Efficient Removal of Siloxane from Biogas by Using β-Cyclodextrin-Modified Reduced Graphene Oxide Aerogels

Abstract

In this study, β-cyclodextrin-modified reduced graphene oxide aerogels (β-CD-rGOAs) were synthesized via a one-step hydrothermal method and were used to remove hexamethyldisiloxane (L2) from biogas. The β-CD-rGOAs were characterized by the Brunner–Emmet–Teller technique, using Fourier-transform infrared spectroscopy, Raman spectrometry, scanning electron microscopy (SEM), contact angle measurements, and X-ray diffraction. The results of the characterizations indicate that β-CD was grafted onto the surface of rGOAs as a cross-linking modifier. The β-CD-rGOA had a three-dimensional, cross-linked porous structure. The maximum breakthrough adsorption capacity of L2 on β-CD-rGOA at 273 K was 111.8 mg g−1. A low inlet concentration and bed temperature facilitated the adsorption of L2. Moreover, the β-CD-rGOA was regenerated by annealing at 80 °C, which renders this a promising material for removing L2 from biogas.

Removal of Hexamethyldisiloxane by NaOH–Activated Porous Carbons Produced from Coconut Shells

“…When evaluating the quality of an adsorbent, it is also important to consider the stable regeneration capacity of the adsorbent in addition to its adsorption capacity [8]. Therefore, repeated regeneration experiments were performed using saturated L2 APC-4 by heating it at 100 • C for 100 min, then reusing it as an adsorbent for L2 adsorption at the same conditions at a C in of 83.82 mg L −1 , V g of 50 mL min −1 and bed temperature of 20 • C. Figure 6 presents each cycle's Q B,th and t B,th values.…”

“…The dose-response model was used to simulate the measured dynamic data to investigate the adsorbent's removal performance for L2. Adsorption breakthrough curves are often described using this model, which can be represented by the following Equation (8).…”

“…VMS can be removed from biogas environments using various methods, including adsorption [7][8][9], absorption [10], cryogenics [11], biological and membrane separation [12]. Adsorption has become one of the most widely investigated and effective methods of removing VMS due to its high efficiency, economic feasibility, and ease of operation [13].…”