Improving Evaporator Fouling Control and Operating Costs in Ethanol Production

Results at a Glance

This case study examines how Apex improved evaporator fouling control at a 100 MMGPY ethanol facility while reducing overall treatment spend. By implementing a targeted dual-product evaporator treatment program using EFX 5000 and EFX 6000, the facility achieved slower fouling rates, easier offline cleaning, and improved operational stability without increasing chemical costs.

Evaporators are critical to maintaining throughput and efficiency in ethanol production. When mineral and organic fouling accumulate on heat transfer surfaces, plants experience rising delta pressures, reduced capacity, and increasingly difficult cleanings during shutdowns.

A 100 MMGPY ethanol facility in central South Dakota was experiencing persistent evaporator fouling that limited production efficiency and increased maintenance demands. Although a competitive chemistry program was already in place, it was not delivering the level of fouling control required to support long-term operating goals. The facility partnered with Apex to evaluate an alternative approach focused on improving evaporator cleanliness while maintaining — and ultimately reducing — treatment spend.

Results at a Glance

Facility Background

• Industry: Ethanol/Biofuels
• Application: Evaporator fouling control and CIP support
• Challenge Area: Mineral and Organic fouling driving elevated pressures and difficult cleanings
• Apex Solution: EFX 5000 & EFX 6000 Evaporator Fouling Control Program

The facility operates multi-effect evaporators as part of its ethanol concentration process. Prior to working with Apex, fouling buildup caused elevated delta pressures across evaporator effects, forcing frequent and increasingly aggressive cleaning during outages. These conditions reduced uptime, increased maintenance costs, and constrained production efficiency.

The Challenge

The ethanol plant faced several interrelated challenges:

• Mineral and organic fouling accumulation on evaporator heat transfer surfaces
• Increasing delta pressure across evaporator effects
• Frequent and labor-intensive cleaning during shutdowns
• Reduced throughput and lost production opportunities
• Limited improvement from the existing treatment chemistry

The plant needed a solution that could improve fouling control without increasing operating costs or requiring equipment changes.

The Apex Solution

Apex implemented a two-product evaporator treatment strategy using EFX 5000 and EFX 6000, designed to target different fouling mechanisms within the evaporator train.

Key elements of the solution included:

• Dosing EFX 6000 at the beginning of the first evaporator effect at 20 ppm
• Applying EFX 5000 to the second evaporator effect at 27 ppm
• Supporting proper application through equipment installation and field oversight
• Conducting lab analysis to characterize foulants and confirm treatment alignment
• Monitoring evaporator performance using delta pressure trends, steam load, and throughput data

This approach allowed Apex to target fouling more effectively while maintaining overall treatment economics.

Results & Operational Impact

Performance improvements were observed during the trial period and continued after full-scale implementation:

• Slower rate of delta pressure increase across evaporator effects, indicating improved fouling control
• Reduced solids removal during hydroblasting, confirming lower foulant accumulation
• Improved offline cleaning efficiency during scheduled shutdowns
• Overall reduction in evaporator treatment spend compared to the previous chemistry program

While detailed throughput gains continue to be evaluated, the operational indicators clearly demonstrated improved evaporator cleanliness and stability. Based on these results, the facility permanently adopted the EFX 5000 and EFX 6000 program and began influencing implementation at other sites within its organization.

Applicable To

This solution is relevant for:

• Ethanol and biofuel facilities operating multi-effect evaporators
• Plants experiencing mineral or organic fouling
• Facilities seeking to improve evaporator performance without increasing chemical spend
• Operations focused on reducing downtime and improving cleaning efficiency

Conclusion

This case study illustrates how targeted evaporator chemistry can improve fouling control while reducing operating costs. By implementing a dual-product treatment strategy, Apex helped this ethanol facility stabilize evaporator performance, simplify maintenance, and support long-term production goals.

For ethanol producers facing fouling-related challenges, Apex delivers data-driven solutions that balance performance, cost control, and operational reliability.

Results at a Glance

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