Abstract: A mixed integer linear programming (MILP) model for optimization of surplus byproduct gases was built with the mini-mum operation cost as its objective function. Compared with previous optimization models, this model chooses a shorter time period and considers the influence of boiler penalty values (BPV) and gasholder penalty values (GPV) on the optimization results. Calculation results by the model based on real production data indicate that GPV and BPV are sensitive to the optimization results. Thus it is necessary to evaluate GPV and BPV reasonably. Compared with manual operation results, the optimal calculation results are able to re-duce the gas storage fluctuation of the gasholder, improve the electricity generation of boilers by 45.9%, and thus make the operation of the byproduct gas system safe and stable.