Browsing by Author "Wu, Chunfei"

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    Efficient-and-Stable CH4 Reforming with Integrated CO2 Capture and Utilization using Li4SiO4 Sorbent
    (Elsevier, 2021-08-16) Lv, Zongze; Qin, Changlei; Chen, Shuzhen; Hanak, Dawid P.; Wu, Chunfei
    CO2 capture and utilization has been considered as an up-and-coming short- to mid-term approach to mitigate the excessive CO2 emission. Comparing to the conventional separate capture, transportation and conversion arrangement, the integrated CO2 capture and utilization (ICCU) could largely simplify the complex process and reduce the energy consumption. However, the poor stability of high-temperature CO2 sorption/desorption severely limit the potential of ICCU. Therefore, it is indispensable to develop a new sorbent/catalyst system ensuring the high-efficiency and long-term operation of the ICCU. In this paper, we propose and demonstrate the feasibility and performance of using K2CO3-doped Li4SiO4 as an efficient CO2 sorbent for ICCU operating at a relatively low temperature by dry reforming of methane. Results show that the ratio of H2/CO produced is stabilized at 1±0.05 in the pre-breakthrough stage, and the duration extends to be 1.6 times of the original value in the cyclic operations, displaying an excellent performance in reaction matching and process stability.
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    Fundamental studies of carbon capture using CaO-based materials
    (Royal Society of Chemistry, 2019-03-26) Sun, Hongman; Wang, Jianqiao; Liu, Xiaotong; Shen, Boxiong; Parlett, Christopher; Adwek, George O.; Anthony, Edward J.; Williams, Paul T.; Wu, Chunfei
    Detailed understanding of the mechanisms of the fast stage during CaO carbonation is important to the design of novel efficient CaO materials. This work systematically studies the formation of CaCO3 product layer on the outside surface of CaO grains during the fast reaction stage for carbon capture using two types of CaO adsorbents. The carbonation at 400 ˚C filled the small pores in the commercial CaO grains and no distinct product layer of CaCO3 was observed. However, a distinct layer of CaCO3 with a thickness around 90 nm was observed on the outside surface of the commercial CaO grains after the carbonation at 600 ˚C because the internal pores in the CaO grain had been filled and a layer of CaCO3 product was deposited on the outside surface of the CaO grain. For sol-gel CaO, the carbonation reaction is limited by the availability of useful porosity for the growth of CaCO3 product (confinement effect), instead of by the diffusion of ions in the critical layer of the CaCO3 product. No surface product layer was observed. Therefore, fabricating nano-CaO having dimensions less than the critical thickness of the CaCO3 layer (~90 nm) is of potentially great significance if it can be done cheaply and in bulk.