Preparation And Adsorptive Property Of Activated Carbon Fiber From Liquefied Poplar Bark

In this thesis, activated carbon fibers from liquefied poplar bark were prepared by phenol liquefaction, melt-spinning, curing, carbonization and steam activation. Pore structure and Cu (Ⅱ) ions adsorption capacities were investigated. Pseudo-first order and pseudo-second order kinetic models are applied in order to understand the adsorption kinetics of Cu (Ⅱ) ions. Main research and results are as follows:1. Precursor fibers were prepared from poplar bark. The ratio of bark/phenol, the process of spinning and curing were confirmed. The research from this thesis shows:(1) Liquefied bark should be prepared under the conditions as follow:the ratio of the bark/phenol (containing 5% phosphoric acid solution by weight) was 1:4 by weight, and the reaction time was 2 h by holding at 160 ℃ in oil bath. (2) Resultant fibers should be prepared under the conditions as follow:liquefied bark and HMTA (5%, based on the weight of liquefied bark) were mixed evenly. The mixture was heated from room temperature up to 150 ℃ within 40 min. The temperature was held for 10 min for the liquefied bark spinning solution. Spinning temperature was found during the next process of cooling. (3) Precursor fibers should be prepared under the conditions as follow:resultant fibers were cured by soaking in a solution containing hydrochloric acid and formaldehyde (volume ratio 30:37) as main components at 90 ℃ for 2 h at a heating rate of 15 ℃/h.2. The effect of carbonization temperature and activation temperature on pore structure of activated carbon fiber from liquefied bark were discussed. The research from this thesis shows:(1) Micropore development was dominated in samples with a ratio of 80%. The specific surface area reached a range from 594 m2/g to 1962 m2/g with an average pore diameter of approximately 2 nm to 3 nm. (2) Carbonization temperature and activation temperature play an important role in the formation of pore structure. Higher specific surface area was obtained as the activation temperature increased, especially between 800 ℃ to 900 ℃. Under low carbonization temperature, the pyrolysis of materials were more mild, lead to a severe reaction at high activation temperature.3. Cu (Ⅱ) ions adsorption capacities and adsorption kinetics of Cu (Ⅱ) ions were investigated. The research from this thesis shows:(1) The optimal adsorption condition of Cu (Ⅱ) ions by samples was: the sorbent dosage was 0.25 g, the concentration of Cu (Ⅱ) ions was 10 mg/L, and the adsorption time was 60 min. (2) The adsorption capacity of samples increased with the increasing of activation temperature. (3) The kinetic studies of samples revealed a better correlation with the pseudo-second order model, showing a good performance by the chemical adsorption.