Technology comparison for green hydrogen production

Abstract

Because of greenhouse gas emissions generated by fossil fuels, it has become essential to find non-polluting alternatives. Hydrogen is generally produced from the steam methane reforming (SMR) process which generates a lot of greenhouse gases. However, there are many other processes to produce hydrogen that are cleaner and should be of interest. This study aims at comparing different existing technologies to produce hydrogen in a clean and non-polluting way, in particular biological and thermochemical processes from biomass and water splitting processes. Their comparison is made by analyzing several parameters such as the type of raw materials, energy sources, efficiency, waste generation, CO2 emissions and, hydrogen production rate. Among the biological processes to produce hydrogen from biomass, dark fermentation seems to be the best due to its high production efficiency. Thermochemical processes are also interesting because of their maturity, but they generate a lot of waste such as tar and ashes. Water splitting processes coupled with renewable energy have the advantage of being zero greenhouse gas generating. The electrolysis is the best from the point of view of production efficiency which reaches 80%.