Shell Oil is funding a project that is studying the potential of adding lime to seawater to store carbon dioxide (CO2) in the sea.
Due to increased CO2 levels, the oceans have become more acid. Adding lime (calcium hydroxide) to seawater will increase the alkalinity of the water, making the water absorb more CO2 and reducing the release of CO2 from the water into the atmosphere.
Tim Kruger, a management consultant at London-based Corven, believes that this can be done most economically where there's plenty of limestone, and plenty of energy that is too remote to exploit for conventional commercial purposes.
"There are many such places — for example, Australia's Nullarbor Plain would be a prime location for this process, as it has 10,000km3 of limestone and soaks up roughly 20MJ/m2 of solar irradiation every day," said Kruger.
Although the process generates CO2 emissions, on paper it sequesters twice as much of the warming gas than it produces. Kruger says the process is therefore 'carbon negative'.
'This process has the potential to reverse the accumulation of CO2 in the atmosphere. It would be possible to reduce CO2 to pre-industrial levels,' he explained.
"We think it's a promising idea," says Shell's Gilles Bertherin, a coordinator on the project, which is being developed in an "open source" manner. "There are potentially huge environmental benefits from addressing climate change — and adding calcium hydroxide to seawater will also mitigate the effects of ocean acidification, so it should have a positive impact on the marine environment."
Sources and Links:
Shell Oil funds "open source" geoengineering project to fight global warming, at:
Mongabay.com
'Turning back the clock on climate change' - A technology to reverse climate change? To reduce ocean acidification? And that also promises to increase food production? Cath O’Driscoll investigates, at:
Chemistry & Industry Magazine
Adding lime to seawater feasibility study, funded by Shell, at:
Showing posts with label seawater. Show all posts
Showing posts with label seawater. Show all posts
Tuesday, November 4, 2008
Monday, May 7, 2007
Cloud Seeding
Cloud seeding is proposed by John Latham and Stephen Salter, who suggest to spray droplets of seawater high up into the air, so that the tiny particles of salt from these droplets will make clouds thicker and more reflective. The project featured prominently in the BBC documentary:
https://www.youtube.com/v/fg7J8P-uXqM
Stephen Salter proposes to make rain with floating wind turbines that make very choppy waves, known as Faraday waves. A high-frequency ultrasonic generator would spin seawater around inside a grooved drum, producing tiny waves that are thinner than a human hair, throwing tiny droplets of water from their crests up into the air. As this fine mist of sea-spray evaporates, tiny particles of sea-salt remain in the air and get sucked up into the air, especially when the sunshine causes rising currents of air. These little salt particles act as centres attracting extra droplets to form darker clouds further up in marine stratocumulus clouds. Stephen envisages a multitude of ships to criss-cross the oceans, remotely controlled with their position tracked through GPS and their destination determined by weather patterns. This idea of making rain in this way could also be combined with another idea discussed earlier in this group, i.e. of exploiting temperature differences in the sea. http://groups.google.com/group/greenhouseeffect/msg/4a21d06ae5b08c04
The deeper you go down into the ocean, the colder it gets. At the lowest points, the temperature is near freezing point. Ships could drag a pipe along, reaching down a few hundred metres into the ocean. Through this pipe, cold water could be pumped up by a solar-powered pump to be released back into the sea from a little tower of, say, two metres high. As the cold water falls down into the sea, the evaporation will act as an air-conditioner. Furthermore, condensation around the top of the pipe will drip down and can be captured in containers, to be sold as fresh water. So, apart from harvesting clean, potable water in the above way, such a ship could also be anchored at a location where it could throw part of the seawater up into the air in the way Stephen Salter proposed, as a fine mist, in order to produce more rain in the proximity of a dry area on land.
Stephen Salter proposes to make rain with floating wind turbines that make very choppy waves, known as Faraday waves. A high-frequency ultrasonic generator would spin seawater around inside a grooved drum, producing tiny waves that are thinner than a human hair, throwing tiny droplets of water from their crests up into the air. As this fine mist of sea-spray evaporates, tiny particles of sea-salt remain in the air and get sucked up into the air, especially when the sunshine causes rising currents of air. These little salt particles act as centres attracting extra droplets to form darker clouds further up in marine stratocumulus clouds. Stephen envisages a multitude of ships to criss-cross the oceans, remotely controlled with their position tracked through GPS and their destination determined by weather patterns. This idea of making rain in this way could also be combined with another idea discussed earlier in this group, i.e. of exploiting temperature differences in the sea. http://groups.google.com/group/greenhouseeffect/msg/4a21d06ae5b08c04
The deeper you go down into the ocean, the colder it gets. At the lowest points, the temperature is near freezing point. Ships could drag a pipe along, reaching down a few hundred metres into the ocean. Through this pipe, cold water could be pumped up by a solar-powered pump to be released back into the sea from a little tower of, say, two metres high. As the cold water falls down into the sea, the evaporation will act as an air-conditioner. Furthermore, condensation around the top of the pipe will drip down and can be captured in containers, to be sold as fresh water. So, apart from harvesting clean, potable water in the above way, such a ship could also be anchored at a location where it could throw part of the seawater up into the air in the way Stephen Salter proposed, as a fine mist, in order to produce more rain in the proximity of a dry area on land.
Sam Carana
- March 3 2006
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