Blue hydrogen is worse for the climate than coal
arstechnica.com
arstechnica.com
The 3.5% methane leakage is really quite well supported. But it looks at the hydrocarbon industry as a whole, with the majority of emissions coming from natural-gas-fed pneumatic actuators and liquid hydrocarbon storage tank venting. Both of those are huge issues for mature legacy designs, but we've been using instrument air for pneumatic actuators for decades, and likewise hooking up liquid storage tank vents to the flare. So the 3.5% is dominated by the oldest minority of natural gas plant, and today's natural gas developments would have less leakage. But I won't overegg that, I think 1.5-2% is pretty realistic.
The 85% efficiency of carbon capture is also way off for new developments which would expect to capture 95% of CO2 emissions. So that 15% of CO2 emissions going to atmosphere is slashed to 5%.
This is a fantastic study, but we shouldn't kid ourselves that it's answered questions for once and for all about blue hydrogen GHG emissions, it's just one method of estimating. As per the cliché... "more research is needed in this area".