SO2 Emission Control | BLDJ1W/100W Single Alkali Desulfurization System

🌊 Processing Capacity

• 📉 Gas Volume: 10,000 to 1,000,000 m3/h
• 🌡️ Allowable Gas Temp: <= 180 °C
• 🌫️ Inlet Sulfur Density: 1 to 1000 mg/Nm3
• ⚖️ Casing Pressure: -6000 to +6000 Pa

🎯 Purification Performance

• ✅ Outlet Emission: < 35 mg/Nm3
• ✅ Operating Resistance: 800 to 1300 Pa
• ✅ Scaling Risk: Near Zero (Clear Liquid)
• ✅ System Availability: > 98%

🏭 Ideal Applications

• 🏗️ Space-Constrained Sites: Compact footprint
• 🔥 Medium/Small Boilers: Industrial heating
• ⚗️ Complex Flue Gas: Low/Medium Sulfur
• ♻️ Byproduct Recovery: Sodium Sulfate recovery viable

The Single Alkali Working Principle

The Single Alkali process utilizes a highly soluble sodium-based absorbent (typically Sodium Hydroxide NaOH or Sodium Carbonate Na₂CO₃) to react with sulfur dioxide in the flue gas. Because sodium salts are highly soluble, the absorption takes place in a “clear liquid” state, completely eliminating the scaling and blockages that plague calcium-based systems inside the tower.

Core Chemical Reactions (Using NaOH):

1. Hydration: SO₂ + H₂O ⇌ H₂SO₃
2. Primary Absorption: H₂SO₃ + 2NaOH = Na₂SO₃ + 2H₂O (Forms sodium sulfite)
3. Excess Absorption: H₂SO₃ + Na₂SO₃ = 2NaHSO₃ (Forms sodium bisulfite when SO₂ is in excess)

Internal Component Configuration

The BLDJ1W series absorption tower is designed for maximum gas-liquid contact time and mist elimination:

• Absorber Body: Constructed of heavy-duty Carbon Steel with an interior lining of anti-corrosion Glass Flake coating to withstand the acidic environment.
• Slurry Spray Layers: Composed of advanced atomizing spray layers equipped with high-efficiency Silicon Carbide (SiC) nozzles. Droplets are controlled to 200 to 500 microns, maximizing the specific surface area for the chemical reaction.
• Multi-Stage Demister: Features two stages of high-efficiency demisters with an automated flushing system. Flue gas is forced through curved channels, separating entrained liquid droplets via inertia and gravity before exiting the stack.
• Circulation & Wash Pumps: Special desulfurization pumps featuring polymer-lined casings and wear-resistant impellers ensure continuous, stable liquid delivery.

Zero Internal Scaling

Because the sodium-alkali absorption liquid is completely clear and free of suspended solid calcium, the spray nozzles and demister blades will never scale or clog. This ensures the tower runs continuously without maintenance shutdowns.

Ultra-Fast Reaction Kinetics

Sodium alkali has a reaction rate with SO2 that is significantly higher than limestone (calcium carbonate). This allows for a much lower Liquid-to-Gas (L/G) ratio, meaning smaller circulation pumps, less power consumption, and a smaller tower height.

Compact Space Footprint

Designed specifically for retrofitting existing facilities, the Single Alkali system requires minimal land area. It bypasses the need for massive limestone preparation silos and complex gypsum dewatering systems.

The Clogging Crisis of Small Calcium Systems

Many small-to-medium plants attempted to use miniature limestone-gypsum systems to save money. The result? Severe scaling. Calcium sulfate hardens inside the spray nozzles and demisters, causing catastrophic blockages. This forces the plant to shut down the boiler frequently to physically chip away the scale, leading to massive production losses.

Relentless Regulatory Penalties

Environmental authorities demand continuous, unbroken SO2 compliance (< 35mg/Nm3). If a poorly designed FGD system trips or clogs, SO2 spikes are instantly recorded by the CEMS (Continuous Emission Monitoring System). This triggers automated, exorbitant fines and risks the revocation of your operating license.

Industrial Steam Boilers

Ideal for textile, paper, and food processing plants utilizing medium/small coal-fired or biomass boilers where land for a large FGD plant is physically unavailable.

Chemical & Metallurgical Kilns

Treats off-gases from specific chemical roasting, glass manufacturing, or ceramic kilns that produce low-to-medium sulfur concentrations but require ultra-high availability.

Projects Requiring Na2SO4 Recovery

In regions or industries where Sodium Sulfate (Na2SO4) has resale value (e.g., glass or detergent manufacturing), the single alkali method turns waste into a profitable byproduct.

For over 20 years, Ever-power has been the trusted authority in heavy industrial air purification. Our BL series is a technologically mature solution honed through decades of field application.

• ✔️ Full Value-Chain Integration: We don’t just sell parts. We provide Process Engineering ➔ Precision Manufacturing ➔ Site Installation ➔ Intelligent Commissioning.
• ✔️ Proven by Industry Giants: Our FGD systems successfully safeguard the compliance of massive conglomerates, including Tongchuan Shengwei, Shanshui Group, and Huarun Power.
• ✔️ Uncompromised Quality: Fully ISO certified, holding numerous environmental patents, ensuring every tower meets rigorous pressure and anti-corrosion standards.

The Cost of the Wrong System

• Maintenance Bleed: Forcing a limestone system into a small application leads to constant nozzle scaling. The labor cost of cleaning, combined with boiler downtime, destroys profitability.
• High CapEx: Building ball mills, slurry tanks, and vacuum filters for a small 50,000 m3/h boiler is an immense waste of capital.

The Ever-power Upgrade ROI

• CapEx Slashed: The system requires no complex grinding or dewatering equipment, reducing the initial investment by up to 40% compared to equivalent wet calcium systems.
• 100% Uptime: The clear-liquid absorption means zero scaling. Your boiler stays online, ensuring continuous production and absolutely zero environmental fines.

🇻🇳 Hanoi Textile Manufacturing (Vietnam)

Application: 75 t/h Coal-fired Steam Boiler

Challenge: The plant was located in a dense urban zone with zero space for a large FGD plant, facing imminent shutdown due to new SO2 regulations.

Solution: Ever-power engineered a compact BLDJ100W Single Alkali system. The entire footprint required less than 40m2. Outlet SO2 stabilized at 25 mg/Nm3, saving the plant from closure.

🇮🇳 Gujarat Chemical Works (India)

Application: Chemical Roasting Kiln Exhaust

Challenge: Fluctuating sulfur loads causing severe scaling in their old calcium-based scrubber, leading to weekly maintenance halts.

Solution: Retrofitted with our Single Alkali system using NaOH. The “clear liquid” absorption immediately ended all scaling issues. Boiler uptime increased to 99.5%, and maintenance costs dropped by 80%.

🇨🇳 Shaanxi Regional Heating Unit (China)

Application: 2x 35 t/h Winter Heating Boilers

Challenge: Required ultra-low emissions (<35mg) but possessed limited budget and extreme space constraints.

Solution: A single shared BLDJ1W absorber tower was designed for both boilers. The high reactivity of the sodium alkali ensured compliance during peak winter firing without requiring a massive tower.

🇧🇷 Sao Paulo Food Processing (Brazil)

Application: Biomass/Bagasse Boiler

Challenge: Needed an easy-to-operate system with low pumping power to maintain the factory’s overall green energy efficiency profile.

Solution: The low L/G ratio of our Single Alkali system meant much smaller circulation pumps were required. The system consumed 40% less parasitic electricity than a standard scrubber while eliminating SO2.