Comparative Studies Between Hydrothermal Carbonation and Torrefaction for Biofuel Production from Poultry Litter

Abstract

The results of comparative experiments on the production of biofuel from poultry litter (PL) by the method of low-temperature pyrolysis (Torrefaction) and hydrothermal carbonization are presented. Comparison of the obtained results shows that as a result of hydrothermal carbonation of PL (processing temperature 180-210 °C, treatment time 240 minutes), the carbon content in the manure can be increased by 1.35 times, and the oxygen content is reduced in 2.2 times, the lower heat of combustion of the fuel obtained, which is similar in its characteristics to lignites, can be increased by 1.25 times to 19.7 MJ/kg. As a result of low-temperature pyrolysis in the fluidized bed at a temperature of 300 °C in a nitrogen medium and superheated water vapor, the carbon content can be increased by 1.16 times, and the oxygen content is reduced in 2.8 times. The lowest heat of combustion of the fuel produced can be increase by 1.13 times to 18.8 MJ/kg. Considering that the technology of PL treatment by low-temperature pyrolysis in the fluidized bed requires significantly less processing time (360-480 seconds), this technology can be fully considered as an alternative to hydrothermal carbonization.