Studies On Preparation Of Activated Carbon From Waste Textile Fibers By Molten Salt And Evaluation Of Their Performance

Reuse and recycle of waste textile fibers have been a significant topic in current society. Taking advantage of this important resource, waste textile fibers, can not only reduce environmental pollution, but also save lots of resources. It corresponds to national strategies of sustainable development and low-carbon economy. Herein, we focus on waste textile fibers reusing technology, and employ a new molten salt method to convert waste textile into activated carbon materials, which can be performed good adsorption or high capacity. This study will build a practical and theoretical foundation on the waste textile fibers recycling and resuing. The main contents and results of this thesis are listed as follow:(1) Microcrystalline cellulose powder(Mccp) was used as testing reagent to investigate the effect of experimental facts including temperature, the weight ratio of Mccp to Na NO3 and molten salts, heating treat time on structrure, composition and performance of prepared carbon in the static air atmosphere, and their absorption performance was evaluated by absorbing mythlene blue soltuion. The results show that the optimum condition is temperature of 400 degrees Celsius, the weight ratio of1:0.5:10, and time of 2.0 h. The best yield of carbon is 29.13%, and the maximal adsorptive capacity for methylene blue(MB) Qmax is 702.31mg/g. The adsorption dynamics and thermodynamics behavor of activated carbon demonstrate that adsorption process of Mccp-AC is a very complex spontaneous exothermic reaction,and physical and chemical adsorption both exist. The kinetic adsorption behavior seems to correspond to pseudo-second-order model.(2) Waste cotton cloth was used as precursor to be converted into activated carbon(cotton-AC) with molten salt method. The effect of temperature, the weight ratio of waste-cotton to Na NO3 and molten salts, and reaction time on the structure,surface composition, and specific surface area were investigated, and the electrochemical capacitive performance of the prepared cotton-AC in the inert atmosphere(N2) was tested to obtain the best condition. The best experimental condition for preparing cotton based activated carbon is temperature of 700 degreesCelsius, the weight ratio of 1:1:10, time of 60 min. XRD, SEM and FTIR results indicate the Cotton-AC is consist of a large amount of microcrystalline, and amorphous carbon with well-developed pore structure inside the activated carbon and amount functional groups on the surface. The BET surface area is as high as1304.5m2/g with pore volume of 2.42cm3/g. The specific capacitance of Cotton-AC is200.00F/g under the charge-discharge current density 250 m A/g and still remain83.34% when the current density increase to 10.0A/g. Moreover, the energy density is19.37Wh/kg and power density is 450 W/kg. After 1500 cycles of charge-discharging,the specific capacitance retention is 90%.(3) Lastly, primary investigation of four kinds of different fibers precursors,including polyester, polyester-cotton, wool and ramie, were carried out to prepare different activated carbon at the same condition. The results show specific capacitance of polyester-AC, polyester-cotton-AC, wool-AC and ramie-AC are 276.38F/g,256.67F/g, 355.83F/g and 236.1F/g, respectively.