FORFRANDE FOR FRAMSTELLNING AV ETANOL, VARVID RAVARUFLODET UPPDELAS I ETT FLODE RIKT PA FAST SUBSTANS OCH ETT SUBSTRATFLODE FRITT FRAN FAST SUBSTANS, VARVID DET SISTNEMNDA FLODET EFTER BEARBETNING DELVIS BRINGAS I

EtOH is prepd. from a raw material stream consisting of a carbohydrate-contg. substrate mixed with cellulose fibres and/or other non-fermentable solids. The mixt. is subdivided into a solids-enriched stream, (A), and into a solids-free substrate stream. The solids-free stream is fermented in one or more fermentation vessels. A fermentation vessels. A fermentation liquor stream is sub-divided by centrifuging into >=1 yeast concentrate-contg. stream and a yeast-free stream. The yeast concentrate stream is returned to the fermentation vessel, whereas the yeast-free stream is separated into an EtOH-enriched stream and into a residual stream, (B), at least part of which is recycled to the fermentation vessel. Novelty consists in (i) contacting the solids-enriched stream, (A), with at least part of the residual stream (B) and (ii) sub-dividing the mixt. obtd. into an almost completely substrate-depleted solids stream and into a substrate-enriched stream which is returned to the fermentation vessel. Energy requirement and water consumption are very low and sugar yield is very high.