液化石油气水蒸气重整镍催化剂新型载体研究

This work aims at exploiting a kind of catalyst as a substitute of imported catalyst for LPG steam reforming. The Ni based catalysts were prepared by impregnation of nickel nitrate solutions on four kinds of supports respectively. Support SA was prepared by co-precipitation from a mixture of the solutions of Na2SiO3·6H2O and Al(NO3)3·9H2O by means of a solution of NH4·H2O at 343 K and pH=6.5. Support AS was prepared in different precipitation sequence compared with support SA. Support MC’s were prepared with modified natural mineral as raw materials. MC-1 was calcined at 1 100 ℃ and MC-2 at 900 ℃. The LPG steam reforming reactions were carried out at atmosphere in a continuous -flow type fixed-bed reactor. The effects of supports on steam reforming activity are investigated. X-ray Differaction (XRD), Thermal Gravity-Differential Thermal Gravity (TG-DTG) and Transmission Electron Microscope (TEM) are used to characterize the catalysts. The catalytic activity of the catalysts were studied at 750 ℃ and water/hydrocarbon=2.0. The results were as follows: the catalysts prepared in our lab have excellent activity for LPG steam reforming reaction compared to the traditional Ni/α-Al2O3 catalyst. The activity of Ni/SA catalyst was superior to others. Under the optimized experimental condition, 100% conversion and 94.46% selectivity were obtained. Support SA calcined at 1300℃ was mainly composed of α-Al2O3　and Si2Al6O13 crystal. The precipitation sequence of supports significantly affected the catalyst activity. The catalyst prepared with Si-Al precipitation sequence is better than that of Al-Si sequence.