The effect of relative feed of steam and the temperature of the activation process on the yield and quality of activated aspen charcoal
Aspen on wood supplies of deciduous species ranks the second place in Russia. Resources are not being used well, that is of interest to researchers at the present time. Purpose: to obtain active carbon (AC) on the basis of aspen wood with sufficiently high sorption characteristics. To do this, the necessary studies were carried out, in which the influence of the main factors of the activation process on the yield and quality of the AC produced was studied. For activation, a sample of industrial control, which corresponded to Russian standart 7657, was used. The control system was obtained from aspen wood on a modular pyrolysis-retort unit at a final pyrolysis temperature of 600°C. Conventional methods of analysis were used to determine the quality parameters of the AС.Mathematical methods of experiment planning were used to determine the regularities of activation processes. Of the many factors that affect the activation process, we have chosen three main ones: temperature ( X 1), specific water vapor consumption ( X 2) and the duration of the activation process ( X 3).The temperature of the activation process varied in the range of 760…820 C, the specific flow rate of water vapor was 1.3-1.8 kg/kg charcoal, the duration of activation varied from 90 to 120 minutes. As the response functions were taken: Y 1 - yield of AC (%); Y 2 - total pore volume (cm3/g); Y 3 - adsorption activity of iodine (%). The experiment allowed us to obtain regression equations adequately describing the influence of the main acting factors on the output and properties of the AC. The results obtained for the activation of aspen AC were compared with similar studies that were carried out on the activation of birch charcoal. As a result of the research it was determined that the output of AC from both aspen and birch is more influenced by the specific consumption of steam. The total pore volume of AC depends on the temperature and specific steam flow rate. While activating, the aspen control unit has a greater impact specific steam consumption. The aspen AC has an iodine activity rate of about 15-20% higher than the birch AC obtained under the same conditions.