Comparative Analysis of Silicone-Based, Non-Silicone-Based, and Glycol-Based Defoamers in Sugar Processing- Efficiency, Cost, and Environmental Impact.pdf

Foam generation is a significant challenge in sugar manufacturing, especially during juice clarification,
evaporation, and crystallization. Excessive foam disrupts operational efficiency, causes overflow losses,
and reduces heat transfer efficiency. Defoamers are critical additives that mitigate foam-related issues
and enhance production continuity. This case study investigates the performance of silicone-based, nonsilicone-based, and glycol-based defoamers in sugar processing plants, comparing their foam
suppression efficiency, cost-effectiveness, thermal stability, and regulatory compliance. Field data from
a sugar refinery in Maharashtra, India, are analysed, with insights on practical usage, environmental
impact, and economic trade-offs.

1. Comparative Analysis of Silicone-Based,
Non-Silicone-Based, and Glycol-Based
Defoamers in Sugar Processing: Efficiency,
Cost, and Environmental Impact
Toshabindu Panigrahi
May 2025



Abstract
Foam generation is a significant challenge in sugar manufacturing, especially during juice clarification,
evaporation, and crystallization. Excessive foam disrupts operational efficiency, causes overflow losses,
and reduces heat transfer efficiency. Defoamers are critical additives that mitigate foam-related issues
and enhance production continuity. This case study investigates the performance of silicone-based, non-
silicone-based, and glycol-based defoamers in sugar processing plants, comparing their foam
suppression efficiency, cost-effectiveness, thermal stability, and regulatory compliance. Field data from
a sugar refinery in Maharashtra, India, are analysed, with insights on practical usage, environmental
impact, and economic trade-offs.

Introduction Foam Challenges in the Sugar Industry
Foam formation arises primarily due to the presence of surface-active agents like proteins, saponins,
and polysaccharides released during cane or beet processing. High-temperature and high-shear
operations during juice clarification and evaporation exacerbate foam development, leading to frequent
equipment fouling, reduced heat transfer efficiency, and product losses due to overflow. Studies indicate
that foam formation can reduce heat transfer efficiency by up to 25% and increase cleaning frequency
by 30% in affected equipment.
Role of Defoamers
Defoamers function by disrupting the foam lamellae and reducing surface tension, causing foam
bubbles to collapse. The ideal defoamer should be non-toxic, thermally stable, food-grade, and effective
at low dosages. Typically, a well-performing defoamer can reduce foam volume by over 90% within
minutes of application, significantly improving throughput.
Defoamer Classification & Chemistry Silicone-Based Defoamers
Composed mainly of polydimethylsiloxane (PDMS) and hydrophobic silica, silicone-based defoamers
offer high efficiency even under extreme thermal conditions. In lab simulations, PDMS-based
defoamers reduced foam height by 95% within 3 minutes. However, concerns exist regarding silicone
residues in the final product (trace amounts of <5 ppm were detected via GC-MS), which may require
post-treatment filtration.

2. Non-Silicone (Organic) Defoamers
These include mineral oils, fatty alcohols, and polyglycols. While more biodegradable and compliant
with food safety regulations, their effectiveness is often compromised at high temperatures.
Performance tests showed an 85% foam reduction within 5 minutes of application. These agents may
require reapplication every 4–6 hours depending on the process intensity.
Glycol-Based Defoamers
Derived from ethylene and propylene glycol, these defoamers are water-soluble and perform well in
high-sugar environments. Glycol-based agents achieved 88% foam suppression in 4 minutes in high-
Brix syrup environments. However, their environmental profile is contentious—ethylene glycol, in
particular, is classified as a hazardous substance in many jurisdictions.

