# Reference method for measuring emissions of vinyl chloride from manufacturing: part III C-4

## Calculation of Emissions from Polyvinyl Chloride Plants Downstream from the Stripping Operations

### C-4.1 Scope

Calculations are given to determine the vinyl chloride emissions downstream from the stripping operations in polyvinyl chloride plants by measuring the residual vinyl chloride monomer in the product resins or resin slurries, or measuring vinyl chloride in process vents downstream from the stripper, or both.

### C-4.2 Calculation of Emissions Based on Resin Samples Only

The emission rate is calculated assuming total evolution of the residual vinyl chloride in the resin or resin slurry during all operations subsequent to stripping. Equation C-4-1 is to be used to calculate the mass emission rate.

(C-4-1)
where
• ERvc/pvc = mass emission rate of vinyl chloride per production of polyvinyl chloride, kg VC per 100 kg PVC
• Crvc = average of the residual vinyl chloride in the three samples on a dry basis, ppm VC by weight
• 10-4 = conversion factor, ppm to kg VC per 100 kg PVC

### C-4.3 Calculation of Emissions Based on Vent Gas Samples Only

The emissions of vinyl chloride downstream from the stripping operation can be determined by measuring the emissions from every process vent of all operations following the stripper.

The mass emissions of vinyl chloride expressed on the basis of 100 kg of polyvinyl chloride produced (ERvc/pvc) are calculated for every vent according to calculation Method C-2.

The total mass emission of vinyl chloride is the sum of the mass emissions from all vents following the stripper.

### C-4.4 Calculations of Emissions Based on Both Resin Samples and Vent Gas Samples

The emissions of vinyl chloride downstream from the stripping operation can be determined by measuring the residual vinyl chloride in the product resin after any processing following the stripper, and concurrently measuring the emissions into the atmosphere from all process vents of all operations between the resin sampling point and the stripper.

The mass emissions of vinyl chloride expressed on the basis of 100 kg of polyvinyl chloride produced (ERvc/pvc) are calculated for the vents sampled using Method C-2.

The emissions from all operations following the resin sampling point are calculated using the equation given in section C-4.2. If two or more resin streams are sampled, the mass emission rate (ERvc/pvc) as calculated for each stream shall be weighed in proportion to the quantity produced as obtained from the plant production records.

The total of the emissions of vinyl chloride downstream from the stripper is obtained by summing the emissions (ERvc/pvc) from each vent sampled and adding to this quantity the sum of the weighed emission rates calculated from the residual vinyl chloride of the product resin streams.