Abstract
One of the main challenges for commercialising calcium looping (CaL) as a CO2 capture technology is maintaining a high level of sorbent reactivity during long-term cycling. In order to mitigate the decay in carrying capacity, research has moved towards producing enhanced sorbents. However, this creates potential problems related to ease of scaling up production techniques and production costs, and raises the question as to whether such approaches can be used at large scale. On the other hand, a key advantage of CaL over other carbon capture technologies is synergy with the cement industry, i.e., use of spent sorbent as a feedstock for clinker production. In this work two enhanced materials: (i) limestone doped with HBr through a particle surface impregnation technique; and (ii) pellets prepared from limestone and calcium aluminate cement, were tested in a 25 kWth dual fluidised bed pilot-scale reactor in order to investigate their capture performance and mechanical stability under realistic CaL conditions. Moreover, the spent sorbent was then used as a raw material to make cement, which was characterised for phase and chemical composition as well as compressive strength. The HBr-doped limestone showed better performance in terms of both mechanical strength and stability of the CO2 uptake when compared to that of pellets. Furthermore, it was shown that the cement produced has similar characteristics and performance as those of commercial CEM 1 cement. This indicates the advantages of using the spent sorbent as feedstock for cement manufacture and shows the benefits of synthetic sorbents in CaL and suitability of end-use of spent sorbents for the cement industry, validating their synergy at pilot scale. Finally, this study demonstrates the possibility of using several practical techniques to improve the performance of CaL at the pilot scale, and more importantly demonstrates that commercial-grade cement can be made from the lime product from this technology.
| Original language | English |
|---|---|
| Pages (from-to) | 392-401 |
| Journal | Applied Energy |
| Volume | 225 |
| DOIs | |
| Publication status | Published - 1 Sept 2018 |
| MoE publication type | A1 Journal article-refereed |
Funding
The research leading to these results has received funding from the European Community's Research Fund for Coal and Steel (RFCS) under grant agreement no. RFCR-CT-2014-00007. This work was funded by the UK Carbon Capture and Storage Research Centre (UKCCSRC) as part of Call 2 projects. UKCCSRC is supported by the Engineering and Physical Sciences Research Council (EPSRC) as part of the Research Council’s UK Energy Programme, with additional funding from the Department of Business, Energy and Industrial Strategy (BEIS – formerly DECC). In addition, the authors wish to thank Almantis Inc. and Longcliffe UK for providing the materials used in this work.
Keywords
- Calcium looping
- CCS
- Cement
- Pilot plant
