Nanotubes for Carbon Capture

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Chemistry


It is now a widely accepted fact that carbon emissions from fossil fuel combustion and change in land use are forcing a rapid increase in atmospheric CO2 levels, with consequent enhancement of the greenhouse gas (GHG) effect leading to climate change. The UK has set a target of reducing the net CO2 emission by 80% by 2050 (compared to a 1990 baseline). In order to achieve this target, multiple measures must be implemented. The development of a simple air capture technology to remove CO2 from the atmosphere would go far to achieving these goals and provide an option for accelerating the correction and possibly reversing the trend in atmospheric CO2 concentrations. Much effort is being expended on capturing CO2 from fossil fuel plants, however, 50% of the emission comes from small distributed sources and transport. Considerable progress could be made if it was possible to develop a small-scale low maintenance device for local CHP (Combined Heat and Power) plants or domestic use. One of the major challenges in developing such a technology lies in the choice and development of a material that can efficiently absorb but also easily and with low energy cost desorb and concentrate the captured CO2 for further large scale storage or use in chemical synthesis approaches that are currently being developed. This proposal consists of a number of interdisciplinary and speculative research activities that collectively are focused on the goal of determining the feasibility of developing a small scale carbon capture system (CCS) based on the adsorption properties of chemically functionalised carbon nanotubes (CNT).Carbon nanotubes (CNT) are cylinders of pure carbon with diameters on the order of some nm and lengths that can range from 100nm to mm. They exist both as single-walled CNT where the wall of the cylinder is 1 atom thick and as multi-walled nanotubes where a number of cylinders are nested inside each other. The bulk material is extremely lightweight and highly porous and due to its high surface area is very suitable for gas storage applications. CNT also possess a high thermal and electrical conductivity and exhibit a rich chemistry. These properties all make them very promising materials for efficiently and selectively adsorbing and desorbing CO2. The worldwide production of CNT has increased dramatically in the past couple of years and the price is falling rapidly, making the large scale application of bulk quantities of CNT feasible. The activities to be addressed within this Feasibility Account include the synthesis and characterisation (including toxicological studies) of new CNT material with a high selectivity and affinity for CO2 adsorption as well as potential for the development of selective gas sensors, the modelling and design of a small scale CCS taking into account extensive feedback from public consultation and a life cycle analysis to determine the economic and environmental feasibility of the development of such a system. Each activity in itself has the potential to produce ground-breaking developments and high impact results while the results of the combined suite of activities will provide a firm foundation for taking these ideas forward at a later stage to develop a prototype carbon capture system.

Planned Impact

The suite of research activities that will be addressed in the proposal are all focused towards the development of a new approach towards the small scale capture and storage of CO2. It is widely accepted that further increase in CO2 levels in the atmosphere will invariably affect local and global weather patterns, leading to a higher occurancy rate of the extreme weather conditions, including hurricanes, floodings, extreme droughts, etc. The economic repercussions of these extreme conditions are immense, with the cost of a single wave of floodings in the UK in 2007 estimated at 14million ( However, these local impacts are dwarfed by the potential catastrophic scenarios proposed for the global environment in case of further increase in CO2 levels. Thus, there are serious concerns about the very sustainability of modern technologies and, consequently, society in general. From this perspective, we believe that the general public (in the UK and worldwide) is ultimately the main beneficiary of this research, as the proposed research activities should point the way towards the development of a small scale carbon capture and storage technology that can be operated on the local community and domestic level this empowering the general public to contribute towards the reduction and control of CO2 levels. If the Feasibility Account is successful then the timescale for the development of a prototype CCS based on the properties of CNT,could be as short as 3-5 years. The nature of the topic makes it very accessible to the general public, which immediately opens many avenues for public engagement. Furthermore, the planned activities offer an opportunity for direct public participation at the very initial research stage allowing a dialogue to be developed between stakeholder groups that can have a major impact on the public perception of the technology and indeed on the futher R&D activities. The second most important group of beneficiaries wil be within the commercial private sector. A successful outcome of the research activities will lay the foundation for a larger collaborative activity and investment in the development of a prototype device for CO2 capture. The results of the research activities should allow us to determine which type of small scale CCS is going to be the most effective (CHP or domestic air capture systems) and provide the basis for a strong case for further support from both the Research Councils and the commercial sector. One can easily envision a broad range of business opportunities focused on further improvement or commercialization of the technology, nanomaterials technologies, development of the appropriate infrastructure (associated with collection and storage of CO2), CO2 trading and so on. Development of the new ideas and technologies in these complementary sectors may provide a boost not only for the local regional economy in Scotland but for the UK in general. The developments will also impact on the environmental agencies and regulatory bodies, who must account for and adapt to the new emerging environmental challenges and economic opportunities. Finally, the third most important beneficiaries will be the staff working on the project. Researchers in this project will benefit from carrying out novel and interesting research activities that on a relatively short time scale have the potential to lead to a partial solution to one of the most important evironmental and technological problems we are facing today. They will have the opportunity to work in a cross-disciplinary environment where they will be dependent on each others results and where they have to deliver on time. This is extremely valuable training regardless of whether their chosen career lies in academia or industry. In addition, they will all have the unusual opportunity to interact directly with the general public at an early stage of the project and participate in an interesting sociological experiment.


