【作者】 李丽娟；

【导师】 李彦旭；

【作者基本信息】 广东工业大学 ， 环境工程， 2007， 硕士

【摘要】 目前，广东省有为数众多的企业在生产过程中排出大量含苯系有机废气，其采用的废气处理方法大多是活性炭吸附法，由于活性炭在使用中受到吸附容量、再生、成本、操作等诸多因素的制约，使企业迫切需要新型的废气处理工艺及方法。而在我国山西、陕西、内蒙、贵州等这些贫油富煤的省份蕴藏着大量的弱粘结性煤，其居民煤气工程多采用直立炉造气，副产大量半焦，这些半焦堆积如山，严重污染环境。因此，从环境与洁净煤技术利用角度考虑，亟待开发利用这些半焦的新思路和新产品。本课题在综述国内外文献的基础上，以我国工业半焦为原料来制备有机废气吸附剂，着眼于改进活性半焦的制备工艺，提高其对有机废气的吸附性能。实验所选原料半焦分别来自于陕西神木和山西大同，采用不同浓度的HNO₃、H₂O₂在不同温度下对原料半焦进行活化，以及负载表面活性剂进行深度活化和改性，共制备出30余种活性半焦。利用固定床反应器进行活性评价，研究了改性温度、空速对有机废气吸附性能的影响；借助物性参数测定与结构表征，研究影响活性半焦吸附有机废气的内在因素；考察了活性半焦制备过程中不同酸洗浓度以及活化工艺参数对所得活性半焦吸附有机废气性能的影响结果。固定床活性评价结果表明：原料半焦是吸附剂吸附性能的决定因素，比表面积和孔容较大、挥发份含量较低的半焦适宜制备有机废气吸附剂。10～20目的大同半焦用30％的硝酸浸泡，在20℃的恒温振荡器中振荡24h，水洗干燥后制备的活性半焦对甲苯的吸附性能较原料半焦有显著的提高。且在空速为2000h^-1时对甲苯的吸附性能最佳。实验结果进一步表明：高温浸泡改性的半焦对甲苯的吸附活性改善较好，故对半焦进行高温处理是提高其对甲苯吸附活性必不可少的步骤之一。制备改性半焦吸附剂的最佳实验条件是将10～20目的大同半焦用45％的硝酸在80℃的恒温水浴锅中浸泡24h，再用蒸馏水洗至清洗液的pH值与蒸馏水的pH值基本一致。洗涤完后放入110℃烘箱中干燥至恒重。该条件下制备的半焦吸附剂对甲苯的吸附容量达到50.29g甲苯／100gC。更多还原

【Abstract】 At present, there are a large number of enterprises discharging great amount of benzene organic exhaust gas in the course of production in Guangdong province. These enterprises usually use activated carbon adsorption to treat organic exhaust gas. But now they are crying for some new-style treatments and technology, because a good many matters restrict activated carbon, such as adsorption capacity, regeneration, cost, manipulation, etc. And that many provinces hold great amount of feebleness felt coal in store in our country, though they have not too much oil. People there generally adopt erective kilns to produce coal gas, at the same time produce a great deal of semi-coke. Mass semi-coke piled up look as if mountains, which is serious pollution for environment. Therefore, thinking over environment and clean coal technology, we must seek ask for some new method and production to make use of semi-coke.On the basis of national and international literature summarization, this thesis focus on the preparation methods of activated semi-coke in order to increase adsorption capacity for toluene organic exhaust gas. In this experiment, two kinds of raw semi-coke are selected, that is ShenMu semi-coke from ShanXi province and DaTong semi-coke from ShanXi province. After pre-activation they are modified with HNO₃ and H₂O₂ at the condition of differently concentration and temperature, as well as loaded surface active agent. And about thirty samples of activated semi-cokes are prepared. The fixed-bed reactor is used to test adsorption property and study the influence of temperature and space velocity on toluene adsorption effect. By means of the measurements of physical property and structure, the effect factor of activated semi-coke adsorption is investigated. Furthermore the effects of different acid washing concentration as well as the factors of activation process on the adsorption properties of obtained activated semi-coke were studied.Through evaluation of toluene adsorption properties, it is concluded that: the raw material is the decisive factor of toluene adsorption property. The semi-coke which has larger specific surface area, pore and lower volatility is propitious to be modified as toluene sorbent. The DaTong raw semi-coke samples need to be crushed into 10～20 mesh and then, they are activated by soaking 30% nitric acid and vibration at normal temperature for 24 hours, after washing and drying the sample is a super activated semi-coke with high toluene adsorption capacity and long breakthrough time. Besides the optimal space velocity is 2000h^-1.Results of our experiments show:Through soaking at higher temperature, activated semi-coke gain high performance toluene adsorption, so which is considered to be the absolutely necessary step to improve toluene adsorption.The optimum conditions for preparation of activated semi-coke are: 10-20 mesh DaTong semi-coke soaked by 45% nitric acid , temperature 80℃, 24 hours and then washed and drying. The toluene capacity of the adsorbent is 50.29g toluene/100gC.更多还原