Considerable energy is consumed during steel manufacturing process.Byproduct gas emerges as secondary energy in the process;however,it is also an atmospheric pollution source if it is released into the air.Therefore,the optimal utilization of byproduct gas not only saves energy but also protects environment.To solve this issue,a forecast model of gas supply,gas demand and surplus gas in a steel plant was proposed.With the progress of energy conservation,the amount of surplus gas was very large.In a steel plant,the surplus gas was usually sent to boilers to generate steam.However,each boiler had an individual efficiency.So the optimization of the utilization of surplus gas in boilers was a key topic.A dynamic programming method was used to develop an optimal utilization strategy for surplus gas.Finally,a case study providing a sound confirmation was given. Considerable energy is consumed during steel manufacturing process. Byproduct gas emerges as secondary energy in the process; however, it is also an atmospheric pollution source if it is released into the air. Wherefore, the optimal utilization of byproduct gas not only saves energy but also protects environment. solve this issue, a forecast model of gas supply, gas demand and surplus gas in a steel plant was proposed. With the progress of energy conservation, the amount of surplus gas was very large. In a steel plant, the surplus gas was usually sent to boilers to generate steam.However, each boiler had an individual efficiency.So the optimization of the utilization of surplus gas in boilers was a key topic. A dynamic programming method was used to develop an optimal utilization strategy for surplus gas .Finally, a case study providing a sound confirmation was given.