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Description Functionalization schemes were successfully developed for carbon (CNT) with emphasis being placed on the application of multiwalled nanotubes that are readily available at a reasonable cost.
A major problem was encountered with the porosity of the functionalised material. After wet chemical treatment the functionalised CNT material was significantly less porous than the pristine material and the surface pore structure became blocked due to efficient carbonate/carbamate formation. The uptake of CO2 was determined and found to be limited by the material porosity. A method was found to avoid this problem towards the end of the project - it is currently being used in the follow-up project and very promising results are being obtained.
Currently air capture from the available materials is not an economic option although the general public was found to be positive towards the idea of carbon capture from air but not necessarily using domestic units.
The chemically functionalised multi-walled nanotubes used in this project were studied for their toxicological properties and found to be safe.
Exploitation Route The detailed modelling put strict criteria on the properties of materials that would need to be developed for CO2 capture from air. The targeted materials were shown to be unlikely to be useful for this particular application but could be more promising for situations where there is a higher CO2 partial pressure. The outreach activities showed that the general public is open to the idea of carbon capture and storage but showed some scepticism for a domestic direct air capture unit. These
Sectors Chemicals,Energy,Environment,Other

Description The findings were used to determine the strategy for future research into the developments of materials for carbon capture at the University of Edinburgh and led to further funding. The simulation of air capture indicated that the materials currently available were better suited to capture from more CO2 rich sources such as the emission from gas-fired power stations. This is the current target for the carbon-based materials. The social science study into the perception and response of the general public was extremely useful and showed that the public would be favourable towards domestic air capture units if suitable, economically viable materials could be developed to make this a feasible option. The toxicology studies provided confirmation that the aerials under consideration could be considered safe.
First Year Of Impact 2012
Sector Environment
Impact Types Societal

Description EPSRC
Amount £1,097,861 (GBP)
Funding ID EP/J02077X/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 07/2012 
End 07/2015
Description Industrial CCS
Amount £858,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 06/2016 
End 07/2019
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact The First and Second Public Engagement events were a successful way of providing information to members of the public about the key ways in which CO2 reduction from the atmosphere can be achieved. At the first event (a working group of ca 20) the public sample was not quite a 'lay' one, however, since participants had already been involved in a CCS PE event 6 weeks prior to this PE event, or were MSc students with a professional interest in the topic. Nonetheless, the survey results showed clearly that the information and discussions had a strong impact on levels of knowledge and attitudes (which became more positive with respect to all the technologies).
The second event was a presentation during the Edinburgh International Science Festival in 2012 with ca. 700 visitors per day.
The discussions at both events provided a more nuanced understanding of attitudes and perceptions. There was a clear preference for afforestation but also a realisation that this would probably be hard to scale-up quickly enough to have a big enough impact on CO2 emissions. Participants tended to lean towards CCS as a more scaleable, realistic option. As for the domestic-DAC unit, there was interest but many questions raised about practicality, reliability, costs and safety. The concept of a neighbourhood DAC unit, as opposed to a domestic unit, was received favourably

The main impact has been to inform further research activities in the development of materials for carbon capture.
Year(s) Of Engagement Activity 2011,2012