500 m³/h Biogas Plant Complete Sizing Guide: BDS Biological Scrubber, DMG Gas Holder and Flare Configuration

When designing a 500 m³/h anaerobic digestion biogas plant (common in municipal sludge, food waste, and industrial wastewater treatment), selecting standardized, field-proven equipment with appropriate safety margins is critical for long-term reliability and CAPEX/OPEX optimization.

1. Biogas Flare Selection: Stepping Up to the 650 m³/h Standard Tier (DN150 PN10)

To ensure safe emergency combustion during peak gas production or CHP generator trips, the biogas flare must be sized slightly above the 500 m³/h nominal flow—stepping up to our 650 m³/h standard tier (Flange DN150 PN10). Depending on site duty and pipeline pressure, EnvironTec provides three distinct models:

• Option A — Model FAII-650 (Emergency / High Cost-Effectiveness): Designed for 25/30 mbar inlet pressure with outer dimensions of Φ1,500 mm × 7,700 mm. Ideal for intermittent emergency flaring where budget efficiency is prioritized.
• Option B — Model FAIII-650 (Continuous Enclosed Ground Flare / High-Spec): Designed for 25/30 mbar inlet pressure (flow range 390–650 m³/h) with dimensions of Φ1,700 mm × 8,377 mm. Equipped with an SS310S multi-nozzle Venturi burner and 170mm ceramic fiber insulation for 24/7 continuous, smokeless, invisible-flame combustion (850–1,100°C).
• Option C — Model FAIV-650 (Booster-Integrated High-Pressure Flare / Landfill & Low-Pressure): Integrates an explosion-proof VFD biogas booster blower (boosting pressure to 90 mbar / 10–20 kPa), fabricated in SS304L or SS316L for landfill gas or low-pressure collection networks.

2. Double Membrane Gas Holder: Why 2 Hours of Storage (1,000 m³) Selects Model DMG-1150

International biogas regulations recommend at least 2 hours of buffer storage: 500 m³/h × 2 hours = 1,000 m³ effective biogas volume. In EnvironTec's 2026 standard catalog, this matches Model DMG-1150 (Inner Effective Volume: 1,000 m³), featuring an outer membrane volume of 1,150 m³, maximum operating pressure of 22 mbar, 18 foundation anchor plates, and outer dimensions of Φ13.75 m diameter × 10.31 m height.

3. Biological Scrubber (BDS): Scaling Packing Volume by Inlet H2S Concentration

EnvironTec's BDS model numbers represent the effective microbial packing volume (m³), calibrated at a baseline of 2,500 ppm inlet H2S reduced to 200 ppm outlet H2S:

• Scenario 1 (Inlet H2S = 2,500 ppm → Outlet ≤ 200 ppm): Requires 60 m³ of packing volume → Select Model BDS-60 / BDS-65 (Tower dimensions: Φ2.90 m × 11.00 m height).
• Scenario 2 (Inlet H2S = 1,250 ppm → Outlet ≤ 200 ppm): Half sulfur load requires half packing volume (30 m³) → Select Model BDS-30 (Tower dimensions: Φ2.50 m × 7.50 m height).
• Scenario 3 (Inlet H2S = 5,000 ppm → Outlet ≤ 200 ppm): Double sulfur load requires double packing volume (120 m³) → Step up to Model BDS-125 (125 m³ packing, Tower dimensions: Φ3.50 m × 14.00 m height).
• Scenario 4 (Strict Outlet < 50 ppm or Non-Standard High Load): Select BDS-Custom-Made or pair BDS with our DTII-500 / DTII-800 Dry Scrubber or ACF-650 Active Carbon Filter, plus GF-650 Gravel Filter and GC-650 Biogas Chiller (23.2 kW cooling capacity).