The Effect of Clay Insulator Use on Corn Cob Carbonization Reactor Heat Loss

Abstract

Carbonization is a highly energy-intensive process for converting biomass into solid fuel, especially in conventional systems without heat insulators. During the process, heat losses are unavoidable; thus, it is vital for utilizing insulators to minimize the losses. Clay, a naturally abundant and inexpensive material, could be used as an insulator. The corn cob carbonization process is carried out using a used oil drum as a carbonization kilns (reactor), with 200 L capacity and 1.25 mm thickness, by adding a Y-shaped pipe with a diameter of 100 mm in the center of it. The testing procedure involved coating one drum with a 1.5 cm clay insulator and leaving the other drum uninsulated. Each drum was then filled with 21 kg of dried corn cobs. A type K thermocouple is attached to the reactor's side wall and cover, and then connected to a Graphtec type GL240 datalogger for automated temperature measurement and recording. The study and analysis showed that in the absence of insulators, heat losses due to radiation and convection reached 3611.94 W (55.64%) during a 220-minute charcoal production (carbonization process). Meanwhile, when an insulator was used, the heat loss was reduced to 2320.69 W (35.75%) during the 170-minute charcoal production (carbonization process). Therefore, the utilization of clay insulators can result in 14.89% reduced heat losses and 22.73% shorter carbonization time.