Characteristics of hydrochar and hydrothermal liquid products from hydrothermal carbonization of corncob

Abstract

© 2017, Springer-Verlag GmbH Germany. Corncob (CC) was converted to renewable fuel resource by hydrothermal carbonization (HTC). HTC was performed by varying process temperature (160–200 °C), residence time (1–3 h), and biomass to water ratio (BTW) (1:5 to 1:15). The properties of hydrochar were significantly enhanced where the fixed carbon and carbon content of hydrochar increased at about 24.9 and 83.7% from original contents in CC, respectively. The calorific values and yield of hydrochar were between 19.3–23.5 MJ/kg and 50.1–58.6%. The optimal condition for the production of hydrochar as solid fuel was determined at 200 °C, 3 h residence time, and BTW of 1:5 with maximum energy yield of 68.74%. In addition, hydrothermal liquid was characterized where volatile fatty acid, furfural, furfuryl alcohol, and hydroxymethylfurfural were the most abundant compositions with their highest yields of 17.3, 11.5, 7.9, and 5.1%, respectively. Process temperature was the most influencing variable on product properties and characteristics. The results suggested that corncob has high potential as a source for solid fuel and valuable platform chemicals.