Transforming Cotton Gin Trash to Engineered Functional Carbon Structures

Abstract This paper investigates the carbonization of cotton gin trash (CGT) into carbon structures shaped under the influence of different operating conditions including the impact of endogenous fatty acids impurities present in CGT. As expected, both KOH activation and high carbonization temperature increase the material surface area and porosity. Furan and arene groups are formed from 400 °C to 800 °C but the proportion of the furan groups are highest at 600 °C. This is due to the conversion of the fatty acids in CGT to furan units. XRD data reveals the presence of three aromatic layers at 400 °C, followed by structural rearrangement to the formation of five stacks aromatic layers at 800 °C consisting mainly of protonated and non‐protonated condensed arene groups. Interestingly, a reduction in the number of aromatic structures is observed if no acid pretreatment of CGT to remove inorganic impurities is conducted prior to pyrolysis to 600 °C. Two potential applications of the synthesised carbons are shown; one for the formation of 5‐hydroxymethylfurfural (80%) from fructose, which compares favorably to other porous carbon materials produced under harsher conditions, and another derived CGT carbon material which shows a good uptake of hydrogen for storage.