Decomposition of NO_x Precursors during Gasification of Wet and Dried Pig Manures and Their Composts over Ni-based Catalysts

摘要

Catalytic decomposition of NO_x precursors during gasification of wet and dried pig manures and their composts was investigated over a commercial Ni/Al_2O_3 and nickel loaded on Loy Yang brown coal char (Ni/LYBCC) in a two-stage fixed-bed reactor. A substantial amount of NH_3 (0.52 wt 96, wet basis) was emitted during the dehydration of wet pig manure (WPM). During WPM pyrolysis, the nitrogen in volatiles was mainly converted to NH_3, nitrogen in tar, and N_2. The Ni-based catalysts are active for removing all the NO_x precursors from pyrolysis of wet and dried livestock wastes at 650 ℃. However, the moisture emitted during WPM pyrolysis can promote Ni/LYBCC gasification, causing the catalyst deactivation for NH_3 decomposition. The possible nitrogen transformation routes for WPM gasification are also discussed in this work. Such an approach may lead to the development of a clean livestock waste gasification technology.