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Calcium looping is techno-economically feasible for industrial CO 2 reduction. Carbide slag as a waste from the PVC (polyvinyl chloride) industry is a good candidate for low-cost calcium-based CO 2 sorbents. A novel synthetic sorbent with rich mesopores was fabricated from high alumina cement, carbide slag, and byproduct of biodiesel, in order to overcome the loss in CO 2 capture capacity of calcium-based sorbents with the number of carbonation/calcination cycles. The CO 2 capture capacities of synthetic sorbents were examined under the severe calcination condition of high CO 2 concentration and high temperature, which is close to the actual atmosphere for industrial applications. The effects of high alumina cement addition, byproduct of biodiesel addition, calcination condition, and steam addition in carbonation atmosphere on CO 2 capture by the synthetic sorbents were also discussed. Results show that the synthetic sorbent with 90 wt % CaO achieves the highest CO 2 capture capacity of about 0.27 g/g after 30 cycles under the realistic calcination condition, which is 1.7 times higher than that of carbide slag. N 2 physisorption measurement reveals typical mesoporous structure in the synthetic sorbent with 90 wt % CaO and large amounts of pores in the range of 10−100 nm are maintained over 10 cycles. C 12 A 7 (Ca 12 Al 14 O 33 ) and C 2 AS (Ca 2 Al 2 SiO 7 ) are found in the synthetic sorbent, which are uniformly distributed as the pore skeleton between CaO grains. The combining effect of the mesoporous structure and stabilization of pores over the repeated cycles is responsible for the high CO 2 capture capacity of the synthetic sorbent. The synthesized mesoporous CO 2 sorbent appears promising for the implementation of the cost-effective CO 2 capture technique.

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