Obiettivo The aim of the project is to include two innovative unit operations in an ethanol from biomass total system plant so as first to reduce the energy demand of the plant which becomes more energy self sufficient and, secondly, to improve its economics. The two unit operations are the pervaporation of the dilute ethanol-containing fractions originating from the distillation unit and the electrophoresis of the effluent from the biogas digesters treating the spent liquor after distillation. The yearly expected energy saving is slightly below 3 GWh for a production of about 8 x 1000 hl ethanol and the treatment of about 28 x 1000 m3 effluent. The payback is 3.5 years on average for the two innovative unit operations, by comparison with a similar total system plant without the two improved unit operations.The project had to be abandoned in 1992 for two main reasons :- the permit for building the digester next to the factory was not granted by the Municipality and no agreement had been reached so far concerning another site. Consequently, it was no possible to implement the electrophoresis unit;- there was a lack of techno-economic success prospect for the pervaporation step. 2 pervaporation units of different makes were tested. None of them were able to reach the initial specifications, i.e. 2,000 l/d ethanol at 99.8 vol % on a stable basis.One of the 2 units succeeded in reaching the specified concentration. However, with the time, the flowrate and concentration were falling down. This was linked to a progressive membrane clogging probably due to the presence of impurities and by-products (notably methanol) in the input. Consequently, the 2 pervaporation units were dismantled and sent back to the manufacturers.The pervaporation process uses synthetic membranes to separate water from a dilute ethanol-containing solution in order to concentrate the ethanol in the latter. The membrane consists of an inactive porous backing-layer and an active pore-free layer, a few micrometre tick, consisting of cross-linked and specially treated polyvinylalcohol. The electrophoresis plant consists of a semipermeable filter which separates two chambers. The lower chamber contains a moving brine (NaCl) solution and the positive electrode. The upper chamber (floating on top of the brine) contains the effluent to be treated and the negative electrode. The pervaporation unit is linked with the distillation treating the dilute plant ethanol-containing mash originating from the fermentation plant and the electrophoresis unit is linked to treat the effluent from methane digesters treating anaerobically the spent liquor from the distillation unit before final disposal.The dilute ethanol-containing stream is heated and introduced in a fractionation distillation tower. Anhydrous ethanol is removed at one particular height of the tower. High ethanol-containing condensates are recycled. Low ethanol-containing condensates pass through the pervaporation plant before being recycled.Energy and mass balances as well as pressures and temperatures will be continuously monitored for the pervaporator as a function of quantitative and qualitative changes in membrane modules. Programma(i) ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989 Argomento(i) 1.10 - BIOLOGICAL TREATMENT Invito a presentare proposte Data not available Meccanismo di finanziamento DEM - Demonstration contracts Coordinatore HANS-EGON FANGMEIER Contributo UE Nessun dato Indirizzo BRENNEREIBESITZUNTERNEHMEN POSTFACH 1224 2840 Diepholz Germania Mostra sulla mappa Costo totale Nessun dato
