Plasma Catalytic Co-reforming Of Dilute Bioethanol And Methane For Hydrogen Production

Bioethanol is a renewable and carbon-recycling feedstock for hydrogen production,but the dilute bioethanol produced from biomass fermentation contains a large amount of water,therefore needs to be purified through expensive rectification before it can be used.Co-reforming of dilute bioethanol and methane is a technical route for efficient hydrogen production from dilute bioethanol,which can improve the efficiency of hydrogen production without rectification process.Compared with conventional thermal catalysis,plasma catalysis has the advantages of high product selectivity,and the fast start and stop,compact structure of plasma,which provides a promising method for efficient hydrogen production from co-reforming of dilute bioethanol and methane.In addition,in order to meet the requirements of proton exchange membrane fuel cells for hydrogen fuel,an exploratory study is conducted on plasma regeneration of CuCl/Al₂O₃,which is a CO sorbent.The contents and main results are summarized as follows:1?Reforming of dilute bioethanol and its co-reforming with methane for hydrogen production by gliding arc plasma is studied.Under the condition of dilute bioethanol only,ethanol conversion increases rapidly with the increase of specific energy input.When specific energy input is 81.0 kJ/mol,ethanol is almost converted completely?98.4%?.However,the energy cost is up to 4.2 kWh/Nm³,and the energy efficiency is only 40%.Keeping the total flow rate constant,addition of methane in the feed would lead to significant increase of the total hydrogen production rate and energy efficiency.2?Co-reforming of dilute bioethanol and methane for hydrogen production is studied by coupling gliding arc plasma with Ni/CeO₂/Al₂O₃ catalyst.With the gas hourly space velocity?GHSV?of 5250 ml·g^-1·h^-1,SEI of 81.0 kJ/mol,total flow rate?F_t?of 3.5 SLM and M/E of8,compared with plasma alone,the total carbon conversion,energy efficiency and total hydrogen production rate increase from 34%,65%and 3.75 SLM to 96%,71%and 4.71 SLM,respectively,and the energy cost reduces from 2.45 kWh/Nm³ to 1.77 kWh/Nm³.3?Regeneration of the CO sorbent?CuCl/Al₂O₃?by dielectric barrier discharge?DBD?plasma and its discharge characteristics are explored.The increase of input power and discharge gas flow rate are favorable to the rapid regeneration of sorbent.When the input power is 15 W and the discharge gas?N₂?flow rate is 270 SCCM,the CO desorption efficiency is 100%after 15 min-regeneration process.And after six consecutive“adsorption-desorption”cycles,the performance of the sorbent has no significant change.This preliminarily shows that plasma desorption has the characteristics of fast and high desorption efficiency,which can rapidly and completely regenerate the CO sorbent?CuCl/Al₂O₃?,and has the feasibility of reuse.Packing with CuCl/Al₂O₃ can increase the reactor capacitance and displacement current,and make the discharge more uniform.During the regeneration process of CuCl/Al₂O₃,the desorption of CO leads the increase of discharge power,total capacitance and gas capacitance in the first six minutes.After six minutes,those discharge parameters are unchanged.The dielectric capacitance hardly changes during regeneration process.