Power Groups: Thermal Power

I. Customer Pain Points

Power generation groups (specifically thermal power plants) face three core challenges regarding flue gas treatment: "regulatory compliance pressure," "soaring costs," and "equipment corrosion." These issues directly threaten unit operations and profitability:
1. Upgraded Emission Standards: "Legacy Processes" Are No Longer Sufficient
China's *Emission Standard of Air Pollutants for Thermal Power Plants* (GB 13223-2011) mandates limits of "SO₂ ≤ 50 mg/m³" and "NOₓ ≤ 100 mg/m³" (with a stricter limit of ≤ 50 mg/m³ in key regions). The EU's *Industrial Emissions Directive* (2010/75/EU) imposes even stricter limits: "SO₂ ≤ 30 mg/m³" and "NOₓ ≤ 40 mg/m³." However, traditional methods—such as the "limestone-gypsum method" (with a desulfurization efficiency of 90%) and "SCR denitrification" (with an efficiency of 80%)—are unable to simultaneously remove SO₃ (acid mist, at concentrations of 10–50 mg/m³) and heavy metals (specifically Hg, at concentrations of 0.1–1 mg/m³). Consequently, enterprises frequently incur fines for "exceeding limits on synergistic pollutants" (in 2022, China recorded 1,200 cases of thermal power plants exceeding emission limits, with an average fine of 800,000 RMB per case).
2. High Operating Costs: The "Activated Carbon + Regeneration" Model Is Unsustainable
Traditional desulfurization and denitrification processes utilizing activated carbon require a multi-step sequence: "adsorption → steam regeneration → sulfuric acid recovery." The cost of regeneration alone exceeds 0.5 RMB per kilogram of SO₂, while the replacement cost for catalysts (typically vanadium, titanium, and tungsten) exceeds 200 RMB per cubic meter. For a single one-million-kilowatt power generation unit, the annual cost of desulfurization and denitrification exceeds 50 million RMB—accounting for 15% of the unit's total operating costs.
3. Severe Equipment Corrosion: A Threat to Unit Lifespan
When SO₃ combines with water, it forms sulfuric acid mist (H₂SO₄, at concentrations of 10–30 mg/m³), which corrodes induced draft fans and chimneys (at a corrosion rate exceeding 0.1 mm per year). Because traditional processes lack a design for the "synergistic removal of SO₃," power generation units experience an unplanned shutdown rate of 5% (based on 2022 statistics for unplanned shutdowns in China's thermal power sector); each individual shutdown results in financial losses exceeding 2 million RMB. Low Value of Byproducts Hinders Implementation of "Circular Economy"
The utilization rate of desulfurization gypsum (CaSO₄·2H₂O) generated by the limestone-gypsum method is merely 60% (with the remaining 40% being stockpiled). Furthermore, the dilute sulfuric acid (10–30%) produced during activated carbon desulfurization cannot be sold directly due to its low concentration, resulting in an annual loss of value exceeding 1 million RMB per power generation unit—a situation that fails to meet the "resource circulation" requirements mandated by the "Dual Carbon" goals.

II. Application Objectives

The four core objectives driving power generation groups to adopt activated carbon technology are closely aligned with the principles of "Compliance, Cost Reduction, Safety, and Circularity":

Strict Compliance and Mitigation of Regulatory Risks
Meeting Global Flue Gas Emission Standards for Thermal Power Plants:
China GB 13223-2011: SO₂ ≤ 50 mg/m³, NOₓ ≤ 100 mg/m³ (≤ 50 mg/m³ in key control areas);
EU Directive 2010/75/EU: SO₂ ≤ 30 mg/m³, NOₓ ≤ 40 mg/m³;
US EPA Mercury and Air Toxics Standards (MATS): Hg ≤ 0.003 lb/MWh.

Synergistic Removal of Multiple Pollutants and Elimination of Equipment Corrosion
Activated carbon employs a synergistic mechanism of "adsorption + catalysis" to remove SO₂, NOₓ, SO₃, and Hg. Notably, the removal rate for SO₃ exceeds 95% (reducing acid mist concentration to < 1 mg/m³), thereby lowering the corrosion rate of induced draft fans to < 0.02 mm/year and reducing the rate of unplanned shutdowns to < 1%.

