Centrifuge
Clarifying decanters for bioethanol
Bioethanol, which depends on the fermentation of plant-based sugars and starches, is a gasoline substitute. The most commonly used feedstocks are corn and sugar cane.
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). Decanter centrifuges 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.
The centrate (thin stillage) with proteins, yeast and microfibers, is evaporated to produce a syrup, also known as "thick stillage". If corn is used as feedstock the thick stillage also contains corn oil that can be obtained with centrifugal separators to get the most out of your raw material and process. After deoiling the thick stillage is mixed with the wet cake from the decanter and dried to form DDGS.
In ethanol production from sugar-based feedstocks like sugar cane or molasses vinasse is produced in the distillation stage. After further concentration by evaporation the vinasse concentrate is treated by decanters. The finally obtained vinasse products are used as additives in animal feed and as fertilizer.
Features & Benefits
- Highest separation efficiency and drier cake due to deep pond design with high g-volume, automatic differential speed adjustment and always full torque
- Energy efficient design: small solids discharge diameter and energy jets for less energy demand
- Robust and reliable operation: external gears for less exposure to high temperatures, oil + air lubrication for all main bearings
- Advanced wear protection: Tiles and tungsten carbide protection for longer uptime
- VFD drive for high flexibility because of bowl speed changing during production
- Compact Design: small footprint, easy access to all service relevant parts
The smaller the diameter of the discharged solids or liquids in a decanter centrifuge, the less the energy consumption. GEA decanters for bioethanol are in deep-pond design. Deep-pond designs come with smaller solids and liquid discharge diameters (DS2 and DL2) than shallow-pond designs (DS1 and DL1) which makes them very energy efficient. The difference in energy consumption can be up to 30 percent.
The discharge diameter is one feature to reduce energy consumption, energy jets is another. GEA Energy Jets deflect the discharged liquid in such a way that it supports the bowl's rotation (right). This results in energy savings of up to 10 percent, compared with a decanter bowl without energy jets (left).
