褐煤基活性焦的制备及脱硝应用

Preparation and Denitration Application of Lignite Base Activated Coke

针对褐煤低热值、高灰高水含量、低附加值的特点,采用高温水蒸气活化试验制备了褐煤基活性焦。试验得出最佳活化工艺条件为:活化温度850℃、水蒸气通入量1.0 kg/(kg.h)、活化时间2h,此时活性焦的碘吸附值达到500 mg/g以上,烧失率为34%,在相同活化条件下,脱灰褐煤活性焦比原褐煤活性焦具有更高的碘吸附值。活性焦经3种不同质量分数10%、20%、30%硝酸铜溶液浸渍、煅烧后,制备的选择性催化还原法(SCR)脱硝催化剂在20 min内具有较高的脱硝率,活性焦脱硝率均能达到80%以上,符合工业化要求。

According to the features of low calorific value, high ash and high moisture contents and low additional value of the lignite, a high temperature steam activated experiment was applied to prepare the lignite base activated coke.An optimal activated technical condition obtained from the experiment was activated temperature of 850 ℃ ,steam flow quantity of 1.0 kg/（ kg · h） and activated time of 2 h.Under this condition, an iodine adsorption value of the activated coke was over 500 mg/g,the ignition lost rate was 34% and under the same activated condition, the activated coke of the de-ash lignite would have a higher iodine adsorption value than the activated coke of the raw lignite.After the immersion in an copper nitrate solution with three different quantity fraction of 10% ,20% and 30% and calcinations for the activated coke, the prepared SCR denitration catalyst would have a high denitration rate within 20 min and the denitration rate of the activa- ted coke all could be over 80% and could meet the industrial requirements.