Influence of Impregnation Medium on the Adsorptive Performance of Silica Sulfuric Acid for the Removal of Gaseous o-Xylene: Comparison on Ethyl Acetate and Water

Reactive Adsorption of Gaseous Anisole by MCM–41-Supported Sulfuric Acid

To achieve the efficient resource treatment of aromatic volatile organic compounds (VOCs) of high toxicity, this work chose anisole as a representative pollutant and investigated its removal by an MCM–41-supported sulfuric acid (SSA/MCM–41) adsorbent. The results indicate that the SSA/MCM–41 adsorbent exhibited a reactive temperature range of 110–140 °C, in which the anisole removal ratio (Xa) was greater than 95%. The collected breakthrough adsorption data fit the dose–response model. In the comprehensive analysis of the process conditions, reducing the flow rate enhanced the theoretical breakthrough time and adsorption capacity (tB,th and QB,th), while reducing the inlet concentration or raising the bed height resulted in a first increasing and then slightly decreasing trend in the QB,th. As a result, the highest tB,th and QB,th were 73.82 min and 247.56 mg g−1, respectively. The FTIR and 1H/13C NMR results demonstrate that the adsorbed products included both 4-methoxybenzenesulfonic acid and 1-methoxy-4-(4-methoxyphenyl)sulfonylbenzene. Accordingly, the mechanism of reactive adsorption was proposed. Meanwhile, the spent SSA/MCM–41 could be desorbed and regenerated for cyclic reuse. It is believed that the results obtained will assist in promoting the application of the novel gas–solid adsorption approach in VOC treatment.

Reactive Adsorption Performance and Behavior of Gaseous Cumene on MCM-41 Supported Sulfuric Acid

Efficient removal of cumene from gaseous streams and recovery of its derivatives was accomplished using a MCM-41-supported sulfuric acid (SSA/MCM-41) adsorbent. The results indicated that the removal performance of the SSA/MCM-41 for cumene was significantly influenced by the process conditions such as bed temperature, inlet concentration, bed height, and flow rate. The dose–response model could perfectly describe the collected breakthrough adsorption data. The SSA/MCM-41 adsorbent exhibited a reactive temperature region of 120–170 °C, in which the cumene removal ratios (X_c) were greater than 97%. Rising the bed height or reducing the flow rate enhanced the theoretical adsorption performance metrics, such as theoretical breakthrough time (t_B,th) and theoretical breakthrough adsorption capacity (Q_B,th), whereas increasing the inlet concentration resulted in t_B,th shortening and Q_B,th rising. As demonstrated in this paper, the highest t_B,th and Q_B,th were 69.60 min and 324.50 mg g⁻¹, respectively. Meanwhile, the spent SSA/MCM-41 could be desorbed and regenerated for cyclic reuse. Moreover, two recoverable adsorbed products, 4-isopropylbenzenesulfonic acid and 4, 4′-sulfonyl bis(isopropyl-benzene), were successfully separated and identified using FTIR and ¹H/¹³C NMR characterization. Accordingly, the relevance of a reactive adsorption mechanism was confirmed. This study suggests that the SSA/MCM-41 has remarkable potential for application as an adsorbent for the resource treatment of cumene pollutants.