Abstract
The control of low-concentration VOCs in coal-fired flue gas is one of the research hotspots at present. In this work, K2CO3 and K2CO3-KCl were employed to activate the agricultural wastes (pistachio nut shell) to prepare activated carbon (AC), named PSAC-1 and PSAC-2, respectively. By testing the adsorption performance of the prepared AC and commercial activated carbon (CAC) for the five target VOCs, it was observed that the adsorption capacity of PSAC-2 was the best compared to the other two. Particularly, the adsorption capacity of PSAC-2 (225 mg·g-1) for phenol was 3.8 times that of CAC (59 mg·g-1). In addition, the pseudo-first-order model, pseudo-second-order model, and Elovich model all fitted the adsorption process well, which indicated that both physical adsorption and chemical adsorption existed simultaneously, in which physical adsorption played a dominant role and chemical adsorption played a minor role. Weber-Morris kinetic model was used to illustrate the rate-controlling mechanism; the results confirmed that the stage of external membrane mass transfer was the control stage of adsorption rate. The results of this study can provide some references for the commercial production of biomass-derived AC and the removal of VOCs in coal-fired flue gas.
Highlights
With the continuous development of China's economy and the improvement of urbanization, VOCs emissions will continue to grow nationwide, "Fourteenth Five-Year" period, air quality to further improve, VOCs prevention is one of the "protagonists"
It is found that K2CO3 was never been used in producing pistachio shell Activated carbon (AC), the pistachio shell AC was not applied to the control of low concentration VOCs in coal-fired flue gas, either
The adsorption of micropores occurs within the range of 0 ~ 0.4 relative pressure, hysteresis loops due to capillary condensation can be observed in the range of 0.4 ~ 1.0 (Fig. 2a), this illustrates that CAC has the adsorption characteristics of mesoporous pores
Summary
Abstract: The control of low concentration VOCs in coal flue gas is one of the research hotspots at present. Activated carbon (AC) is often used as adsorbent for the control of VOCs due to its rich pore structure and thermal stability. By comparing the differences in pore size structure and functional groups between biomass AC and commercial AC, it was found that biomass AC had better properties. The adsorption performance of different ACs on low concentration VOCs was tested at low-medium temperatures. It is concluded that biomass AC has excellent adsorption performance, and its maximum adsorption capacity can reach 3.8 times that of commercial AC. All the three adsorption kinetic models had good fitting on the adsorption process of ACs, indicating that physical adsorption is dominant in the adsorption process, while chemical adsorption existed. Using the Weber-Morris kinetic model to fit the adsorption process, it was found that the stage of external membrane mass transfer is the control stage of adsorption rate
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
