Welcome to the Cquestrate blog
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Talk at the Smith School
On 27 October Tim Kruger delivered a seminar at Oxford University’s Smith School of Enterprise and the Environment.
The first half of the seminar was a talk explaining Cquestrate, while the second half was given over to a question and answer session, with some tough and incisive questioning from those attending.
I recorded the first half of the seminar which you can see here:
Tim Kruger at the Smith School from cquestrate on Vimeo.One person has left a comment so far, why not join in the discussion?
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Cquestrate animated
We’re really pleased to unveil the animation that we’ve been putting together to explain the Cquestrate project. Have a look and I’ll tell you a little more about it afterwards.
Cquestrate from cquestrate on Vimeo.Although the Cquestrate process is actually fairly simple to understand on a basic level, we’ve had feedback asking for more visual tools help explain what is being investigated. We think this animation does a great job of that.
It was put together by the Birmingham-based Eight Eyed Sea Bass. They’re quite rightly very proud of their work and have written about it on their blog. The audio was provided by The Audio Suite, also based in Birmingham. We’d like to thank them again for their hard work in putting this together.
Cquestrate is continuing to push forward and develop a process that could make a hugely positive impact on the world. There are still areas where help is needed and we could do with more people hearing about our work. Please help us spread the word.
We’d like to thank the following people for passing the video on already:
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Burning Boats
Burning boats is not something that an environmentalist would normally recommend – it is wasteful and generates greenhouse gases – but do not worry because the boats that I have burnt are metaphorical and not real.
I have resigned from my role as a management consultant at Corven (www.corven.com) and am now working full-time on Cquestrate. I have sufficient funding to take me through until the end of the year, by which point it should be clearer what the prospects for this process are.
The last few days have seen some really interesting leads emerging, especially around the area of growing algae. The waste products from the calcination of the limestone are low grade heat and carbon dioxide, which are two things that algae need, so the process has strong synergies with improving the efficiency of algaculture. Watch this space for more updates.
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Energy independence
So you want to produce all the fuel you need without importing it in from other countries, with all the messy politics that that can involve. Here’s how:
Use the carbon dioxide generated from the first step of Cquestrate’s process to allow you to grow algae (the availability of carbon dioxide is the rate limiting constraint if you have even a moderate amount of sunlight). Vent off any oxygen generated from photosynthesis and then decompose the algae in anoxic conditions (no oxygen) – this will generate methane. With solar irradiation at 20MJ per m2 per day and an efficiency of converting sunlight to chemical energy of 1%, you are able to generate 730GJ per ha per year. Wholesale prices for methane are ~USD10 per GJ, so you have a per hectare yield of ~USD7,300. Farmers would be delighted with that kind of yield.
Now, it isn’t quite that simple – there are high capital and operational costs involved in growing algae – but there are reasons to believe that producing methane will be far cheaper than producing biodiesel (although biodiesel sells for more). For a start, if you want to produce biodiesel you have to get it out of the algae cells, by breaking down the cell walls and using solvents, which involves energy and expense. Methane by contrast is a gas, which will separate out without the need for any expensive processing.
Another benefit is that algae don’t by choice produce much of the lipids that you need to produce biodiesel. You have to stress the algae, by making the conditions in which they grow abnormal. Photoynthesis yields sugars – the algae then have to go through a series of biochemical steps to convert those sugars into lipids – and each step reduces the overall energy efficiency conversion from sunlight to chemical energy. By contrast, to produce methane all you need to do is to allow the algae to do what they do most naturally – produce sugars – and then allow them to decompose (this is helped by two sets of organisms – the first set breaks sugars down into acetic acid and the second set breaks acetic acid down into methane and carbon dioxide). The energy efficiency of this decomposition process is, in theory 95%, but in practice is closer to 80%.
Current projects which seek to produce biodiesel from algae use the flue gases from power stations as they are a concentrated source of carbon dioxide. This means that the algae needs to be grown near the power station and that tends to mean high land prices. Cquestrate’s process can be performed on cheap land far away from a power station as its source of carbon dioxide is from the calcination of limestone.
