Patent ID: 7765714

Claim:
A process of reducing the VOC and CO emissions in dryer offgas that is discharged into the atmosphere from a moist organic product dryer comprising the steps of: a. separating said dryer offgas into a first portion and a second portion; b. directing said first portion of the dryer offgas to a hot gas flow side of a rotary waste heat evaporator; c. removing moisture from said first portion of the dryer offgas within said rotary waste heat evaporator thereby forming a reduced moisture dryer offgas portion; d. combusting fuel and combustion air in a combination furnace and mixing chamber; e. directing said reduced moisture dryer offgas portion into said mixing chamber for mixing with the combustion products of step d; f. introducing the mixture from step e into a thermal oxidizer and forming a hot gaseous output from the thermal oxidizer, the temperature of the hot gaseous output from the thermal oxidizer being raised to a sufficient level so as to decrease the VOC and CO content of the mixture from step e; g. bringing said second portion of said dryer offgas into indirect heat exchange relationship with said hot gaseous output from said thermal oxidizer within a primary heat exchanger to preheat said second portion of the dryer offgas; h. recycling said preheated second portion of dryer offgas back to said dryer; and i. discharging the hot gaseous output from the thermal oxidizer to the atmosphere after indirect heat exchange with said second portion of the dryer offgas of step g.