Assessment framework for gaseous pollutant emissions from decentralized pyrolysis units in urban canopies: Case study in Singapore

• Development of assessment framework for point-source urban emission. • Applicability of industrial emissions standards in residential settings. • CFD simulations of air pollutant dispersion from decentralized pyrolysis unit. • Use of data from currently operational system to assess potential urban deployment. This study aims to establish an assessment framework for analyzing gaseous emissions from a decentralized pyrolysis unit within an urban environment, with a focus on a case study conducted in Singapore. The framework integrates Computational Fluid Dynamics (CFD) modelling to evaluate pollutant dispersion, considering factors such as emission source characteristics and urban canopy effects. Specifically, we apply this framework on a point source emission within an actual field site, namely the Bishan-Ang Mo Kio Park, Singapore which is surrounded by high-rise buildings. Our findings highlight the significance of emission source characteristics, particularly in conservative scenarios characterized by low wind speeds, reduced emission temperatures, and lower emission heights. Furthermore, the suitability of current industrial emission limits in Singapore for residential settings was evaluated, suggesting adjustments for specific pollutants like PM 2.5 . Additionally, guidelines for defining emission source buffer zones based on air quality indexes were proposed, aiding decision-making in the siting of future units amidst multiple options. The assessment framework offers versatility for applications across various regions and waste types, contributing to enhanced air quality management strategies in urban settings.