Preparation and Performance of Ni-Based Catalysts Supported on Ca_(12)Al_(14)0_(33) for Steam Reforming of Tar in Coke Oven Gas

摘要

The catalytic activities of the Ni-based catalysts with Ca_(12)Al_(14)O_(33) as carrier for the steam reforming of tar from coke oven gas were studied. The carriers were prepared with three methods, high temperature roasting (HTR), coprecipita-tion (CP) and sol-gel (SG), respectively. Compared to the catalyst with CP, the catalyst with HTR showed stronger peaks of NiO as well as Ca_(12)Al_(I4)O_(33),similar to the one with SG, and had obviously higher catalytic activity than those with CP and especially with Al_20_3 as carrier, just slightly lower than that with SG. When the calcination temperature was 1350°C (HTR-1350), the prepared catalyst showed the strongest peaks of Ca_(12)Al_(I4)O_(33)and NiO and the highest surface area, resulting in the excellent performance for tar reforming. For Ni/Mg-Ca_(12)Al_(I4)O_(33) catalyst with HTR-1350, the catalytic activity and stability were improved as the reforming temperature and the steam/carbon ratio (S/C) rose, and especially at 850°C and the S/C ratio of 12:1, the hydrogen yield can reach 93-16%, with the carbon conversion reaching 97.14%.