Neutral alcohol and Extra Neutral Alcohol (ENA, also known as neutral spirit) is highly concentrated and purified ethanol of agricultural origin, which is used for alcoholic beverages or for industrial applications.
We design distilleries to process ethanol from a wide range of starch or sugar-containing crops. Feedstocks include wheat, corn, milo, barley, rye, potatoes, cassava, sweet potatoes and wet milling by-products, as well as sweet sorghum, sugar cane and sugar beet in the form of molasses, thick juice or syrups, and last but not least products from cellulose conversion processes.
Vogelbusch process for neutral alcohol production
Yeast is used to ferment sugars into ethanol which is refined and concentrated in further process steps.
STARCH: Grains and tubers are milled before they are used in the process. Starch or by-products from wet milling plants do not require any special treatment and are fed directly to liquefaction.
SUGAR: Molasses and sugar syrups seldom require special treatment; they are diluted, acidified and fed straight to the fermentation unit. For substrates containing large amounts of inhibiting substances (affecting fermentation), pasteurization and/or stripping may be necessary. Occasionally, a sludge removal process may be required.
Starch is treated by liquefaction and saccharification to obtain glucose as a fermentable sugar. The partly saccharified substance is cooled down and fed directly to the fermentation unit. Final conversion of the starch into glucose takes place simultaneously during fermentation. To reuse water and latent heat, the Vogelbusch HotMash© process recycles a decanted stillage stream to liquefaction/saccharification.
At the fermentation stage, yeast is employed to convert monosaccharides into alcohol.
Fermentation units can be implemented as batch, fed batch or continuous processes. Continuous systems are generally cheaper and easier to operate. Batch systems are often preferred for highly inhibiting substrates (e.g. low-grade molasses) or situations in which feedstocks must be frequently switched (e.g. molasses vs. grain).
The Vogelbusch standard fermentation process in alcohol production is our advanced MultiCont© continuous fermentation.
Fermentation of the substrate starts in a pre-fermenter under adjusted conditions that promote yeast growth. The fermenting mash flows steadily through a series of main fermenters, while the alcohol concentration increases to a range of 12 - 14 %vol, (depending on the raw material). From the last fermenter the alcohol mash is fed to an intermediate tank for distillation.
The heat generated during fermentation is removed via external heat exchangers, exhaust air from the fermenters is led through a scrubber for recuperation of alcohol.
With some non-fibrous substrates such as molasses or starch milk, yeast recycling can be used to improve yield and accelerate fermentation.
The alcoholic mash is preheated and fed to the distillation section where the crude alcohol is stripped from the mash, leaving behind an alcohol-free liquid, the stillage. The crude alcohol vapors are purified and concentrated in several process columns and fed to rectification for further refining and concentration to at least 96% vol,.
Vogelbusch column systems are individually tailored to the desired quality specifications and analytical and organoleptic characteristics. Process schemes are optimized for separation of impurities and avoidance of undesired chemical reactions and the temperature range of the columns is selected for superior product quality.
Recovery rates from fermented mash to final product of 97.5% are typical.
Energy saving features include the Vogelbusch MultiPressure column system and advanced thermal integration techniques, bringing the steam demand for distillation and rectification down to 1,950 kg per 1,000 liters of neutral alcohol.
A dehydration process is used to obtain super dry ethanol for pharmaceutical or industrial applications. Standard Vogelbusch technology employs a pressure swing adsorption (PSA) process using molecular sieves. The final water content can be reduced to 0.01 %wt.
As only the sugar respectively starch is needed for the process, the remaining ingredients of the raw material in turn can provide valuable co-products.
Stillage from beet or cane molasses is directly fed to the evaporation section. The concentrated molasses stillage (vinasses) can be sold as animal food additive or fertilizer, or incinerated to generate process steam.
Grain stillage contains proteins, minerals, fat and fibers that make a valuable animal feed. Insoluble substances in grain stillage are separated in a decanter and mixed with concentrated stillage from the evaporation section before it is sent to the drying section. The dried product is sold as powdered or pelletized distillers’ dried grains with solubles (DDGS). Alternatively, especially for smaller plants, stillage and the solids from decanter can be sold directly.
