Technology and Energy Economics of Sugar Production: Possibilities of Process Development

摘要

The energy required to make food is made up of the parts for the production of the raw materials through agriculture, together with the technological processing of the raw materials and the further treatment of the product until it is consumed. The energetic input is equal to the main and by-product energetic values created. An analysis of food production according to the Input-Output balancing is thus possible.rnThe specific energy input in relation to product in white sugar manufacturing form beet (including pulp drying) ranges between 6 and 12,5 MJ/kg. The minimum achievable at present lies below 4 MJ/kg. An essential precondition to reach this value is the energy link between pulp drying and sugar processing. Moreover, new ways to be found in crystallization, with innovations in continuous evapo-crystallization playing a key role.rnThe evapo-crystallization tower (VKT) enables the optimum design and construction of calandrias and stirrers for all cells in the cascade. As the individual cells can be by-passed and cleaned separately, high availability of the proposed plant is always ensured. Given the continuous pans with mechanical circulation can be Operated with small temperature differentials; this can be utilized for double-effected evaporation within a crystallization stage. Depending on the crystallization system, heating steam requirements are reduced by 35-50%.rnThe further development of evaporator technology in the sugar industry based not only on the requirement for high k-values, but also requires besides this a compact cost effective design of the operation with a minimum temperature gradient between heating steam and vapour. Based only on evaporator design, achieving a high heat flux density (kW/m2) at low temperature gradient, e.g. 8 stage evaporator systems with an economically interesting heating surface utilization can be realised.