Petrochemical Enterprises

I. Customer Pain Points

Processes such as catalytic cracking, sulfur recovery, and ethylene cracking in petrochemical enterprises generate high-concentration, multi-component, and corrosive flue gas, presenting three core challenges: "difficulty in regulatory compliance," "severe corrosion," and "high costs."

Stricter emission standards; "legacy processes" fail to achieve simultaneous compliance

China’s *Emission Standard of Pollutants for Petroleum Refining Industry* (GB 31570-2015) mandates limits of SO₂ ≤ 50 mg/m³, NOₓ ≤ 100 mg/m³, and particulate matter ≤ 20 mg/m³; the EU’s *Industrial Emissions Directive* (2010/75/EU) imposes even stricter limits of SO₂ ≤ 30 mg/m³ and NOₓ ≤ 40 mg/m³. However, traditional "amine-based desulfurization + SCR denitrification" technologies address only specific pollutants and cannot simultaneously remove SO₃ (acid mist at 10–50 mg/m³), heavy metals (Hg at 0.1–1 mg/m³), or VOCs (benzene series at 50–200 mg/m³). This leads to frequent fines for exceeding limits on these co-pollutants (in 2022, China recorded 600 cases of petrochemical flue gas emission violations, with an average fine of 700,000 RMB).

Severe equipment corrosion threatens unit service life

SO₃ combines with water to form sulfuric acid mist (H₂SO₄, concentration 10–30 mg/m³), which corrodes catalytic cracking unit regenerators and induced-draft fans (corrosion rate > 0.1 mm/year). Traditional processes lack designs for the simultaneous removal of SO₃, resulting in an unplanned unit shutdown rate of 6% (based on 2022 statistics for China's petrochemical industry), with losses exceeding 5 million RMB per shutdown event. High operating costs make the "activated carbon + regeneration" model unsustainable.
Traditional activated carbon desulfurization and denitrification processes require an "adsorption → steam regeneration → sulfuric acid recovery" cycle. Regeneration costs are ≥0.5 RMB/kg of SO₂, and catalyst (vanadium-titanium-tungsten) replacement costs are ≥200 RMB/m³. For a typical 10-million-ton-scale integrated refining and chemical enterprise, annual desulfurization and denitrification costs exceed 30 million RMB, accounting for 10% of total operating costs.

VOCs and heavy metals face restrictions under international conventions.

Petrochemical flue gas contains benzene-series compounds (VOCs, concentration 50–200 mg/m³) and mercury (Hg, concentration 0.1–1 mg/m³). Emissions must comply with the *Minamata Convention on Mercury* (Hg ≤ 0.003 lb/MWh) and the *EU VOC Directive* (VOCs ≤ 50 mg/m³). Traditional processes achieve VOC removal rates of <50% and Hg removal rates of <60%, failing to meet international compliance standards (e.g., one enterprise suffered losses exceeding 10 million RMB when its products were rejected by the EU due to excessive mercury levels).

II. Application Objectives

Petrochemical enterprises adopt activated carbon technology with four core objectives, centering on compliance, cost reduction, safety, and international expansion:
Strict compliance to mitigate global regulatory risks.
Meeting the following standards:
China GB 31570-2015: SO₂ ≤ 50 mg/m³, NOₓ ≤ 100 mg/m³, Particulate Matter ≤ 20 mg/m³;
EU 2010/75/EU: SO₂ ≤ 30 mg/m³, NOₓ ≤ 40 mg/m³, VOCs ≤ 50 mg/m³;
*Minamata Convention on Mercury*: Hg ≤ 0.003 lb/MWh. Synergistic Multi-Pollutant Removal and Prevention of Equipment Corrosion
Activated carbon achieves synergistic removal of SO₂, NOₓ, SO₃, Hg, and VOCs through a combined "adsorption + catalysis" process. Notably, the SO₃ removal rate 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 the unplanned shutdown rate to <1.5%.
Cost Reduction and Replacement of High-Energy-Consumption Processes
The operating cost for activated carbon (specifically bituminous coal-based activated coke) is merely 0.2–0.4 RMB per kg of SO₂ removed—one-third the cost of amine-based desulfurization. Furthermore, the material can be regenerated 3–5 times (at 30% of the cost of fresh carbon). For instance, a large-scale refining and chemical enterprise (processing over 10 million tons annually) reduced its combined desulfurization and denitrification costs from 30 million RMB to 9 million RMB—a 70% reduction.
Compliance with International Conventions and Expansion into Overseas Markets
Activated carbon achieves VOC removal rates exceeding 95% (reducing benzene-series compounds to <5 mg/m³) and Hg removal rates exceeding 90% (meeting the standards of the Minamata Convention). This facilitates market entry into the EU and the US; for example, one enterprise saw a 15% increase in product export volume after adopting this technology.