Our engineering approach is best-of-breed performance in terms of primary energy and freshwater consumption
More on » THERMAL INTEGRATION
Depending on its quality, neutral alcohol is suitable for a variety of applications
We have the technology and experience to design processes for a wide range of applications and product specifications. They are individually tailored to comply with pharmacopoeia or producer specifications and with national and international ethyl alcohol standards such as EN, GOST, JAAS and many others.
Analytic and organoleptic testing is one of the tasks in our laboratory.
Vogelbusch offers flexible design concepts with highly specialized custom solutions that optimize process economics for
Highly skilled experts are also available to upgrade or revamp existing plants to increase capacity, improve yield and/or product quality, and save energy and water.
| Consumption for 1,000 l neutral alcohol | ||
| Wheat | kg | 2,630 |
| Starch content | % | 58 |
| Steam* | kg | 2,350 [4,800] |
| Power | kWh | 135 [285] |
| Cooling water** | m³ | 105 [185] |
| Process water*** | m³ | 4.6 |
| Soft water | m³ | 0.4 |
| Consumption for 1,000 l neutral alcohol | ||
| Corn | kg | 2,350 |
| Starch content | % | 65 |
| Steam* | kg | 2,300 [4,100] |
| Power | kWh | 130 [240] |
| Cooling water** | m³ | 100 [175] |
| Process water*** | m³ | 5.0 |
| Soft water | m³ | 0.4 |
| Consumption for 1,000 l alcohol | ||
| Cassava chips | kg | 2,350 |
| Starch content | % | 65 |
| Steam | kg | 2,350 |
| Power | kWh | 150 |
| Cooling water * | m³ | 100 |
| Process water ** | m³ | 4.8 |
| Soft water | m³ | 0.4 |
| Consumption for 1,000 l alcohol | ||
| Beet molasses | kg | 3,240 |
| Sugar content * | % | 50 |
| Steam | kg | 2,250 [3,350] |
| Power | kWh | 80 [110] |
| Cooling water ** | m³ | 100 [170] |
| Process water *** | m³ | 7.0 |
| Soft water | m³ | 0.4 |
| Consumption for 1,000 l alcohol | ||
| Cane molasses | kg | 3,270 |
| Sugar content * | % | 50 |
| Steam | kg | 2,300 [3,450] |
| Power | kWh | 80 [110] |
| Cooling water ** | m³ | 120 [180] |
| Process water *** | m³ | 7.7 |
| Soft water | m³ | 0.4 |
| Consumption for 1,000 l alcohol | ||
| Cane or sweet sorghum juice | kg | 10,700 |
| Sugar content * | % | 15 |
| Steam | kg | 2,050 [3,400] |
| Power | kWh | 80 [110] |
| Cooling water ** | m³ | 110 [180] |
| Process water *** | m³ | 1.0 |
| Soft water | m³ | 0.4 |
The economic minimum capacity of a potable alcohol plant in Europa is at 60,000 liters per day (= 17,000 tons per year); provided that energy and raw material cost are favourable it may be down to 30,000 liters per day in other regions.
For 1,000 liters potable alcohol (on average sugar / starch content, all on wet basis) the Vogelbusch process typically requires
Combination of feedstocks is possible, but higher investment costs have to be taken into account.
Decisive factors for the plant location are
For a 60,000 liters per day facility 5 to 6 hectare are required.
Capital expenditure depends on plant capacity and configuration as well as local conditions. Costs for the process plant (excluding building, auxiliaries, infrastructure) for a 60,000 liters per day facility are in the range of 5 to 20 million euros.
In detail this is however depending on the available infrastructure and the raw material used. Grain based plants require higher investment compared to sugar.
Figures are for general reference only since each project has its own particularities that need consideration.
With permits on hand engineering and construction takes 18 - 24 months.
Complete our design questionnaire (check Links & Downloads section below) and send it back to us to get a professional opinion on your project.
