Performance comparison of microwave and conventionally heated reactors for sorption enhanced reforming of ethanol over Ni impregnated SBA-15

Abstract

Hydrogen production from steam reforming of ethanol (SRE) and sorption enhanced steam reforming of ethanol (SESRE) over nickel impregnated SBA-15 catalyst was investigated in both conventionally and microwave heated reactor systems. Characterization results showed that 10 wt% Ni loaded SBA-15 exhibited Type IV isotherm with H1 hysteresis, which indicates mesoporous structure. Its surface area and mean pore diameter values were 493 m2/g and 6.5 nm, respectively. Results obtained in SRE tests showed high activity of this catalyst. With the change in the heating mechanism from conventionally heated reactor to microwave heated reactor, hydrogen yield value increased from 3.5 to 4.5 where the maximum possible hydrogen yield value is six for the SRE reaction. Capture of CO2 with CaO resulted in higher hydrogen purity and lower CO and CO2 amount in the gas mixture in the first 100 min in both heating systems. With in-situ capture of CO2, the hydrogen purity reached to 90% with negligible CO and CO2 in the first 40 min in microwave heated reactor. TGA results revealed that while conventional heating caused 45% coke formation, the coke formation was only 3% in microwave heated reactor. Highly steady reactor performance, with coke minimization could be achieved as a result of performing activity tests in the system which was heated by a focused microwave reactor.