Cost Reduction and Replacement of Energy-Intensive Processes
The operating cost of activated carbon (particularly activated coke derived from lignite) is merely 0.2–0.4 RMB per kilogram of removed SO₂—approximately one-third the cost of the limestone-gypsum method. Furthermore, the material can be regenerated 3 to 5 times (with regeneration costs amounting to only 30% of the cost of new carbon). Consequently, a 1,000 MW power generation unit saw its annual desulfurization and denitrification costs plummet from 50 million RMB to 15 million RMB—a reduction of 70%.

High-Value Utilization of Byproducts: Realizing a Circular Economy
The concentrated sulfuric acid (30–50%) generated during activated carbon desulfurization can be sold directly (for use in fertilizers and the chemical industry). Furthermore, the mercury (Hg) recovery rate exceeds 90% (recovered as HgS residue, valued at 5,000 RMB per ton)—for a specific power generation unit, the annual revenue from these byproducts exceeds 2 million RMB, offsetting 10% of its operating costs.

III. Significance of Application

The application of activated carbon in the treatment of flue gas from thermal power plants serves as a core pillar supporting enterprises in achieving "regulatory compliance, cost reduction and efficiency improvement, and 'Dual Carbon' targets":

• Compliance Baseline: Globally, 80% of cases involving thermal power plants exceeding emission limits stem from a failure to adopt "synergistic treatment" processes. Activated carbon is one of the few technologies capable of simultaneously removing SO₂, NOₓ, SO₃, and Hg while maintaining controllable costs; it directly determines whether an enterprise can secure the necessary "Pollutant Discharge Permit."
• Safety Assurance: Between 2021 and 2022, 60% of unplanned shutdown incidents at Chinese thermal power plants were attributed to SO₃ corrosion of induced draft fans. Activated carbon's design—featuring "synergistic SO₃ removal"—can reduce a unit's unplanned shutdown rate from 5% to less than 1%, thereby averting losses of 2 million RMB per incident.
• Cost Optimization: A case study from a major power generation group demonstrates that, following the adoption of the "activated coke desulfurization and denitrification" process, annual operating costs were reduced by 70% (specifically, a 80% reduction in limestone consumption and a 50% reduction in catalyst replacement frequency). This is equivalent to an annual increase in profit of 35 million RMB.
• Support for "Dual Carbon" Goals: The CO₂ emissions generated by activated carbon-based desulfurization and denitrification are only half of those produced by the traditional limestone-gypsum method (0.1 tons of CO₂ per ton of SO₂ vs. 0.2 tons of CO₂ per ton of SO₂). For a specific power generation unit, this translates to an annual reduction of 50,000 tons of CO₂ emissions—equivalent to planting 270,000 trees. IV. Application History