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Making the deserts bloom
The first step of the process - heating limestone up until it breaks down and produces lime also generates carbon dioxide. This can be used to help grow algae – either for food or for biofuels. It also allows the growth of biomass in very dry environments. How so? Think of it this way:
Say you wanted to grow a crop in an arid environment – you haven’t got much water, so you seal your water and the crop that you are growing inside a greenhouse. Sealing it up stops the water evaporating away, but as the plants grow they use up all the carbon dioxide in the greenhouse. So you decide to put some fresh air into the greenhouse, but when you do this you have to remove the old air, and when the old air leaves you lose all the moisture … back to square one – it doesn’t work.
If, however, you have a sealed tank of water and into it you introduce pure carbon dioxide, you are in a much better position. The tank has a transparent lid, so you have sunlight; the water in the tank contains algae – you have everything you need for photosynthesis. Because the tank is sealed you will not lose water by evaporation. (You will need to vent off a small amount of oxygen generated by the photosynthesis, but you will only lose a small amount of moisture because of this).
Some fairly simple chemistry shows that for every kg of sugars that you produce, you need to use 600g of water. Undoubtably, you will lose some more water in the practical application of the process, but the water usage will be less than 10kgs of water for every kg of sugar produced. This sounds like a lot, until you realise that growing crops in really dry places like Egypt requires 1000 kgs of water for every kg of crop produced.
Or to put it another way, it is possible to grow crops with 1% of current water usage. So, paradoxically, the way to make the deserts bloom is to heat the right kind of rocks up.
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International interest in Cquestrate
Given the potential magnitude of the Cquestrate project we expected interest in this website to come from around the world and, glancing throught the website statistics, that’s certainly been borne out.
So far we’ve had 12,726 visitors from 63 countries with the USA, the UK, Germany, Canada and Australia making up the top five. The intro video on the homepage has been viewed almost 3,000 times.
Although the working language on the Cquestrate website is English, the website has already been written about in several other languages:
- It’s interesting to see a non-English speaking country providing the 3rd highest number of visitors and that’s thanks to an excellent article on the German website Jetzt.de
- Within 24 hours of the project launching publicly someone had translated the press release into Spanish.
- Another Spanish article appeared on Neofronteras.com
- Lenta.ru ran an article in Russia
- The French version of Gizmodo featured Cquestrate and there was also a discussion in a French forum
- We’ve also come across mentions in Japanese and Dutch.
As and when I come across articles about Cquestrate they are tagged using delicious and then featured on the Cquestrate links page.
We may get to the stage where it would be useful to have the content on this site translated into as many languages as possible so our international visitors can get the most from Cquestrate. That may be part of the next phase of the website. If you have any other suggestions to develop the site please use the comments below or go to the dedicated website development page.
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Research commissioned
We have recently commissioned two pieces of research to develop the process.
The first part addresses the Energy Balance of the process – how much energy is required to drive the process? While we know how much energy is required to thermally decompose (calcine) limestone into lime and carbon dioxide (this is after all what people in the lime industry do every day), we need to change the process slightly, so that we are able to capture pure carbon dioxide, which is much easier to sequester. Through contacts from this website I have been in touch with the German Lime Association who have been able to provide some very useful and encouraging information on current energy requirements and indications on what the requirements for the altered system might be. At the same time as we are gathering empirical data, we are also creating a computer model of the energy requirements of the altered calcination system – this work is being undertaken by Dr Panos Parris and Dr George Manos both at University College London. They will be reporting out in the first week in September.
The second piece of research is on the environmental impact of adding the lime to seawater. This work is being carried out by Professor Gideon Henderson, Dr Heather Bouman and Dr Ros Rickaby, all at the Department of Earth Sciences at the University of Oxford. This research will be a preliminary assessment of the effects of the process and will identify further areas of research to determine whether, and how, this process can be conducted in an environmentally beneficial way. They will be reporting out in the middle of September.
