Steel Mill Exhaust Calorific Value Increase - 理润科技（北京）有限公司

Application direction

Blast furnace gas (BFG) and basic oxygen furnace gas (BOFG) are the most importantsecondary energy sourcesin long-process steel production, characterized by their high combustible content:

TypicalBFGcontainsCO (20–25%)andCO2(18–22%), accounting for40–50% by volume.

BOFGtypically containsCO (60–70%)andCO2(3–8%), with total combustible components reaching65–75%.

Studies show thatsystematic optimization of CO utilization efficiencyin these gases can reduce a steel plant’scarbon emission intensity by 15–20%.

By applyingPressure Swing Adsorption (PSA)technology to enrich CO concentration to>80%and recycling it back into the blast furnace,15–30% of fossil fuel consumptioncan be replaced. A large steel enterprise demonstrated that this process reducedcoke ratio by 8–12 kg per ton of hot metal, cuttingCO2emissions by over 500,000 tons annually. When coupled withamine-based or calcium-looping CO2capture technologies(energy consumption <2.5 GJ/tCO2), the capture cost can be controlled at200–300 RMB per ton. Captured CO2can be used forenhanced oil recovery (EOR), improving oil recovery rates by7–15%, thereby forming aclosed-loop CCUS system.

In regions wherenatural gas prices exceed 2.5 RMB/m³, applying PSA technology to enrich BFG to>80% COyieldssynthetic gas with a heating value of 2100±300 kcal/Nm³. A coastal steel plant case study showed that replacing30% of natural gas demandwith this technology resulted infuel cost savings of over 200 million RMB annuallyand reducedCO2emissions by ~1.2 million tons per year, with a payback period of only2.3 years.

Core Advantages

Cost-Effective and Feasible CO Purification

By adopting advanced adsorption separation technology, efficient CO/N2 separation can be achieved even under high-N2 atmospheres (60–80%). The purification cost is controlled at 0.8–1.2 RMB/Nm3, representing a 30–40% reduction compared to conventional processes

Integrated CO2 Removal and Capture

The removal of CO2 (15–25%) from steel mill gases can be deeply integrated with carbon capture systems to generate high-concentration CO2 streams (>90%). This reduces capture energy consumption by 30–40% and controls the overall capture cost at 200–300 RMB per ton of CO2 capture is cost-effective

Ultra-Low Energy Consumption

Through multi-process collaborative optimization, the comprehensive energy consumption for CO2 capture is reduced to <1.8 GJ/t (compared to 2.5–3.5 GJ for conventional processes). When integrated with CO enrichment systems, energy consumption can be further reduced to below 1.5 GJ/t, achieving over 40% energy savings

Gas Calorific Value Enhancement Effect

After purification, ineffective components such as CO2 can be removed at rates of 85–95%, increasing the effective components (CO + H2) concentration by 15–25%. As a result, the gas heating value improves by 20–30%, reaching 1,800–2,200 kcal/Nm³

Steel Mill Off-Gas Heating Value Enhancement

Low-Carbon Transition Path Selection

For steel enterprises targetingphased emission reductions of 15–25%, adopting ablast furnace gas (CO2: 18–22%) carbon capture process coupled with CO enrichment (concentration≥80%) and recyclingcan reduce coke consumption by8–12 kg per ton of hot metal. This represents one of the most practical and operable technology pathways currently available.

High-Calorific Gas Solution
For enterprises requiringclean fuel gas with a calorific value of 1,800–2,400 kcal/Nm³andzero flaring, upgrading blast furnace gas quality (CO + H2≥75%) can replace30–50% of natural gas consumption. This achieves agas utilization rate of over 98%, savingfuel costs exceeding the hundred-million-yuan annually.

Application Areas

Carbon Resource Utilization Solution for Integrated Steel Plants
For integrated steel plants equipped with1,000–6,000 m3blast furnacesand30–350 t converters, high-efficiency recovery ofblast furnace gas (CO 20–25%, recovery≥90%)andconverter gas (CO 60–70%, recovery≥85%)enables the annual production of500,000–1,000,000 tons of industrial-grade CO (purity≥99.5%). This CO can be used to produceformic acid (specific consumption 0.65 t CO/t),acetic acid, and other high-value chemicals, creatingan additional benefit of 100–150 RMB per ton of steel.

Deep Steel–Coking Integration Process

· Hydrogen Source Assurance:Hydrogen extraction from coke oven gas (H₂ ≥55%, purity 99.99%)

· Carbon source optimization:CO enrichment from BF/BOF gases (concentration ≥98%)

· Synthesis advantage:Use of advanced catalysts (selectivity >98%)

This integrated approach enables the production of300,000–500,000 tons of methanol per million tons of steel, or200,000–300,000 tons of ethylene glycol, with an overallenergy efficiency improvement of 18–25%.

Resource Utilization of Industrial Exhaust Gas