Cold-setting processes emissions

Emissions for the cold-setting processes can be described as follows  

Phenolic Vapours of formaldehyde and phenol may be emitted because of the vapour pressure of these constituents. But, as the polymerisation occurs at ambient temperature, these vapour pressures are low and given the consumption rates, the emissions are insignificant 

Resol-ester The resin contains unreacted phenol and formaldehyde, but their emissions are extremely low and environmentally insignificant 

---

The chemistry behind many of these gas-hardened processes is similar to the cold-setting processes. Beeause of the gaseous form of the catalysts, it is sometimes necessary to collect and treat their emissions. 

The EPA of the USA has set a standard of 4 kg SO2 emissions per tonne of sulfuric acid produced and mandated a stack height of 30-50 m from ground level. In urban areas local authorities even insist on a stack height of 100 m. The cold process proposed in this section has zero emission of SO2 since liquid sulfur trioxide and DM water will be fed by metering pumps, and no exhaust stack needs to be provided. 

---