Environmental monitoring and benchmarking of VCM airborne emissions for a major PVC plant in Taiwan with 15 PVC plants in the USA.

ABSTRACT

Vinyl chloride monomer (VCM) is classified as group 1 carcinogenic to humans by the International Agency for Research for Cancer (IARC). In 2012, USEPA promulgated a new VCM emission standard as part of National Emission Standards for Hazardous Air Pollutants (NESHAP) for polyvinyl chloride (PVC) and copolymer plants. The standard was set by benchmarking of peer plants with maximum achievable control technology (MACT). This study performs an emission assessment of a world-class PVC plant in Taiwan according to the MACT analysis. The emission data obtained were then benchmarked with baseline emission estimates of 15 PVC plants in the USA. Results of this study show seven types of VCM emissions stripped resin of suspension/dispersion, wastewater, process vent, heat-exchange system, storage tank, equipment leaks, and other sources (gasholder). All the emission factors are complied with their MACT emission limitations (MEL) and ranked either #1 or #2 among the 15 plants. They are also summed and benchmarked against the production capacity of each plant, showing a negative power function with a fair correlation (R2 = 0.73). Among seven types of emissions, stripped resin contributes the highest (51.7%) by average emission factor of the 15 plants plus this study plant.