Feasibility study of a small-scale fertilizer production facility based on plasma nitrogen fixation

Over the last century, the nitrogen fertilizer production sector has been dominated by the Haber-Bosch process, used to convert inert N2 into more reactive NH3. This process, coupled with steam methane reforming for H2 production, currently represents the cheapest and most efficient technology in the sector but is recognized as environmentally impacting. Recently, non-thermal plasma-based nitrogen fixation gained some interest as its theoretical minimum energy cost for N2 fixation into NO and NO2 has been estimated to be 0.2 MJ/mol N, lower than the current best available Haber-Bosch-based technology energy cost of 0.49 MJ/mol N and because this technology allows for implementation in small-scaled facilities with modest impact on the cost of the final product. Thus far, a lower energy cost than the Haber-Bosch process has however not been reached yet. Therefore, it is important to evaluate if the benefit of small-scale facilities is significant for the development of plasma-based technologies. This work focuses on studying whether a hypothetical small-scale fertilizer production facility based on a rotating gliding arc plasma for nitrogen fixation can be a local competitive alternative to a classical Haber-Bosch and steam methane reforming based facility. Capital expenditures, gas price, CO2 allowances, levelized cost of energy and transport costs are considered in this comparative model which is used to understand the impact of such parameters on the fertilizer production costs. As the energy cost for plasma-based nitrogen fixation is currently the main drawback to the industrial implementation of the technology, the energy cost requirement for a plasma-based facility to be an economically viable alternative in the upcoming years is studied as a function of the prices of energy and natural gas.