Welcome to the Cquestrate blog
With a couple of days left before the website launches we’re just finalising content, producing explanatory videos and making sure that everything is working properly.
We’ve had to move very quickly to ensure that everything is in place as soon as possible. With the first phase of the website almost complete it’ll soon be a case of making sure that word goes out to the people who can help further this project.
The scope is so large that we need a wide spread of expertise – if you, or anyone you know anyone, can help in any way then we look forward to your input. Have a look at the questions we need to answer and leave your comments on the relevant pages.
The production of high concentration (or pure) carbon dioxide flue gases from the calcination of limestone provides an opportunity to allow the production of biomass in arid environments.
At the same time that plants obtain carbon dioxide from the air, they lose water into the air. On a hot, dry day plants have the ‘choice’ of either going ‘thirsty’ or ‘hungry’ – if they open their stomata – the holes in their leaves that allow the diffusion of carbon dioxide into the plant – then they can obtain carbon dioxide, but they will lose water. If they close their stomata they lose less water, but cannot obtain the carbon dioxide that they need to perform photosynthesis. When water is plentiful plants are able to lose water as they obtain carbon dioxide, but when water is scarce they cannot obtain carbon dioxide. Conventionally we think of a desert as an area that is lacking in water – in reality it is the scarcity of carbon dioxide (and plants inability to ‘trade’ water for carbon dioxide) that restricts the growth of plants. By supplying carbon dioxide to plants in a desert, they can get by with far less water.
This part of the idea is less developed than the ‘adding lime to seawater’ part, but could be just as, if not more, important. Initial conversations with specialists in the areas of algae cultivation and water resource management are positive, but we need to develop this further. We are interested to hear from anyone who has worked on anything similar and to find out what are the barriers to making this work in a practical way.
If you have any experience in, or knowledge of, this area then please get in touch with us. This project cannot progress without your input.
The idea works like this:
- First, you heat limestone to a very high temperature, until it breaks down into lime and carbon dioxide.
- Then you put the lime into the sea, where it reacts with carbon dioxide dissolved in the seawater.
The important point is that when you put lime into seawater it absorbs almost twice as much carbon dioxide as is produced by the breaking down of the limestone in the first place.
This has the effect of reducing the amount of carbon dioxide in the atmosphere. It also helps to prevent ocean acidification, another problem caused by the increase in the amount of carbon dioxide in the atmosphere.
If done on a large enough scale it would be possible to reduce carbon dioxide levels back to what they were before the Industrial Revolution.
The first step of the process – breaking down limestone into lime and carbon dioxide – seems counterintuitive as it uses a lot of energy and actually produces carbon dioxide. But this carbon dioxide can either be safely stored away or used to help grow crops in very dry areas. You can find out more about this here.
One of the questions I often get asked is: if this is so simple why hasn’t it been done before? The idea has been around for a number of years. It was first suggested by Haroon Kheshgi in 1995, but it was considered uneconomic as the process uses a large amount of energy. What we are interested in doing is using stranded energy to drive the process.
Stranded energy is energy that is remotely located, so it is not economically viable to exploit. For example, in a desert there is plenty of energy available, but it would cost too much to transfer the energy to where anyone wants it, so it never gets used. So, paradoxically, in a desert energy is abundant and cheap, but worthless. This process can use that stranded energy.
We couldn’t have got this far without the help of a large number of people who have been extremely generous with their time and expertise. We are developing this project in an open source way, so, if you are interested to help, please get involved.