Stainless Steel Anaerobic Digester Tanks for Citrus Processing Plants

Stainless Steel Anaerobic Digester Tanks for Citrus Processing Plants

Shijiazhuang Zhengzhong Technology Co., Ltd (Center Enamel) delivers premium stainless steel anaerobic digester tanks engineered specifically for citrus processing plants, transforming high-acid, organic-rich wastewater into biogas energy and compliant effluent. These tanks address the unique challenges of citrus effluents—high BOD, low pH, and essential oils—while ensuring durability, hygiene, and energy recovery for sustainable operations worldwide.

As a leading storage tank manufacturer worldwide. Center Enamel can provide Glass Lined Steel(GLS) tanks, fusion bonded epoxy tanks, stainless steel tanks, galvanized steel tanks and aluminum geodesic dome roofs, Wastewater and Biogas Project Equipments for global customers.

WasteWater Treatment Project Equipment Supply

Citrus Wastewater: Composition and Treatment Challenges

Citrus processing generates over 700 million m³ of wastewater annually from juice extraction, peeling, and washing, characterized by BOD (2,500-4,500 mg/L), COD (5,000-10,000 mg/L), TSS (500-1,500 mg/L), pH <4.5, and inhibitory limonene oils. These traits cause foaming, sludge bulking, and corrosion in standard systems, risking odors, eutrophication, and regulatory violations. Anaerobic digestion excels by degrading 70-90% organics without aeration, producing 0.3-0.5 m³ biogas/kg COD while detoxifying oils.

Key hurdles include:

• Acidity inhibiting methanogens, requiring pH buffering.
• Oils causing hydrophobicity and biomass washout.
• Seasonal peaks overwhelming facilities.
• Nutrient imbalances (low N/P) needing supplementation.

Center Enamel tanks mitigate these via robust stainless steel construction and optimized designs.^[2]

Superiority of Stainless Steel Construction

Stainless steel (304/316L grades) outperforms concrete or coated steel in citrus environments due to corrosion resistance against H2S, acids, and limonene. Tanks last 25+ years with minimal maintenance, featuring smooth, non-porous surfaces for hygiene and easy CIP, essential for food-grade compliance.

Benefits include:

• Withstands pressures up to 0.5 bar and temperatures 35-55°C.
• Non-reactive, preserving biogas/digestate quality.
• Heat retention boosts energy efficiency by 20%.
• Global certifications: ISO 9001, CE, NSF/ANSI 61.

Unlike alternatives prone to delamination, stainless steel ensures zero leaks and low OPEX.

Innovative Design and Engineering Features

Center Enamel's cylindrical tanks with domed roofs (500-10,000 m³) optimize gas collection and stress distribution. Modular bolted assembly cuts install time by 50%, suiting remote citrus regions.

Core components:

• Mixing Systems: Hydraulic/mechanical agitators handle oils/TSS, preventing scum (90% dead zone reduction).
• Heating Jackets: Maintain mesophilic/thermophilic conditions for 60-80% VS reduction.
• Biogas Systems: Double-sealed holders capture >95% methane, with flares and monitoring.
• Controls: SCADA-integrated sensors track pH, VFA, temperature for real-time tweaks.

Operational Performance and ROI

Digesters achieve 85% COD removal at 6-16 day HRT, yielding biogas for 30-50% plant energy (e.g., boilers/CHP). Odor-free operation complies with EPA/EU limits (BOD <50 mg/L); digestate fertilizes crops, recycling nutrients.

Quantified gains:

• Sludge cut 50-70%.
• Payback 3-5 years via $0.05-0.10/kWh savings, fines avoidance.
• 91% BOD reduction in pilots.

For lemon concentrate plants, tanks handle extreme acidity, ensuring uptime.^[12]

Targeted Applications in Citrus Facilities

Tailored for:

• Juice/pulp wash (high BOD).
• Peel/oil effluents (limonene-rich).
• Evaporator CIP rinses.
• Co-digestion with packhouse waste.

Proven in Florida, Brazil, Mediterranean ops.

Regulatory Compliance and Sustainability

ATEX-rated, gas-tight designs slash methane emissions 95%, earning carbon credits. Supports biorefinery for limonene sales. Meets AWWA D103, food safety standards.

Choose Center Enamel for Citrus Success

Center Enamel's stainless steel anaerobic digesters turn citrus waste into profit, delivering unmatched reliability. Contact us for custom solutions.