The application of activated carbon in the treatment of flue gas from thermal power plants has gradually gained widespread adoption, driven by the convergence of "upgraded emission standards" and the "demands of the circular economy":
1980s: The Inception Phase
Germany's Lurgi GmbH pioneered the use of activated coke (derived from lignite) to treat thermal power plant flue gas (with an SO₂ concentration of 1,000 mg/m³). Utilizing a process involving "moving-bed adsorption combined with thermal regeneration," the technology achieved a desulfurization efficiency of 95%, marking the advent of the first industrialized activated carbon-based desulfurization technology.
2000s: The Promotion Phase
China's "11th Five-Year Plan" designated "flue gas desulfurization and denitrification in thermal power plants" as a key priority, thereby driving the adoption of "integrated activated carbon processes." In 2005, a 1,000 MW power generation unit successfully utilized activated coke to reduce its SO₂ concentration from 1,000 mg/m³ to 30 mg/m³, becoming the first domestic project to meet the applicable emission standards.
2010s: The Upgrading Phase
The implementation of the EU's *Industrial Emissions Directive* (2010/75/EU)—which mandated strict limits of "SO₂ ≤ 30 mg/m³ and NOₓ ≤ 40 mg/m³"—spurred the widespread adoption of modified activated carbon (specifically, carbon loaded with NH₃ or K₂O). In 2015, a power generation unit in Germany deployed this modified carbon, resulting in an increase in NOₓ removal efficiency from 60% to 85%, while maintaining an SO₂ removal efficiency of 95%.
2020s: The Intelligent Phase
China's *14th Five-Year Plan for a Modern Energy System* established a requirement that the "comprehensive treatment rate for thermal power plant flue gas" must reach or exceed 90%. In response, activated carbon technologies have been integrated with "online monitoring and automated regeneration" systems to enable "precision adsorption"—for instance, by automatically adjusting the movement speed of the activated coke based on real-time SO₂ concentrations—thereby achieving a 20% reduction in operational costs. V. Mechanism of Action
Activated carbon addresses the challenges associated with thermal power plant flue gas—specifically its "multiple pollutants, high concentrations, and high corrosivity"—through a triple-action mechanism comprising "physical adsorption + chemical catalysis + synergistic regeneration":
1. Physical Adsorption: "Broad-Spectrum Sieving" via Pore Structure
Micropores (<2 nm): Constituting 60–70% of the total pore volume, these pores adsorb small-molecule pollutants (e.g., SO₂, with a molecular diameter of ≈0.36 nm; NO, ≈0.317 nm) via van der Waals forces. Their adsorption capacity reaches 200–300 mg/g (five times that of limestone).
Mesopores (2–50 nm): Acting as "transport channels," these pores facilitate the diffusion of medium-sized pollutant molecules (e.g., SO₃, ≈0.4 nm; Hg⁰, ≈0.3 nm) into the micropores; simultaneously, they adsorb heavy metal mercury (Hg, molecular diameter ≈0.3 nm).
Macropores (>50 nm): Serving as "entry channels," these pores allow large fly ash particles (>1 μm) to enter the interior of the activated carbon, though their direct contribution to adsorption is negligible.
2. Chemical Catalysis: "Targeted Conversion" via Surface Functional Groups
SO₂ Removal: Basic functional groups on the activated carbon surface (such as pyrones and pyridones) adsorb SO₂; this is followed by catalytic oxidation (involving O₂) to convert the SO₂ into SO₃, which ultimately combines with water to form H₂SO₄ (stored within the activated carbon's pore structure).
NOₓ Removal: Activated carbon loaded with NH₃ converts NOₓ into N₂ via Selective Catalytic Reduction (SCR) at reaction temperatures of 120–150°C, achieving a removal efficiency of >85% (without the need for additional catalysts).
Hg Removal: Chlorine-containing functional groups (-Cl) on the activated carbon surface convert elemental mercury (Hg⁰) into mercuric chloride (HgCl₂, a water-soluble form) through chemical adsorption, achieving a removal efficiency of >90%. 3. Synergistic Regeneration: A "Key Step" in Cost Reduction
Through thermal regeneration (at 400–500°C under an inert gas atmosphere), saturated activated carbon desorbs H₂SO₄, converting it into SO₂ (at a concentration of 10–15%). This SO₂ is then sent to a sulfuric acid plant to be processed into concentrated sulfuric acid (98%). Meanwhile, Hg is concentrated within the regeneration residue, achieving a recovery rate of >90%. The adsorption capacity of the regenerated carbon can reach 80% of that of fresh carbon, yet its cost is only 30% of the cost of fresh carbon.

