| The research on preparation of coal-based activated carbon was made in this thesis with the rich lignite resources in Yunnan province. This research in one hand made good use of the coal resource of Yunnan province to promote the social and economic progress, and in the other hand relieved the situation in the active carbon industry caused by the exhausted timber resources, which was significant to the protection and of environment and ecological balance.The preparation of active carbon with lignite carbocoal through extrusion was adopted in the technical process in this thesis. The carbonization of MILE lignite and the relationship between burn rate and carbonize time was studied at the temperature 400,500,600C respectively. The conclusion was that the burn rate increased with the temperature and the carbonization rate increased with the carbonization time. And it can be seen from the analysis of charcoal that the moisture content and volatile component had pronounced decreased, and the ash content, fixed carbon and sulphur content had a heavy increase. In order to the influences of temperature and the time on the physical and chemical properties of charcoal, the charcoal was determined according to the iodine value measurement with GB/T7702.7-1997. The iodine value increased slightly with the temperature and time. The optimal technical conditions were determined as the carbonization temperature 500 C, carbonization time 1.5 hours.In this research, the lignite carbocoal with size -100 mesh was granulated with the binder coal tar, amylum, wasted honey and cellulose, Then activated carbon can be obtained by activation with water vapor to applied to treat waste water. Researches were made with different conditions on the materials with coal tar as binder. Experiment results showed that under the conditions of activation temperature 700 C, activation time 4 hours, and the steam flow for 1088.39ml/min, the iodine value could reach 1136.39mg/g. Orthogonal experiments were made on the materials with cellulose as binder. The analyzing of the single-index results indicates that the steam flow was the major factor, and the activation temperature, time and carbonization time were also important factors. The iodine value would reach 775.37mg/g in the presenceof steam flow for 1200ml/min, at 650C with activating for 5 hours and carbonizing for 0.5 hour. Orthogonal researches were also made on materials with wasted honey as binder. And the multi-index analysis was made on the results, which showed the influence of factors on indexes. The overall-balance analysis of the research results indicated that the iodine value could be 891.91mg/g with steam flow for 1000ml/min at 600 C, and the activation and carbonization time 6 hours and 0.5 hour, respectively. Single-index standard deviation was made on the experiment results on materials with amylum as binder, which showed that under the conditions of steam flow 1200ml/min, at 650C and activating for 6 hours. The iodine value of the activated coal could be 729.39mg/g at the possibility of 99.9%, and be within 695.12 to 763.66mg/g at 95%.The properties of the products obtained with cellulose, honey and amylum as binders were not good as those with coal tar but these three binders caused no pollution, so they were very promising. This thesis only touched parts of the research, binders used in the future would be those which would contribute to the suspendable development.Based on the non-isothermal thermogravimetry of raw materials, the activation energy and frequency element of lignite were calculated through the two-stage-reaction model of pyrolysis. The activation energy and frequency element in the first temperature range were 47.37KJ/mol, 5.80x103, and those in the second temperature range were 152.74KJ/mol and 4.63x108. It can be seen from the activation energy that it was easy to pyrolysize at first, but with the evolution of volatile component, the high melting point ash contents increased and the activation energy that need in the polyrisis reactive also incr... |
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