城市污泥两段式催化热解制合成气研究

Two-stage catalytic pyrolysis of sewage sludge for syngas production

为了把城市污泥中温热解产生的挥发性产物转化为可直接利用的洁净可燃性气体或重要的化工原料合成气,采用两段式热解装置对城市污泥进行了催化热解实验研究,讨论了不同催化剂对城市污泥热解挥发性产物的催化裂解能力,结果表明:城市污泥在热解终温500℃,热解液产率最大,超过500℃,热解液产率减少,热解气增多,固相产率基本不变;城市污泥热解液的裂解温度需在900℃以上,产生的气体组分主要为H2、CO、CH4等小分子非冷凝性气体;Ni/分子筛复合催化剂对热解液转化为合成气的作用效果较好,合成气体(H2+CO)体积含量占气体总量的85%以上.

Syngas production from sewage sludge via a two-stage catalytic pyrolysis reactor was investigated, for further utilization of volatile products evolved during one-stage pyrolysis. In addition, the catalytic performance of different catalysts was studied. The results showed that the maximum liquid（aqueous and oil phase） yield was obtained at a final pyrolysis temperature of 500℃. Moreover, when the pyrolysis temperature was above 500℃, increasing gas yield and relative stable solid yield were observed. The further pyrolysis of liquid products could be achieved when the temperature was over 900℃, in which small-molecule non-condensable gases, mainly including H2, CO and CH4, were generated. The Ni/ molecular sieve catalyst seemed to be more effective at pyrolysis than other catalysts, and over 85% syngas（H2 ＋ CO） content could be obtained.