ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of valence of copper on adsorption of dimethyl sulfide from liquid hydrocarbon streams on activated bentonite

Huan Huang, De-Zhi Yi, Yan-Nan Lu, Xiao-Lin Wu, Yun-Peng Bai, Xuan Meng, and Li Shi

The State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China

E-mail: yyshi@ecust.edu.cn

Abstract: Samples of activated bentonite and activated bentonite modified with CuCl and CuCl₂, separately, were tested as dimethyl sulfide (DMS) adsorbents. The adsorption and desorption behaviours of DMS on the adsorbents were studied systematically. The adsorbents were characterised by nitrogen adsorption, XRD, and DMS-TPD tests. The addition of CuCl and CuCl₂ to the activated carbon significantly enhanced the adsorption capacity of DMS, despite a notable decrease in the specific surface area and total pore volume of the activated bentonite. It is presumed that copper cation species may act as an adsorption site for DMS. The adsorption capacity of Cu(II)-bentonite was better than that of Cu(I)-bentonite. The DMS-TPD patterns indicate that the stronger electrophilicity of Cu(II) compared to that of Cu(I) caused it to interact with the DMS molecules more strongly, thus contributing to a better adsorptive performance. The Cu(II)-bentonite calcined at 150°C had the best DMS removal performance with a high sulphur capacity of 70.56 mg S g⁻¹ adsorbent. The DMS removal performance became much lower with the increase in the calcination temperature, which appeared to be due to the decrease in the CuCl₂·2H₂O phase and the formation of the monoclinic Cu(OH)Cl phase.

Keywords: valence – copper – adsorption – dimethyl sulfide – bentonite

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0408-7

Chemical Papers 68 (1) 98–104 (2014)