Mercury Specialist

Sulfur Impregnated Activated Carbon

Q: How does sulfur impregnated carbon remove mercury?

Elemental sulfur dispersed in the carbon pores reacts with mercury vapor (Hg⁰) to form stable mercuric sulfide (HgS). This chemisorption mechanism is highly selective for mercury even in the presence of other flue gas components like SO₂, NOx, and moisture.

Q: Sulfur vs KI impregnation for mercury — which is better?

Sulfur-impregnated carbon is more cost-effective for high-temperature applications (up to 200°C) such as coal-fired flue gas. KI-impregnated carbon excels at lower temperatures and is preferred for nuclear off-gas and radioactive iodine removal. For most industrial mercury applications, sulfur is the standard choice.

Q: Is spent sulfur-impregnated carbon hazardous waste?

The captured mercury is bound as mercuric sulfide (HgS), which is thermally stable and non-leachable. In most jurisdictions spent carbon passes the TCLP leach test (Hg < 0.2 mg/L) and is classified as non-hazardous. Always confirm against your local regulations — we provide typical TCLP data on request to support your waste classification.

Q: Can sulfur carbon be injected directly into hot flue gas?

Yes. Because it works up to 200°C, sulfur-impregnated carbon can be used in fixed guard beds or as powdered activated carbon (PAC) injected upstream of the particulate collector, avoiding the capital cost of flue gas pre-cooling. Pellet form is used for guard beds; PAC form for direct injection.

Q: What sulfur loading do I need for my Hg concentration?

For typical coal flue gas (5–30 μg/Nm³ Hg), 5–10% sulfur loading is sufficient. Higher-concentration streams such as chlor-alkali off-gas or waste incineration may warrant 10–15%. Higher loading raises capacity but slightly lowers surface area, so we match loading to your inlet concentration and target outlet for the best cost-per-gram-Hg.

Sulfur-loaded carbon for mercury (Hg⁰) vapor capture from coal-fired power plants, waste incinerators, and chlor-alkali plants. >99% removal efficiency.

⚡ Quick Answer

Sulfur impregnated activated carbon is coal-based pellet or granular carbon loaded with 5–15% elemental sulfur that reacts with mercury vapor (Hg⁰) to form stable, non-leachable mercuric sulfide (HgS). It captures mercury from coal-fired flue gas, waste incineration, and chlor-alkali off-gas at over 99% efficiency and operates up to 200 °C.

Sulfur Loading: 5 – 15% by weight
Hg Removal: > 99% (ASTM D6784)
Mercury Capacity: ≥ 4 mg Hg/g
Operating Temp: 20 – 200 °C

Product Overview

Sulfur impregnated activated carbon is specifically designed for mercury vapor (Hg⁰) removal from flue gas, industrial exhaust, and process streams. Elemental sulfur is uniformly distributed within the carbon's micropore structure, where it reacts with gaseous mercury to form thermally stable mercuric sulfide (HgS) — a non-leachable compound safe for landfill disposal.

Unlike standard activated carbon which relies on physical adsorption alone, sulfur impregnation provides a chemical reaction pathway that is highly selective for mercury even at elevated temperatures (up to 200°C) and in the presence of competing gases like SO₂, NOx, and HCl.

Key Applications

Coal-fired power plant flue gas
Municipal waste incineration
Chlor-alkali plant cell gas
Cement kiln exhaust
Natural gas mercury guard beds
Crematorium emission control
Gold mining process gas
Industrial boiler flue gas

Regulatory Standards & Test Methods

Standard	Context
ASTM D6784 (Ontario Hydro Method)	Benchmark mercury measurement in flue gas
EPA MATS (40 CFR Part 63)	US coal plant Hg limit: 1.2 lb/TBtu
EU IED Directive 2010/75/EU	EU industrial Hg emission limit: 0.03 mg/Nm³
China GB 13271	Boiler mercury limit: 0.05 mg/m³
Typical Hg inlet in coal flue gas	5 – 30 μg/Nm³
Outlet after S-AC bed	< 0.5 μg/Nm³

Application Example

Chlor-Alkali Plant — Mercury Guard Bed, Southeast Asia

A chlor-alkali plant producing 100,000 MT/year of caustic soda uses mercury cells that generate 5–15 μg/Nm³ Hg in the hydrogen off-gas stream. A 1,200-liter sulfur-impregnated carbon bed (10% S loading, Φ4mm pellets) maintains outlet Hg below 0.2 μg/Nm³ continuously. Carbon is replaced every 24 months. HgS-laden spent carbon is classified as non-hazardous waste after TCLP leach testing confirms <0.2 mg/L leachate Hg.

