eprintid: 14983 rev_number: 2 eprint_status: archive userid: 1 dir: disk0/00/01/49/83 datestamp: 2023-11-10 03:29:34 lastmod: 2023-11-10 03:29:34 status_changed: 2023-11-10 01:58:19 type: article metadata_visibility: show creators_name: Fong, K.K. creators_name: Tan, I.S. creators_name: Foo, H.C.Y. creators_name: Lam, M.K. creators_name: Tiong, A.C.Y. creators_name: Lim, S. title: Optimization and evaluation of reduced graphene oxide hydrogel composite as a demulsifier for heavy crude oil-in-water emulsion ispublished: pub keywords: Alkalinity; Crude oil; Demulsification; Efficiency; Emulsification; Emulsions; Hydrogels; Produced Water; Reduced Graphene Oxide, Alkaline conditions; Demulsification efficiency; Environmental-friendly; Heavy crude oil; Hydrogel composites; Interfacial interaction; Kappa carrageenan; Polyethyleneimine, Graphene note: cited By 8 abstract: The rising production of produced water from oilfields had been proven to bring detrimental environmental effects. In this study, an efficient, recyclable, and environmental-friendly reduced graphene oxide immobilized κ-Carrageenan hydrogel composite (κCaGO) was fabricated as an alternative sorbent for crude oil-in-water demulsification. Polyethyleneimine (PEI) was employed to form a stable hydrogel composite. The conditions for the immobilization of graphene oxide (GO) on PEI-modified κ-Carrageenan (κC) beads were optimized appropriately. An immobilization yield of 77 was attained at 2 PEI, 2 h immobilization activation time, and pH 6.5. Moreover, the synthesized κCaGO is capable of demulsification with an average demulsification efficiency of 70. It was found that the demulsification efficiency increases with salinity and κCaGO dosage, and it deteriorates under alkaline condition. These phenomena can be attributed to the interfacial interactions between κCaGO and the emulsion. Furthermore, the κCaGO can be recycled to use for up to six cycles without significant leaching and degradation. As such, the synthesized κCaGO could be further developed as a potential sorbent substitute for the separation of crude oil from produced water. © 2020 Chemical Industry and Engineering Society of China date: 2021 publisher: Materials China official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103935652&doi=10.1016%2fj.cjche.2020.08.027&partnerID=40&md5=6598672857abc3e3cb74163448a2198d id_number: 10.1016/j.cjche.2020.08.027 full_text_status: none publication: Chinese Journal of Chemical Engineering volume: 33 pagerange: 297-305 refereed: TRUE issn: 10049541 citation: Fong, K.K. and Tan, I.S. and Foo, H.C.Y. and Lam, M.K. and Tiong, A.C.Y. and Lim, S. (2021) Optimization and evaluation of reduced graphene oxide hydrogel composite as a demulsifier for heavy crude oil-in-water emulsion. Chinese Journal of Chemical Engineering, 33. pp. 297-305. ISSN 10049541