VI. Application Methods

A major power generation group has adopted a combined process featuring an "activated coke moving bed (primary treatment) + aqueous ammonia injection (NOₓ removal) + thermal regeneration (byproduct recovery)." This system is designed to address scenarios characterized by "high pollutant concentrations, multiple contaminants, and high corrosivity."
1. Activated Coke Moving Bed: Primary Treatment Unit (SO₂, SO₃, Hg)
Applicable Scenarios: Megawatt-scale power units (flue gas flow rate: 1 million m³/h; SO₂ concentration: 800–1500 mg/m³; NOₓ concentration: 300–500 mg/m³).
Process Steps:
Adsorption: Flue gas enters the moving-bed adsorption tower (packed with activated coke, particle size: 5–10 mm) at a flow velocity of 0.5–1.0 m/s, with a contact time of 5–10 seconds. This achieves SO₂ removal rates of >95%, SO₃ removal rates of >95%, and Hg removal rates of >90%.
Movement: Saturated activated coke is discharged from the bottom of the tower and conveyed to the regeneration system, while fresh activated coke is replenished from the top of the tower.
Key Parameters:
Activated Coke Specifications: Lignite-based; Iodine Value ≥ 800 mg/g; Mechanical Strength ≥ 90%.
Adsorption Capacity: SO₂ ≥ 300 mg/g; Hg ≥ 50 mg/g.
Regeneration Cycle: 6–12 months (adjusted based on flue gas pollutant concentrations).
2. Aqueous Ammonia Injection: Auxiliary NOₓ Removal Unit
Applicable Scenarios: Flue gas with low NOₓ concentrations (<300 mg/m³). Process Steps:
Aqueous ammonia (5–10%) is injected at the inlet of the adsorption tower, where it undergoes an SCR reaction with NOₓ on the surface of the activated carbon (at 120–150°C), achieving an NOₓ removal efficiency of >85%.
3. Thermal Regeneration System: Byproduct Recovery (Concentrated Sulfuric Acid, Hg)
Applicable Scenario: Regeneration of saturated activated coke.
Process Steps:
Heating: The saturated activated coke is fed into a regeneration furnace (at 400–500°C under N₂ protection), where the adsorbed H₂SO₄ decomposes into SO₂ (at a concentration of 10–15%).
Conversion: The generated SO₂ is sent to a sulfuric acid plant to be converted into concentrated sulfuric acid (98%); meanwhile, the mercury (Hg) present in the regeneration residue is enriched and processed into HgS residue (with a recovery rate of >90%).

VII. Application Process

Taking a 1,000 MW thermal power unit as an example (with a flue gas flow rate of 1,000,000 m³/h, SO₂ concentration of 1,000 mg/m³, NOₓ concentration of 400 mg/m³, and SO₃ concentration of 20 mg/m³):
Pre-treatment: Electrostatic Precipitator (removes fly ash with an efficiency of 99.5%, reducing fly ash concentration to <50 mg/m³).
Main Treatment: Activated Coke Moving-Bed Adsorption Towers (2 units, operated alternately; each unit holds 500 tons of coke with a particle size of 5–10 mm) → Aqueous Ammonia Injection System (5% aqueous ammonia, injection rate: 10 m³/h).
Regeneration System: Thermal Regeneration Furnace (400°C, N₂ protection) → Sulfuric Acid Plant (converts SO₂ into 98% concentrated sulfuric acid) → Hg Recovery Unit (processes regeneration residue into HgS residue).
Emissions: Stack Discharge (SO₂ ≤ 30 mg/m³, NOₓ ≤ 40 mg/m³, SO₃ ≤ 1 mg/m³, Hg ≤ 0.003 lb/MWh).

VIII. Application Results

Following the retrofit of a 1,000 MW power unit, key performance indicators demonstrated significant improvement (based on actual operational data):

Parameters	Pre-retrofit (Limestone-Gypsum + SCR)	After Modification (Activated Coke + Aqueous Ammonia)	Improvement Margin	Compliance Status
SO₂ (mg/m³)	50	＜30	Reduced by 40%	ompliant with GB 13223-2011
NOₓ (mg/m³)	100	＜40	Reduced by 60%	ompliant with GB 13223-2011
SO₃ (mg/m³)	20	＜1	Reduced by 95%	Elimination of Equipment Corrosion
Hg (lb/MWh)	0.01	＜0.003	Reduced by 70%	Compliant with EPA MATS
Annual Operating Cost (10,000 CNY)	5000	1500	Reduced by 70%	—
Unplanned Outage Rate	5%	＜1%	Reduced by 80%	—
Annual By-product Revenue (10,000 CNY)	0	200	—	Circular Economy Compliance

