Hydrogen-rich syngas from wet municipal solid waste gasification using Ni/Waste marble powder catalyst promoted by transition metals

摘要

Gasification of wet municipal solid waste (MSW) coupled with in-situ CO_2 capture is an attractive option for MSW disposal, allowing chemical and energy recovery. In this study, the Ni-CaO based catalysts were prepared with waste marble powder (WMP) as an alternative to CaO and promoted by different transition metals (i.e., Fe, Cu, Co and Zn). The bimetallic catalysts were prepared by the impregnation method and characterized by different analytical techniques. The catalyst performance for wet MSW gasification was evaluated in a fixed-bed reactor at optimized conditions (850 °C and 50% moisture content of MSW). The results revealed that the addition of Ni-WMP catalyst greatly enhanced the dry gas yield (DGY), H_2 yield, carbon conversion efficiency (CCE) and reduced the tar content from 0.73 to 1.16 N.m~3Ag, 212 to 509 mL/g, 61.70% to 76.40% and 9.11 to 3.9 wt%, respectively, compared to without catalyst. In contrast to the Ni-WMP catalyst, the transition metal promoted catalysts showed higher catalytic activity towards H_2 yield (549-629 mL/g), DGY (1.19-1.30 N.m~3/ kg), and lower tar content (3.45-2.93 wt%). The results revealed that Co promoted bimetallic catalyst performed better than Fe, Cu and Zn promoted catalysts. The tar content produced was also analyzed via GC-MS (gas chromatography-mass spectrometry) to understand the effect of different catalysts on tar composition. According to experimental results, the bimetallic promoted catalysts can be ranked as Ni-Co-WMP ＞ Ni-Cu-WMP ＞ Ni-Fe-WMP ＞ Ni-Zn-WMP based on H_2 yield and tar removal.