In energy-intensive industries such as steel, cement and chemical engineering, large amounts of waste heat are generated during production processes (e.g., blast furnace gas and waste heat from sintered ore). Harnessing this waste heat to produce steam that drives small steam turbines for power generation enables cascade utilization of energy, thus achieving energy conservation and consumption reduction.

Blast Furnace Gas Waste Heat Power Generation System for Iron and Steel Enterprises

This project was implemented at an ironmaking plant affiliated to a large-scale iron and steel group with an annual steel output of over 5 million metric tons. During the production process, blast furnace smelting generates massive amounts of high-temperature waste gas (blast furnace gas, at approximately 800°C) and waste heat from sintered ore cooling (at approximately 400°C). The enterprise installed a waste heat power generation system, which consists of a waste heat boiler and a 15MW back pressure steam turbine. After capturing waste heat, the system produces medium-pressure steam (parameters: 350°C, 3.5MPa) to drive the steam turbine for power generation. The low-pressure steam generated post-power generation can also be used for heating or process heating, achieving cascade utilization of energy.

Operating income

Energy Conservation & Consumption Reduction: Annual power generation reaches approximately 120 million kWh, equivalent to saving 40,000 metric tons of standard coal and cutting external power procurement costs by around RMB 60 million (calculated based on an industrial electricity price of RMB 0.5/kWh). The energy utilization rate has increased from the original 40% to over 65%.

Cost Savings: It reduces the enterprise’s reliance on the power grid and eases the power consumption pressure during peak electricity price periods. Meanwhile, the multi-stage utilization of steam eliminates additional fuel consumption, resulting in annual fuel cost savings of approximately RMB 20 million.

Environmental & Compliance Benefits: Annual carbon dioxide emissions are reduced by around 100,000 metric tons. The project complies with the requirements of the national Guiding Opinions on Industrial Waste Energy Recovery and Utilization and is eligible for preferential tax policies for energy conservation and emission reduction.