German Alberto Barrera Atuesta
Colombia
Spray drying of concentrated vinasse in a drying chamber (Spry Dryer) has thermal and electrical energy requirements for correct operation. The temperature of the air entering the chamber must be 250 to 300°C, and the outlet temperature is a function of the final moisture level of the product, the raw material entering the chamber and the environmental conditions. This means that energy requirements are high. Concentrated vinasse contains solids diluted in a stream of water, which through its passage through the atomizer becomes thousands of small droplets with a controlled diameter. The air comes into contact with the droplets that are released from the atomizer, transferring heat from the air to each of the droplets, and drying the product without altering the physical-chemical characteristics of the solids (powder obtained) and reducing the temperature of the gases leaving the chamber due to moisture gain. To achieve the above, it is necessary to heat the air with a fuel with a low moisture content, which does not contain impurities, and which has a stable composition and stable calorific value that allows it to maintain a constant temperature and adjust to different operating conditions. High and low voltage electrical power is required to operate the pumps, mixers, fans, dehumidified air transport equipment, rotary valves and lighting. Energy scheme looks for alternatives through cogeneration and trigeneration processes to have surplus energy sales and to supply its own demand. The possibility of using reciprocating motors or microturbines is explored, seeking to bring the plant energy efficiencies to 85-92%.