Abstract

It had been noted in the previous edition of this Encyclopedia, that removing solvents by condensing them from an inert gas in a water-cooled condenser is inefficient, and may create a potentially hazardous condition at the point of discharge. Vapor pressures of most solvents are relatively high. Therefore, at temperatures obtainable in a water-cooled heat exchanger these substances maintain an appreciable partial pressure in the discharging gas. An environmentally unacceptable high VOC (volatile organic compound) level in the emitted gas, and the fact that the remaining solvent concentration is in many cases above the lower explosive limit, makes a water-cooled heat exchanger an unlikely instrument for solvent recovery.