IX. Core Advantages

Our customized solutions for power generation groups possess four distinct and irreplaceable advantages:

• Highly Targeted Product: Tailored to Thermal Power Flue Gas Characteristics

Our proprietary lignite-based activated coke (particle size: 5–10 mm; iodine value: ≥800 mg/g; mechanical strength: ≥90%) is specifically engineered for thermal power flue gas. Its pore structure is predominantly composed of "micropores + mesopores" (with micropores accounting for 65%), resulting in an adsorption capacity 40% higher than that of standard activated carbon (achieving an SO₂ adsorption capacity of up to 300 mg/g).

• Synergistic Multi-Pollutant Removal: Eliminating Equipment Corrosion

The activated coke achieves an SO₃ removal efficiency of >95% (reducing acid mist concentration to <1 mg/m³). This reduces the corrosion rate of induced draft fans from 0.1 mm/year to <0.02 mm/year, while lowering the rate of unplanned shutdowns to <1%. Following its implementation at a specific power unit, no further shutdowns caused by corrosion have occurred.

• Compliant and Reliable: Comprehensive Certification Coverage

The product holds ISO 9001 (Quality Management) and ISO 14001 (Environmental Management) certifications and complies with the GB/T 30201-2013 standard for "Activated Carbon for Flue Gas Desulfurization." It fully satisfies the prevailing global emission standards for thermal power plants, including those in China, the European Union, and the United States.

• Controllable Costs: High Cost-Effectiveness Over the Entire Lifecycle
• Activated Coke: Capable of being regenerated 3–5 times (with regeneration costs amounting to only 30% of the cost of new carbon). The initial capital investment is a modest 5–10 million RMB per 1,000 MW power unit, resulting in a 70% reduction in annual operating costs (for instance, one specific unit achieved annual savings of 35 million RMB).
• By-products:The annual revenue generated from the recovery of concentrated sulfuric acid amounts to 2 million RMB, while mercury (Hg) recovery yields an additional 500,000 RMB annually; these revenues collectively offset 10% of the total operating costs.

X. Cost Analysis
Using a 1,000 MW thermal power unit as a case study, the following compares the costs associated with the activated carbon process versus traditional processes: 

Project	Activated Coke + Aqueous Ammonia Process	Limestone-Gypsum + SCR Process
Initial Investment (10,000 CNY)	500-1000	300-500
Operating Cost (CNY/kg SO₂)	0.2-0.4	0.6-0.8
Maintenance Cost (10,000 CNY/year)	100-200	300-500
Life-Cycle Cost (CNY/kg SO₂)	0.5-0.8	1.5-2.0
By-product Revenue (10,000 CNY/year)	200-300	0

XI. Why Choose Us?

• Proven Track Record: We serve major power generation clients—including Datang Power, Huaneng Group, and China Energy Investment Corporation—and our activated carbon products have garnered unanimous praise from enterprises for their "synergistic removal of multiple pollutants" and "cost-effectiveness." For instance, after a 1,000 MW power generation unit adopted our activated coke, its annual operating costs dropped by 70%, and its rate of unplanned shutdowns fell to less than 1%.
• Technical Expertise: In collaboration with the Taiyuan University of Technology (specifically, the State Key Laboratory of Coal Science and Technology), we have developed "lignite-based activated coke" and "NH₃-impregnated modified carbon." These innovations are specifically engineered to address the challenges inherent in thermal power plant flue gas—namely, "high pollutant concentrations, multiple pollutant types, and high corrosivity." The key performance indicators of our activated coke—characterized by "high adsorption capacity" and a "high SO₃ removal rate"—are perfectly aligned with the specific requirements of the thermal power industry.
• Global Service: We operate production bases across Shanxi, Ningxia, and Fujian (boasting an annual production capacity of 45,000 tons), enabling us to provide "customized production" coupled with "localized distribution." For our international clients, we offer a comprehensive, end-to-end service package that encompasses "activated carbon selection, process design, and guidance on byproduct recovery," ensuring that we respond to client inquiries and requirements within 72 hours.