Hydrogen Production Via Catalytic Steam Gasification Of Bio-oil/Biochar Slurry

To achieve sustainable low-carbon hydrogen production,steam gasification of biomass or biomass derived fuels is deemed to be the ideal option.However,biomass is bulky and of low volumetric energy density and poor grindability,high logistic cost would be a major constraint that impedes biomass utilization for hydrogen production.The catalysts developed are of good performance,but deactivation resulted from carbon deposition and sintering is major impediment in their industrial application.To resolve these problems,bioslurry with characteristics of heavy oil was generated via flash pyrolysis of biomass,and perovskite-type catalysts were prepared and evaluated in steam gasification of bioslurry process using a fixed bed.The H₂ yield and carbon conversion were examined as a function of perovskite-type catalysts,temperature,water to carbon molar ratio?WCMR?and feedstock weight based hourly space velocity?W_bHSV?.A gasification system for syngas production via steam gasification of liquid biomass was designed,patented and fabricated,providing guarantee for this work.La_1-xK_xMnO₃?x=0,0.1,0.2,0.3?,LaFeO₃,La_0.8X_0.2FeO₃?X=Ce,Mg,K?and LaCo_1-xCu_xO₃?x=0,0.1,0.2,0.3?perovskite-type catalysts were prepared by the amorphous citrate precursor method.Hydrogen-rich syngas production from the catalytic steam reforming of bio-oil over La_1-xK_xMnO₃ perovskite-type catalysts and from the catalytic steam gasification of bioslurry over LaFeO₃,La_0.8X_0.2FeO₃?X=Ce,Mg,K?and LaCo_1-xCu_xO₃?x=0,0.1,0.2,0.3?perovskite-type catalysts were investigated by using fixed bed reactor.The results showed the presence of the ABO₃perovskite crystalline phase for all samples prepared.Both high temperature and low W_bHSV led to higher H₂ yield.The perovskite phase is well preserved under the reaction atmosphere.The catalytic activity of La_1-xK_x MnO₃ perovskite-type catalysts followed an order of La_0.8K_0.2MnO₃>La_0.7K_0.3MnO₃>La_0.9K_0.1MnO₃>LaMnO₃.An optimum WCMR of 3 was obtained for La_0.8K_0.2MnO₃ catalyzed reaction.For the La_0.8K_0.2MnO₃ catalyst,a highest hydrogen yield of 67.5%and a highest carbon conversion of 65.3%were obtained at 800 ^oC with a combination of WCMR=3 and W_bHSV=12 h^-1.The catalytic activity of LaFeO₃,La_0.8X_0.2FeO₃ followed an order of La_0.8Ce_0.2FeO₃>La_0.8K_0.2FeO₃>LaFeO₃>La_0.8Mg_0.2FeO_3.LaCo_1-xCu_xO₃ followed an order of LaCo_0.9Cu_0.1O₃>LaCo_0.8Cu_0.2O₃>LaCo_0.7Cu_0.3O₃>LaCo O₃.An optimum WCMR of 2 was obtained for La_0.8Ce_0.2FeO₃ and LaCo_0.9Cu_0.1O₃ catalyzed reaction.Under the optimum operational conditions(temperature=800?,WCMR=2 and W_bHSV=15.4 h^-1),a highest hydrogen yield of 82.0%and a highest carbon conversion of 65.6%for La_0.8Ce_0.2FeO₃ and a highest hydrogen yield of 75.3%and a highest carbon conversion of 80.4%for LaCo_0.9Cu_0.1O₃ were obtained.A steady-state Aspen Plus simulation model had been well developed to predict the mass and energy balances for a duel fluidized bed?DFB?gasification process to produce H₂.The calculated results of the process simulation model showed that 2266kg wood chips,6200 kg air and 450 kg H₂O were needed for producing 90 kg H₂,in the meantime,3137 kg CO₂,484.3 kg H₂O,4758 kg N₂ and 14.07 kg ash were produced.DFB biomass steam gasification process had a H₂ conversion of 50.8%and a H₂ yield of 39.7 g H₂ per kg wood chips?wet?.It indicates that the production efficiency is about 38.9%based on the LHV of wood chips,the electricity consumption,and H₂.