Microwave-assisted acid pre-treatment of Cyperus rotundus for cellulose enhancement Agung Cahyono (a*), Mujaroh Khotimah (b)
a) Agriculture and Biosystems Engineering Study Program, Biosystems Engineering Department, Faculty of Agricultural Technology, Universitas Brawijaya, Malang, Indonesia 65145 *agungc[at]ub.ac.id
b) Environmental Engineering Study Program, Biosystems Engineering Department, Faculty of Agricultural Technology, Universitas Brawijaya, Malang, Indonesia 65145
Abstract
This study explored the use of microwave irradiation and sulfuric acid to enhance the cellulose and hemicellulose contents of Cyperus rotundus, a potential bioethanol feedstock. A completely randomized design (CRD) with two factors, H2SO4 concentration and microwave heating time, was applied. 10 grams of Cyperus rotundus powder (100 mesh) were soaked in 100 mL of distilled water and sulfuric acid (98%) with concentrations of 1%, 1.5%, 3%, and 4.5% (v/v), then exposed to microwave radiation at 2450 MHz and 950 Watt for 25, 35, or 45 minutes. The cellulose, hemicellulose, and lignin contents were measured using the NREL method, and the lignocellulose microstructure was observed using Scanning Electron Microscopy. The optimal conditions were achieved with 1.5% (v/v) H2SO4 and 45 minutes of microwave irradiation, which increased the cellulose content of Cyperus rotundus powder from 22.91% to 43.62%. This study demonstrated the effectiveness of microwave-assisted acid pre-treatment for improving the bioethanol potential of Cyperus rotundus.
