Objetivo To save energy in treating waste from citrus fruit processing industries by integrating thermal and mechanical drying processes, also producing "citrus meal" and "citrus molasses" which can be used as animal feed.The innovation relates chiefly to thermo-mechanical drying and production of molasses by reverse osmosis. The average energy saving anticipated, compared with other ways of waste disposal, is 1682 toe/yr.The 1987/1988 campaign saw a change in the nature of the waste from the citrus fruit processing industry ("citrus paste"), this being the raw material used by the project, compared with the traditional characteristics of the material on which the design of the project was based. Consequently proposed technology is now unsuited to the present situation.A series of tests to check whether it was possible to adapt the technology to the new raw material turned out to be disappointing : the machines cannot be adapted to the new situation.In view of the major modifications which would be needed to adapt the project to the new kind of citrus paste, whose characteristics depend on the pressing techniques used upstream of this project, it has been decided to abandon the project. The contractor may put forward fresh proposals for the demonstration project when the technological options for pressing by the upstream processing industries have become absolutely clear and firm, so as to produce a citrus paste with definite and unvarying characteristics.The paste left over from citrus fruit processing (20000 t/year) is mixed with lime water then fed into twin presses; the purpose of the lime water is to increase the pressing yield to 50% by weight of juice relative to the citrus paste entering the machine. The output from the press therefore is juice and solid waste. The solid matter is dried in a 3-way rotary drier heated by a multi-fuel burner. The dried matter is then reduced to citrus meal(13% humidity) by hammer mills before going into storage.The pressed-out juice is stored and filtered, preheated to 75-80 deg. C and fed into the modules of a reverse osmosis concentrator. The filtering operation is intended to avoid the need for over frequent washing of the membranes. These are highly selective and arrest the nutrients dissolved in the juice while letting through a permeate with a low concentration of solids; the permeate is later discharged. The liquid residue, now partly concentrated, passes from the membranes into a double-acting evaporator where it is further concentrated, emerging as "citrus molasses".The evaporator, like the heat exchanger upstream of the reverse osmosis concentrator, is heated by recovering sensible heat from the flue gases from the rotary drier.Preheating the juice reduces its viscosity so as to increase the efficiency of reverse osmosis; heating the first stage of vacuum concentration to 75 deg. C (and the second stage to 45 deg. C) makes the system more energy efficientCitrus meal and molasses are used to make animal feed stuffs. This technology has the advantage of making beneficial use of waste which would otherwise be burnt, dumped or would undergo heat treatment in a way wasteful of energy. Programa(s) ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989 Tema(s) 3.4 - INDUSTRY Convocatoria de propuestas Data not available Régimen de financiación DEM - Demonstration contracts Coordinador SNAMPROGETTI SPA Aportación de la UE Sin datos Dirección Viale Alcide De Gasperi 16 20097 SAN DONATO MILANESE Italia Ver en el mapa Coste total Sin datos
