Graphitized Petroleum Coke Production Process Overview

1. Overview

Graphitized petroleum coke (GPC) is a high-purity carbon material produced by heat-treating petroleum coke at extreme temperatures (2,500–3,000°C) to convert amorphous carbon into crystalline graphite. It is widely used in lithium-ion battery anodes, electrodes, and high-temperature applications.

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2. Early Processes

Key Steps (Acheson Process)

1. Raw Material Preparation:

• Feedstock: High-sulfur petroleum coke from delayed coking.
• Calcination: Heated to 1,200–1,400°C in rotary or shaft kilns to remove volatiles and moisture.

1. Graphitization Furnace:

• Acheson Furnace: Batch-type resistance-heated furnace with coke bed as resistor.
• Process:
  • Layered coke mixed with graphitization agent (e.g., quartz sand) placed in furnace.
  • Electric current (5,000–10,000 A) applied for 20–50 hours.
  • Temperature: ~2,800°C.

1. Cooling & Post-Treatment:

• Slow cooling over days to prevent cracking.
• Crushing, milling, and purification (acid washing).

Technical Challenges

• High energy consumption (6,000–8,000 kWh/ton).
• Inhomogeneous temperature distribution.
• Long cycle time (5–7 days per batch).
• Poor yield due to oxidation and impurities.

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3. Modern Advanced Processes

Key Innovations

1. Longitudinal Graphitization (LWG) Technology:

• Continuous vertical furnace with controlled atmosphere (argon/nitrogen).
• Advantages:
  • Faster heating/cooling (cycle time: 24–48 hours).
  • Energy savings (~3,500 kWh/ton).
  • Higher purity (ash content <0.1%).

1. Induction Heating:

• Electromagnetic induction furnaces for precise temperature control.
• Reduced thermal stress and improved crystallinity.

1. Continuous Graphitization Reactors:

• Rotary tube furnaces with automated feeding.
• Real-time monitoring via AI and IoT sensors.

Equipment

• Modern Furnaces:
• LWG furnaces (e.g., Siemens-style).
• Induction graphitization furnaces.
• Tunnel kilns with inert gas protection.
• Auxiliary Systems:
• Gas purification units (HCl/Cl₂ removal).
• High-efficiency dust collectors.

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4. Technical Parameters

Parameter	Traditional (Acheson)	Modern (LWG)
Temperature	2,800–3,000°C	2,800–3,000°C
Graphitization Time	50–70 hours	20–30 hours
Energy Consumption	6,000–8,000 kWh/ton	3,000–4,000 kWh/ton
Carbon Yield	70–80%	85–95%
Resistivity	8–12 μΩ·m	5–7 μΩ·m
CTE* (×10⁻⁶/°C)	2.5–3.5	1.5–2.5

CTE: Coefficient of Thermal Expansion

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5. Key Challenges & Solutions

1. Temperature Uniformity:

• Issue: Hotspots/cold zones in traditional furnaces.
• Solution: Multi-zone induction heating + AI-based thermal management.

1. Energy Efficiency:

• Solution: Waste heat recovery systems (e.g., preheating feedstock).

1. Oxidation & Contamination:

• Solution: Inert gas shielding (N₂/Ar) and vacuum furnaces.

1. Feedstock Quality:

• Requirement: Low sulfur (<0.5%) and metals (Ni, V <50 ppm).
• Innovation: Advanced calcination with catalytic additives.

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6. Operational Steps (Modern Process)

1. Feedstock Preparation:

• Crude coke → Calcination (1,400°C) → Pulverizing (D50: 10–20 μm).

1. Furnace Loading:

• Automated feeding into LWG furnace with graphite crucibles.

1. Graphitization:

• Ramp-up to 2,800°C at 100°C/hour; hold for 10–15 hours.

1. Cooling & Extraction:

• Controlled cooling under inert gas (50°C/hour).

1. Post-Processing:

• Milling, sieving, and surface coating (pitch/chemical vapor deposition).

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7. Future Trends

• Microwave Graphitization: Ultra-fast heating (<1 hour) with targeted energy.
• Sustainable Processes: Hydrogen as reducing agent to cut CO₂ emissions.
• Nano-Structured GPC: Enhanced electrochemical performance for batteries.

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8. CHYCARBON: Pioneering the Future of Graphitized Petroleum Coke

At CHYCARBON, we are not just manufacturers of graphitized petroleum coke – we are innovators, engineers, and visionaries committed to redefining the boundaries of advanced carbon materials. With decades of expertise and a relentless pursuit of excellence, we have positioned ourselves as a global leader in high-performance GPC production, powering industries from lithium-ion batteries to aerospace.

Our Commitment to Innovation

• Cutting-Edge Technology: We are trusted by Fortune 500 companies to provide customized solutions to steel companies and the world’s leading foundries, driving the transition to a green economy.
• Breakthrough Capacity: By integrating continuous graphitization reactors and automated systems, we have scaled production to meet surging global demand, delivering 150,000+ tons annually with precision and reliability.
• Sustainable Solutions: Pioneering eco-friendly practices, including waste heat recovery and hydrogen-based reduction, we reduce carbon footprints while maintaining ultra-low impurity levels (ash <0.1%, sulfur <0.03%).

Our Vision

At CHYCARBON, we believe that the future of carbon lies in smarter, cleaner, and more efficient technologies. By continuously challenging the status quo, we aim to:

• Double Production Capacity by 2030 through modular furnace expansions.
• Achieve Zero-Waste Operations via closed-loop recycling systems.
• Empower Global Decarbonization with GPC that enables longer-lasting batteries and cleaner industrial processes.

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Join us in shaping a carbon-powered future – where innovation meets responsibility.