Determination of calorific values of bio-chars and pyro-oils from pyrolysis of beech trunkbarks

In this study, the beech trunkbark was pyrolyzed to obtain bio-char and pyro-oil for determining their calorific values. Experiments were designed to investigate the effects of both the heating rate and temperature of pyrolysis on pyro-oil and bio-char yields and their characteristics. 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 pyro-oil yield of 34% was obtained at a final pyrolysis temperature of 750 K. It was concluded that both the temperature and heating rate had a significant effect on both yield of pyro-oil and bio-char resulting from pyrolysis of beech trunkbark. The yield of pyro-oil increases from 24 to 27% for 2 K/s run and it increases from 27 to 34% for 100 K/s run as the final temperature was raised from 550 to 800 K. The yield of bio-char decreases from 59 to 42% for 2 K/s run and it decreases from 43 to 29% for 100 K/s run as the final temperature was raised from 550 to 800 K. (C) 2004 Elsevier B.V. All rights reserved.