炭基载体对超声加压浸渍法制备锌基脱硫剂中温硫化性能的影响

Influence of carbon-based support on desulfurization performance of Zn-based sorbents prepared by high-pressure impregnation under ultrasound-assistance

以活性炭(AC)、褐煤半焦(LSC)、烟煤半焦(BSC)和褐煤焦(LC)4种炭基材料作为载体,利用超声辅助加压浸渍法分别制备了氧化锌炭基系列中温煤气脱硫剂。借助固定床硫化反应测试装置、氮气吸附、XRD和SEM等手段对4种脱硫剂的脱硫性能、物相组成、比表面积和孔结构进行了测试和表征。结果表明,超声辅助加压浸渍法能够有效改善炭基材料的孔隙结构,加压水热处理后的褐煤半焦比表面积可增大为原来的11倍;炭基材料种类不会影响氧化锌炭基脱硫剂中活性组分的赋存形态,但直接影响活性组分的上载率及其在载体表面分散的均匀性,进而影响脱硫剂的中温硫化性能。褐煤半焦制备的脱硫剂Zn/LSC中较高的活性组分利用率和丰富的孔隙结构使其脱硫效果最佳,脱硫精度达到99.99%时的穿透时间和实际硫容分别达到11.0 h和5.17%。褐煤半焦孔结构最易于改性,是加压水热合成中温煤气脱硫剂的一种优良的载体材料,这也是资源相对丰富的褐煤有效利用的途径之一。

Zn-based sorbents were prepared by uploading Zn O particles on different carbon materials（ activated carbon,lignite semi-coke,bituminous semi-coke and lignite coke） using high-pressure impregnation under ultrasound-assistance. The physical properties, loading amounts of metal components and desulfurization performances were characterized by BET,XRD,SEMand fixed-bed reactor,respectively. The results showthat the high-pressure impregnation under ultrasound-assistance method has a great improvement on the physical structures of carbon-based supports,and the BET surface area of sorbent prepared by lignite semi-coke support increases by 11 times. The type of carbon support affects the desulfurization behavior through the loading and the uniform dispersion of active component on support. The higher availability of active component and abundant pore structures result in a good desulfurization performance for Zn / LSC sorbent, having the maximum desulfurization efficiency,sulfur capacity and breakthrough time of 99. 99%,5. 17% and 11. 0 h,respectively.The lignite semi-coke is much easier than other carbon-based materials to be modified,and could be well used as support materials for hydrothermally synthesizing sorbent by high-pressure impregnation under ultrasoundassistance.