Making Iron More Efficiently and Generating Power with Oxygen

This patent describes an integrated system that uses extra oxygen in a blast furnace to make iron more efficiently, while also capturing the furnace's waste gases to generate electricity and reduce carbon dioxide emissions.

What it covers

The patent describes a system that combines iron production in a blast furnace with power generation and carbon dioxide capture. It introduces "super-enriched air" into the blast furnace, containing about 32% to 70% oxygen (Claim 1), which helps gasify coal more effectively. This process generates a fuel-rich "top gas" (Claim 1) that includes carbon monoxide, carbon dioxide, hydrogen, and nitrogen. Instead of just venting this gas, the system recovers it and uses it to generate electricity in a combined cycle power generation system (Claim 12). Before using the top gas for power, carbon dioxide can be removed from it (Claim 4, 7), making the power generation cleaner and allowing for CO2 sequestration. For example, a steel mill could use this system to not only produce iron but also power its own operations or even sell excess electricity, all while reducing its carbon footprint.

What it doesn't cover

• —Does not cover blast furnace operations using standard air or oxygen enrichment levels below 32 molar percent oxygen.
• —Does not cover systems where the blast furnace top gas is simply flared or used only for heating without generating power in a combined cycle system.
• —Does not cover methods of iron production that do not involve the gasification of coal in the blast furnace.
• —Does not cover power generation systems that do not specifically utilize blast furnace top gas with a calorific value greater than about 110 btu/scf.
• —Does not cover systems that produce iron without also integrating a carbon dioxide removal system for the top gas.

The clever bit

The novelty lies in the specific integration of very high oxygen enrichment (32-70% oxygen, "super-enriched air") in the blast furnace with a system to capture and utilize the resulting high-energy top gas for efficient power generation and carbon dioxide removal. This creates a self-sustaining energy loop while simultaneously enabling carbon capture.

Why it matters

This patent is significant because it addresses two major challenges in the iron and steel industry: energy efficiency and environmental impact. By integrating power generation and CO2 capture directly into the blast furnace process, it offers a pathway to reduce fuel consumption (specifically coke, Claim 6) and greenhouse gas emissions. This approach can make iron production more economically and environmentally sustainable, which is crucial for an industry known for its high energy use and carbon footprint.

Real-world examples

• 1.Integrated steel mills
• 2.Industrial gas suppliers (e.g., Air Products, Linde, Air Liquide)
• 3.Carbon capture and storage (CCS) projects
• 4.Combined cycle power plants