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This work aims to provide initial research on green ammonia production and compare it with the fossil-fueled synthetic methane reforming process on the basis of techno-economic parameters. Green ammonia is produced from hydrogen that is produced in PEM electrolyzers. In this way the decarbonization of electricity leads directly to decarbonization of produced ammonia, without the need for natural gas. For the green ammonia processes, system is designed for two objectives: minimum import of electricity for electrolyzers and minimum cost of green ammonia production. Minimum import of electricity is achieved with oversizing the equipment for production (wind and PV) and storage (hydrogen) of renewable electricity, which is more capital-intensive. With the technical and economic assumptions made in the model, it can be seen that almost 100% green ammonia (min-exchange scenario) can be produces at cost lower than 150 eur/MWh, which is almost double the price of fossil ammonia. On the other hand, fossil ammonia produces 282 gCO2 per unit of energy (kWh), while min-exchange scenario for green ammonia produces almost zero emissions.

The subject of this dissertation is advanced inorganic membranes and their application in membrane reactors (MRs). The reaction studied is the ethanol steam reforming (ESR) reaction using Co-Na/ZnO catalysts, chosen because of their high activity and stability. The Co-Na/ZnO catalysts were prepared by a co-precipitation method and it was found that promotion with a moderate amount of Na (1.0 wt%) produced a catalyst with stable ethanol conversion and product selectivity. Higher cobalt loading, higher W:E ratio, higher reaction temperature, and lower space velocity enhanced the conversion of ethanol to H2 and CO2 while reducing the formation of undesirable acetaldehyde. Acetaldehyde was a primary product of the ESR reaction. Studies of the effect of hydrogen permeance on the ESR reaction at 623 K were performed in MRs equipped with silica-based and palladium-based membranes of different hydrogen permeances, and the highest ethanol conversion enhancement of 44 % and hydrogen molar flow enhancement of 69 % compared to a packed-bed reactor (PBR) were obtained in a MR fitted with a membrane with the highest hydrogen permeance. An operability level coefficient (OLC), defined as the ratio of the hydrogen permeation and hydrogen formation rates, was suggested as a useful tool for estimating performances of MRs for different reforming reactions such as methane dry reforming (MDR), methane steam reforming (MSR), methanol steam reforming (MeSR), and ethanol steam reforming (ESR) reactions. Studies of the effect of pressure (1-10 atm) on the ESR reaction at 623 K were carried out in a PBR and a MR fitted with a Pd-Cu membrane prepared by an electroless plating of palladium and copper at 333 K. Comparison studies showed that increasing pressure in both reactors resulted in decreasing ethanol conversions and increasing hydrogen molar flows. Compared to the PBR, higher ethanol conversions and hydrogen molar flows were obtained in the MR for all pressures studied. Increasing pressure was favorable for enhancing ethanol conversion and hydrogen molar flow in the MR compared to the PBR, and the highest ethanol conversion enhancement of 48 % with the highest hydrogen molar flow enhancement of 55 % was obtained at 10 atm in the MR. Ph. D.