Study Preparation Process Of Activated Carbon From Corpus Amygdaloideum

In this study, in order to make a full use of almond shell, which is formed duringprocessing almond kernel in food industry, almond shell was subjected to pyrolysis to prepareliquid products (pyroligneous acid and wood tar), gas (combustible wood gas), and solidproduct (charcoal). The resultant shell charcoal was then mixed with potassium hydroxide(powder or solution) and zinc chloride to prepare activated carbon. Relative parameters of theactivated carbon such as methylene blue adsorption value, iodine adsorption value andspecific surface area were measured. Pore size distributions were examined by the methods ofBJH, T-plot diagram, and adsorption-desorption isotherm equation. Optimal conditions tomake activated carbon with excellent performance were investigated by orthogonalexperiment. Activated carbons prepared by different methods were then examined in the viewof the adsorption capability of chromium (VI) and lead (II) ions. The results were reported asfollows.1. To prepare activated carbon with potassium hydroxide powder, the optimal conditionswere to mix the almond shell charcoal particle (0.9mm) with potassium hydroxide powderwith a ratio of3, and to heat the mixture at temperature of800C for3hours. The specificsurface area of the resultant activated carbon was2675m2/g, and the iodine adsorption valuewas2183.96mg/g, and the methlene blue adsorption value was586.26mg/g.2. To prepare activated carbon with potassium hydroxide solution, the optimal conditionswere to immerse the almond shell charcoal particle in the solution with a concentration of60%and with a ratio of the charcoal to the solution of2, and to heat the mixture at thetemperature of900C for2hours. The specific surface area of the resultant activated carbonwas1567.53m~2/g, and the iodine adsorption value was1488.28mg/g, and the methlene blueadsorption value was453.81mg/g.3. To prepare activated carbon with zinc chloride, the optimal conditions were toimmerse the almond shell charcoal particle in the zinc chloride solution with a concentrationof60%and with a ratio of the charcoal to the solution of2, and to heat the mixture at thetemperature of600C for1hour. The specific surface area of the resultant activated carbon was1137.28m~2/g, and the iodine adsorption value was1100.12mg/g, and the methlene blueadsorption value was210.18mg/g.4. Adsorption capabilities of the activated carbon obtained by the method of thepotassium hydroxides solution immersion to chromium (VI) and lead (II) ions were examinedin the views of pH, amount of the carbon added, adsorption time, initial concentration of theions. The results showed that adsorption amount of the activated carbon to chromium (VI)and lead ions were119.05mg/g and71.43mg/g, respectively. The linear correlationcoefficient of isothermal equation of the former was R~2=0.9987, and R~2=0.9965for thelatter.