We’re all familiar with the negative consequences of living in a polluted world. We also intuitively understand that drinking clean water and breathing clean air improves health and saves lives. The military, however, believes that going green can save lives for reasons beyond those connected with helping keep the environment less polluted. A recent article about the U.S. military’s search for alternative energy sources discusses how fewer lives would be placed at risk if the military didn’t have to maintain a supply chain for petroleum-based products [“Pentagon Prioritizes Pursuit Of Alternative Fuel Sources,” by Steve Vogel, Washington Post, 13 April 2009]. If the Pentagon is successful in its search, it will not only have an impact on military lives, however, it will have a long-term effect on everyone since the military is the largest single user of energy in America. The war in Iraq has been the primary motivation for the Pentagon’s interest in alternative energy sources. Vogel reports that about half of the casualties in Iraq have resulted from the detonation of improvised explosive devices (IEDs) and that many of those explosions were aimed at convoys carrying fuel.
“Spurred by this grim reality, the Pentagon, which traditionally has not made saving energy much of a priority, has launched initiatives to find alternative fuel sources. The goals include saving money, preserving dwindling natural resources and lessening U.S. dependence on foreign sources. ‘The honest-to-God truth, the most compelling reason to do it is it saves lives,’ said Brig. Gen. Steven Anderson, director of operations and logistics for the Army. ‘It takes drivers off the road.’ Other than fueling jet engines, the largest drain on U.S. military fuel supplies comes from running generators at forward operating bases.”
According to the article, “the wars in Afghanistan and Iraq have required more fuel on a daily basis than any other war in history.” This should not be too surprising considering the military’s reliance on planes, tanks, trucks, and information technologies. The Pentagon’s search for alternative energy sources is taking some interesting twists.
“Garbage, for example, is a commodity never in short supply when the Army goes to the field. A battalion-size forward operating base generates a ton of trash a day. The Pentagon is developing mobile units — small enough to fit on a five-ton flatbed trailer — that use an anaerobic microbial process to convert garbage into oil.”
Initial tests of the garbage-to-oil converters were semi-successful (they did produce oil from garbage), but the difficult conditions in which they operated meant that the units frequently broke down. The Pentagon is investing money to develop a hardier version. Although the “Tactical Garbage to Energy Refinery” helps the environment by turning trash into oil, burning the refined oil still generates greenhouse gases. A more environmentally friendly experiment involves “lightweight, flexible photovoltaic mats that could be rolled up like a rug and used at forward bases to draw solar power for operating equipment.” Another effort, sponsored by the Defense Advanced Research Projects Agency (DARPA), is looking “to convert algae into jet propulsion fuel 8, or JP-8, that could power Navy and Air Force aircraft.” To learn more about this kind of approach, read my post entitled The Potential of Pond Scum. The military is also spraying foam on tents to insulate them from Iraq’s harsh weather. According to Vogel, using the foam reduces energy costs by $2 million a day. Plans are also in the works to spray structures in Afghanistan.
“Other initiatives include $27 million to develop a hybrid engine the Army could use in tactical vehicles and $2 million to develop highly efficient portable fuel cells that could reduce the battery load carried by infantry soldiers. The Pentagon is also testing the use of solar and geothermal energy to provide power at installations. The Army, for example, is partnering with a private firm to build an enormous, 500-megawatt solar farm at Fort Irwin, Calif. The farm would supply the 30 to 35 megawatts needed to operate the installation, with the remaining available for sale to the California electrical grid.”
A Utah-based company is set to reveal hybrid-engine technology in a Hummer H3 that could go a long ways towards meeting the military’s goals [“Utah firm’s goal for SUV: 140 mpg,” by Jasen Lee, Deseret News, 13 April 2009].
“Raser Technologies Inc., headquartered in Provo, … plans to unveil a prototype hybrid electric vehicle that could get about 140 miles per gallon. The vehicle was developed in partnership with German engine company FEV and was designed to achieve more than 100 miles per gallon in typical city driving, with near zero emissions, by driving up to 40 miles per day in all-electric mode.”
One area the military is apparently not looking into is what to with human waste. Sewage is not a subject that most of us spend time thinking about — we’re just happy to get rid of it. But scientists in Sweden have been thinking a lot about it [“Yellow Is the New Green,” by Rose George, New York Times, 27 February 2009]. George notes that “human excrement is rich in nitrogen, phosphorus and potassium, which is why it has been a good fertilizer for millenniums and until surprisingly recently.” Flushed untreated into rivers and oceans, however, these nutrients can “suffocate life.” There are already programs that turn sewage sludge into cheap fertilizer, but urine presents a different challenge. She says that urine is also nutrient rich. According to George, it contains “contains 80 percent of the nutrients in excrement.” Folks in Sweden have been experimenting with how to take advantage of the nutrients found in human waste while still operating a system that offers all of the health benefits associated with good sanitation treatment systems (i.e., eliminating cholera and other waterborne diseases). They are experimenting with urine-diversion toilets to separate urine from excrement and providing the urine as an alternative phosphorous fertilizer to farmers.
