More value from bioethanol productions
Stillage dewatering and corn oil recovery
Ethanol production from starch-based feedstocks like corn and wheat, creates tons of stillage which can be used in animal feed, preferably as dried distiller’s grain with solubles (DDGS).
If corn is used as feedstock the stillage also contains oil that can be obtained with centrifuges to get the most out of your raw material and process.
There are several options to recover the corn oil from your DDGS process. Every option has its unique set of pros and cons. GEA has all the necessary centrifuges as well as the separation expertise to help you find the best option for you.
Corn oil skimming with skimming decanters
Skimming decanters have been developed by GEA in the early 1990s to help the Spanish olive oil industry save water and improve oil quality.
For the recovery of corn oil from stillage, skimming decanters can be installed before the actual stillage clarification to extract the oil as early as possible.
However, proper separation results and oil recovery rates can only be obtained with the help of chemicals facilitating the mechanical separation process in the skimming decanters.
Corn oil skimming with 2-phase separating or skimming decanters
The Varipond system for GEA skimming decanters makes it easy for producers to adapt the decanter to changing feed conditions or flow rates. Adjust the separation zone during operation for fast and precise results. No standstills, no tedious exchange of decanter parts, no unnessecary product loss. Instead, instant adjustment of the decanters setting and instand results. .
The advantages at a glance
- Very early extraction of the oil in the overall process minimizes possible oil losses
- Decanters are a proven and familiar technology for plant managers and operators
- Maximum product yields
- Fast and easy adaption of your GEA skimming decanter with GEA Varipond
Thin stillage de-oiling
This new process set-up developed by GEA moves the corn-oil recovery to after stillage clarification but before evaporation. As the oil is now separated from the thin-stillage, disk-stack separators can be used instead of decanters. Separators have higher g-forces as well as clarification areas than decanter centrifuges and thus have better separation results.
Thin stillage de-oiling with high speed disk-stack centrifuges
This thin stillage de-oiling comes with convincing results as experienced from our first customer installations: it is still early enough in the overall process to recover as much oil as possible.
Another huge benefit we have experienced: this process runs with greatly reduced to no demulsifiers/chemicals.
The advantages at a glance
- Greatly reduced to no chemicals needed
- Very high g-force and clarification area in disk-stack centrifuges capture even the smallest oil droplets and make for high yields
- No free oil in heavy phase (de-oiled syrup)
- Reduced fouling in your evaporator stage
- Disk-stack separators fully CIP possible
- Disk-stack centrifuges are low-maintenance centrifuges compared to decanters
- Protein phase as a separate on-top by-product with additional value
Conventional corn oil recovery from syrup
Conventionally, a decanter centrifuge separates the stillage into thin stillage and wet distillers grain (WDG) which is then dried to produce DDGS. In this process corn oil is being recovered from the thick stillage (evaporated thin stillage). Ethanol producers benefit from a DDGS with less fat and higher protein content as well as additional income from the corn oil which can be used as a feedstock for i.e. green diesel.
Conventional corn oil recovery from syrup
The advantages at a glance
- Additional income from the obtained corn oil
- DDGS with less fat and higher protein content
- Proven process setup
- Disk-stack centrifuges are low-maintenance centrifuges compared to decanters
Whole stillage decanters
Whole stillage decanters separate the stillage into a centrate called "thin stillage" which contains proteins and microfibers, and a solids phase called wet cake that contains the coarse constituents of the grain's fiber.
Oil skimming decanters
Oil skimming decanters separate the oil from the rest of the suspension consisting of solids and water. GEA has developed this design in the early 1990s for olive oil recovery.
High speed separators
High speed separators are able to capture smallest oil dropplets due to their high separation efficiency making for top recovery rates.
