The comprehensive evaluation of available pilot-scale H2S abatement process in a coke-oven gas: Efficiency, economic, energy, and environmental safety (4ES)

Abstract

This study implemented the comprehensive evaluation of desulfurization efficiency-energy potential-economic-safety into three different processes for removing hydrogen sulfide from coke oven gas. Three different processes were NH3 absorption, MDEA process, Fumaks wet oxidation process. NH3 and MDEA process utilized the conventional absorption-stripping configuration with absorbent while the wet oxidation process was composed of two consecutive H2S removal processes. Energy potential and safety assessment were augmented besides conventional assessment such as economic and removal efficiency. The energy potential of coke oven gas was evaluated in terms of Low heating value. The dispersion distance of H2S gas was evaluated in case of leakage accident for safety assessment. The desulfurization efficiencies of NH3 absorption, MDEA, wet oxidation were 76.5%, 94.3%, 99.0%. For evaluating energy potential low heating value of NH3 absorption, MDEA, wet oxidation were 17.81 MJ/m3, 17.89 MJ/m3, and 18.37 MJ/m3. The capital costs of NH3 absorption, MDEA, wet oxidation were $ 38.0/Nm3∙y, $ 50.6/Nm3∙y, and $ 67.5/Nm3∙y. Overall, the wet oxidation exhibited the highest H2S removal efficiency and energy potential but the highest cost required and relatively high H2S dispersion distance. The MDEA showed moderate performance on efficiency, cost, and safety. The NH3 absorption process showed the cheapest cost consumed and relatively safe but lowest H2S removal and energy potential. Wet oxidation, Therefore, wet oxidation would be suited for meeting strict environmental regulations. MDEA process would be suited for power utilization and less strict environmental regulation with lower cost. NH3 absorption would be suited for direct utilization to other processes.