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Poster Presentation 3-25
Separation of Solid Residues after SSF and SHF in Fuel Ethanol Production from Softwood
Mats Galbe, Linda Pilcher, and Christian Roslander
Telephone: 46-462228299; Fax: 46-462224526; E-mail: Mats.Galbe@kat.lth.se
The interest for production of fuel grade ethanol from various lignocellulosic materials using enzymatic hydrolysis has been the subject of research for a long time. Much hard work has been directed towards improvement of the yields in some of the most important individual steps such as pretreatment, hydrolysis and fermentation. Efforts have also been made to improve the process as such. This includes studies on the effect of recirculation of process streams to minimize fresh water consumption and effluent streams.
One of the major technical challenges still to be met, especially in the SSF process, is the separation of the solid residue from the liquid. This residue consists mainly of lignin and residual cellulose and hemicellulose. In SSF, yeast cells are also present. The residue tends to become very sticky and very difficult to separate from the liquid.
Common solid separation methods of these materials often result in a slow filtration rate. When a filter press is utilized an extremely compact filter cake is rapidly formed. Employment of a decanter centrifuge, on the other hand, is rapid but yields a solid phase having a low dry matter content. In this work, a rather new technology has also been studied. A vibrating membrane separation unit (VSEP) was used to separate material from SSF or SHF. Due to high shear forces the membrane surface is not easily fouled, and the liquid flux through the membrane is maintained at a high level. Results from this study will be presented.
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