Yields and Heating Values of Liquids and Chars from Spruce Trunkbark Pyrolysis

Experiments were designed to investigate the effects of both the heating rate and temperature of pyrolysis on liquid product and charcoal yields. The temperature was maintained at 550, 600, 650, 700, 750, and 800 K, while the heating rates were 2, 5, 10, 20, 40, and 100 K/s. The maximum liquid product yield of 35.2% was obtained at a final pyrolysis temperature of 700 K. It was concluded that both the temperature and heating rate had a significant effect on both yield of liquid product and charcoal resulting from pyrolysis of beech trunkbark. The yield of liquid product increases from 23.4 to 27.3% for 2 K/s run and it increases from 30.5 to 35.2% for 100 K/s run as the final temperature was raised from 550 to 700 K. The yield of charcoal decreases from 66.8 to 49.6% for 2 K/s run and it decreases from 52.7 to 37.8% for 100 K/s run as the final temperature was raised from 550 to 800 K. The higher heating values (HHVs) of liquid products increase from 26 to 29 MJ/kg for 2 K/s run and it increases from 30 to 35 MJ/J for 100 K/s run as the final temperature was raised from 550 to 750 K. The HHVs increase with increasing both the heating rate and the pyrolysis temperature up to 750 K. The HHVs of charcoals increase from 23 to 29 MJ/kg for 2 K/s run and from 26 to 35 MJ/J for 100 K/s run as the final temperature was raised from 550 to 800 K.