硝酸改性褐煤半焦制备烟气脱硫剂

在硝酸质量分数分别为25%,45%和65%条件下改性褐煤半焦,制备出了烟气二氧化硫吸附剂,并在固定床反应装置上模拟烟气组成进行了脱硫活性测试。利用工业分析、元素分析、酸碱滴定和孔隙结构测定等分别对硝酸改性褐煤半焦制备的烟气脱硫剂工业组成、元素组成、表面酸碱性以及表面积、孔容等进行分析和表证。实验结果表明:随着硝酸对褐煤半焦的改性,制备的改性半焦烟气脱硫剂脱硫活性有所提高;硝酸处理造成半焦挥发分即含氧基团和含氮基团增加,导致表面酸性上升;改性半焦表面积和孔容的增加是二氧化硫脱除硫容提高的主要原因。

The SO2 Adsorbent Prepared by the Oxidation with HNO3 from Lignite Semi-Coke

The modified semi-coke desulfurization adsorbents were prepared from lignite semi-coke by oxidation of HNO3 at concentration of 25%,45% and 65%.The SO2 removal capacities for modified semi-coke adsorbents were test in a fixed bed reactor.The composition,surface acid-base properties and pore structure for semi-coke and modified semi-coke samples were characterized by means of proximate analysis,elemental analysis,acid-base titration and N2 isothermal adsorption/temperature-programmed desorption methods.The experiments have shown that the HNO3 modification can promote the SO2 removal capacity for modified semi-coke adsorbents;The HNO3 modification for semi-coke results in the formation of oxygen-containing groups and nitrogen-containing groups,and the rise of surface acid content;The surface area and micro-pore volume on modified semi-coke play an important role in the process of removal SO2.