Production of 5′-hydroxymethylfurfural by the hydrothermal treatment of cotton fabric wastes using a pilot-plant scale flow reactor

We developed a hydrothermal pilot-plant scale flow reactor, which enables the continuous treatment of both a glucose solution and a cotton-containing fabric waste slurry at the liter-per-hour scale. The mechanical characteristics of the pilot-plant scale flow reactor were examined using two different reactor volume sizes of 441 mL and 2685 mL. The cotton fabric wastes pretreated with cellulase were subjected to hydrothermal treatment. The hydrothermal system using the larger size flow reactor enabled for the first time the continuous treatment of cotton-containing slurry wastes to produce 5′-hydroxymethylfurfural (HMF) at 200–235 °C. The HMF yield reached 21.3% using glucose and 7.9% using cotton fabric waste, and only a limited number of byproducts were observed. This study elucidated that it is possible to scale-up a hydrothermal flow reactor to a practical scale beyond that used for laboratory experiments.