Assessment of emission-source contribution to spatial dispersion for coal crusher agglomeration using prognostic model

Abstract

The emission of inhalable particulates (PM 10 ) from coal comminution processing is detrimental to the air quality. However, limited works have been carried out for the estimation of emission and dispersion of PM 10 from coal crushers and its ancillary operations. In this study, field-based measurements and regulatory dispersion model coupled with Weather Research Forecasting (WRF) were applied to investigate the assimilative capacity (AC) of a region with operational coal crushers. The model run was found ‘acceptable’ when compared with measured values according to set performance criteria. Furthermore, the validated model parameterization was used to forecast the dispersion effects by various emission control alternatives recommended by regulators viz. covering of conveyor belts, paving of the unpaved road, reducing feed rate, etc. Results suggested that the major contribution of PM 10 was from transportation and loading of coal after crushing, while PM 10 levels from crushing dissipated in a smaller area. Paving of transport roads and bunker/silo-based loading were effective control measures as emissions reduced by 30.67%–52.51%. The relationship between distance and emission load revealed that PM 10 concentrations below 100 μg/m 3 were achieved at approximately 750 m away from emission sources in the present study. Crusher's operations with existing emissions of 23.43 g/day/m 2 were detrimental for the region's AC and needed to be stepped down to 11.71 g/day/m 2 . In particular, using modeled meteorological data provided reasonable forecasts for allowable emissions and planning to site crusher operations. Correction to the low-wind conditions resulted in a better simulation of mean annual estimates than daily estimates of PM 10 . Such visualization of spatially explicit frameworks will guide policymakers in strengthening regulations. • Emissions from coal crushers and linked transport roads evaluated for spatial dispersion. • Transport bottlenecks are formed at feed point of crushers resulting in lower dispersion. • Emission reduction vis-à-vis dispersion by adopting controls recommended by regulators forecasted. • Paved roads and bunker/silo based loading enhanced available assimilative capacity. • Wind speed was key variable with low wind correction resulted in better mean annual estimates.