H2S Scrubber System: Industrial Hydrogen Sulfide Removal

Why Our H2S Scrubber Is Different

About XICHENG EP

XICHENG EP LTD is an industrial air pollution control equipment manufacturer with 16+ years of production experience, 2,600+ systems shipped, and installations in 60+ countries. We manufacture in Shenzhen, China, with in-house PP fabrication, FRP winding, and assembly capabilities. Every H2S scrubber undergoes a water-tightness test, electrical continuity check, and full-load recirculation test before crating and shipment.

Certifications and Compliance

• CE Marking — Machinery Directive 2006/42/EC, EMC Directive 2014/30/EU
• RoHS — 2011/65/EU compliant materials
• ISO 9001:2015 — Quality management system
• ISO 14001:2015 — Environmental management system
• SGS material testing — PP sheet, FRP laminate, weld integrity
• Designed to meet US EPA NESHAP and OSHA 1910.94 ventilation standards
• Design basis per EU 2010/75/EU Industrial Emissions Directive (IED)

How H2S Scrubbing Works

Hydrogen sulfide removal uses chemical absorption — the H₂S-laden gas contacts a scrubbing solution inside a packed column, where a fast chemical reaction converts the gaseous pollutant into a non-volatile compound that stays dissolved in the liquid phase. The cleaned gas exits through a demister at the top; the spent scrubbing liquid is recirculated with automatic chemical replenishment.

Method 1: Caustic Scrubbing (NaOH)

The most widely used H2S scrubbing method. Reaction: H₂S + 2NaOH → Na₂S + 2H₂O. Sodium sulfide remains dissolved in the scrubbing liquid. Removal efficiency: 95-99% at L/G ratio 0.7-0.9 L/m³ with 1.0-1.2 m of PP packing depth. Chemical cost: $0.30-0.60 per kg H₂S removed. Spent caustic requires oxidation before discharge — typically air sparging in a separate tank. See our caustic scrubber system guide for detailed design parameters.

Method 2: Oxidative Scrubbing (NaOCl or H₂O₂)

Oxidizing agents convert H₂S directly to elemental sulfur: H₂S + NaOCl → S↓ + NaCl + H₂O. The sulfur precipitates as a fine yellow solid, filtered from the recirculation loop. Preferred when spent liquid discharges to municipal sewer — sulfate is far less regulated than sulfide. Chemical cost: $0.80-1.50 per kg H₂S removed. Higher chemical cost than caustic, but lower waste treatment cost often makes this the cheaper total-cost solution.

Method 3: Chelated Iron (for loads above 100 kg H₂S/day)

For continuous high-load applications, a chelated iron catalyst cycles between Fe³⁺ and Fe²⁺: H₂S + 2Fe³⁺ → S↓ + 2Fe²⁺ + 2H⁺. The catalyst is regenerated by air oxidation and is not consumed. Only air and small chelating-agent makeup are required. Higher capital cost than caustic, but for loads above 200 kg H₂S/day, the payback from eliminated chemical purchases is typically 12-18 months.

Technical Specifications

Parameter	Caustic System	Oxidative System
H₂S inlet range	10 – 50,000+ ppm	10 – 5,000 ppm
H₂S outlet	＜1 – 10 ppm	＜1 – 5 ppm
Removal efficiency	95-99%	97-99%+
L/G ratio	0.7-0.9 L/m³	0.5-0.8 L/m³
Packing depth	1.0-1.2 m (PP Pall rings)	0.8-1.0 m (PP Pall rings)
Gas velocity	1.0-1.5 m/s	1.0-1.5 m/s
Operating pH	8-10	7-9 (NaOCl) / 8-10 (H₂O₂)
Chemical consumption	~2.4 kg NaOH / kg H₂S	~2.1 kg NaOCl / kg H₂S
Waste product	Na₂S solution (requires oxidation)	Elemental S slurry (filterable)
Materials	PP / FRP / Dual-Laminate	PP / FRP (NaOCl compatible)

Industries and Applications

Industry	H₂S Source	Typical Concentration	Recommended Chemistry
Wastewater treatment	Headworks, clarifiers, sludge dewatering	10-500 ppm	NaOH + NaOCl two-stage
Biogas purification	Anaerobic digester gas	500-5,000 ppm	NaOH or chelated iron
Petroleum refining	Sour water stripper, fuel gas, flare gas	1,000-50,000+ ppm	NaOH with spent caustic oxidation
Natural gas processing	Raw natural gas, amine tail gas	500-20,000 ppm	Amine + caustic polishing
Chemical manufacturing	Reactor vents, sulfur recovery tail gas	100-5,000 ppm	NaOH or NaOCl
Pulp and paper	Kraft process, black liquor oxidation	100-2,000 ppm	NaOH with NaOCl polishing