“The price of phosphorus fertilizers rose 50 percent in the past year in some parts of the world, as phosphate reserves, the largest of which are in Morocco and China, dwindle. (The gloomiest predictions suggest they’ll be gone in 100 years.) Although half of sewage sludge in the United States is already turned into cheap fertilizer known as ‘biosolids,’ urine contains hardly any of the pathogens or heavy metals that critics of biosolids claim remain in mixed sewage, despite treatment.”
That is why George claims that “yellow is the new green.” Urine separation is also being tried in countries like China and South Africa. The benefits of separating urine from excrement go far beyond its application as a fertilizer.
“Research by Jac Wilsenach, now a civil engineer in South Africa, found that removing even half of the nutrient-rich urine enables the bacteria in the aeration tanks to munch all the nitrogen and phosphate matter in solid waste in a single day rather than the usual 30. Urine diversion also makes for richer sludge and produces more methane, which can be turned into gas or electricity, Mr. Wilsenach said. In short, separating urine turns a guzzler of energy into a net producer.”
George realizes that getting the developed world to consider alternative ways to dispose of human waste is an uphill battle. She holds out greater hope for developing nations that “have money to invest in alternatives but few sewers.” As long as there are people, however, there will be challenges associated with their waste. The developed world seems more enthralled by other green technologies like a new concrete mix that actually helps clean the air [“Concrete that Clears the Air,” by Adam Aston, BusinessWeek, 31 March 2008].
“Concrete is about to start helping in the fight against air pollution, thanks to a new recipe spiked with titanium dioxide, a compound that becomes chemically active in sunlight. Originally concocted by Italy’s Italcementi for its bright white, self-cleaning features, the product, called TX Active cement, also neutralizes air pollutants such as benzene, carbon monoxide, nitrogen oxide, and others.”
The more surface that can be exposed the better the concrete works. The technology is being put to work in places like Los Angeles (which has a major air pollution problem) and in Minnesota (where a number of advances in concrete were put to use when replacing a collapsed bridge). The Minnesota project erected wavy sculptures at each end of the bridge made from the air cleaning concrete [“Concrete Is Remixed With Environment in Mind,” by Henry Fountain, New York Times, 30 March 2009]. The Minnesota bridge also included other concrete innovations.
“The bridge, built to replace one that collapsed in 2007, killing 13 people, is constructed almost entirely of concrete embedded with steel reinforcing bars, or rebar. But it is hardly a monolithic structure: the components are made from different concrete mixes, the recipes tweaked, as a chef would, for specific strength and durability requirements and to reduce the impact on the environment.”
Concrete is not a subject that generates much cocktail party conversation, but Fountain notes that “every year about a cubic yard of concrete is produced for each of the six-billion-plus people on the planet. … The manufacturing of Portland cement is responsible for about 5 percent of human-caused emissions of the greenhouse gas carbon dioxide.”
The concrete used in the Minnesota bridge “replaced much of the Portland cement with two industrial waste products — fly ash, left over from burning coal in power plants, and blast-furnace slag. Both are what are called pozzolans, reactive materials that help make the concrete stronger. Because the CO2 emissions associated with them are accounted for in electricity generation and steel making, they also help reduce the concrete’s carbon footprint. Some engineers and scientists are going further, with the goal of developing concrete that can capture and permanently sequester CO2 from power plants or other sources, so it cannot contribute to the warming of the planet.”
The Economist reports that another common material — iron — can help the environment by treating industrial wastewater [“Green iron,” 4 December 2008 print issue].
“A research project in China suggests that iron shavings from factories can be a cheap and efficient way to clean up polluted water. And because such scrap is widely available, the system could be particularly useful in developing countries. … Iron powder (technically called zero-valent iron by chemists to show that it has not oxidised) has been used to treat groundwater for more than a decade, and to remove dangerous substances such as trichlorethene (used in paint strippers and adhesives) and arsenic. But no one had tried using iron shavings to treat water discharged from factories before. … Compared with biological treatment alone, big improvements have been recorded. The removal of nitrogen has gone from 13% to 85%; phosphorus from 44% to 64%; and colours and dyes from 52% to 80%.”
Although the process doesn’t make the water potable, it cleans it enough that the wastewater can be safely treated through normal sanitation facilities. Historically, developing nations have been big polluters and any effort to help them keep the environment cleaner is welcome. A cleaner environment means a healthier environment and that saves lives.
