 |
|
Rocky water source
June 12, 2008Water from rock, easier than blood from stone
Gypsum, a rocky mineral is abundant in desert regions where fresh water is usually in very short supply but oil and gas fields are common. Writing in International Journal of Global Environmental Issues, Peter van der Gaag of the Holland Innovation Team, in Rotterdam, The Netherlands, has hit on the idea of using the untapped energy from oil and gas flare-off to release the water locked in gypsum.
Fresh water resources are scarce and will be more so with the effects of global climate change. Finding alternative sources of water is an increasingly pressing issue for policy makers the world over. Gypsum, explains van der Gaag could be one such resource. He has discussed the technology with people in the Sahara who agree that the idea could help combat water shortages, improve irrigation, and even make some deserts fertile.
Chemically speaking, gypsum is calcium sulfate dihydrate, and has the chemical formula CaSO4.2H2O. In other words, for every unit of calcium sulfate in the mineral there are two water molecules, which means gypsum is 20% water by weight.
van der Gaag suggests that a large-scale, or macro, engineering project could be used to tap off this water from the vast deposits of gypsum found in desert regions, amounting to billions of cubic meters and representing trillions of liters of clean, drinking water.
The process would require energy, but this could be supplied using the energy from oil and gas fields that is usually wasted through flaring. Indeed, van der Gaag explains that it takes only moderate heating, compared with many chemical reactions, to temperatures of around 100 Celsius to liberate water from gypsum and turn the mineral residue into bassanite, the anhydrous form. "Such temperatures can be reached by small-scale solar power, or alternatively, the heat from flaring oil wells can be used," he says. He adds that, "Dehydration under certain circumstances starts at 60 Celsius, goes faster at 85 Celsius, and faster still at 100 degrees. So in deserts - where there is abundant sunlight - it is very easy to do."
van der Gaag points out that the dehydration of gypsum results in a material of much lower volume than the original mineral, so the very process of releasing water from the rock will cause local subsidence, which will then create a readymade reservoir for the water. Tests of the process itself have proved successful and the Holland Innovation Team is planning a pilot study in a desert location.
"The macro-engineering concept of dewatering gypsum deposits could solve the water shortage problem in many dry areas in the future, for drinking purposes as well as for drip irrigation," concludes van der Gaag.
Inderscience Publishers
Chemically speaking, gypsum is calcium sulfate dihydrate, and has the chemical formula CaSO4.2H2O. In other words, for every unit of calcium sulfate in the mineral there are two water molecules, which means gypsum is 20% water by weight.
van der Gaag suggests that a large-scale, or macro, engineering project could be used to tap off this water from the vast deposits of gypsum found in desert regions, amounting to billions of cubic meters and representing trillions of liters of clean, drinking water.
The process would require energy, but this could be supplied using the energy from oil and gas fields that is usually wasted through flaring. Indeed, van der Gaag explains that it takes only moderate heating, compared with many chemical reactions, to temperatures of around 100 Celsius to liberate water from gypsum and turn the mineral residue into bassanite, the anhydrous form. "Such temperatures can be reached by small-scale solar power, or alternatively, the heat from flaring oil wells can be used," he says. He adds that, "Dehydration under certain circumstances starts at 60 Celsius, goes faster at 85 Celsius, and faster still at 100 degrees. So in deserts - where there is abundant sunlight - it is very easy to do."
van der Gaag points out that the dehydration of gypsum results in a material of much lower volume than the original mineral, so the very process of releasing water from the rock will cause local subsidence, which will then create a readymade reservoir for the water. Tests of the process itself have proved successful and the Holland Innovation Team is planning a pilot study in a desert location.
"The macro-engineering concept of dewatering gypsum deposits could solve the water shortage problem in many dry areas in the future, for drinking purposes as well as for drip irrigation," concludes van der Gaag.
Inderscience Publishers
Unusual microbial ropes grow slowly in cave lake
Deep inside the Frasassi cave system in Italy and more than 1,600 feet below the Earth's surface, divers found filamentous ropes of microbes growing in the cold water, according to a team of Penn State researchers.
U. of Colorado researcher identifies tracks of swimming dinosaur in Wyoming
The tracks of a previously unknown, two-legged swimming dinosaur have been identified along the shoreline of an ancient inland sea that covered Wyoming 165 million years ago, according to a University of Colorado at Boulder graduate student.
Brightening up old church windows
Somber semi-darkness, flickering candles and the smell of incense - visitors to old churches are delighted by this atmosphere, especially at Christmas time. Yet only a few of them will have noticed that Gothic churches are growing darker inside with every passing year. The reason: Deposits of soot and pollution on the window panes combine with dampness and gases in the air, ingredients of the corroding glass and microorganisms to form a thickening and coarse layer. A good example is the Mariendom in Erfurt . For years, curators and preservation experts have been looking for the ideal means of cleaning the grimy Gothic windows which have badly darkened over the centuries. The problem: The cle
Turning cakes and ale into fertilizer
Many companies, by nature of their business, produce waste material, and what to do with that waste can often cause problems, in terms of both cost and damage to the environment. Now, a Newcastle University research centre has been set up specifically to provide assistance to companies which produce waste materials that have the potential to be recycled for use on the land, as fertilizers, soil conditioners and contamination amerliorants. The Recycling to Land Research and Advisory Centre, based in the Department of Agricultural and Environmental Science at Newcastle University, and at the University's Cockle Park Farm, is a centre of excellence for the scientific evaluation of the suitabili
RAS PN99/30 UK Sends Clover and Rocks Into Space
ROYAL ASTRONOMICAL SOCIETY PRESS INFORMATION NOTE
More Gypsum Current Events and Gypsum News Articles
 | Gypsum Construction Handbook, Centennial Edition 2000 by United States Gypsum USG Corporation |
| The Chemistry and Technology of Gypsum: Asymposium (Astm Special Technical Publication// Stp) | |
| Gypsum Construction Handbook, With Product and Construction Standards by United States Gypsum | |
 | The Natural Plaster Book: Earth, Lime, and Gypsum Plasters for Natural Homes (Natural Building Series) by Cedar Rose Guelberth, Dan Chiras For builders of natural homes (straw bale, cob, adobe, rammed earth, and other natural materials), this unique step-by-step guide takes the confusion out of choosing, mixing, and applying natural plasters. From principles to practicalities, and with every stage of the process illustrated, The Natural Plaster Book details the entire process of plastering with earth, lime, and gypsum for a... |
| Gypsum Construction Handbook, 90th Anniversary Edition 1992 by Robert Carlson, Marketing Comm United States Gypsum Co | |
 | Gypsum Construction Handbook with Product and Construction Standards |
| Repairing and Extending Finishes, Part I: Plaster, Gypsum Board and Ceramic Tile by H. Leslie Simmons | |
| Recommended Specifications for the Application and Finishing of Gypsum Board | |
 | Specifications for the Application and Finishing of Gypsum Panel Products GA-216-2004 by Gypsum Association Includes specifications for the application and finishing of gypsum panel products and related items and accessories to interior walls and ceilings and to exterior... |
 | The 2007-2012 Outlook for Gypsum Plaster Building Boards and Lath in Japan by Philip M. Parker This study covers the latent demand outlook for gypsum plaster building boards and lath across the prefectures and cities of Japan. Latent demand (in millions of U.S. dollars), or potential industry earnings (P.I.E.) estimates are given across some 1,000 cities in Japan. For each city in question, the percent share the city is of it’s prefecture and of Japan is reported. These comparative... |
| © 2009 BrightSurf.com |