How to Order

1. Send your operating data: Gas flow rate (CFM or m³/hr), inlet H₂S concentration (ppm), required outlet limit per your permit, gas temperature, and available site footprint. Contact our engineering team at air-emissions.com/contact.
2. Receive your proposal: Within 48 hours, we provide a preliminary sizing, process flow diagram, budget price, and delivery timeline — no obligation.
3. Review and approve: Once the proposal meets your requirements, we issue a formal quotation with detailed technical specifications.
4. Engineering and drawing approval: We produce the P&ID, general arrangement drawing, and electrical schematic for your review and sign-off before fabrication begins.
5. Manufacturing and testing: 6-10 weeks fabrication. Pre-shipment water-tightness test, recirculation test, and control system checkout. You are welcome to inspect at our facility or via video call.
6. Shipping and commissioning: Containerized sea freight or air freight. Remote commissioning support via video call included. Optional on-site supervision available.

Complete Your System

An H2S scrubber works best as part of an integrated air treatment system:

• Upstream: PP ductwork to convey H₂S-laden exhaust from the source to the scrubber inlet — corrosion-resistant, single-material system eliminates duct leaks
• Downstream: Activated carbon adsorber as a polishing stage for residual H₂S and odor compounds below 1 ppm
• Liquid waste: Spent caustic oxidation tank — air sparging or peroxide dosing to convert sulfides to sulfates before sewer discharge
• Monitoring: Continuous H₂S analyzer at the stack outlet with data logging for compliance reporting

Global Shipping

We ship H2S scrubber systems worldwide from our Shenzhen manufacturing facility. Regular containerized sea freight to ports in North America (Los Angeles, Houston, New York), Europe (Rotterdam, Hamburg, Antwerp), the Middle East (Jebel Ali, Dammam), Southeast Asia (Singapore, Port Klang), and Australia (Sydney, Melbourne). Air freight available for urgent deliveries and smaller units. All equipment is crated, shrink-wrapped, and container-loaded with desiccant for ocean transit.

Frequently Asked Questions

What does an H2S scrubber remove?

An H2S scrubber removes hydrogen sulfide — a toxic, corrosive gas with a rotten-egg odor — from industrial exhaust, biogas, and foul air streams. The scrubber chemically converts H₂S into a dissolved salt (sodium sulfide) or elemental sulfur. A properly sized system achieves 95-99%+ removal, reducing outlet H₂S below 1 ppm for odor-sensitive sites or below 10 ppm for health compliance.

What scrubbing chemistry should I use for H₂S?

Caustic (NaOH) is the most common and lowest chemical cost — $0.30-0.60 per kg H₂S removed. Use caustic if you have on-site wastewater treatment that can handle sulfide-containing effluent. Use oxidative (NaOCl or H₂O₂) if you discharge directly to a municipal sewer — sulfate is far less regulated than sulfide. Use chelated iron for continuous loads above 200 kg H₂S/day — higher capital cost but near-zero chemical cost pays back in 12-18 months. We help you choose based on your waste-handling situation.

What is the typical lead time?

Standard fabrication lead time is 6-10 weeks from drawing approval, depending on system size and complexity. Rush fabrication (4-5 weeks) is available for time-sensitive projects at a 15-20% premium. Sea freight adds 2-6 weeks depending on destination; air freight adds 3-7 days. Contact us with your required on-site date and we will confirm feasibility.

Can you build an H2S scrubber to our specific dimensions?

Yes. Every system is custom-engineered. We size the vessel diameter and height to your gas flow rate and H₂S concentration, select the packing depth and type to your removal target, and configure the layout — vertical or horizontal, indoor or outdoor, with your choice of nozzle and access port locations — to your site constraints. There is no standard catalog size you are forced into.

What maintenance does an H2S scrubber require?

Daily: check sump pH and liquid level. Weekly: inspect and calibrate the pH or ORP probe. Monthly: check demister pressure drop. Quarterly: inspect spray nozzles for clogging. Annually: drain sump, inspect vessel interior and packing condition, replace pH probe. PP vessels require no internal recoating. The recirculation pump should be inspected every 2,000 operating hours. Packing media replacement every 5-7 years under normal operation.

Do you offer mini or small H2S scrubbers for lab or pilot-scale use?

Yes. For low-flow applications — laboratory fume hood exhaust, pilot plant vents, or electrical control rooms — we build compact H2S scrubbers starting at 500 CFM (850 m³/hr). These mini H2S scrubber units use the same packed-column design as our industrial systems, scaled down to a single PP column with a small-footprint sump tank and integrated dosing pump. For flows below 200 CFM, an activated carbon adsorber with H₂S-impregnated media is typically more cost-effective than a wet scrubber. Contact our team with your flow rate and we will recommend the right scale.

Learn More

• Gas Scrubber Design Calculation Guide — Step-by-step formulas and sizing methods
• Caustic Scrubber System Introduction — How NaOH scrubbing works for acid gases
• What Is a Gas Scrubber? — Fundamentals of wet scrubbing technology
• Packed Bed Tower Scrubbers — Deep dive into packed column design