Hydrogen-rich syngas production by chemical looping reforming on crude wood vinegar using Ni-modified HY zeolite oxygen carrier

Abstract

The crude wood vinegar contained a large amount of water and a small amount of complex organic compounds, which was difficult to industrialize practically. An efficient oxygen carrier was prepared by Ni-modified HY zeolite (Ni/HY) to produce hydrogen-rich syngas by chemical looping reforming (CLR) on crude wood vinegar. The yield of gas, conversion efficiency, H2/CO, oxygen carrier structure and carbon deposition were investigated to obtain the optimal preparation of oxygen carrier and the optimal CLR performance. The results showed that HY zeolite was the most suitable carrier for CLR among five different molecular sieves. Compared with HY zeolites modified by different metallic oxides, Ni/HY had the highest H2 yield of 64.68%, gasification efficiency of 85.29% and structural characteristics. Further, water volume had a great impact on the CLR performance. The optimal water volume was + 15% with H2 yield of 68.4%, carbon conversion efficiency of 37.58% and gasification efficiency of 92.38%. Furthermore, the particle size of oxygen carrier increased with the increase of Ni loading. The best performance with gasification efficiency of 96.17% and carbon conversion efficiency of 39.41% could be obtained when the Ni loading was 20%.Moreover, the CO yield, gasification efficiency and carbon conversion efficiency gradually increased with temperature increasing. After CLR for the long-term reaction time, 900 °C was the best reaction temperature to achieve gasification efficiency of 107.29% and the lowest carbon deposition of 3.71%.