, presented in September at a U.S.-China CO2 emissions symposium in Hangzhou, were an unreserved endorsement of this technique, according to Bill Bourcier, a geochemist at Lawrence Livermore National Lab in California and a member of the study team.
GreenGen uses integrated gasification combined cycle (IGCC) technology that is supposed to facilitate carbon capture. According to the feasibility study, GreenGen is currently selling 0.1 MT of captured CO2 per year to beverage producers, and is preparing to increase the amount it captures to between 1 and 2 MT per year. While the China Huaneng Group, which is GreenGen’s majority stakeholder, has previously said it would sell its CO2 for use in enhanced oil recovery, the U.S. and Chinese research team was tasked with quickly evaluating whether CO2 could be safely stored in saline aquifers around Tianjin that are bounded by numerous geological faults.
The study found that removing water would substantially lower the risk of CO2 leakage and simultaneously provide an economically viable source of industrial water.
The report conservatively estimates the cost of purifying the relatively dilute water at RMB14-18 ($2.28-2.93) per cubic meter. That figure is twice the cost of desalinating seawater in California, but Bourcier says the real cost is likely much lower, perhaps as low as 50 cents per cubic meter. Either way, he says, it's “small potatoes” within the total operating budget of a coal-fired power station.
The optimal CO2 injection site Bourcier et al identified is 8 kilometers from the Tianjin plant site. According to their plan, before injection would begin in the 2-kilometer-deep aquifer, water would be extracted for six months. Thereafter, CO2 injection at that site would be accompanied by ongoing water removal via additional wells a few kilometers away (see image above). Bourcier says the binational team has been asked to deliver more precise numbers by mid-December; the operation could be running within a year if it gets a green light.
Chinese researchers, meanwhile, are evaluating alternate sites for an enhanced water recovery demonstration. Qi Li, a professor at the Chinese Academy of Sciences' Institute of Rock and Soil Mechanics in Wuhan, recently completed a national assessment of Chinese CCS potential. Qi told me via e-mail earlier this year that he is seeking funds for a demonstration in Western China's Xinjiang Province.
Xinjiang is not just where Li found the greatest capacity for CO2 storage in saline aquifers (44,680 megatons) and the most potential for enhanced water recovery (355 billion gallons). Xinjiang also has China's second largest coal reserves and a dearth of potable water supplies. The province is a target for coal-based chemical and liquid fuels production, which consumes roughly 10 tons of water for every ton of product. But demand for potable water there is already several times greater than its sustainable supply. Qi makes the case for Xinjiang's predicament/opportunity in this 2013 presentation.
Bourcier, meanwhile, is looking for opportunities to demonstrate enhanced water recovery in the United States. His group is interested in a saline aquifer near Bakersfield, California, that has a risk profile similar to the Chinese site. As Bourcier puts it, there would be no shortage of takers for the recovered water: “It is an opportune time to have a freshwater by-product in California.”
A massive vehicle that can haul loads weighing more than 500 metric tons—the equivalent of 350 VW Golfs—just hit the work site in Siberia, claiming the title of the world’s largest dump truck.
But it has another claim that makes it even more impressive: an electric drive motor. Electric-powered vehicles have been around to do heavy lifting in mines for years, but those trucks, known as trolley trucks, received their electricity from overhead power lines.
Context is everything in understanding the U.S.-China climate deal struck in Beijing by U.S. President Barack Obama and Chinese President Xi Jinping last week. The deal's ambitions may fall short of what climate scientists called for in the latest entreaty from the Intergovernmental Panel on Climate Change, but its realpolitik is important.
By 2040, the world’s energy supply mix will be divided into nearly four equal parts; Oil, gas, coal and low-carbon sources—nuclear and renewables—according to the International Energy Agency’s (IEA) 2014 World Energy Outlook.
The assessment by the IEA finds that under current and planned policies, the average temperature will also increase by 3.6 degrees Celsius by 2100. Renewable energy takes a far greater role in new electricity supply in the near future—expanding from about 1700 gigawatts today to 4550 gigawatts in 2040—but it is not enough to offset the global dominance of fossil fuels.
“As our global energy system grows and transforms, signs of stress continue to emerge,” IEA Executive Director Maria van der Hoeven, said in a statement. “But renewables are expected to go from strength to strength, and it is incredible that we can now see a point where they become the world’s number one source of electricity generation.”
Renewable energy production will double as a share of world electricity demand by 2040, according to the report. But that still does not dethrone coal in electricity generation. Coal will simply shift regionally from the United States and China to Southeast Asia and India, according to the EIA.
The least sexy fuel of all, energy efficiency, is poised to be a winner in coming decades and could have an even greater impact if some of the world’s largest energy users carry through with proposed efficiency plans. Efficiency measures are set to halve the global growth in energy demand from 2 percent annually to about 1 percent beginning in 2025, according to the IEA.
Efficiency standards for cars and more stringent energy efficiency targets for industry and everyday devices are key to slowing the demand for energy, but they do not necessarily help diminish the world’ reliance on fossil fuels because the true price of fossil fuels are not acurately reflected in the price people pay in some regions.
Fossil fuels receive about $550 billion in subsidies in 2013, compared to $120 billion for all renewable energies. Although the fossil fuel subsidies were $25 billion lower than 2012, there is still vast room for improvement to end price breaks for the mature industries, especially in gas and oil-rich nations, which offer the bulk of the subsidies.
“Subsides to fossil fuels, which encourage wasteful consumption, remain a big problem, despite major efforts on the part of many countries around the world to reduce or eliminate them— primarily where they have become too much of a burden on the public purse,” the IEA states.
Despite the prevalence of fossil fuel subsidies, efficiency and renewables are gaining ground. The IEA’s 2014 World Energy Outlook was released at the same time that the U.S. and China pledged to reduce their carbon emissions by nearly a third by 2030. The targets are non-binding, but do provide a new benchmark for international negotiations. Such policies help to stall fossil fuel growth and reduce energy prices over all. Even in the Middle East, where energy is heavily subsidized in many countries, several countries have implemented stricter building codes for improve efficiency.
The reliance on oil, particularly in the transportation sector, remains fairly steady, according to IEA’s projections. Although there will be some movement toward gas-fueled vehicles, electric transportation, and energy efficiency improvements, the growth in oil for transport and in petrochemicals will largely mask those developments.
The picture painted by the IEA does not take into account technology breakthroughs that could change the picture significantly. Lower cost batteries for renewable-energy storage and advances in tidal power, among many other technologies, could greatly change the energy mix a quarter century from now.
Data centers have no use for all of the waste heat that they generate, but there are plenty of situations in which waste heat isn’t wasted at all: say, inside your house, in the middle of winter, especially if you live somewhere cold. The obvious solution here is to just live in a data center and bask in its warmth, or slightly less ridiculously, put a very small data center in your home or office that generates a useful amount of heat on demand.