Alkali Resistant Coalescer: Reliable Separation in Caustic Environments
Product Introduction
The Alkali Resistant Coalescer is a specialized filtration system engineered to deliver uncompromised gas-liquid and liquid-liquid separation in environments dominated by alkaline fluids (caustic solutions) and corrosive alkaline gases. Unlike conventional coalescers, which degrade rapidly when exposed to alkalis (e.g., sodium hydroxide, potassium hydroxide, ammonia, or amine-based compounds), this coalescer combines alkali-inert materials, chemically stabilized coalescing media, and corrosion-resistant construction to maintain 99.9%+ contaminant removal efficiency.
Industries such as natural gas processing (amine sweetening units), aviation fuel handling (alkaline additive contamination), and hydraulic systems (alkaline hydrolysis byproducts) face significant risks from alkali-induced equipment failure, product contamination, and regulatory non-compliance. The Alkali Resistant Coalescer eliminates these challenges, protecting downstream assets, ensuring fluid purity, and reducing lifecycle costs.
Key Features & Advantages
1. Superior Alkali Resistance
Inert Material Construction: Housing made from Hastelloy® C-22 (nickel-chromium-molybdenum alloy) or 316L stainless steel with PTFE lining resists caustic pitting, crevice corrosion, and stress corrosion cracking from NaOH, KOH, NH₃, and amine solutions.
Alkali-Stable Media: Proprietary ceramic-reinforced polypropylene fibers or PVDF-impregnated glass microfibers prevent alkali-induced swelling, dissolution, or fiber shedding.
Seal Integrity: EPDM (ethylene propylene diene monomer) or Viton® (fluoroelastomer) seals withstand alkali permeation, avoiding leaks even in high-pH environments (pH 10–14).
2. High-Efficiency Coalescence in Alkaline Streams
Beta Ratio (β) > 25,000: Removes 99.9% of droplets ≥0.1 μm, including emulsified alkali-water mixtures, alkaline gas condensates, and particulates in caustic fluids.
Multi-Stage Design: Optional pre-coalescers (for bulk alkali/liquid separation) and fine coalescers (for submicron droplets) ensure tailored performance in complex alkaline streams.
3. Extreme Environmental Tolerance
Temperature Range: -40°C to +200°C (-40°F to +392°F), with cryogenic variants for LNG (liquefied natural gas) and high-temperature models for refinery alkaline off-gases.
Pressure Resistance: Rated for up to 250 bar (3625 psi), suitable for high-pressure amine sweetening units and hydraulic systems.
4. Longevity & Cost Efficiency
Extended Lifespan: 36–60 months in alkaline environments (vs. 6–12 months for standard coalescers), driven by alkali-inert materials and anti-corrosion media.
Low Maintenance: Hot-swappable cartridges and self-cleaning media reduce downtime by 50% during alkaline service changeouts.
5. Compliance with Industry Standards
Certifications: API 618 (gas processing), NACE MR0175 (sour service), ISO 16889 (hydraulic fluids), ASTM D1655 (aviation fuel), and PED 2014/68/EU (pressure equipment).
Working Principle
The Alkali Resistant Coalescer integrates alkali inertness with proven coalescence mechanics to ensure stable separation:
1. Alkali-Resistant Media Interaction
Alkaline fluid (gas or liquid) enters the coalescer and flows through the ceramic-polypropylene media. Alkalis (e.g., NaOH, ammonia) do not degrade the media, as the inert coating repels chemical attack and prevents structural breakdown.
2. Droplet Capture & Coalescence
Capture: Submicron droplets (0.1–5 μm) of water, alkaline condensates, or contaminants collide with media fibers via turbulent flow and electrostatic attraction.
Merging: Captured droplets merge into larger aggregates (50–1000 μm) due to the media’s tortuous pathways and hydrophobic/hydrophilic coatings. The alkali-resistant design ensures consistent fiber spacing, even in alkali-saturated streams.
3. Separation & Discharge
Gravity Separation: Enlarged droplets settle at the bottom of the housing (e.g., alkaline water in amine units, free water in alkaline hydraulic oil).
Clean Fluid Exit: Purified gas/liquid exits through the upper outlet, while collected alkali/water mixture is drained via a corrosion-resistant valve (e.g., Hastelloy® trim).
Application Scenarios
1. Natural Gas Amine Sweetening Units
Challenge: Amine sweetening units use aqueous amine solutions (e.g., monoethanolamine, MEA) to remove H₂S/CO₂ from natural gas. Alkaline amine condensates and entrained droplets foul compressors and reduce pipeline efficiency.
Solution: Removes 99.9% of alkaline condensates and water (β>25,000), meeting ISO 13678 pipeline specs. Hastelloy® C-22 housing resists amine corrosion, protecting compressors and extending unit life.
2. Aviation Fuel Alkaline Contamination Control
Challenge: Jet fuel (Jet A-1) may be contaminated with alkaline additives (e.g., corrosion inhibitors) or undergo alkaline hydrolysis, forming emulsified water-alkali mixtures. These risk icing in fuel lines or engine injector clogging.
