Removal of Elemental Mercury Using Seaweed Biomass-Based Porous Carbons Prepared from Microwave Activation and H₂O₂ Modification

Abstract

In this article, two kinds of seaweed biomass-based porous carbons were prepared by a green and efficient method of microwave activation/H 2 O 2 synergistic modification from seaweed biomass resources. The Hg 0 capture performance of seaweedbased porous carbons was tested in a fixed-bed reactor system. The results show that microwave activation greatly increases the surface area of porous carbons. The porous carbons (S8W30 and E8W30) modified with 30% H 2 O 2 exhibit excellent Hg 0 removal capacity at 120 °C. NO, O 2 , and low concentrations of SO 2 in flue gas have a positive effect on the removal of Hg 0 . Water vapor and high concentrations of SO 2 exhibit a negative effect on the process of Hg 0 capture. The oxygen-containing functional groups (CO and C−OH/C−O−C groups) on the surface of the modified porous carbon, which are mainly produced by H 2 O 2 modification, are considered to be the main active sites for Hg 0 capture. The X-ray photoelectron spectroscopy (XPS) analysis shows that the adsorbed Hg 0 can be oxidized to Hg 2+ . The modified porous carbons exhibit good development and application prospects compared with commercial activated carbon (AC) or other activated carbons.

Clean Modification of Carbon-Based Materials Using Hydroxyl Radicals and Preliminary Study on Gaseous Elemental Mercury Removal

“…The XPS spectral changes of O 1s on the adsorbent surface before and after the Hg 0 adsorption are indicated in Figure b. The peak with 531.1 ± 0.7 eV belonged to lattice oxygen ([O]). , The peak with 532.1 ± 0.3 eV represents chemically adsorbed oxygen (O*). − The peak centered at 533.1 ± 0.4 eV corresponds to C–O . The peak with 534.2 ± 0.1 eV is considered to be O in H 2 O. ,, …”

“…In the past 3 decades, a series of Hg 0 remediation technologies, mainly containing already existing air pollutant controlling devices, adsorption capture, catalysis, traditional oxidation, and advanced oxidation, have been applied to remove of Hg 0 from coal-burning flue gas. − ,− Among various methods, adsorption capture is recognized as a promising Hg 0 capture technology because it possesses a simple process flow and lower requirements of devices and does not produce waste liquid. − Among various common adsorption materials, carbon materials (e.g., activated carbon, biomass carbon, etc.) are widely used porous materials for adsorbing Hg 0 in coal-burning flue gas as a result of the developed porous structure. , However, a lack of active sites on the carbon material surface impedes the large-scale application of these carbon materials in the gaseous Hg 0 capture field. , Common modification methods for carbon materials, such as acid/alkali, sulfide, halide, metal oxide, etc., have shortcomings, such as high energy consumption, extreme operating conditions, and/or secondary pollution .…”

Hg0 Removal by Straw Biochars Prepared with Clean Microwave/H2O2 Modification

“…), which can oxidize the adsorbed Hg 0 to Hg 2+ . Therefore, the Hg 0 capture process can be elucidated as follows [51][52][53][54][55][56][57][58]:…”

“…Supporting Information for this article can be found under DOI: 10.1002/ceat.202100009. This section includes additional references to primary literature relevant for this research [53][54][55][56][57][58].…”

Characteristic and Performance of Ni, Pt, and Pd Monometal and Ni-Pd Bimetal onto KOH Activated Carbon for Hydrotreatment of Castor Oil

“…Activated carbon is a viable choice as a support material due to its adjustable porosity, which can be controlled through various synthesis and preparation methods [25]. Chemicals such as H 3 PO 4 , H 2 O 2 , and Na 2 CO 3 are often used in activating the carbon material [26][27][28]. However, the utilization of KOH as the activation chemical in the chemical activation method offers notable advantages, as it has been experimentally proven to generate well-developed microporosity and a high surface area [29][30][31].…”