Thin Stillage Clarification

摘要

Systems and methods for improving the quality of solids and liquids recovered at atmospheric pressure and temperature from a stillage stream generated as a by-product of an ethanol production process, the recovered solids having higher bio-available amino and fatty acids than evaporation-produced condensed solubles, the recovered liquids having less total solids and total suspended solids than evaporation-produced condensate. A static mixer includes an input for receiving the stillage stream combined with a GRAS anionic polymer, a cylindrical mixing chamber that controllably mixes the stillage stream and the polymer to generate wet flocculated solids and liquid co-product, and a discharge chute that outputs the wet flocculated solids and liquid co-products onto a moving, gravity filter belt having a membrane surface that separates the output from the static mixer into recovered liquids in the form of clarified, thin stillage and recovered solids in the form of dry flocculated solids.

主权项

1. A system for improving quality of solids and liquids recovered at atmospheric pressure and temperature from a stillage stream generated as a by-product of an ethanol production process, the recovered solids having higher bio-available amino acids and fatty acids than evaporation-produced condensed solubles obtainable from the stillage stream, the recovered liquids having less total solids (TS) and total suspended solids (TSS) than centrifuge-produced thin stillage obtainable from the stillage stream, the system comprising:
a static mixer having:
(i) an input for receiving the stillage stream and for receiving a predetermined amount of generally-regarded-as-safe (GRAS) anionic polymer, the combined stillage stream and GRAS anionic polymer forming a GRAS-treated stillage;(ii) a cylindrical mixing chamber configured to mix the GRAS-treated stillage at a predetermined laminar flow rate that chemically generates wet flocculated solids and liquid co-product; and(iii) a discharge chute for outputting the wet flocculated solids and liquid co-products from the cylindrical mixing chamber; and a moving, gravity filter belt being sloped at an angle relative to the discharge chute, one end of the filter belt positioned to receive the wet flocculated solids and liquid co-products output from the discharge chute of the cylindrical mixing chamber, the filter belt having a membrane surface configured to allow liquid co-products and liquids settling out from the wet flocculated solids to pass therethrough as clarified, thin stillage, the membrane surface further configured to retain and discharge dry flocculated solids at the other end of the filter belt;wherein the clarified, thin stillage represents the recovered liquids and the dry flocculated solids represent the recovered solids.