Investigation and Optimisation of the Steady-State Model of a Coke Oven Gas Purification Process

Turbulences in energy prices have a major effect on the energy industry. These disturbances should allow more efficient operation and the optimisation of technologies, leading to more versatile operation with model-based methods. In our study, a coke oven gas purification system was examined. The system consists of three columns, which interact and are modelled in Aspen Plus. After identifying the steady-state model, sensitivity analyses were conducted to obtain more information on the effects of the parameters that can and cannot be influenced by operating circumstances. Finally, the model was used to carry out optimisation studies to find the most beneficial operating conditions under the gas composition requirements. Two optimisation strategies were examined. In the case when only the purity was concerned, 0.54 g/Nm³, 0.01 g/Nm³, and 0.03 g/Nm³ concentrations were found for H₂S, NH₃, and HCN, respectively. However, when the washing water temperature was included, the concentrations of H₂S, NH₃, and HCN increased to 1 g/Nm³, 0.5 g/Nm³, and 0.04 g/Nm³, still below the environmental regulations. However, the latter case will be more feasible energetically because it can be completed without using refrigeration and facilitates lower washing water streams.