将脱硫石膏中废弃的CaSO4加以资源化利用，制备成钙基载氧体应用于化学链燃烧，具有原料易得、成本低廉和载氧率高的特点。以脱硫渣为原料，先进行提纯处理，根据课题组采用的模板-溶胶凝胶燃烧合成法制备CaSO4-CuO、CaSO4-Fe2O3、CaSO4-CuFe2O4混合载氧体。在高温固定床反应器上对这4种载氧体与煤进行了5次还原氧化循环试验，研究4种脱硫渣系列煤化学链的反应机理和硫释放规律。试验发现基于提纯后的脱硫渣，制备的脱硫渣-CuO反应活性明显提高，且负载CuO减少了含硫气体的释放；脱硫渣-Fe2O3提高了氧载体反应活性对煤气化的催化作用；脱硫渣-CuFe2O4混合载氧体提高了碳转化率，具有良好的反应活性和循环特性，应用于煤化学链燃烧完全可行；掺入Cu、Fe元素的脱硫渣载氧体，活性明显提高，但在多次循环过程中混合载氧体出现了部分烧结、失活现象；在脱硫渣混合载氧体与煤的副反应中，Cu、Fe元素表现出良好的固硫效果，其中脱硫渣-CuFe2O4混合载氧体与煤副反应中，释放的SO2气体体积分数峰值仅为37×10-6。

The waste CaSO4 from desulfurized gypsum is used as resource to prepare calcium-based oxygen carrier for chemical looping combustion, which has the characteristics of easy access to raw materials, low cost and high oxygen loading rate. The desulfurized slag was used as raw material, CaSO4-CuO, CaSO4-Fe2O3 and CaSO4-CuFe2O4 mixed oxygen carriers were prepared according to the template-sol-gel combustion synthesis method adopted by the research group. Five reduction and oxidation cycles of the four oxygen carriers and coal were carried out in a high temperature fixed bed reactor. Discovery of the reaction mechanism and sulfur release rule of coal chemical chain were studied in detail. The results show that the mixed oxygen carriers of desulfurized slag-CuO reaction activity is obviously improved, and the loaded CuO reduces the release of sulfur-containing gas. Desulfurized slag-Fe2O3 improves the reaction activity of the oxygen carrier. Desulfurized slag-CuFe2O4 mixed oxygen carriers increases the carbon conversion efficiency, has good reaction activity and circulation characteristics, and it is completely feasible to be used in coal chemical looping combustion. The activity of oxygen carrier of desulfurized slag mixed with Cu and Fe increases obviously, but the mixed oxygen carrier has partially sintered and deactivated during multiple cycles. In the side reaction of desulfurization slag mixed oxygen carrier and coal, Cu and Fe show good sulfur fixation effect, in the side reaction of desulfurized slag-CuFe2O4 mixed oxygen carrier and coal, the peak concentration of SO2 gas is only 37×10-6.

0 引言

1 试验

   1.1 脱硫渣的提纯

   1.2 载氧体的制备和燃料准备

   1.3 试验装置和步骤

   1.4 试验数据处理

2 试验结果与分析

   2.1 脱硫渣系列混合载氧体与煤的化学链燃烧特性

   2.2 副反应中硫的演化规律

   2.3 载氧体表征分析

3 结论