The study in question is deeply flawed. To arrive at its negative assessment for blue hydrogen, it posits that blue hydrogen consumes 23% more natural gas (per unit of hydrogen) than gray hydrogen and captures only 52% of total carbon emissions. It also conflates the total rate of fugitive methane emissions with the rate of emissions sensitive to rate of consumption. The rate that they effectively assume for the latter is 4 to 5 times higher than best estimates from industry, the DOE, and the EIA. 

The model for blue hydrogen production on which the study is based is naive. It appends an inefficient process for carbon capture to an SMR plant design predicated on an assumption of cheap natural gas with no concern for carbon emissions. The design is not at all representative of how a reforming plant specifically designed for blue hydrogen production would be built. The authors are not chemical process engineers.