Construction of Calcium-Manganese Composite Desulfurizer for Synergistic Removal of SO2/Hg0
Under the carbon neutrality strategy, biomass boilers have emerged as key facilities for renewable energy utilization, yet are characterized by low-concentration SO2 emissions. Ca-based dry desulfurization presents a promising technology for biomass boiler flue gas purification due to its compact structure, low capital investment and simple operation and maintenance. However, it is generally limited by the low adsorbent utilization and insufficient desulfurization efficiency. Herein, this study developed a novel Ca-Mn composite adsorbent through a synergistic strategy integrating F127 surfactant to optimize dispersion and Mn loading to enhance oxidation efficiency. The resulting adsorbent not only significantly increased the breakthrough sulfur capacity of the Ca-based material but also markedly improved the synergistic removal of Hg0. It was demonstrated that the introduction of Mn elements and F127 effectively suppressed the agglomeration of Ca(OH)2 crystallites and induced an oxygen vacancy-rich structure, while simultaneously optimizing the pore structure of the adsorbent. The modified adsorbent exhibited the enlarged specific surface area and pore volume, which favored to enhance the reaction mass transfer and effectively prevent the pore blockage and coverage of active sites by desulfurization products. The Mn sites and oxygen vacancies formed catalytic centers, which not only accelerated the desulfurization reaction by promoting SO2 oxidation but also enabled the adsorbent to couple with Hg0 catalytic oxidation functionality. Consequently, the simultaneous removal of SO2 and Hg0 was significantly enhanced on the Ca-Mn composite adsorbent.