热煤气一体化净化工艺中的脱硫反应特征

利用固定床反应器考察了高温煤气脱硫除尘一体化净化工艺中沉积粉尘对高温煤气脱硫剂脱硫性能的影响.结果表明,表面沉积粉尘对脱硫剂初次硫化行为有明显的影响,且与脱硫剂的组成和结构有关.利用钢厂赤泥制备的脱硫剂,含有多种惰性杂质,且具有较大的孔径结构,易于和粗煤气中的粉尘作用,造成脱硫剂硫容的减小.硫化气氛中,H2O的存在造成脱硫剂硫容和脱硫效率的降低,但不会影响因表面沉积粉尘造成的脱硫剂硫容的减小.多次硫化-再生循环实验表明,硫化-再生循环过程有助于减小表面沉积粉尘对脱硫剂脱硫行为的影响.经历一定次数的硫化-再生循环后,粉尘对脱硫剂脱硫行为的影响逐渐消失.

HIGH TEMPERATURE DESULFURIZATION CHARACTERISTICS IN THE SIMULTANEOUS SULFUR AND DUST REMOVAL PROCESS

The combined process for simultaneous desulfurization and dust removal is promising for hot gas cleaning because of its more compact process and lower cost. The understanding of desulfurization characteristics is the key to develop the combined processes due to the influence of deposited dust on desulfurization performance of sorbents. In this work, the interaction of sorbents with deposited dust was investigated in a fix-bed reactor. The results show that the influence is related with the composition and textural properties of sorbents. The sorbent based on an iron oxide waste material could interact with the deposited dust causing the decrease of sulfur capacity due to the various components and large pore size. The presence of H_2O in the reactant gas could deteriorate the desulfurization performance of sorbent, but it could not weaken the negative influence of deposited dust on the sulfur capacity of sorbent. The sulfidation/regeneration cycles are further conducted to evaluate the influence. It is found that the influence became negligible after several cycles. The BET surface area, pore volume and SEM surface morphology of sorbents are also measured to investigate the mechanisms.