Objetivo To demonstrate that reverse osmosis separation techniques and the use of membranes can be successfully applied to the sugar industry.Estimates suggest it will be possible to treat one-fifth of annual syrup production with a membrane of 1,200 m2 to yield a saving of 1,900 tons of oil.The contract was stopped before completion because of a fall in economic viability.One out of the 5 modules was built and tested during the 1985 and 1986 sugar campaigns at the designed working pressure.The technical results were favourable and are as follows for the 1415 hours of the 1986 campaign (mean values) :- inlet flow-rate : 16. 6 m3/h- concentrate flow-rate : 10. 26 m3/h- permeate flow-rate : 6. 24 m3/h- specific permeate flow-rate : 12. 5 l/m2 x h- concentrate concentration : 16-20 deg. Brix- permeate concentration : 0. 434 deg. Brix- pressure : 36. 5 bars- temperature : 80-88 deg. C- electricity consumption : 10 kWh/m3 permeate.The results were in line with the initial objectives. However, the long term(2 or more sugar campaigns) viability of the membranes at their initial performance was questionable, since they showed to be very sensitive to bacterial fouling and frequent washings were necessary, leading to chemical/mechanical stress on the membranes.Theenergy saving was 0. 0271 TOE/m3 permeate, very close to the forecast.To reach an acceptable economic viability with the assumption of fuel oil prices at their 1986 level, it appeared necessary either to keep the membranes for at least 3 sugar campaigns at their initial performance level, or to require a greater production from the membranes.To achieve this latter point, a third test campaign was carried out in 1987 with the Reverse Osmose module working at a higher pressure : 41 bars instead of 36 bars. The permeate flow-rate increase was however not proportional to the increase in pressure; this was probably due to a much higher hardness of the sugar juice than usual and to the ageing of the membranes. Furthermore, it appeared that the membranes could not work satisfactory for more than2 campaigns, leading to an excessive membrane replacement cost.At this stage, it was decided to terminate the contract.The processing of sugar beet requires sugar syrups to be concentrated from12 deg to 65 deg Brix, a process almost entirely achieved by evaporation.To reduce the energy cost required for the concentration process, a reverse osmosis stage has been introduced into the processing sequence which will preconcentrate the sugar syrups from 12 deg. C to 20 deg. C Brix. Mechanical energy is then used to replace thermal energy.Energy savings are estimated at 75% of the preconcentration energy requirement.The permeate, which still contains small amounts of saccharose, feeds the diffusion process (extraction of sugar from the beet) upstream of concentration.The plant's maximum potential is 100 m3/h (20 m3/h over 5 units) and consists of one feed unit, five reverse osmosis units and one washing unit. Programa(s) ENG-ENALT 2C - Programme (EEC) of demonstration projects relating to the exploitation of alternative energy sources and to energy saving and the substitution of hydrocarbons, 1983-1985 Tema(s) 3.2 - 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
