STEAM GASIFICATION OF ALMOND SHELLS IN A FLUIDIZED-BED REACTOR - THE INFLUENCE OF TEMPERATURE AND PARTICLE-SIZE ON PRODUCT YIELD AND DISTRIBUTION

The steam gasification of ground almond shells has been carried out in a continuous, bench scale, fluidised bed reactor in order to evaluate the effects of particle size and operating temperature on the product yield and distribution. The mean particle size was varied from nearly 300 mu m to over 1 mm and the bed temperature from 600 to 800 degrees C. The results reveal that for smaller particle sizes differences in product yield and distribution practically disappear as the higher tem perature bound is approached, whereas for particles above 1 mm in diam eter the yield continues to increase over the entire temperature range , never reaching that attained by the smaller particle systems. This b ehaviour is indicative of the increasing significance of extra- and/or intra-particle heat transfer limitations with increasing particle siz e. (C) 1997 Elsevier Science Ltd.