Characterization and Comparison of Cellulose Extraction from Ginger Stalk by Two Different Chemical Treatments

Agricultural residues are important renewable biomass resources that have not received much research attention. Ginger stalk is a major agricultural waste in China.The extraction of cellulose from ginger stalk would convert this waste into a high value-added product and, simultaneously, contribute to environmental protection. This research studied the characteristics of cellulose extracted from ginger stalk by two different treatments:(i) potassium hydroxide(KOH) treatment and(ii) nitric acid-ethanol(NAE) treatment. The optimal condition for the KOH treatment was obtained, it was at 1∶30 solidto-liquid ratio(SLR) for 5 h extraction time with 14 wt% KOH. The optimal condition for the NAE treatment was as follows: 1∶40 SLR, 4 h extraction time, and a reaction temperature of 90℃. However, the cellulose obtained by NAE treatment was severely degraded than that by KOH treatment. The Fourier-transform infrared(FT-IR) spectroscopy analyses revealed that both treatments successfully dissolved the lignin and hemicellulose. Two treatments showed a higher cellulose yield, and the extracted cellulose had more crystal structure.

Agricultural residues are important renewable biomass resources that have not received much research attention. Ginger stalk is a major agricultural waste in China.The extraction of cellulose from ginger stalk would convert this waste into a high value-added product and, simultaneously, contribute to environmental protection. This research studied the characteristics of cellulose extracted from ginger stalk by two different treatments： （i） potassium hydroxide （KOH） treatment and （ii） nitric acid-ethanol （NAE） treatment. The optimal condition for the KOH treatment was obtained, it was at 1 ： 30 solid- to-liquid ratio （SLR） for 5 h extraction time with 14 wt% KOH. The optimal condition for the NAE treatment was as follows： 1 ： 40 SLR, 4 h extraction time, and a reaction temperature of 90~C. However, the cellulose obtained by NAE treatment was severely degraded than that by KOH treatment. The Fourier-transform infrared （FT-IR） spectroscopy analyses revealed that both treatments successfully dissolved the lignin and hemicellulose. Two treatments showed a higher cellulose yield, and the extracted cellulose had more crystal structure.