Technical Specifications

Model	HojeeMerc S-Series
Impregnant	Elemental Sulfur (S)
Sulfur Loading	5 – 15% by weight
Base Carbon	Coal pellet Φ4mm / Granular 4×10
Mercury Capacity	≥ 4 mg Hg/g carbon
Hg Removal Rate	> 99% (ASTM D6784)
Operating Temp	20 – 200 °C
Iodine Number	500 – 800 mg/g
Hardness	> 92%
Moisture	< 5%
Bulk Density	0.45 – 0.58 g/cm³

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Other Impregnated Products

KOH Impregnated — H₂S →Silver Impregnated — Antibacterial →KMnO₄ Impregnated — VOC →K₂CO₃ Impregnated — Low-Corrosivity H₂S →H₃PO₄ Impregnated — Ammonia/Amines →← All Impregnated AC

Why Sulfur Carbon vs Alternatives

🎯

Highly Selective

HgS chemisorption is extremely selective — SO₂, NOx, CO₂ and moisture in flue gas do not competitively displace mercury, unlike physical adsorbents.

🔥

High-Temp Capable

Effective up to 200°C, making it suitable for direct injection into hot flue gas streams without pre-cooling — reduces capital cost significantly.

♻️

Safe Disposal

HgS product is thermally stable and passes TCLP leach tests (Hg <0.2 mg/L), classifying spent carbon as non-hazardous in most jurisdictions.

📏

Proven at Scale

Used in EPA MATS compliance at hundreds of US coal plants since 2015. ASTM D6784 test data available on request.

Packaging & Handling

25 kg

Sealed PE-lined bags

Kraft-paper outer, low-dust fill for guard beds

500 kg

Jumbo bags + liner

Forklift ready, palletized for FCL

1000 kg

Super sacks

Bulk power-plant / incinerator supply

Custom

Drums / OEM

Steel drums for regulated Hg-service sites

Sulfur-impregnated carbon is kept sealed to prevent sulfur loss and moisture uptake in storage. Spent, mercury-laden carbon should be handled per local hazardous-material rules; we supply typical TCLP data to support your waste classification.

Frequently Asked Questions

How does sulfur impregnated carbon remove mercury?

Elemental sulfur dispersed in the carbon pores reacts with mercury vapor (Hg⁰) to form stable mercuric sulfide (HgS). This chemisorption mechanism is highly selective for mercury even in the presence of other flue gas components like SO₂, NOx, and moisture.

Sulfur vs KI impregnation for mercury — which is better?

Sulfur-impregnated carbon is more cost-effective for high-temperature applications (up to 200°C) such as coal-fired flue gas. KI-impregnated carbon excels at lower temperatures and is preferred for nuclear off-gas and radioactive iodine removal. For most industrial mercury applications, sulfur is the standard choice.

Is spent sulfur-impregnated carbon hazardous waste?

The captured mercury is bound as mercuric sulfide (HgS), which is thermally stable and non-leachable. In most jurisdictions spent carbon passes the TCLP leach test (Hg < 0.2 mg/L) and is classified as non-hazardous. Always confirm against your local regulations — we provide typical TCLP data on request to support your waste classification.

Can sulfur carbon be injected directly into hot flue gas?

Yes. Because it works up to 200°C, sulfur-impregnated carbon can be used in fixed guard beds or as powdered activated carbon (PAC) injected upstream of the particulate collector, avoiding the capital cost of flue gas pre-cooling. Pellet form is used for guard beds; PAC form for direct injection.

What sulfur loading do I need for my Hg concentration?

For typical coal flue gas (5–30 μg/Nm³ Hg), 5–10% sulfur loading is sufficient. Higher-concentration streams such as chlor-alkali off-gas or waste incineration may warrant 10–15%. Higher loading raises capacity but slightly lowers surface area, so we match loading to your inlet concentration and target outlet for the best cost-per-gram-Hg.

Mercury Compliance Made Simple

Tell us your Hg concentration, temperature, and flow rate. We will recommend the right sulfur loading and bed size.

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