A three-dimensional CFD numerical simulation study on pressurized oxy-fuel gasification of poultry manure in an industrial-scale gasifier

As a renewable energy source, the thermal conversion of poultry manure, is a promising waste treatment solution that can generate circular economic outputs such as energy and reduce greenhouse gas emissions. Currently, pressurized gasification of poultry manure is still a novel research field, especially when combined with a novel technological route of oxy-fuel gasification. Oxy-fuel gasification is a newly proposed and promising gasification technology for power generation that facilitates future carbon capture and storage. In this work, based on a commercially operated industrial-scale chicken manure gasification power plant in Singapore, we presented an interesting first exploration of the coupled pressurization technology for oxy-fuel gasification of poultry manure using CFD numerical simulation, analyzed the effects of pressure and oxygen enrichment concentration as well as the coupling mechanism between them, and discussed the conversion and emission of nitrogen- and sulfur-containing pollutants. The results indicate that under oxy-fuel gasification condition (Oxy-30, i.e., 30%O₂/70%CO₂), as the pressure increases from 0.1 to 0.5 MPa, the CO concentration in the syngas increases slightly, the H₂ concentration increases to approximately 25%, and the CH₄ concentration (less than 1%) decreases, resulting in an increase in the calorific value of syngas from 5.2 to 5.6 MJ·m⁻³. Compared to atmospheric pressure conditions, a relatively higher oxygen-enriched concentration interval (Oxy-40 to Oxy-50) under pressurized conditions is advantageous for autothermal gasification. Pressurization increases NO precursors production and also promotes homogeneous and heterogeneous reduction of NO, and provides favorable conditions for self-desulfurization. This work offers reference for the realization of a highly efficient and low-energy-consumption thermochemical treatment of livestock manure coupled with negative carbon emission technology.