A novel calcium looping (CaL) process integrated with a spent bleaching clay (SBC) treatment is proposed whereby fuels and/or heat from regeneration of SBC provide supplemental energy for the calcination process; in addition, the regenerated SBC could be used to synthesize enhanced CaO-based sorbents. Composite samples were prepared with various doping ratios together with the regenerated SBC via a pelletization process. All pellets were subjected to thermogravimetic analysis (TGA) tests employing severe reaction conditions to determine the optimal doping ratios and regeneration method for the SBC-based sorbents. These results demonstrate that pellets containing combustible components showed higher CO 2 uptake, due to the improved pore structure, which was verified by N 2 adsorption measurements. The as-prepared sorbent "L-10PC" (90% CaO/10% pyrolytic SBC) achieved a final CO 2 uptake of 0.164 g(CO 2) g(calcined sorbent)-1 after 20 cycles, which was 67.3% higher than that of natural limestone particles. A new larnite (Ca 2 SiO 4) phase was detected by XRD analysis; however, the weak XRD peak associated with it indicated a low content of larnite in the pellets, which produced a smaller effect on performance compared to cement. A synergistic effect was achieved for a sample designated as "L-5PC-10CA" (85% CaO/5% pyrolytic SBC/10% cement), which resulted in the highest final uptake of 0.208 g(CO 2) g(calcined sorbent)-1. Considering the simplicity of the pyrolysis regeneration process and the excellent capture capability of pellets doped with pyrolytic SBC, the proposed system integrating CaL with SBC pyrolysis treatment appears to be promising for further development.

Synthetic biomass-templated cement-supported CaO-based sorbents were produced by granulation process for high-temperature post-combustion CO 2 capture. Commercial flour was used as the biomass and served as a templating agent. The investigation of porosity showed that the pellets with biomass or cement resulted in enhancement of porosity. Four types of sorbents containing varying proportions of biomass and cement were subject to 20 cycles in a TGA under different calcination conditions. After first series of tests calcined at 850°C in 100% N 2 , all composite sorbents clearly exhibited higher CO 2 capture activity compared to untreated limestone with exception of sorbents doped by seawater. The biomass-templated cement-supported pellets exhibited the highest CO 2 capture level of 46.5% relative to 20.8% for raw limestone after 20 cycles. However, the observed enhancement in performance was substantially reduced under 950°C calcination condition. Considering the fact that both sorbents supported by cement exhibited relatively high conversion with a maximum value of 19.5%, cement promoted sorbents appear to be better at resisting of harsh calcination conditions. Although flour as biomass-templated material generated significantly enhancement in CO 2 capture capacity, further exploration must be carried out to find the way of maintaining outstanding performance for CaO-based sorbents under severe reaction conditions.

Steam hydration was used to reactivate spent cement‐supported CO2 sorbent pellets for recycle. The effect of steam hydration on the reactivity of sorbents was investigated in a bubbling fluidized reactor. A specially designed impact apparatus was developed to evaluate the strength of the reactivated pellets as well as determine the effect of ‘superheating’. It was found that the reactivity of synthetic pellets was elevated significantly over that of raw limestone after steam hydration. The CaO conversion of spent pellets increased from 0.113 to 0.419 after hydration, whereas that of spent limestone ranged from 0.089 to 0.278. The CaO conversions of hydrated samples calcined under different conditions achieved the identical level, proportional to the degree of hydration. As expected, the mechanical strength of synthetic pellets declined severely after reactivation. Large cracks emerged on hydrated limestone as seen in scanning electron microscope images. By contrast, similar cracks were not observed for synthetic pellets after hydration, although hydration did produce higher porosity than seen with limestone and an increased surface area, which enhanced CO2 capacity and was associated with an increase in strength loss. The breakage rate of superheated, steam‐reactivated limestone‐derived pellets was about half that of hydrated samples. This demonstrates that superheating treatment (which allows the annealing of stacking faults and mechanical strain produced by hydration) could enhance the strength of hydrated pellets. This work demonstrated that combining steam hydration with superheating can both reactivate the spent synthetic pellets and reduce strength decay associated with the hydration process. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

A system incorporating spent bleaching clay (SBC) into the calcium looping (CaL) process has been proposed. In this paper, prepared sorbents doped with regenerated SBC and cement were tested in a bubbling fluidized bed (BFB) to examine in detail their cyclic CO 2 capture capacity and attrition properties. The results revealed that the cyclic CO 2 capture capacity of pellets modified by pyrolyzed SBC and/or cement showed significantly better performance than limestone, which is consistent with the thermogravimetric analyzer (TGA) results. This is due to the improvement of pore structure and enhanced sintering resistance created by adding support materials to the sorbent. The elutriation rates of the composites prepared with pyrolyzed SBC and/or cement were consistently lower than for crushed limestone. Scanning electron microscopy (SEM) images indicated that the pellets possessed higher sphericity than limestone particles, thus reducing surface abrasion. Limestone exhibited a high attrition rate (diameter reduction rate) of 10.7 μm/cycle, which could be eliminated effectively by adding regenerated SBC and/or cement. 'L-5PC-10CA' (85% lime/5% pyrolyzed SBC/10% cement) exhibited an attrition rate of only 7.9 μm/cycle. Based on the analysis of breakage and probability density function (PDF) for particle size distribution, it appeared that pellets without cement experienced breakage (mostly chipping and disintegration) and surface abrasion, whereas 'L-10CA' (90% lime/10% cement) and 'L-5PC-10CA' mainly suffered surface abrasion, combined with some chipping. C

A novel bacterium, designated strain DL503, was isolated from a Daqu sample and its taxonomic position determined using a polyphasic taxonomy. Strain DL503 was a Gram-stain-negative, facultatively anaerobic, non-sporulating, motile and coccoid-rod-shaped bacterium. Optimum growth occurred at 20-45 °C, pH 5.0-10.0 and 1.5 % (w/v) NaCl. Comparative analysis of the 16S rRNA gene sequence showed that the isolate belongs to the genus Franconibacter, showing highest levels of similarity with respect to Franconibacter pulveris JCM 16471 (98.94 %) and Franconibacter helveticus DSM 18396 (98.39 %). Cells contained the quinones Q-8 and MK-8, and the polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, three unidentified polar lipids and three unidentified amino lipids. The DNA G+C content was 53.3 mol% and the major fatty acids were C16 : 0, C17 : 0 cyclo, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), summed feature 4 (C17 : 1 iso I and/or C17 : 1 anteiso B) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The DNA-DNA relatedness values between strain DL503 and its close relatives, including F. pulveris JCM 16471 and F. helveticus DSM 18396, were 51.5±0.5 % and 45.2±1.1 %, respectively. Based on phylogenetic analysis, phenotypic and genotypic data, it is concluded that the isolate represents a novel species of the genus Franconibacter, for which the name Franconibacter daqui sp. nov. is proposed. The type strain is DL503 (=LMG 29914=CGMCC 1.15944).