III. Application Significance

The application of activated carbon in flue gas treatment for petrochemical enterprises serves as a core pillar for achieving "compliant operations, cost reduction and efficiency improvement, and international market expansion":
Compliance Baseline: 65% of global cases involving petrochemical flue gas emission violations stem from a failure to adopt "synergistic treatment" processes. Activated carbon is one of the few technologies capable of simultaneously removing SO₂, NOₓ, SO₃, Hg, and VOCs at a controllable cost, directly determining an enterprise's ability to secure discharge permits and international orders.
Safety Assurance: Between 2021 and 2022, 55% of unplanned shutdowns in China's petrochemical sector were caused by SO₃-induced corrosion of induced draft fans. The "synergistic SO₃ removal" design of activated carbon technology can reduce the unit's unplanned shutdown rate from 6% to below 1.5%, preventing a loss of 5 million RMB per incident. Cost Optimization: A case study of a petrochemical group shows that adopting the "activated coke desulfurization and denitrification" process reduced annual operating costs by 70% (an 80% reduction in amine solution usage and a 50% decrease in catalyst replacement frequency), effectively increasing profits by 21 million RMB per year.
International Expansion: After adopting activated carbon, a company reduced its mercury (Hg) emissions to 0.002 lb/MWh and VOC emissions to 20 mg/m³—meeting EU standards—and increased its annual export volume from 800,000 tons to 920,000 tons.

IV. Application History

The application of activated carbon in flue gas treatment within petrochemical enterprises has become increasingly widespread, driven by a combination of stricter emission standards and international treaty obligations:
1990s: Initial Stage
ExxonMobil (USA) pioneered the use of activated coke (bituminous coal-based) to treat flue gas from fluid catalytic cracking (FCC) units (with an SO₂ concentration of 800 mg/m³). Utilizing a "moving bed adsorption + thermal regeneration" process, it achieved a desulfurization efficiency of 95%, marking the first industrial application of activated carbon desulfurization technology.
2000s: Promotion Stage
China’s "11th Five-Year Plan" prioritized petrochemical flue gas desulfurization and denitrification, driving the adoption of "combined activated carbon processes." In 2008, a refinery with a processing capacity of over 10 million tons adopted activated coke, reducing SO₂ concentrations from 800 mg/m³ to 30 mg/m³ and becoming the first domestic project to meet the compliance standards.
2010s: Upgrading Stage
The implementation of the EU Industrial Emissions Directive (2010/75/EU)—mandating SO₂ ≤ 30 mg/m³ and VOCs ≤ 50 mg/m³—accelerated the adoption of modified activated carbon (impregnated with NH₃ or K₂O). In 2015, BASF (Germany) utilized modified activated carbon, resulting in an increase in NOx removal efficiency from 60% to 85% and a VOC removal rate exceeding 95%. 2020s: The Intelligentization Stage
China’s "Action Plan for Green Development of the Petrochemical and Chemical Industry during the 14th Five-Year Plan" mandates a "synergistic treatment rate for petrochemical flue gas of ≥90%." By combining activated carbon with an "online monitoring + automatic regeneration" system, precise adsorption is achieved (e.g., automatically adjusting the moving speed of activated coke based on SO₂ concentration), thereby reducing operating costs by 20%.

