Abstract
To investigate the correlation and mechanism of inherent calcium species in coal on the preparation and performance of activated carbon (AC) when using flue gas activation. In this study, XCaCO3/AC (X means calcite contents in coal, 0–8 wt.%) was successfully produced by mixing different contents of calcite and demineralized Taixi coal and then using flue gas activation. The textual evolution and methylene blue (MB) removal of AC were conducted by a series of characterizations and tests, and revealed its mechanism. Coal with a high content of calcium could result in a low yield of AC. Calcite could transform into calcium oxide. During AC preparation by flue gas activation, calcium oxide also could react with CO2 and transform into calcium carbonate. Calcite in coal reduced the degree of AC's graphitization. The calcite in coal promotes the increment of CO, COO, and π-π* of AC linearly as the calcite content increases. Due to the excessive catalytic effect of calcite, high-content calcium could result in inferior porosity through promoting the collapse of pore topology. Calcite in coal strengthens the methylene blue (MB) removal capacity of AC. The 5CaCO3/AC possesses the utmost MB adsorption capacity, up to 118.8 mg/g, which is higher by 122.9% than AC of 53.3 mg/g. The various kinetics models were also verified and data was well matched to Pseudo second-order kinetics (R2=0.9165 for AC and R2=9729 for 3CaCO3/AC). Calcite in coal increases the content of CO and π–π* of AC, which strengthens chemical adsorption by functional groups complexation and π–π* stacking. Meanwhile, the existence of calcium species, OH− and CO32− is beneficial for ion exchange and complexation, respectively. Thus, the removal ability of MB by AC is enhanced. The results of this investigation could cast novel light on the high-performance AC design by utilization of high-calcium coal, and further multiple pollutants treatment.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
