Organic Mixed Matrix Membrane Technologies (ORGMEMT) for Post-Combustion CO2 Capture

Lead Research Organisation: University of Liverpool
Department Name: Chemistry


The UK Government has set targets for the reduction of CO2 emissions of 80 % by 2050. Post-combustion capture of CO2 from power plants is key if we are to achieve these targets. Post-combustion CO2 capture is challenging due to the low concentration of CO2 in the waste stream and the presence of impurities (H2O, NOx, SOx, etc). Post-combustion capture adds energetic cost via the requirement to capture and compress the CO2. Amine-based scrubbing processes are being evaluated for post-combustion CO2 capture. This is a costly process, and the amines are corrosive. Other candidate technologies include physical adsorption into solid sorbents coupled with pressure-swing or temperature-swing adsorption/desorption. In principle this may lower the energy overhead, but the volume of sorbent required is extremely large, limiting the range of sensible materials. Membrane-based processes have potential advantages over the above. In particular, there are no losses due to heat required to regenerate and release CO2 from the spent sorbent or solvent, and the footprint for the technology and amount of material required is comparatively small.

Here, we will develop advanced mixed matrix membranes (MMMs) technology utilising organic fillers, rather than inorganic fillers, that could be cost-effectively fitted to power plants to separate and capture CO2. There has been much research on inorganic-organic MMMs, using fillers such as zeolites and MOFs. However, it is challenging to achieve a homogeneous dispersion of the inorganic filler particles in the polymer matrix. This is exacerbated by the lack of compatibility between most fillers, which are frequently crystalline inorganic or metal-organic materials, and the membrane polymers, which are invariably amorphous and organic. We build therefore on our unique report of organic-organic MMM (Angew Chem Int Ed, 2013) , where excellent dispersion of the organic filler was found and there was good adhesion between the organic polymer and the organic filler, both of which are predominantly aromatic structures. We address this by bringing together two UK groups who have pioneered in the development of novel porous membranes (Budd) and new microporous organic materials (Adams, Cooper).

Planned Impact

The outputs of this work will be (i) a thorough understanding of organic-organic mixed matrix membranes (MMM), (ii) a library of organic-organic MMM, tested for gas sorption, separation, and mechanical properties, (iii) a unique UK-based high throughput gas separation facility, (iv) an established high throughput IR-based method for monitoring gas separation, (v) two scientists trained in rational design and characterization of MMM and (vi) patent protection of relevant IP.

The ultimate output of the project will be new MMM, fully tested for CO2 capture, including key data on aging and stability to impurities such as NOx, SOx, H2O etc. These MMM will have the potential to impact dramatically on the national economy, through carbon capture and storage techniques, which has been estimated to have the potential to save the UK billions of GDP ( Economic beneficiaries will be companies and/or IP groups who wish to take the technology developed during the project further. Engagement with industry will be facilitated by the Knowledge Centre for Materials Chemistry, KCMC. Both Liverpool and Manchester are founder members of the KCMC, whose remit is to help support innovation in companies through knowledge transfer, usually delivered through Collaborative Research and Development projects between its partners and Industry. The results from this project will be disseminated to the TSB funded Materials Chemistry Special Interest Group (MC-SIG) which is run by the KCMC and involves a number companies including large blue-chip companies and SMEs from the UK. In addition the KCMC will promote the research findings to an extensive industry network and aim to identify future collaborators to commercially exploit the science and technology developed in the project. The KCMC activities have provided industrial income to the Universities of Liverpool and Manchester of over £4.5M and engagement with > 250 companies (10/08 - 03/13). We also have a specific, day-one industry partner.

More generally, society will benefit from the potential reduction in CO2 being released to the atmosphere, highlighted as the main contributor to global climate change. Society will also benefit from the trained personnel emerging from the programme equipped to contribute to UK industry in a high-tech sector. Project advances of societal interest will be disseminated via the press offices at the Universities of Liverpool and Manchester, working with EPSRC as appropriate.
Description Highly permeable glassy polymers can be used in carbon capture and storage. However, loss of free volume in these materials over time (aging) limits their applicability. Introduction of a secondary filler phase can reduce this aging, although the cost of some of these fillers mean that they are unlikely to be commercially viable. We are developing, through this research grant, cheaper water and acid tolerant hyper-cross-linked (polyaromatic) polymer 'sponges' as an alternative filler. On addition of the filler to the membrane the composite material display a slower loss of permeability over time, while the performance of the membranes is largely unaffected.
Exploitation Route Too early to say for definite, but the materials we are developing could be used as separation media for a wide range of applications in the chemical and energy sectors. We have also recently started a CSC PhD student on this project, to continue developing some materials discovered during this project.
Sectors Chemicals,Energy,Environment