Gas adsorptive desulfurization of thiophene by spent coffee grounds-derived carbon optimized by response surface methodology: Isotherms and kinetics evaluation

• Published in: Journal of environmental chemical engineering 2020-10, Vol.8 (5), p.104036, Article 104036
• Main Authors: Aouled Mhemed, Hiba, Marin Gallego, Mylène, Largeau, Jean-François, Kordoghli, Sana, Zagrouba, Fethi, Tazerout, Mohand
• Format: Article
• Language: English
• Subjects: Chemical and Process Engineering; Chemical engineering; Chemical Sciences; Desulfurization; Engineering Sciences; RSM; Spent coffee grounds-derived carbon (SCG-AC); Thiophene
• ISSN: 2213-3437; 2213-3437; 2213-2929
• DOI: 10.1016/j.jece.2020.104036

•Activated carbon from spent coffee grounds (SCG-AC) was optimized through RSM.•The adsorptive desulfurization of thiophene was investigated by SCG-AC.•Thiophene removal from gas by SCG-AC was assessed at ambient conditions.•The adsorption of thiophene via SCG-AC followed the Langmuir–Freundlich isotherm.•The thiophene adsorption’s kinetic was described by the Elovich model. The elimination of sulfur compounds in the FCC gasoline is indispensable to protect downstream equipment. Researchers are trying to find technological innovations to produce the famous “zero sulfur” fuel. Many adsorbents, such as spent coffee grounds-derived carbon (SCG-AC), have been claimed to be effective in H2S removal. However, no study has been conducted to exploit its ability to eliminate the organo-sulfur compounds present in FCC gasoline such as thiophene. This work involves the optimization by the response surface methodology (RSM) of different operating conditions of activated carbon (AC) production by the chemical activation (H3PO4) of SCG. RSM was used to estimate the variables considered in the preparation of AC using the Box–Behnken Design (BBD). The optimized SCG-AC was used for the adsorption of thiophene through batch tests at ambient conditions. The equilibrium experimental data of the thiophene adsorption were analyzed by Langmuir, Freundlich, and Langmuir–Freundlich isotherms. The adsorption isotherm data fit the Langmuir–Freundlich isotherm where the adsorption’s kinetics were described by the Elovich model. The optimum SCG-AC exhibited the highest adsorption capacity, with up to 2.23 mmol/g. These results revealed that SCG-AC is a promising and economical adsorbent for the elimination of thiophenic sulfur compounds.