Abstract:
Cotton Gin waste is a potential feedstock for production of several compounds since it is rich in
cellulose. The objective of present work was to isolate cellulose from Cotton Gin Waste (CGW)
followed by conversion into Cellulose Acetate. CGW was collected from the industry and
washed at 80°C water for 15-20 minutes to remove all kinds of dirt, seeds and particulates.
Alkali Treatment was carried out with 10% Sodium Hydroxide solution (by volume) at 80 °C for
1.5 hours to remove waxes. Bleaching was performed with 5% Hydrogen Peroxide (H2O2) and
6% Sodium Hydroxide (NaOH) for 1 hour at 70 °C water to remove lignin. Acid treatment was
done with 10% sulfuric acid for 1 hour at 80 °C. Fine cellulose powder was isolated and
characterized by standard methods. 2.5 grams of cellulose was mixed with 36 mL
dichloromethane, 0.5 mL acetic acid, 5 mL acetyl chloride and 1 mL sulfuric acid in a 250 ml
flask. The mixture was heated in a reflux assembly at 75 ᵒC. The mixture was then filtered
through a sieve to remove non-soluble solids. These solids were mixed with 60 mL chloroform
and mixed for 30 minutes. The mixture was passed through a sieve. Both filtrates were mixed for
15 minutes and filtered through a Whatman filter paper 42. The filtrate was evaporated at 65 ᵒC
and cellulose acetate was formed on the surface of the beaker. FTIR (Fourier Transform Infrared
Spectroscopy) was performed to confirm the formation of desired product. Out of 2.5 grams of
cellulose powder, only 0.5 grams of cellulose acetate was produced and conversion efficiency
was 20%. The overall conversion of CGW to cellulose powder was roughly 50% (by weight)
while that of CGW to cellulose acetate was roughly 10%. There is further need for process
optimization to increase the efficiency and economy of the procedure.
