A green technology for the preparation of high capacitance rice husk-based activated carbon. (20th January 2016)

• Record Type: Journal Article
• Authors: Liu, Dechen; Zhang, Wenli; Lin, Haibo; Li, Yang; Lu, Haiyan; Wang, Yan
• Is Part Of: Journal of cleaner production. Volume 112:Part 1(2016:Jan.)
• Page Start: 1190
• Page End: 1198
• Publication Date: 2016-01-20
• Subjects: Green preparation technology -- Rice husk -- Activated carbon -- Supercapacitor -- Recycle; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2015.07.005
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Rice husk (RH) is a kind of biomass with huge amount in the world. Comprehensive utilization of RH is of great significance for a sustainable society. In this paper, a green technology to produce high capacitance rice husk-based activated carbon (RHC) was developed. High capacitance RHC was prepared by KOH activation of RH. The waste liquid produced in the washing procedure of RHC was transformed into nano-SiO2 by acidification with HCl. The KCl saline solution produced from the preparation of nano-SiO2 was used to obtain water via evaporation and prepare KOH via electrolysis. Importantly, the collected water and KOH was reused in this technology. The obtained RHC possessed a specific surface area as high as 3263 m 2 g −1, and exhibited a high specific capacitance of 330 F g −1 in 6 mol L −1 KOH aqueous solution. The nano-SiO2 was amorphous with average diameter of ∼30–40 nm. In addition, the economic analysis demonstrated a significant gross profit margin of 70.72% for the products. The technology is simple, feasible, low-cost and environmentally friendly for large-scale production. Highlights: A green preparation technology of rice husk based activated carbon was developed. RHC exhibits the highest specific capacitance of 330 F g −1 . The recycle of water and activating agent KOH was realized. A significant gross profit margin of 71.2% is estimated for the product. This technology reduces reagent, water consumption and eliminate pollution.