As part of the open source approach we are taking, we will publish the research results on the website as soon as we receive them
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Conversations about Cquestrate
Cquestrate launched just over two weeks ago and we’ve already seen a great level of discussion on the website. Some of the comments and contributions have started to move the project forward in encouraging ways.
However, discussions about Cquestrate aren’t restricted to this website and it has been fascinating to read, and contribute to, what has been going on elsewhere. Here’s a very small sample:
- Alexis Madrigal covered Cquestrate on the Wired Science blog
- FT.com’s Undercover Economist mentioned Cquestrate after meeting Tim Kruger
- Larvatus Prodeo has hosted a long-running, well-informed debate
- A Slashdot post on the day that Cquestrate launched has so far attracted 874 comments (some funny, some actually quite helpful)
- On the day of launch, Cquestrate was featured in the top 5 ‘upcoming’ environmental stories on Digg
- Cquestrate has made news abroad and has been picked up on in France by Gizmodo.fr and in the djibnet.com forum. Also in Spain on NeoFronteras.
When I come across anything useful I use del.ici.ous to ‘tag’ the page. Links to these tagged pages are collected automatically on our links page for all to see.
Unfortunately, it can be tricky to find all of these conversations. However, it’s important we do our best to follow them – we don’t want to miss out on some potentially valuable information.
If you are part of a community that has discussed Cquestrate or if you’ve blogged about the project, please let us know in the comments below.
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Prevention is better than a cure
Prevention is better than a cure – but if you can’t prevent something from happening then you sure want to have a cure.
Heating up vast quantities of limestone to reduce the amount of CO2 in the atmosphere and mitigate ocean acidification would not be necessary if we drastically reduced our emissions of CO2. People have suggested in comments posted to this site that what we need to do is have serious reforestation efforts and increase our energy efficiency to prevent runaway climate change - I couldn’t agree more. But we need to recognise that even if it were possible to change the way that people behave, that reforestation and energy efficiency may simply not be sufficient to solve the problem.
There are concerns that this process involves the processing of colossal quantities of limestone, but then the size of the problem is colossal too. There’s an interesting blog at Wired about what the author, Alexis Madrigal, calls “Gesturengineering” – we need to recognise that changing lightbulbs and not putting our TV on standby, whilst useful and necessary steps to reduce our emissions, are not sufficient – gestures alone are not enough. We need to recognise that the steps we need to take to tackle climate change will need to be much more than cosmetic – that they will affect our economic well-being and may have some side-effects – there probably is no perfect pain-free solution.
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Why bother heating up the limestone?
It seems like heating up limestone until it breaks down into lime is a lot of hard work to get alkalinity into the ocean. Why not put the limestone directly in the water?
Well, the problem is that limestone is very insoluble, which explains the continuing existence of the White Cliffs of Dover. It is possible to get limestone to dissolve in water, but you have to grind it to an extremely small size and even then it dissolves very slowly. To enhance the ability of the oceans to act as a carbon sink, you need the reaction to take place in the top 100m of the ocean, as this is the layer where most of the mixing with the atmosphere takes place. Even small particles of limestone sink like stones (which is after all what they are) and little of the required reaction will occur in the right place. To grind limestone down into a fine enough powder is both expensive both in terms of energy and in terms of the equipment required. Also the energy that is required is mechanical energy which is much more expensive than heat energy.
There are other sources of alkalinity that can be added. Kheshgi identified mineral deposits of soda ash (Na2CO3) as one such source, but noted that using the world’s entire recoverable resources of soda ash would offset just a single year of CO2 emissions. Caldera and Rau have put forward an idea that reacts CO2 from the flue gases of power stations with limestone and then puts the resulting calcium bicarbonate solution into the sea – this has a lot of merit – it addresses CO2 before it is emitted, but does not remove CO2 from the air after it has been emitted, as the process described on this website does.
All these methods can be used – the questions are how can they be done in an environmentally beneficial way and how can they be done economically? These are the key questions we are trying to answer – and with your help we will
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