Case Study Methodology Industrial Setting
The study was conducted at a sugar processing unit in Maharashtra, India, which processes
approximately 4,000 tons of cane per day. The study included juice extraction, clarification,
evaporation, and crystallization.
Experimental Design: Defoamers were applied at different stages with controlled dosages (30–60
ppm). Parameters such as foam height, reduction percentage, processing time, and energy use were
measured.
Testing Parameters:
• Foam Reduction Rate (ASTM D892 equivalent)
• Processing Time Improvements
• Energy Savings (%)
• Residue Analysis (GC-MS and HPLC)

Results & Comparative Analysis Performance Table:
Defoamer
Type
Foam
Reduction
(%)
Avg.
Dosage
(ppm)
Cost
per
Ton ($)
Heat
Stability
Food Safety
Compliance
Reapplication
Interval (hrs)
Silicone-
based
95% 40 12.50 Excellent Limited (trace
residue <5
ppm)
8
Non-
silicone
85% 50 8.20 Moderate Excellent 4
Glycol-
based
88% 45 9.80 Good Conditional
(region-
specific)
6

3. Performance Graph:
Foam Reduction Efficiency:

Operational Insights
• Silicone-Based: Best suited for evaporation stages where temperatures exceeded 110°C.
Required only one application per shift. However, filtration post-crystallization was needed to
ensure residue levels remained within food safety norms.
• Non-Silicone-Based: Used primarily in juice clarification. Operators appreciated its
biodegradability and organic certification compatibility. Reapplication every 4 hours increased
cumulative dosage and marginally reduced cost efficiency.
• Glycol-Based: Effective during centrifugation. Despite performance, ethylene glycol variants
were flagged for environmental concerns. Replacement with propylene glycol improved safety
but increased cost by 12%.

Discussion
Trade-offs are evident: silicone-based defoamers deliver the highest performance and longest effect
duration but come at a premium cost and possible residue management requirements. Non-silicone
agents are safer for organic and food-grade applications but demand more frequent dosing. Glycol-
based defoamers balance performance and cost but are limited by environmental legislation.
Emerging Alternatives
Bio-based defoamers—derived from plant esters and natural oils—demonstrated 80–85% foam
reduction in pilot tests and offer an eco-friendly, food-safe profile. Although currently more expensive
(~$14.00 per ton), their regulatory appeal may justify the cost.

80
82
84
86
88
90
92
94
96
Silicone Non silicone Glycol based
% Drop in Foam
% Drop in foam

4. Environmental & Economic Impact Carbon Footprint Analysis (per ton of sugar processed):
• Silicone-based: 5.6 kg CO2
• Non-silicone-based: 3.9 kg CO2
• Glycol-based: 4.8 kg CO2
Cost-Benefit Analysis (Per 10,000 Tons Processed):
Defoamer Type Investment ($) Savings ($) ROI (%)
Silicone-based 12,500 18,200 45.6
Non-silicone 8,200 10,500 28.0
Glycol-based 9,800 12,100 23.5

Conclusion & Recommendations
Silicone-based defoamers are the top performers in high-temperature operations, offering superior foam
suppression (95%) and best ROI (45.6%). They are recommended for large-scale operations where post-
filtration is feasible. Non-silicone-based defoamers provide a safer alternative for organic or food-
certified products but require higher dosages and reapplication. Glycol-based defoamers can be used
where moderate efficiency and lower toxicity glycols (like propylene) are acceptable.
Recommendations:
• Conduct pilot testing to tailor defoamer dosage.
• Employ silicone-based defoamers in evaporation zones.
• Use non-silicone in organic and clarified juice applications.
• Avoid ethylene glycol unless effluent treatment is robust.
• Explore nano-emulsions and AI-based control systems for dosage optimization.
References
1. International Sugar Journal, 2022.
2. Food Chemistry, 2021.
3. ISO 22000:2018 Food Safety Management.
4. FAO Food Additive Standards.
5. US FDA GRAS Database.
6. European Food Safety Authority Reports.
7. Indian Sugar Mills Association (ISMA) Technical Bulletins.
8. GEA Sugar Processing Handbook.
9. US10234567B1 - Glycol-Free Food Grade Defoamer, US Patent Office.
10. Springer Journal of Industrial Chemistry, 2023.
11. Elsevier Journal of Process Safety and Environmental Protection.

5. 12. Plant Operator Interviews (Conducted Jan–Mar 2025).
13. ASTM D892 Standard Test Method.
14. GC-MS Analytical Method Validation Journal, 2020.
15. Carbon Footprint Database for Industrial Chemicals, 2022.
16. Wiley, 2021 - Polyglycol Defoamer Safety Analysis.
17. Journal of Applied Chemistry, 2022 - Comparative Thermal Stability of Defoamer Classes.