Ethanol Production by Dry Milling – Case Study

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Masterflex® (77910-40) L/S® Variable-Speed Pump System with Easy-Load® II Pump Head

Compiled by: Sameer Tawde, Product Manager, Cole-Parmer India
Written by: Vinita Singh, Marketing Manager, Cole-Parmer India

Cole-Parmer’s Masterflex® peristaltic pumps provide an accurate and repeatable pumping solution for the ethanol production process, enabling a precise volume of enzymes to be added continuously.

One of the largest sugar manufacturers in India, Saswad Mali Sugar Ltd, use molasses, a by-product generated from their sugar production, to produce ethanol. Their dry milling site is capable of generating 846 KLPM of ethanol but they were experiencing process downtime and reduced ethanol concentrations from leakage and blockages in their enzyme dosing pumps. Saswad Mali Sugar needed a solution to reduce their losses. They contacted Cole-Parmer. Ethanol is a versatile alcohol used in fuel, beverages and thermometers. Two processes used to produce ethanol from grain are dry milling and wet milling. Dry milling plants generate ethanol, carbon dioxide and distillers’ grain, which is used as a high-protein livestock feed supplement. Wet milling plants create these and additional valuable byproducts such as corn syrup, dextrose, and fructose, however they cost substantially more to build and operate than a dry milling plant.

Cole-Parmer considered Saswad Mali Sugar’s ethanol production process: Debris is removed from the molasses, and the molasses is coarsely ground and mixed with process water. The pH is adjusted and alpha amylase enzymes are added to form “slurry”. The slurry is then heated and moved to liquefaction tanks. As the alpha amylase enzymes start to break the starch down into short-chain dextrins, the slurry is moved to a fermentation tank where glucoamylase enzymes are added to break the dextrins into simple sugars. This mixture is known as “mash”.

To maximize ethanol concentration, it is critical that the enzymes are accurately dosed. Enzymes are added to the tank 24 hours a day, requiring a precise volume delivered at very low rates. The flow needs to be varied based on operating conditions.

Yeast is added to convert the sugar to ethanol and carbon dioxide. The mash is then allowed to ferment for several days, resulting in a mixture that contains about 15% ethanol as well as the solids from the grain and yeast. The mash is then pumped through a distillation system to separate the ethanol off. Once it leaves the distillation columns, the ethanol is about 95% by volume (190 proof).

Saswad Mali Sugar Factory was initially using diaphragm metering pumps to deliver the glucoamylase enzymes but encountered leakage and blockages in the metering pump system. Cole-Parmer stepped in and offered fluid handling expertise that proved invaluable. After careful consideration, Cole-Parmer’s Application Specialist recommended a Masterflex peristaltic pump system and PharMed® BPT thermoplastic elastomer tubing.

The new pump system improved the process exponentially, ensuring accurate and repeatable flow whilst eliminating check and ball valves that were causing the system to block. This customized solution recommended by Cole-Parmer delivered a high degree of durability which reduced maintenance costs, downtime, and improved the overall operating efficiency.

Masterflex pumps: The smart solution

Masterflex pumps are the smart solution for virtually all food & beverage processing applications. They provide a well-balanced range of capacities and flexibility combined with repeatability. They also work with a wide tubing selection to provide precise, reliable, and long-term operation. The Masterflex pumps are designed to efficiently handle a wide range of food & beverage processing applications ―from pumping shear-sensitive products to highly viscous material transfer―while continuously providing accurate and contamination-free flow control. Masterflex pumps never need to be cleaned or serviced between production change-outs because the material is contained within the pump’s flexible tubing. Changing out the tubing is a simple procedure that takes less than a minute.


No contamination, simple operation, low maintenance, multimedia pumping capabilities, compatible with a wide range of tubing materials, and minimized downtime.

The consequences of wrong pump selection can go beyond frequent downtime, maintenance costs, and high demand for spares. Yet with Masterflex peristaltic pumps―which provide accuracy, reliability, durability, and flexibility over a wide range of flows and products―manufacturers can maintain superior product integrity. Masterflex pumps are compatible with a wide range of tubing materials for commercial food processing applications to meet USP, FDA, NSF, and 3A requirements.

Whether it is the transfer of thick molasses or the precise dispensing of additives, Masterflex pumps stand up to the challenge. Once the pump was installed in the unit, Mr. Rahul Tilekar immediately noticed efficiencies. “The Masterflex L/S® pump has marvelously improved my operation,” he said.

The results

Less worries and more efficiency, delivering greater economical value.

After a significant time, the performance of the Masterflex peristaltic pump has more than measured up to expectations. Saswad Mali Sugar experienced:

  • Substantial reduction in service and maintenance costs.
  • User-friendly operation and convenient batch-to-batch changeover.
  • Instead of replacing complete pump units, only the tubing requires changes. This further reduces downtime for maintenance.


Peristaltic pumps can be a superior alternate technology to diaphragm metering pumps in many applications.
Other applications for Masterflex peristaltic pumps include:

Pumping Pizza/Pasta Sauce
Dispensing of Flavorings with Pulp
Pumping Syrups to Cooker
Pumping Icing for Pastries
Transferring Potato Chip Waste Slurry
Cooking Oil Recovery
Pumping Sucrose Gradient
Pumping Preservatives
Transferring Raw Fruit Pieces
Pumping Concentrated Salt Slurry

For any queries related to Masterflex pumps, contact

For any queries outside of India, please contact a Cole-Parmer representative in your region.



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