Journal of Analytical and Applied Pyrolysis, 18 (1990) 127-141 zyxwvutsrqponmlkjihgfedcbaZYXWVU Elsevier Science Publishers B.V., Amsterdam 127 zyxwvutsrqp AN INVESTIGATION OF THE FACTORS CONTROLLING THE PYROLYSIS PRODUCT YIELD OF GREEK WOOD BIOMASS IN A FLUIDIZED BED M.C. SAMOLADA *, T. STOICOS and I.A. VASALOS Chemical Process Engineering Research Institute, Department of Chemical Engineering, Aristotelian University of Thessaloniki, P.O. Box 19517, 540 06 University City, Thessaloniki (Greece) (Received January 10, 1990; accepted May 4, 1990) ABSTRACT Pyrolysis of Greek fir wood samples in a fluidized bed reactor was studied. The experi- mental conditions selected control the yield of gaseous, liquid and solid products. The factors examined were: pyrolysis temperature, mean particle size, pressure, residence time of vola- tiles, lignin content of biomass and moisture content. The experiments were performed on the basis of a 12-run Plackett-Burman fractional factorial design. Statistical analysis of the data showed that the pyrolysis temperature is the main factor affecting the distribution of the yields of liquids, their phenolic fraction and gases in the range of experimental conditions tested. Empirical expressions were obtained from linear regression giving the yields of liquids, phenols and gases in terms of temperature. The maximum predicted yields were 56 and 12 wt.% on a moisture-free basis at 520 and 545 o C for liquids and phenols, respectively. The yield of gases increased proportionally with temperature. Fluidized bed; gases; liquids; phenols; pyrolysis; wood biomass. INTRODUCTION Biomass is a renewable energy resource and has attracted research interest in the development of new techniques for producing valuable chemicals and fuels, especially after the last energy crisis of the 1970s. The term biomass can refer to every product or byproduct derived from photosynthesis. Most interest is in byproduct utilization, for which energy recovery is the main upgrading objective. Greece is not a country with an abundant production of wood. Wood biomass amounts to 20% of the total biomass production. However, consid- erable amounts of wood residues, 348000 dry t/ year [l], originating from thinning and finishing operations of wood, constitute a significant source of 0165-2370/ 90/ $03.50 0 1990 - Elsevier Science Publishers B.V.