CO2 capture by calcium aluminate pellets in a small fluidized bed

Abstract

Synthetic pellets made using calcium aluminate cement and quicklime have been examined in a small fluidized bed reactor to determine their performance in cyclic CO2 capture for up to 20 calcination/capture cycles. Two batches were examined one a "fresh" batch, and the second an "aged" batch of pellets and their performance was compared with the original parent limestone. Carbonation was carried out at 650 ˚C and calcination at 900 ˚C, both with 15 % CO2, balance N2, as a synthetic flue gas.Experiments were also performed with and without steam in the flue gas and showed that steam always improved capture performance. In addition, there was no major attrition associated with the pellets, and pellets tended to perform better in terms of carbon capture than the parent limestone.

Catalytic Toluene Reforming with In Situ CO2 Capture via an Iron–Calcium Hybrid Absorbent for Promoted Hydrogen Production

“…Mechanical strengths of Ca–Al and Ca–Al–Fe were not only significantly promoted in comparison with Ca, but also competitive when comparing with the value (70.9 n ) of a core‐in‐shell CaO–cement absorbent in a previous study . The result of this work was consistent with a previous study which verified that Ca 12 Al 14 O 33 was favorable to enhance mechanical strength of Ca–Al absorbent . Moreover, the elevated mechanical strength of Ca–Al–Fe indicated that Ca 12 Al 14 O 33 was still efficient though this component experienced additional sol–gel processing by citric acid and further calcination at 900 °C in the secondary iron synthesis step (as shown in Figure ).…”

“…Stendardo et al verified the stability of CaO–Ca 12 Al 14 O 33 for capturing CO 2 under severe calcination condition (1000 °C, 85% CO 2 , and up to 200 cycles). Blamey et al revealed that attrition resistance of CaO–Ca 12 Al 14 O 33 was significantly improved in a small fluidized bed, comparing with CaO. The aforementioned researches provided useful reference for the enhancement of cyclic carbonation reactivity and mechanical strength of CaO‐based absorbent.…”

Promoted calcium looping H 2 production via catalytic reforming of polycyclic aromatic hydrocarbon using a synthesized CO 2 absorbent prepared by impregnation

“…All samples contained the basic compound CaO. In Ca‐Al and Fe/Ca‐Al absorbents, Ca 12 Al 14 O 33 was observed, which could be beneficial to enhance the multicycle CO 2 absorption and calcium‐based absorbents' mechanical strength 46,49 . Raman spectra with peaks at 1080 cm −1 (Figure S3) verified the existence of free oxygen (O 2 − ) and Ca 12 Al 14 O 33 in the two absorbents 64 .…”

“…The stability of the CaO–Ca 12 Al 14 O 33 absorbent under multicycle carbonation–calcination conditions has been verified by varying the mass ratios of CaO to Ca 12 Al 14 O 33 46,47 and under mild 46 or severe 48 calcination conditions. Meanwhile, the attrition resistance of CaO–Ca 12 Al 14 O 33 has been examined by fluidized bed tests, which reveal that the mechanical strength can be obviously promoted compared to conventional CaO 49 . The aforementioned research gave beneficial references for promoting the mechanical strength and cyclic CO 2 absorption stability of calcium‐based absorbents.…”

Acidification Optimization and Granulation of a Steel‐Slag‐Derived Sorbent for CO2 Capture

“…Further testing was performed on the steel‐slag‐derived sorbent obtained under the optimum acid pretreatment conditions (denoted CAS). Granulation of steel‐slag‐derived sorbent powder is necessary during practical CO 2 capture process, because the sorbent fines are easily elutriated from the CLP , . Therefore, cylindrical pellets, denoted CAS‐E, with a diameter of 1 mm were prepared by using an E25 extruder.…”