INTEGRATED PROCESSING FOR PROFIT

摘要

THIS paper presents the concept of an Integrated Agro-Industrial Complex (IAIC) producing five or six products from two or three crops. The complex would operate on a year round basis with the 'wastes' of one product being the feedstock for another. The complex could be introduced in stages to an existing sugar mill and is illustrated in block flow diagram and described in the text. The concept is based on existing and developing practice in producing sugar, paper pulp and fertiliser. By integratingoperations we believe the sugar industry could effect a major increase in income, profitability and market flexibility. By expanding into new growth areas the concept could minimise Australia's energy and climate change problems. Potential products of anIAIC include; paper pulp, motor fuel ethanol, Ecophos a non-leaching fertiliser, sugar, lignin and electric power. Crops include; high fibre sugarcanes, sweet sorghum and nalgrass. Other raw materials include; phosphatic mine waste, fertiliser grade potash, lime and hydrogen peroxide. The main 'wastes' arise from producing paper pulp and are pith and other fines removed from bagasse to make a strong paper pulp, and potash pulping black liquor. Integration of sugar milling with the processing of other products allows a major saving in capital and operating costs. In particular it avoids the storage and reclaim of bagasse ahead of paper pulp production. Integration also allows the production of ethanol without the need to produce and dilute molasses feedstock. As an indication, the requirement of modifying an 'average size' sugar mill could be of the order of $100 million and the engagement of 30 extra mill employees. The exact numbers would depend on location and product mix. The major capital and operating costs involve addition of an ethanol plant. Potash pulping without reagent recycling is relatively cheap, as is alkali fertiliser manufacture from crandallites (the overburden waste from certain phosphate mines).