How Beet Sugar is Made - Energy Aspects
The lack of a waste product suitable for fuel drives beet factories to be much more energy efficient than their cane counter-parts. Boiler pressures in a beet factory are typically 4 to 9,000 kPa with superheat up to 520 °C. Coal, gas and oil are all used as fuel although environmental pressures are favouring the use of gas. Many beet factories export surplus electricity to the public grid when processing.
Some factories have installed gas turbine based systems, using a jet engine to drive an alternator then recovering heat from the waste gases with a waste heat boiler. These systems have a much higher power : heat ratio than a conventional power house and hence allow a larger export of electricity or a greater level of thermal efficiency.