Improvements in the factory steam economy at San Antonio.

THIS paper reviews the improvement in factory steam economy at Ingenio San Antonio (ISA), Nicaragua, over recent years, starting from conditions of low economy and moving to an operation with high steam economy, appropriate to a full cogeneration factory. Ideas for further improvements are discussed, and the factors limiting further economies are outlined. The mass/energy balances for the factory through the changes from pre-1998 to the end of the 2001 season are presented. The recent values with steam consumption around 46% to 47% on cane must be considered excellent for a factory with a pol % cane of around 13.3% and one which produces about one third of its sugar as raw sugar, one third direct consumption sulphited sugar, and about one third of its product sugar as recrystallised refined sugar of less than 40 I.U. colour. The ISA factory is considering schemes to reduce the process steam demand further in the future and to increase the production of high-pressure steam from the fibre supply in the cane. These are indicated in the paper. It is hoped to reduce the process steam consumption to around 39% on cane. The experience obtained at ISA should give a lead to other factories considering cogeneration schemes to increase revenue by power export from the factory.