Sugar factory configurations for increased cogeneration

Opportunities for factory cogeneration are increasingly seen as necessary for maintaining the economic viability of the cane sugar factory, both in Australia and overseas. To increase cogeneration export, the procedure is to maximise the production of high-pressure steam and minimising the factory requirements of low-pressure process steam, in order to take more advantage of efficient fully condensing turboalternator systems. Factory configurations that reduce process steam requirements are examined in this paper. Limits to the application of vapour bleeding are discussed and quantified. Vapour recompression is demonstrated as not suited for boosting cogeneration. Practical implementation of some of the process steam-saving strategies is discussed in the light of recent observations and measurements made in factories in several overseas countries. The examination should be helpful to technical staff faced with reconfiguring their factories to meet the low process steam consumption targets necessary for profitable cogeneration.