Thermoanalytical studies of byproduct streams from dry-mill ethanol production

The emission of volatile organic compounds from byproduct streams during drying is a major concern in the dry-mill production of ethanol. Thermogravimetric analysis on distiller's wet grains, distiller's dried grains after the first drier, distiller's dried grains after the second drier, and syrup was conducted to acquire information on the loss of volatiles as a function of temperature. Results show that there is a weight loss in all the samples in the temperature range of 25–100 °C and this weight loss is expected to be mainly due to moisture. It is also observed that devolatilization takes place in distiller's dried grains collected after the first and second rotary driers in between 125 and 220 °C.