V. Mechanism of Action

Activated carbon addresses the challenges of petrochemical flue gas—characterized by multiple pollutants, high concentrations, and high corrosivity—through a triple-action process: physical adsorption, chemical catalysis, and synergistic regeneration.
1. Physical Adsorption: "Broad-spectrum sieving" via pore structure
Micropores (<2 nm): Account for 60%–70% of total pore volume; adsorb small-molecule pollutants (SO₂, molecular diameter ≈0.36 nm; NO, ≈0.317 nm; Hg⁰, ≈0.3 nm) via van der Waals forces, with an adsorption capacity of 200–300 mg/g (five times that of amine solutions).
Mesopores (2–50 nm): Act as "transport channels," allowing medium-sized pollutants (SO₃, ≈0.4 nm; benzene series, ≈0.5 nm; VOCs, ≈0.6 nm) to diffuse into the micropores; simultaneously adsorb heavy metal Hg (molecular diameter ≈0.3 nm).
Macropores (>50 nm): Act as "entry channels," allowing large fly ash particles (>1 μm) to enter the activated carbon interior, though they contribute minimally to adsorption.
2. Chemical Catalysis: "Targeted conversion" via surface functional groups
SO₂ Removal: Basic functional groups on the activated carbon surface (such as pyranones and pyridinones) adsorb SO₂; this is followed by catalytic oxidation (involving O₂) to convert it into SO₃, which ultimately combines with water to form H₂SO₄ (stored within the activated carbon pores).
NOₓ Removal: NH₃-loaded activated carbon converts NOₓ into N₂ via Selective Catalytic Reduction (SCR) at reaction temperatures of 120–150°C, achieving a removal rate of >85% (without the need for additional catalysts). VOC Removal: Surface oxygen-containing functional groups (carboxyl -COOH, hydroxyl -OH) adsorb benzene-series compounds via hydrogen bonding; these are subsequently converted into CO₂ and H₂O through catalytic oxidation (involving O₂), achieving a removal rate of >95%.
Hg Removal: Chlorine-containing functional groups (-Cl) on the activated carbon surface convert Hg⁰ into HgCl₂ (water-soluble) via chemisorption, achieving a removal rate of >90%.
3. Synergistic Regeneration: A "Key Step" in Cost Reduction
Saturated activated carbon undergoes thermal regeneration (400–500°C under inert gas protection), desorbing H₂SO₄ as SO₂ (concentration 10–15%), which is sent to a sulfuric acid plant to produce concentrated sulfuric acid (98%); Hg is concentrated in the regeneration residue, with a recovery rate of >90%. The adsorption capacity of regenerated carbon reaches 80% of that of fresh carbon, while the cost is only 30% of fresh carbon.

VI. Application Methods

Petrochemical enterprises employ a combined process of "activated coke moving bed (primary treatment) + ammonia injection (denitrification) + thermal regeneration (by-product recovery)," covering scenarios characterized by "high concentrations, multiple pollutants, and high corrosivity":
1. Activated Coke Moving Bed: Primary Treatment Unit (SO₂, SO₃, Hg, VOCs)
Applicable Scenario: Flue gas from the regenerator of a fluid catalytic cracking (FCC) unit (SO₂ concentration: 500–1000 mg/m³; NOₓ concentration: 200–400 mg/m³; SO₃ concentration: 10–30 mg/m³).
Process Steps:
Adsorption: Flue gas enters the moving bed adsorption tower (packed with activated coke, particle size 5–10 mm); flow velocity is 0.5–1.0 m/s, and contact time is 5–10 seconds. Removal rates: SO₂ >95%, SO₃ >95%, Hg >90%, VOCs >95%.
Movement: Saturated activated coke is discharged from the bottom of the tower and sent to the regeneration system; fresh activated coke is replenished at the top.
Key Parameters:

