Process modeling and optimization of an eco-friendly process for acid gas conversion to hydrogen

Hydrogen sulfide conversion to hydrogen is an attractive alternative for addressing energy problems, waste management, global warming, and supplying hydrogen in petrochemical and refinery plants. This research is focused on the development of an environmentally friendly process for the decomposition of hydrogen sulfide into hydrogen and elemental sulfur. The developed process includes a thermal cracker to produce hydrogen from hydrogen sulfide and a catalytic isothermal reactor to minimize emissions of sulfur contaminants. In the first step, a process flowsheet is planned for hydrogen sulfide conversion considering a real feed case. In the next step, the planned process is modeled based on the governing equations considering the heat and mass transfer resistances in the steady state condition. Then, optimum operating conditions of the designed process are determined considering the maximum hydrogen productivity and minimum contaminant emissions as objective functions. The results show that the designed process is capable to produce 51.03 kmol h −1 hydrogen and 84.92 kmol h −1 sulfur as main products. In addition, the rate of CS 2 and COS emission is negligible in the proposed process. • An eco-friendly process flowsheet is proposed for H 2 S decomposition to hydrogen. • The proposed process is supported by the membrane modules to produce ultra-pure hydrogen. • The proposed process is modeled based on the mass and energy balance equations. • An optimization problem is formulated to determine the optimal condition of proposed process.