Our project provides a preliminary design analysis of a modular ammonia production plant proposed to be constructed in the Minnesota River Valley. One of the primary goals for the process engineering team was to design a plant capable of being carbon emission free, thus all design decisions were made prioritizing this goal. The process features ammonia synthesis via the Haber-Bosch process with a ruthenium-based catalyst which converts divalent hydrogen and nitrogen into ammonia at high temperature and pressure. The feed reactants are generated on site via electrolysis of water for the hydrogen stream and an air separation membrane system for the nitrogen stream. Both reactant generation methods require no direct carbon input while all electricity is sourced from wind energy produced in the surrounding area. Due to the efforts to make the plant carbon-neutral, manufacturing costs were significantly high resulting in a unit price of $1,480/mt to make the plant break even after the 20-year lifetime at a 10% rate of return. More market research is required to determine a competitive unit price for the Minnesota River Valley area, but this is likely too high based on the wide estimate of $500-$2,000/mt based on preliminary research. Further process modifications must be completed before a modular ammonia production plant that operates with zero carbon emissions can compete on the market. The accuracy of the capital and operating costs are limited by the present lack of heuristic knowledge regarding modular chemical production. There is potential for decreases in capital and operating costs by further optimizing minor equipment, but the capital cost is limited by the capital costs of hydrolysis. Despite these economic concerns, the process engineering team has concluded that a carbon-free ammonia production plant is possible.
Carbon-Free, Modular Ammonia Production Plant
Project Team Member(s):
College of Engineering Unit(s):
Chemical, Biological, and Environmental Engineering
Project Communication Piece(s):
American Institute of Chemical Engineers (AIChE)