Coupling hydrogen separation with butanone hydrogenation in an electrochemical hydrogen pump with sulfonated poly (phthalazinone ether sulfone ketone) membrane

Abstract

Abstract This work reports the novel work of coupling H 2 /CO 2 separation with biomass-derived butanone hydrogenation in non-fluorinated sulfonated poly (phthalazinone ether sulfone ketone) (SPPESK) electrochemical hydrogen pump (EHP) reactor. Due to higher resistance to swelling, SPPESK-based EHP reactor exhibits more excellent reaction rate in elevated temperature (60 °C) and higher butanone concentration (2 M) as 270, 260 nmol cm −2 s −1 , respectively, higher than 240, 200 nmol cm −2 s −1 of Nafion-based EHP reactors. Also, the SPPESK-based EHP reactor remains 90% of initial hydrogenation rate after 4 batches, better than that of Nafion-based EHP reactors, which is only 62%. The energy efficiency of EHP separator reaches 40% under H 2 /CO 2 mixture feed mode, and electricity of about 0.3 kWh is consumed per Nm 3 H 2 product, being superior to energy consumption compared with alternative processes like PSA and electrolysis of water. In addition, SPPESK-based EHP exhibits better hydrogenation stability due to lower CO 2 permeation than Nafion. With increasing CO 2 content in H 2 feed, hydrogenation rate almost keeps constant at around 210 nmol cm −2 s −1 in SPPESK-based EHP reactor while decreases fast to 50 nmol cm −2 s −1 in Nafion/PTFE-based EHP reactor. These results show integration of gas separation with hydrogenation reactor is feasible in SPPESK-based EHP reactor.