The carbon emission issues in the production process of graphite electrodes can be comprehensively addressed through a combination of technological upgrades, process optimization, and energy management strategies, as outlined below:
I. Technological Upgrades: High-Efficiency Equipment and Clean Energy Substitution
1. Graphitization Furnace Technology Iteration
Traditional Acheson furnaces consume as much as 3,200-4,800 kWh per ton of graphite electrodes, with significant temperature variations leading to energy waste. The adoption of Longitudinal Graphitization (LWG) furnaces can shorten heating time to 9-15 hours, reduce electricity consumption by 20%-30%, and achieve more uniform resistivity. For instance, the Xinjiang East Hope Carbon Project reduced energy consumption per ton of electrodes by approximately 300 kWh through the application of LWG furnaces, indirectly lowering carbon emissions.
2. Clean Energy Substitution
Producing one ton of graphite electrodes consumes about 1.7 tons of standard coal and emits 4.5 tons of CO₂. Utilizing green electricity (e.g., solar or wind power) to drive graphitization furnaces enables direct emission reductions. For example, some enterprises in Inner Mongolia have increased the proportion of green electricity to over 50% through “source-grid-load-storage” integration projects, reducing carbon emissions per ton of electrodes by 40%.
3. Waste Heat Recovery Systems
Installing waste heat boilers in the baking and graphitization stages recovers high-temperature flue gas (200-800°C) to generate steam for heating or power generation. The Shanxi Taigu Baoguang Carbon Project achieved annual savings of approximately 2,000 tons of standard coal and reduced CO₂ emissions by 5,200 tons through waste heat recovery.
II. Process Optimization: Reducing Raw Material and Energy Consumption
1. Refined Raw Material Preprocessing
- Calcination Stage: Control petroleum coke properties (true density ≥ 2.07 g/cm³, resistivity ≤ 550 μΩ·m) to minimize subsequent processing energy consumption.
- Impregnation Process: Enhance product bulk density and reduce porosity through “triple impregnation and quadruple baking” or “double impregnation and triple baking.” For example, achieving a secondary impregnation weight gain rate of ≥9% can reduce repeated baking cycles and save 15%-20% in energy consumption.
2. Low-Temperature Forming and Shortened Process Flows
Adopt low-temperature forming techniques (e.g., extrusion at 90-120°C) to reduce volatile emissions and lower subsequent baking temperatures. Simultaneously, optimize production workflows to shorten the cycle from raw materials to finished products, minimizing cumulative energy consumption.
3. Waste Gas Recycling
Flue gases from baking furnaces containing combustible components like CO and H₂ can be purified and reused in heating systems. The Xinjiang East Hope Project saved approximately 300,000 m³ of natural gas annually and reduced CO₂ emissions by 600 tons through waste gas recycling technology.
III. Energy Management: Digitalization and Circular Economy
1. Intelligent Energy Monitoring Systems
Deploy IoT sensors to monitor real-time energy consumption data (e.g., electricity and heat) across production stages, optimizing equipment parameters via AI algorithms. For instance, one enterprise reduced graphitization furnace idle time by 30% through intelligent monitoring, saving approximately 500,000 kWh of electricity annually.
2. Carbon Capture, Utilization, and Storage (CCUS)
Install carbon capture devices at graphitization furnace flue gas outlets to compress CO₂ for underground injection or use as chemical feedstock. Despite current high costs (approximately 300-600 RMB/ton CO₂), CCUS represents a critical long-term pathway for deep decarbonization.
3. Circular Economy Models
- Zero Wastewater Discharge: Treat domestic wastewater for reuse in flue gas scrubbing or landscaping, while implementing cascading utilization of production wastewater. The Shanxi Taigu Project achieved zero wastewater discharge, saving approximately 100,000 tons of water annually.
- Solid Waste Recycling: Return baghouse-collected dust (approximately 344 tons/year) and end-face milling scraps (approximately 500 tons/year) to the production line, reducing raw material consumption and waste treatment-related emissions.
IV. Policy and Market Synergy: Driving Industry Transformation
1. Enforcement of Ultra-Low Emission Standards
Adopt standards such as the Emission Standard of Pollutants for the Aluminum Industry (GB25465-2010), mandating particulate matter, SO₂, and NOx concentrations of ≤10 mg/m³, ≤35 mg/m³, and ≤50 mg/m³, respectively, to compel technological upgrades.
2. Carbon Trading Market Incentives
Include graphite electrode production in the national carbon market to create economic constraints through carbon quota trading. For example, if an enterprise reduces carbon emissions per ton of electrodes from 4.5 tons to 3 tons, it can profit from selling surplus quotas, fostering a positive cycle of emission reductions.
3. Green Supply Chain Certification
Downstream steelmakers can prioritize purchasing low-carbon graphite electrodes to incentivize upstream producers to reduce emissions. For instance, one electric arc furnace steel plant required suppliers to achieve ≤3.5 tons of CO₂ emissions per ton of electrodes, imposing a 10% price premium for non-compliance.
Post time: Aug-12-2025