Solution: EPDM/Viton seals and polypropylene media prevent alkali absorption, ensuring <1 ppm free water and <0.3 μm particulate removal (compliant with ASTM D1655 and DEF STAN 91-91).
3. Hydraulic Oil/Lubricant Alkali Protection
Challenge: Hydraulic systems and industrial lubricants accumulate alkaline byproducts (e.g., soap formation from hydrolysis) from heat and contamination. These alkalis cause seal hardening, pump wear, and oil degradation.
Solution: Breaks alkali-water emulsions, reduces alkali content by 85%, and extends oil life by 50% in alkaline environments.
Technical Data
Parameter | Specification |
|---|
Model | ARC-600 (Single-Stage), ARC-800 (Multi-Stage) |
Fluid Type | Amine solutions, aviation fuel, hydraulic oil, alkaline condensates, sour gas |
Operating Pressure | 1–250 bar (14.5–3625 psi) |
Temperature Range | -40°C to +200°C (-40°F to +392°F); cryogenic variant: -162°C (LNG) |
Flow Rate | 100–100,000 Nm³/h (gas); 50–5000 GPM (liquid) |
Beta Ratio (β) | β≥25,000 @ 0.1 μm; β≥50,000 @ 0.5 μm |
Removal Efficiency | 99.9% for 0.1–5 μm droplets; 99.99% for >5 μm (alkali/water emulsions) |
Pressure Drop | <0.05 bar @ rated flow (stable in alkaline streams) |
Alkali Resistance | NaOH, KOH, NH₃, MEA, DEA, TEA, and other amine solutions (pH 10–14) |
Lifespan | 36–60 months (alkaline environments) |
Certifications | API 618, NACE MR0175, ISO 16889, ASTM D1655, PED 2014/68/EU |
Maintenance Guidelines
1. Routine Inspection
Differential Pressure (ΔP): Monitor weekly; replace media if ΔP exceeds 0.1 bar (initial ΔP: 0.02–0.05 bar), indicating alkali-induced fouling or corrosion.
Visual Checks: Inspect housing for alkali pitting (quarterly) and seals for swelling/cracking (biannual).
2. Media Replacement
Use OEM-certified ceramic-polypropylene media to maintain alkali resistance.
For multi-stage systems, replace all media simultaneously to avoid flow imbalances.
3. Cleaning Protocols
Gas Service: Flush with dry nitrogen to remove residual alkaline condensates.
Liquid Service: Soak in a mild acidic detergent (pH 4–5) to neutralize alkalis, then rinse with deionized water.
4. Troubleshooting
Efficiency Drop: Check for media corrosion (incorrect material selection) or alkali breakthrough (exceeding β-ratio limits).
Leakage: Replace EPDM/Viton seals if swollen; retorque flange bolts to alkali-specific torque specs.
8 Frequently Asked Questions (FAQs)
1. What alkalis can this coalescer resist?
It resists sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonia (NH₃), and amine solutions (MEA, DEA, TEA) with pH 10–14. Consult our alkali compatibility chart for specific concentrations.
2. How does it differ from standard coalescers in amine units?
Standard coalescers corrode in amine/alkali environments (carbon steel degrades rapidly). This model uses Hastelloy® C-22 and alkali-stable media, maintaining efficiency for 36+ months.
3. Can it handle aviation fuel with alkaline additives?
Yes. Polypropylene media repels alkaline fuel additives, preventing swelling and ensuring <1 ppm water removal (compliant with ASTM D1655).
4. What is the maximum alkali concentration it can process?
Handles up to 30% aqueous amine solutions and 10,000 ppm alkaline contaminants in liquid fuels/oils.
5. Is it suitable for high-temperature refinery alkaline off-gases?
Yes. Ceramic-reinforced media withstands +200°C, resisting alkali corrosion in refinery flare gas or FCC unit off-gases.
6. How often should maintenance be performed in alkaline environments?
Inspect ΔP weekly, replace media every 3–5 years (or when ΔP >0.1 bar), and replace seals biannually.
7. Does it comply with offshore amine unit standards?
Yes. Certified to API RP 14E (offshore equipment) and NACE MR0103 (downhole equipment) for alkaline service.
8. What is the ROI for natural gas processors?
Reduces compressor downtime by 70%, cuts media replacement costs by 60%, and prevents alkali-induced corrosion—payback in 8–12 months.
Conclusion
The Alkali Resistant Coalescer is the definitive solution for industries operating in alkaline environments. By combining alkali-inert materials, stabilized media, and high-efficiency separation, it ensures reliable performance in amine sweetening units, aviation fuel purification, and hydraulic systems—even when exposed to NaOH, ammonia, or amine solutions. Whether preventing compressor fouling or extending oil life, this coalescer delivers unmatched durability and efficiency, safeguarding assets and maximizing profitability.
Ready to fortify your operations against alkali damage? Contact our engineers today for a customized solution.
