▲ | FilosofumRex 12 hours ago | |
Never trust anything written by lawyers/economics/MBAs on climate change - only analysis by chemical or mechanical engineers is worth reading. Methane pyrolysis is an old technology from early days of oil refining for production of hydrogen & Ammonia/fertilizer/Methanol. it yields half as much H2 than SMR/ATR so it can't compete on cost, unless there is carbon tax/CO2 penalty. Also, coke produced by pyrolysis is lower quality than that produced by Delayed Coking of crude oil refining. Most of the comments seem to confuse pyrolysis (no O2) with reforming (H2O), which produces CO2. ATR uses partial O2 & H2O and is more energy efficient & cheaper. Commonsense should tell you e- generated by H2 can't compete with CH4, because Ch4 is the feedstock & H2 is the product! | ||
▲ | georgecmu 28 minutes ago | parent [-] | |
Never trust anything written by lawyers/economics/MBAs on climate change - only analysis by chemical or mechanical engineers is worth reading. Just so we know if we should keep reading, which one are you? Methane pyrolysis is an old technology from early days of oil refining for production of hydrogen & Ammonia/fertilizer/Methanol. it yields half as much H2 than SMR/ATR so it can't compete on cost, unless there is carbon tax/CO2 penalty. It's not appropriate to call it "technology," in the same way it's not appropriate to call "combustion" a "technology." There's a very wide variety of technological solutions to realize this family of chemical processes, and some are going to be better than other, depending on the use case or scenario. The report actually covers those pathways reasonably well. Also, coke produced by pyrolysis is lower quality than that produced by Delayed Coking of crude oil refining. Ideally, you would not be producing coke at all, but a higher value material. However, even coke will be of much higher purity than petcoke (before calcining) -- i.e. it would be intrinsically zero-sulfur carbon material, - but I'm not sure what applications it would have that don't involve production of CO2. But obviously the carbon co-product should have value, which would provide a cost offset to the hydrogen. With a high-quality co-product (> $1/kgC), this offset would be significant enough to provide that hydrogen essentially free of charge. SMR and ATR generate significant amounts of CO2 (~10 kgCO2/kgH2), which does not provide a cost offset, and in a fair world would instead incur a significant added cost. Electrolysis requires 4x more energy (also electric, not thermal) and does not have a marketable/valuable co-product. Just on the energy cost alone (50 kWh/kgH2 * 0.12 USD/kWh = 6 USD/kgH2 > 40 USD/MMBTU) electrolyzer hydrogen is not competitive with any of the above. Commonsense should tell you e- generated by H2 can't compete with CH4, because Ch4 is the feedstock & H2 is the product! Didn't parse this statement, sorry. Can you rephrase? |