Tuesday, June 30. 2009China Recruits Algae to Combat Climate Changeby Jonathan Watts
China is the world's biggest emitter of greenhouse gases, largely because it relies on coal for 70 per cent of its power. Almost none of the carbon dioxide is captured, partly because there is no profitable way of using it. Algae may be the answer. The organism can absorb carbon far more quickly than trees, a quality that has long attracted international scientists seeking a natural method of capturing the most abundant greenhouse gas. At ENN's research campus in Langfang, an hour's drive from Beijing, scientists are testing microalgae to clean up the back-end of a uniquely integrated process to extract and use coal more efficiently and cleanly than is possible today. Coal is first gasified in a simulated underground environment. The carbon dioxide is extracted with the help of solar and wind power, then "fed" to algae, which can be then used to make biofuel, fertiliser or animal feed. Foreign experts are enthusiastic. "Algae biofuels and sequestration are being tried in a bunch of places, but never with such an innovative energy mix," said Deborah Seligsohn, of the World Resources Institute, who visited ENN recently with a group of international energy executives. "It is really interesting and ambitious." Researchers at the algae greenhouse plan to scale up the trial to a 100 hectare (247 acre) site over the next three years. If it proves commercially feasible, coal plants around the world could one day be flanked by carbon-cleaning algae greenhouses or ponds. "Algae's promise is that its population can double every few hours. It makes far more efficient use of sunlight than plants," said Zhu Zhenqi, a senior advisor on the project. "The biology has been proven in the lab. The challenge now is an engineering one: We need to increase production and reduce cost. If we can solve this challenge, we can deal with carbon." The algae must be harvested every day. Extracting the oily components and removing the water is expensive and energy intensive. ENN is experimenting with different algae to find a hybrid that has an ideal balance of oil content and growth speed. It is testing cultivation techniques using varying temperatures and acidity levels. Algae tests are also being carried out at the University of Ohio. In Japan, algae is farmed at sea where it absorbs carbon from the air. Elsewhere carbon is sprayed or bubbled into algae ponds. But ENN is focusing on a direct approach. "Here we can control it, like in a reactor," said Gu Junjie, a senior advisor. "Theoretically we can absorb 100% of carbon dioxide emissions through a mix of micro-algae and chemical fixing with hydrogen." This might work on a large scale in the northern deserts of Inner Mongolia, where land is cheap, plentiful and in need of fertiliser. But elsewhere, application may be limited because of the large areas of land or water needed for cultivation. "Algae is not likely to be the main solution for the carbon problem because of the amount of CO2 that needs to be consumed," said Ming Sung, Chief Representative for Asia Pacific of Clean Air Task Force. But, he said: "Algae is part of the solution and is closer to what nature intends. Being one of the simplest forms of life, all it takes is light and CO2 in salt water," The advanced algae, solar and coal gasification technology is the latest stage in the rise of ENN, which has been spectacular even by modern Chinese standards. Founded in 1989 as a small taxi company, it has branched successfully into the natural gas industry and now into the field of renewable energy. The private company now employs about 20,000 people, and owns a golf course and hotel near its headquarters in Hebei province, where a new research campus is under construction. In the short term, ENN's advanced underground coal gasification technology is likely to prove more significant than its algae work. This technique enables extraction of fuel from small, difficult-to-access coal seams, and could double the world's current coal reserves. It also avoids the release of the pollutants sulphur dioxide and nitrogen dioxide. The company is also one of only a small handful in the world capable of mass producing thin-film solar panels, which can be manufactured with less water and energy than conventional photovoltaic materials. Late last year, the World Bank's International Financing Corporation announced a US$136m loan for ENN's solar business. ENN executives have talked to the US department of energy about joint research , a sign that the transfer of low-carbon technologies is no longer a one-way street from west to east. The development of the algae technology trails the others, but Zhu says the results from the 10,000 litre algae greenhouse have been sufficiently encouraging to move ahead. For the 100 hectare test facility, ENN is looking at sites near the company's 600,000 tonne-a-year coal mine in Ordos, Inner Mongolia, where the cold winters will require a heated greenhouse, and a location on Hainan Island, where the hot weather would allow the algae to be grown more cheaply in open ponds, but further away from China's main coal deposits. China building the equivalent of more than one new 500MW coal-fired plant every week and likely to be dependent on coal for at least two decades, the further studies planned by ENN could be crucial. Recognising the continued role of the fossil fuel in China, the European Commission proposed a plan this week to co-finance a demonstration coal plant that aims to have near zero emissions through the use of carbon capture and storage technology. If members states and the European parliament agree on the €50m plan, the facility would be operational by 2020.
