煤质柱状活性炭的尿素改性及其乙炔氢氯化性能

Urea Modification of Columnar Coal Based Activated Carbon and Its Acetylene Hydrochlorination Performance

采用价格低廉的煤质柱状活性炭,分别通过硝酸和尿素液相浸渍后焙烧改性的方法,在活性炭的表面引入氧原子和氮原子,考察了氧和氮掺杂对乙炔氢氯化的影响。结果表明,硝酸改性后,活性炭的表面酸性基团大量增加,转化率及稳定性明显下降,而尿素改性的方法可成功地将氮掺入到活性炭的表面,氮掺杂量随焙烧温度的降低而提高,乙炔氢氯化活性随氮含量的增加而增加,和未改性的活性炭相比,其初始乙炔转化率从55%提高到70%,稳定性也得到了提高。

The effect of oxygen and nitrogen doping on the acetylene hydrochlorination was investigated by introducing the oxygen atom and nitrogen atom on the surface of the low-cost columnar coal based activated carbon by the method of impregnation of nitric acid or urea followed by calcinations.The results showed that the surface acid groups of activated carbon increased greatly after nitric acid modification,the conversion and stability decreased significantly.The method of urea modification could successfully incorporate nitrogen into the surface of activated carbon.The nitrogen doping amount increased with the decrease of calcination temperature,and the activity of acetylene hydrochlorination increased with the increase of nitrogen content.Compared with the unmodified activated carbon,the conversion of acetylene on nitrogen doped carbon was up to70%from55%with lower deactivation rate.