Project			Product Technical Specifications	Testing Standards
1	Shape		Φ9mm×5~12mm	GB/T 30201-2013
2	Moisture		≤3%	GB/T 7702.1-1997
3	Particle size distribution	≥11.2mm	≤2.0%	GB/T 30202.2-2013
		5.6-11.2mm	≥97.0%
		1.4-5.6mm	≤0.7%
		≤1.4mm	≤0.3%
4	Abrasion resistance Compressive strength Bulk density Ash content Volatile matter content Ignition point Iodine value Desulfurization capacity Denitrification rate		≥97%	GB/T 30202.3-2013
5	Compressive strength		≥40daN	GB/T 30202.3-2013
6	Bulk density		≤680g/L	GB/T 30202.1-2013
7	Ash content		≤15%	GB/T 7702.15-2008
8	Volatile matter content		<5%	GB/T 2001-2013
9	Ignition point		≥430℃	GB/T 7702.9-2008
10	Iodine value		≥400mg/g	GB 7702.15-1987
★11	Desulfurization capacity		≥24mg/g	GB/T 30202.4-2013
★12	Denitrification rate		≥45%	GB/T 30202.5-2013

Regeneration cycle: 6–12 months (adjusted based on flue gas concentration).
2. Ammonia injection: Denitrification (NOₓ) auxiliary unit
Applicable scenario: Flue gas with low NOₓ concentration (<200 mg/m³).
Process steps:
Ammonia solution (5–10%) is injected at the adsorption tower inlet; an SCR reaction with NOₓ occurs on the activated carbon surface (120–150°C), achieving a NOₓ removal rate of >85%.
3. Thermal regeneration system: By-product recovery (concentrated sulfuric acid, Hg)
Applicable scenario: Regeneration of saturated activated coke.
Process steps:
Heating: Saturated activated coke is fed into the regeneration furnace (400–500°C, N₂ atmosphere); H₂SO₄ is desorbed and converted into SO₂ (concentration 10–15%).
Conversion: SO₂ is sent to a sulfuric acid plant to produce concentrated sulfuric acid (98%); Hg in the regeneration residue is concentrated and processed into HgS residue (recovery rate >90%).

VII. Application Process

Example: A large-scale integrated refining and chemical enterprise (capacity: 10 million tons/year; FCC flue gas flow: 800,000 m³/h; SO₂: 800 mg/m³; NOₓ: 300 mg/m³; SO₃: 20 mg/m³; Hg: 0.5 mg/m³):
Pre-treatment: Electrostatic precipitator (removes fly ash; efficiency 99.5%; fly ash concentration reduced to <50 mg/m³).
Main treatment: Activated coke moving-bed adsorption towers (2 units, alternating operation; 600 tons of coke per unit; particle size 5–10 mm) → Ammonia injection system (5% ammonia solution; injection rate 12 m³/h).
Regeneration system: Thermal regeneration furnace (400°C, N₂ atmosphere) → Sulfuric acid plant (SO₂ converted to 98% concentrated sulfuric acid) → Hg recovery unit (regeneration residue processed into HgS residue). Emissions: Stack (SO₂ < 30 mg/m³, NOₓ < 40 mg/m³, SO₃ < 1 mg/m³, Hg < 0.003 lb/MWh, VOCs < 20 mg/m³).

VIII. Application Effects

Following the retrofit of a refining and chemical enterprise with a capacity of over 10 million tonnes, key performance indicators improved significantly (based on actual operational data): 

Index	Before Retrofitting (Amine-based Desulfurization + SCR)	After Modification (Activated Coke + Aqueous Ammonia)	Reduction	Compliance Status
SO₂（mg/m³）	50	＜30	Reduced by 40%	Complies with GB 31570-2015
NOₓ（mg/m³）	100	＜40	Reduced by 60%	Complies with GB 31570-2015
SO₃（mg/m³）	20	＜1	Reduced by 95%	Eliminates equipment corrosion
Hg（lb/MWh）	0.01	＜0.003	Reduced by 70%	Complies with the Minamata Convention
VOCs（mg/m³）	80	＜20	Reduced by 75%	Complies with EU Directive 2010/75/EU
Annual Operating Costs (10,000 CNY)	3000	900	Reduced by 70%	—
Unplanned Downtime Rate	6%	＜1.5%	Reduced by 75%	—
Annual By-product Revenue (10,000 CNY)	0	120	—	Circular economy compliance

