Fuel gas production and nitrogen transformation during pig manure pyrolysis from room temperature to 900 degrees C are investigated. The catalytic decomposition of the derived volatiles is also studied. Ammonia, HCN and N-2 were obtained as the main N-containing gases. Ammonia was mainly emitted below 700 degrees C, which corresponds to 24.8 wt% of the nitrogen in the manure. Hydrogen cyanide and N-2 gases obviously formed at temperatures above 700 C, while the HCN concentration was as low as one ninth that of NH3 and one fifth of the concentration of nitrogen even at 900 degrees C. Thermal cracking of the pyrolysis volatiles produced little NH3, but noticeably increased HCN formation. When the prepared nickel-loaded brown coal char (LY-Ni) was added to the second part of the reactor (second stage) as a catalyst, most of the N-containing species in the volatiles converted into N-2 gas. It suggests that LY-Ni has high catalytic activity for the conversion of N-containing compounds. Significant quantities of light fuel gases (H-2, CO and CH4) were also generated. Compared with sand, 5.8 times (H-2 and CO) the amount of gases was produced with the LY-Ni char at 650 degrees C. Decomposition of the manure volatiles depends on the catalyst temperature. Total product gases approximately doubled in yield when the catalyst temperature increased from 450 to 550 degrees C, and the volatiles conversion (based on carbon balance of the manure volatiles) increased from 72.4 wt% to 92.0 wt%. At 600 -700 degrees C, the volatiles conversions stabilized at high levels of 96.7-98.2 wt%. (C) 2013 Elsevier Ltd. All rights reserved.