Oxygen gasification and its syngas upgrading in a fluidized-bed reactor using sand mixed dairy manure

Low heating value dai,y manure, taken directly from a lagoon, was processed using a dryer and a drum sand separator to remove moisture and the sand used for bedding. After the pre-process, the ash content of the daiy manure was reduced from 71% to a minimum of 37%. Oxygen-enhanced gasification was the process chosen to generate high quality synthesis gas. This process limits the nitrogen (N₂) gas composition in the produced synthesis gas compared with the use of normal atmospheric air. Experiments were carried out to investigate the effects of oxygen content and temperature conditions on the syngas composition using a 2-inch diameter fluidized bed reactor. Results showed that the heating value of synthesis gas was increased from 3.9 MJ/kg (104 Btu/ft³) to 6.1 MJ/kg (164 Btu/ft³) by using the oxygen-enhanced gasification process. The increased heating value of the synthesis gas was obtained at a temperature of 710°C in an oxygen gasification process. Then, one mole of alkali solution was used to remove the non-combustible gas to enhance the quality of the syngas. Almost twice as much as the lower heating value (LHV) was obtained from the upgraded oxygen gasified syngas. The results of this study will pave the way for the widespread utilization of low quality animal manure for sustainable production of synthesis gas and electrical power via an oxygen-enhanced fluidized bed gasification process.