IX. Core Advantages

Customized solutions for petrochemical enterprises offering four irreplaceable advantages:
Highly targeted product tailored to petrochemical flue gas characteristics
The developed bituminous coal-based activated coke (particle size: 5–10 mm; iodine value: ≥800 mg/g; strength: ≥90%) is specifically designed for petrochemical flue gas. It features a pore structure dominated by micropores and mesopores (micropores account for 65%) and offers an adsorption capacity 40% higher than standard activated carbon (SO₂ adsorption capacity reaches 300 mg/g).
Synergistic multi-pollutant removal and elimination of equipment corrosion
The activated coke achieves an SO₃ removal rate of >95% (reducing acid mist concentration to <1 mg/m³), lowers the corrosion rate of induced draft fans from 0.1 mm/year to <0.02 mm/year, and reduces the unplanned shutdown rate to <1.5%. One enterprise reported no further shutdowns caused by corrosion after implementation.
Compliance, reliability, and comprehensive certification
The product holds ISO9001 (Quality) and ISO14001 (Environmental) certifications and complies with the GB/T 30201-2013 standard (*Activated Carbon for Flue Gas Desulfurization*), fully meeting major global petrochemical flue gas emission standards (including those of China, the EU, and the USA).
Controllable costs and high cost-effectiveness over the full lifecycle
Activated coke: Regenerable 3–5 times (regeneration cost is only 30% of the cost of new carbon); initial investment is only RMB 6–12 million for a 10-million-ton-scale refining and chemical enterprise; annual operating costs are reduced by 70% (e.g., one enterprise saved RMB 21 million annually).
By-products: Annual revenue of RMB 1.2 million from concentrated sulfuric acid and RMB 0.3 million from mercury (Hg) recovery, offsetting 10% of operating costs.

X. Cost Analysis

Cost comparison between the activated carbon process and traditional processes, using a 10-million-ton-scale integrated refining and chemical enterprise as an example: 

Project	Activated Coke + Aqueous Ammonia Process	Amine-based desulfurization + SCR process
Initial Investment (10,000 CNY)	600-1200	400-800
Operating Cost (CNY/kg SO₂)	0.2-0.4	0.6-0.8
Maintenance Cost (10,000 CNY/year)	80-150	200-300
Life-Cycle Cost (CNY/kg SO₂)	0.5-0.8	1.5-2.0
By-product Revenue (10,000 CNY/year)	120-150	0

11. Why Choose Us?

Proven Track Record: We serve major petrochemical clients such as Sinopec, PetroChina, and BASF. Our activated carbon products—valued for their cost-effectiveness and ability to simultaneously remove multiple pollutants—have earned unanimous praise. Notably, a refinery with a processing capacity of over 10 million tons achieved a 70% reduction in annual operating costs and lowered its unplanned downtime rate to below 1.5% after adopting our activated coke.
Technical Expertise: Through a partnership with the China University of Petroleum (East China), we have developed bituminous coal-based activated coke and NH₃-impregnated modified carbon specifically designed to tackle the challenges of petrochemical flue gas—namely high pollutant concentrations, multi-pollutant profiles, and high corrosivity. Our activated coke delivers high adsorption capacity and superior SO₃ removal rates, perfectly aligning with the industry's requirements.
Global Service: We operate production bases in Shanxi, Ningxia, and Fujian (with a combined annual capacity of 45,000 tons), enabling both customized production and localized distribution. For overseas clients, we offer comprehensive end-to-end services—including product selection, process design, and guidance on by-product recovery—while guaranteeing a response to inquiries within 72 hours.