载体对加压浸渍法制备的锌基脱硫剂的影响分析

Impact analysis of support to Zn-based desulfurizer prepared by high-pressure impregnation method

以4A分子筛(4A),γ-Al2O3(AL),活性炭(AC)和半焦(SC)4种物质作为载体,硝酸锌为活性组分前驱体,采用加压浸渍法制备了系列负载型氧化锌精脱硫剂。借助XRD、BET和固定床脱硫性能测试等手段对负载型氧化锌精脱硫剂的物性参数及其脱硫性能进行了系统的研究。结果显示,载体的种类影响吸附剂中活性组分的成分,进而影响到吸附剂的硫化行为(HZ20/AC>HZ20/SC>HZ20/4A>HZ20/AL)、吸附剂的机械强度和热稳定性(HZ20/SC>HZ20/AC>HZ20/AL>HZ20/4A);加压浸渍法可在将组分浸渍到载体上的同时改变载体的孔隙结构,其中HZ20/SC的孔隙结构得到明显的改善(比表面积和孔容分别增大为原料半焦的13.78和5.17倍),而其它3种吸附剂孔隙结构都较载体本身变差,半焦是实验用4种载体中最适合于加压浸渍法制备脱硫剂用的载体;利用半焦做载体制备出的脱硫剂具有高的脱硫精度和硫容,且具有很好的抗粉化性能,其最佳脱硫效率、硫容和穿透时间分别可达99.97%,4.46 g和23 h。

A series of Zn-based sorbents were prepared by the high-pressure impregnation method with four different supports of 4A zeolite（4A）,γ-Al2O3（AL）,activated carbon（AC） and semi-coke（SC）.By XRD,BET and fixed-bed desulfurization performance testing methods,the physical properties and the desulfurization performances of zinc oxide sorbents were studied.The results show that the support type affects the desulfurization behavior（HZ20/ACHZ20/SCHZ20/4AHZ20/AL）,the mechanical strength and thermal stability（HZ20/SCHZ20/ACHZ20/AL HZ20/4A） through the properties of the active component composition on different supports.The high-pressure impregnation method can impregnate active components onto the support and simultaneously change pore structure of the support.The pore structure of HZ20/SC are obviously improved,and its surface area and pore volume are 13.78 and 5.17 times as big as that of raw SC respectively.But the pore structure of the other three sorbents becomes worse.The semi-coke is one of the optimum supports in this preparing method.The ZnO sorbent prepared using semi-coke as support by the high-pressure impregnation method has high precision,big sulfur capacity and good anti-pulverization performance.The HZ20/SC sorbent has the desulfurization efficiency,sulfur capacity and breakthrough time of 99.97%,4.46 g and 23 h.