This piece originally appeared in Guardian Environment.. ----- Via WorldChanging Re-engineering the earthAn article in the most recent issue of the Atlantic Monthly explores aggressive “geo-engineering” projects:
A permanent fleet of ships sails the globe, churning the ocean with special propellers to spray seawater into the air and make clouds whiter and fluffier. A battery of twenty electromagnetic guns, “each more than a mile long and positioned at high altitudes”, that would fire tens of millions of ceramic frisbees at the gravitational midpoint between the earth and the sun, putting “the Earth in a permanent state of annular eclipse”. Hovering zeppelins spew sulfur dioxide into the air, turning the sky red at sunset. Forests of Freeman Dyson’s genetically engineered trees hungrily suck carbon out of the air. Vented structures, similar to industrial cooling towers, are filled with grids coated in a solution that captures carbon; the captured carbon is then scrubbed off the grids and sequestered deep below ground in exhausted oil wells. Antarctic waters are seeded with iron, producing massive plankton blooms that cool the globe. Perhaps the most unexpected (and frightening) turn in the Atlantic article is the suggestion of a worst-case scenario in which a “rich madman… obsessed with the environment” or “a single rogue nation” sets one of these plans into motion unilaterally, with potentially disastorous global side-effects — in the case of the sulfur aerosols, for instance, it is quite likely that any interruption of the supply of aerosols would produce immediate and catastrophically rapid climate change. An appropriately sobering possibility to consider, for though the scenarios seem outlandish(ly exciting) and the risks are real, they are being given hearing not just at the fringes of scientific debate, but at bodies like the National Academy of Sciences. ----- Vis Mammoth Sensors for Tracking Home Water UseSensors track devices' electricity, water, and gas consumption from one spot.
By Kate Greene
Finding the flush: This sensor attaches to a water pipe and wirelessly communicates changes in pressure to a microcontroller that infers the use of specific fixtures. A Bluetooth transmitter streams the data to a personal computer. - Shwetak Patel, a professor of computer science and electrical engineering at the University of Washington, in Seattle, developed the sensors, which plug directly into existing infrastructure in buildings, thereby eliminating the need for an elaborate set of networked sensors throughout a structure. For example, an electrical sensor plugs into a single outlet and monitors characteristic "noise" in electrical lines that are linked to specific devices, such as cell-phone chargers, refrigerators, DVD players, and light switches. And a gas sensor attaches to a gas line and monitors pressure changes that can be correlated to turning on a stove or furnace, for instance. Now, Patel and his colleagues have developed a pressure sensor that fits around a water pipe. The technology, called Hydrosense, can detect leaks and trace them back to their source, and can recognize characteristic pressure changes that indicate that a specific fixture or appliance is in use. Patel hopes to incorporate electrical, gas, and water sensors into a unified technology and has cofounded a startup, called Usenso, that he hopes will start offering combined smart meters to utility companies within the next year or so. The goal, says Patel, is to make a "smart home" universally deployable. "I looked at the existing infrastructures," he says, "and saw that they could be retrofitted." Smart sensors have become increasingly popular over the past few years as more people have become interested in cutting their utility bills and minimizing the resources that they consume. A number of startups offer to connect utility providers and consumers so that resource use can be tracked over the Internet. So far, however, no company or utility has been able to provide the sort of fine-grain resource usage that Patel hopes to offer with Usenso. The idea behind the water sensor has its origins in Patel's original work with electrical lines. Rather than simply looking at the amount of power consumed by all the devices in a house, he decided to look at noise patterns--irregularities in the electrical signal--that propagated over household power lines as a result of electrical consumption. "Let's say you turn on a light switch in the bathroom and kitchen," he says. "We can tell the difference between the two" due to electrical impulses that resonate at a high frequency. "So if you have two different impulses you see originate from two different locations inside the home, you can trace them back to a particular device," Patel says, noting that location can be determined by the amount of time that it takes for a signal to reach the sensor, which is usually just plugged into a spare wall outlet.
Likewise, Hydrosense consists of a single device attached to a cutoff valve or water bib that monitors the entire plumbing infrastructure. "When you open a valve, the pressure on the entire system goes down," says Patel. "And whenever you change the water flow from static to kinetic, you get a shock wave that propagates throughout the pipes." He explains that the shock wave, while relatively mild, has a characteristic shape that can be used to identify different fixtures--even the distinction between the toilets in different bathrooms. Using data collected in nine homes of varying style and age and with a diversity of plumbing systems located in three different cities, Patel and his colleagues have shown that by monitoring these shock waves, it is possible to identify individual fixtures with 95.6 percent accuracy. "The idea of being able to plug one device into a home and build a picture of what's going on and off is really fascinating," says Adrien Tuck, CEO of Tendril Networks, a company that makes smart meters and plugs for homes. But he suspects that there will be some kinks to iron out before the technology is deployable at a large scale. "If it were easy, it would have been done already," he says, "and that probably means that there are some things that need to be teased out." In addition to monitoring utility usage, Patel says that the sensors can track human activity within a home, which could be useful for elder care and reducing energy waste. He has also developed a fourth sensor that can be integrated into a home's heating and cooling systems. By monitoring pressure changes that occur when people open and close doors and when they enter and exit a room, a sensor within an air-conditioning unit can infer with relative accuracy where people are within a home or apartment, Patel says. Copyright Technology Review 2009. ----- Related Links:
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