The Preparation Of Modified Tobacco Char Based On Low Temperture Plasma And Its Application To Injurant Removal From Flue Gas

China is one of the main tobacco producing country around the world. The annual output of tobacco is over three million tons, in which over one million reject production could not be made as cigarette. Most of these reject tobacco will be discarded or burned which lead to not only resource wasting but also environmental pollution. Injurant removal from flue gas technology by activated carbon has been widely used, As the quantity of activated carbon needed increased, the application of reject tobacco is a meaningful method for activated carbon preparation. Consider the high manufacturing cost of activated carbon, the biomass char which had similar properties as activated carbon but lower cost has received increasing interest in recent years. But the adsorption property of biomass char is poor than the activated carbon. There are many methods were applied into the enhancement adsorption property of biomass char, but are also high-cost. Low temperature plasma technology indicates lots of advantages in changing properties and also cost less in manufacturing. So, this master program will include the preparation of tobacco char using reject tobacco, applied low temperature plasma technology for improving the properties of the tobacco char and the application research of the tobacco char in flue gas harm reduction.First, the physicochemical properties analysis was introduced to the stem and tobacco leaf with different organization from different producing area (Industry analysis, element analysis, XRF analysis, Thermo gravimetric analysis, FTIR analysis and so on), to ensure the wide application of my experiment method for tobacco. The research results indicate the small physicochemical properties difference among these stems or leaves. The difference between stem and leaf could be ignored by contrast to the other biomass.In order to study the impact of pyrolysis conditions on the adsorption properties of tobacco chars, the tobacco were pyrolyzed at 400?,600? and 800? for 10min,20min and 30min. The surface morphology, proe structure and surface chemical composition were tested. The results showed, the specific surface area of chars which pyrolyzed at different conditions has no improvement compared with other biomass chars. While the specific surface area of the chars pyrolyzed at 600? for 30min has a maximum of 1.14m2/g, and they also can not be used as a adsorbents. The impact mechanism of the forming of chars pore structure need more study to make it a rich pore structure.The content of Ca in the tobacco is higher and Ca has an import influence on the formation of chars pore structure. Therefore, through investigating the effect of different presence forms of Ca on the chars pore structure to study the mechanism of the effect of the pore structure formation The study showed that Ca in the tobacco has little effect on the chars pore structure. But the external Ca(NO3)2 and CaCl2 have a significant role in promoting the development of pore structure, and the promotion effect is direct proportion to the concentration of Ca. The promotion of CaCl2 is stronger than that of Ca(No3)2. In pyrolysis reaction, Ca reacts to form carbonates which result in clogging the abundant pore in the surface of the tobacco. So as the specific surface area of the tobacco char is very small, and the tobacco char need washing by acid before it is used as adsorbents.The tobacco char which was pyrolyzed for 60min under 800? was modified with glow low temperature plasma. The influence of modified atmosphere and modification time to the adsorption properties of tobacco char was analyzed. The results showed that low temperature plasma modification would decrease the surface area and increase surface functional groups(C=O, COOH, C=C)of tobacco char, and the longer the modification time is, the more the surface area decreases, while the functional groups content increases first and then decreases. The effect of the modification atmosphere on the specific surface area is relatively small, but it has a great influence on the surface functional groups, the functional groups content of modified char in nitrogen atmosphere was the most, followed by oxyge and air.Though adding the modified tobacco char in the cigarette filter, the removal characteristics ofPAHs in the cigarette smoke and Hg0 in the fixed bed which exhaust fume in the simulative power are studied. Results showed that the addition of modified char in the filter tip has an effect on the removal of PAHs, The elimination works best near the entrance of smoke. Under the co-action of physical and chemical adsorption, the removal rate of most PAHs components decreases firstly and increases later with modification time. The removal rate is highest at 10mins and lowest at 30mins. The removal effect of PAHs in oxygen is higher than that in air. The removal rate of Hg0 increases significantly after tobacco char modification The amount of mercury removal decreases firstly and increases later with modification time, influenced by the pore structure and oxygen functional groups. The modification effect is best when the time reaches 5 minutes. The removal of Hg0 is obviously influenced by the modification atmosphere. Modification char in mercury removal works best under nitrogen atmosphere, followed by oxygen and air.